Add DCTP (Delta Code Transfer Protocol) tool for efficient AI code transfers

DCTP enables efficient transfer of AI-generated code using delta operations
instead of sending complete files for each modification. Features include:

- Parser for DCTP control commands (NEW, DELETE, INSERT_AFTER, REPLACE, RENUMBER)
- Line-numbered code with language-specific comment formats
- Backup/Undo system with session management
- Diff generation for preview functionality
- CustomTkinter GUI with project management, preview, and diff views

dctp/.gitignore

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+__pycache__/
+*.pyc
+*.pyo
+.dctp_backups/
+.dctp_settings.json

dctp/CLAUDE.md

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+# DCTP - Delta Code Transfer Protocol
+
+Du generierst Code im DCTP-Format fuer effiziente Uebertragung.
+
+## Regeln
+
+1. **Zeilennummern am Ende jeder Zeile** im passenden Kommentar-Format
+2. **Immer mit ###FILE: beginnen** bei jedem Codeblock
+3. **Bei Korrekturen NUR die geaenderten Zeilen senden**, nie den ganzen File
+
+## Zeilennummern-Format
+
+- Python/Shell: `code  #Z1`
+- JavaScript/Java/C/C++: `code  //Z1`
+- HTML: `code  <!--Z1-->`
+- CSS: `code  /*Z1*/`
+- SQL: `code  --Z1`
+
+## Befehle
+
+| Befehl | Syntax | Beschreibung |
+|--------|--------|--------------|
+| `###FILE:` | `###FILE:pfad/datei.ext` | Datei angeben |
+| `###NEW` | | Neue Datei, kompletter Inhalt folgt |
+| `###DELETE:` | `###DELETE:Z5-Z12` | Zeilen 5-12 loeschen |
+| `###INSERT_AFTER:` | `###INSERT_AFTER:Z5` | Nach Zeile 5 einfuegen |
+| `###REPLACE:` | `###REPLACE:Z5-Z8` | Zeilen 5-8 ersetzen |
+| `###END` | | Ende des Blocks |
+| `###RENUMBER` | | Zeilennummern neu berechnen |
+| `###CHECKSUM:` | `###CHECKSUM:a3f2b8c1` | Optional: Hash zur Validierung |
+
+## Beispiel: Neue Datei
+
+```
+###FILE:src/calculator.py
+###NEW
+def add(a, b):  #Z1
+    return a + b  #Z2
+  #Z3
+def multiply(a, b):  #Z4
+    return a * b  #Z5
+###END
+```
+
+## Beispiel: Korrektur (REPLACE)
+
+```
+###FILE:src/calculator.py
+###REPLACE:Z4-Z5
+def multiply(a, b):  #Z4
+    """Multipliziert zwei Zahlen."""  #Z5
+    return a * b  #Z6
+###END
+###RENUMBER
+```
+
+## Beispiel: Zeilen einfuegen
+
+```
+###FILE:src/calculator.py
+###INSERT_AFTER:Z2
+  #Z3
+def subtract(a, b):  #Z4
+    return a - b  #Z5
+###END
+###RENUMBER
+```
+
+## Beispiel: Zeilen loeschen
+
+```
+###FILE:src/calculator.py
+###DELETE:Z10-Z15
+###RENUMBER
+```
+
+## Beispiel: Mehrere Dateien
+
+```
+###FILE:src/models/user.py
+###NEW
+class User:  #Z1
+    def __init__(self, name: str):  #Z2
+        self.name = name  #Z3
+###END
+
+###FILE:src/models/order.py
+###NEW
+from .user import User  #Z1
+  #Z2
+class Order:  #Z3
+    def __init__(self, user: User):  #Z4
+        self.user = user  #Z5
+###END
+```
+
+## Wichtig
+
+- Bei Korrekturen: NUR Delta senden, nie kompletten File
+- Nach INSERT/DELETE/REPLACE immer ###RENUMBER
+- Leerzeilen auch nummerieren
+- Zeilennummern werden beim Schreiben automatisch entfernt

dctp/README.md

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+# DCTP - Delta Code Transfer Protocol
+
+Ein Tool um KI-generierten Code effizient in lokale Dateien zu uebertragen. Statt bei jeder Korrektur den kompletten Code neu zu senden, werden nur Aenderungen (Deltas) uebertragen.
+
+## Das Problem
+
+Claude generiert 500 Zeilen Code. Eine kleine Korrektur = nochmal 500 Zeilen. Verschwendung.
+
+## Die Loesung
+
+Zeilennummerierter Code + Steueranweisungen fuer gezielte Aenderungen.
+
+## Installation
+
+```bash
+# Requirements installieren
+pip install -r requirements.txt
+
+# GUI starten
+python dctp_gui.py
+```
+
+## Schnellstart
+
+### 1. Projektverzeichnis waehlen
+
+Klicke auf "Waehlen" und waehle dein Projektverzeichnis.
+
+### 2. KI-Output einfuegen
+
+Kopiere den DCTP-formatierten Output aus deinem Claude-Chat in das Input-Feld.
+
+### 3. Analysieren
+
+Klicke "Analysieren" um eine Vorschau der Operationen zu sehen.
+
+### 4. Ausfuehren
+
+Klicke "Ausfuehren" um die Aenderungen auf deine Dateien anzuwenden.
+
+## DCTP-Format
+
+### Neue Datei erstellen
+
+```
+###FILE:src/calculator.py
+###NEW
+def add(a, b):  #Z1
+    return a + b  #Z2
+###END
+```
+
+### Zeilen ersetzen
+
+```
+###FILE:src/calculator.py
+###REPLACE:Z1-Z2
+def add(a: int, b: int) -> int:  #Z1
+    """Addiert zwei Zahlen."""  #Z2
+    return a + b  #Z3
+###END
+###RENUMBER
+```
+
+### Zeilen einfuegen
+
+```
+###FILE:src/calculator.py
+###INSERT_AFTER:Z2
+  #Z3
+def subtract(a, b):  #Z4
+    return a - b  #Z5
+###END
+###RENUMBER
+```
+
+### Zeilen loeschen
+
+```
+###FILE:src/calculator.py
+###DELETE:Z10-Z15
+###RENUMBER
+```
+
+## Zeilennummern-Format
+
+Die Zeilennummern werden automatisch entsprechend der Programmiersprache formatiert:
+
+| Sprache | Format | Beispiel |
+|---------|--------|----------|
+| Python | `#Z1` | `code  #Z1` |
+| JavaScript | `//Z1` | `code  //Z1` |
+| HTML | `<!--Z1-->` | `code  <!--Z1-->` |
+| CSS | `/*Z1*/` | `code  /*Z1*/` |
+| SQL | `--Z1` | `code  --Z1` |
+
+## Befehle
+
+| Befehl | Beschreibung |
+|--------|--------------|
+| `###FILE:pfad` | Zieldatei angeben |
+| `###NEW` | Neue Datei erstellen |
+| `###DELETE:Z5-Z12` | Zeilen loeschen |
+| `###INSERT_AFTER:Z5` | Nach Zeile einfuegen |
+| `###REPLACE:Z5-Z8` | Zeilen ersetzen |
+| `###END` | Block beenden |
+| `###RENUMBER` | Zeilennummern aktualisieren |
+| `###CHECKSUM:hash` | Datei-Hash validieren |
+
+## Features
+
+- **Vorschau**: Zeigt was passieren wird, bevor es ausgefuehrt wird
+- **Diff-Ansicht**: Zeigt Aenderungen farbig markiert (alt vs neu)
+- **Undo**: Stellt den letzten Zustand wieder her
+- **Backup**: Automatische Backups vor jeder Aenderung
+- **Multi-File**: Mehrere Dateien in einem Durchgang bearbeiten
+- **Checksum**: Optionale Validierung gegen externe Aenderungen
+
+## Einstellungen
+
+- **Projektpfad**: Standard-Projektverzeichnis
+- **Backup-Verzeichnis**: Wo Backups gespeichert werden
+- **Auto-Renumber**: Zeilennummern automatisch aktualisieren
+- **Checksum-Validierung**: Externe Aenderungen erkennen
+- **Theme**: Hell oder dunkel
+
+## Claude-Integration
+
+Kopiere den Inhalt von `CLAUDE.md` in deine Claude-Chats (als Custom Instructions oder am Anfang des Gespraechs), damit Claude im DCTP-Format antwortet.
+
+## Architektur
+
+```
+dctp/
+├── dctp_gui.py          # Hauptfenster (CustomTkinter)
+├── dctp_parser.py       # Core-Logik: parse Steueranweisungen
+├── dctp_executor.py     # Fuehrt Operationen aus
+├── dctp_backup.py       # Undo/Backup-Verwaltung
+├── dctp_diff.py         # Diff-Berechnung fuer Vorschau
+├── requirements.txt     # Dependencies
+├── CLAUDE.md            # Anweisung fuer KI
+└── README.md            # Diese Datei
+```
+
+## Lizenz
+
+MIT License

dctp/dctp_backup.py

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+"""
+DCTP Backup Manager - Handles backup and undo functionality.
+
+Creates timestamped backups before operations and supports
+restoring files to their previous state.
+"""
+
+import json
+import os
+import shutil
+from dataclasses import dataclass, asdict
+from datetime import datetime
+from pathlib import Path
+from typing import Optional
+
+
+@dataclass
+class FileBackup:
+    """Represents a single file backup."""
+    original: str
+    backup: str
+    existed: bool  # Whether the file existed before (for new file handling)
+
+
+@dataclass
+class BackupSession:
+    """Represents a backup session (one execution run)."""
+    timestamp: str
+    files: list[FileBackup]
+
+
+@dataclass
+class BackupInfo:
+    """Info about a backup for display purposes."""
+    timestamp: str
+    file_count: int
+    files: list[str]
+
+
+class BackupManager:
+    """Manages file backups for undo functionality."""
+
+    BACKUP_DIR_NAME = ".dctp_backups"
+    MANIFEST_FILE = "manifest.json"
+    MAX_SESSIONS = 50  # Keep last 50 sessions
+
+    def __init__(self, project_path: str):
+        """
+        Initialize backup manager.
+
+        Args:
+            project_path: Base project directory
+        """
+        self.project_path = Path(project_path)
+        self.backup_dir = self.project_path / self.BACKUP_DIR_NAME
+        self.manifest_path = self.backup_dir / self.MANIFEST_FILE
+        self._current_session: Optional[BackupSession] = None
+        self._ensure_backup_dir()
+
+    def _ensure_backup_dir(self) -> None:
+        """Create backup directory if it doesn't exist."""
+        self.backup_dir.mkdir(parents=True, exist_ok=True)
+
+        # Create .gitignore in backup dir
+        gitignore_path = self.backup_dir / ".gitignore"
+        if not gitignore_path.exists():
+            gitignore_path.write_text("*\n")
+
+    def _load_manifest(self) -> dict:
+        """Load the manifest file."""
+        if self.manifest_path.exists():
+            try:
+                return json.loads(self.manifest_path.read_text())
+            except (json.JSONDecodeError, IOError):
+                return {"sessions": []}
+        return {"sessions": []}
+
+    def _save_manifest(self, manifest: dict) -> None:
+        """Save the manifest file."""
+        self.manifest_path.write_text(json.dumps(manifest, indent=2))
+
+    def start_session(self) -> None:
+        """Start a new backup session."""
+        timestamp = datetime.now().strftime("%Y-%m-%dT%H:%M:%S")
+        self._current_session = BackupSession(timestamp=timestamp, files=[])
+
+    def backup(self, file_path: str) -> Optional[str]:
+        """
+        Create a backup of a file.
+
+        Args:
+            file_path: Path to the file (relative to project or absolute)
+
+        Returns:
+            Backup filename if successful, None if file doesn't exist
+        """
+        if self._current_session is None:
+            self.start_session()
+
+        # Normalize path
+        if os.path.isabs(file_path):
+            full_path = Path(file_path)
+            rel_path = full_path.relative_to(self.project_path)
+        else:
+            rel_path = Path(file_path)
+            full_path = self.project_path / rel_path
+
+        # Check if file exists
+        existed = full_path.exists()
+
+        if existed:
+            # Generate backup filename
+            timestamp = datetime.now().strftime("%Y-%m-%d_%H%M%S")
+            safe_name = str(rel_path).replace(os.sep, "_").replace("/", "_")
+            backup_name = f"{timestamp}_{safe_name}"
+
+            # Copy file to backup
+            backup_path = self.backup_dir / backup_name
+            shutil.copy2(full_path, backup_path)
+        else:
+            backup_name = ""
+
+        # Add to current session
+        self._current_session.files.append(FileBackup(
+            original=str(rel_path),
+            backup=backup_name,
+            existed=existed
+        ))
+
+        return backup_name if existed else None
+
+    def end_session(self) -> None:
+        """End the current backup session and save to manifest."""
+        if self._current_session is None or len(self._current_session.files) == 0:
+            self._current_session = None
+            return
+
+        manifest = self._load_manifest()
+
+        # Convert to dict for JSON storage
+        session_dict = {
+            "timestamp": self._current_session.timestamp,
+            "files": [asdict(f) for f in self._current_session.files]
+        }
+        manifest["sessions"].append(session_dict)
+
+        # Limit number of sessions
+        if len(manifest["sessions"]) > self.MAX_SESSIONS:
+            # Remove old sessions and their backup files
+            old_sessions = manifest["sessions"][:-self.MAX_SESSIONS]
+            for session in old_sessions:
+                for file_info in session["files"]:
+                    backup_file = self.backup_dir / file_info["backup"]
+                    if backup_file.exists():
+                        backup_file.unlink()
+            manifest["sessions"] = manifest["sessions"][-self.MAX_SESSIONS:]
+
+        self._save_manifest(manifest)
+        self._current_session = None
+
+    def restore_last(self) -> tuple[bool, list[str]]:
+        """
+        Restore files from the last backup session.
+
+        Returns:
+            Tuple of (success, list of restored files)
+        """
+        manifest = self._load_manifest()
+
+        if not manifest["sessions"]:
+            return False, []
+
+        # Get last session
+        last_session = manifest["sessions"].pop()
+        restored_files = []
+
+        for file_info in last_session["files"]:
+            original_path = self.project_path / file_info["original"]
+
+            if file_info["existed"]:
+                # Restore from backup
+                backup_path = self.backup_dir / file_info["backup"]
+                if backup_path.exists():
+                    # Ensure parent directory exists
+                    original_path.parent.mkdir(parents=True, exist_ok=True)
+                    shutil.copy2(backup_path, original_path)
+                    backup_path.unlink()  # Remove backup file
+                    restored_files.append(file_info["original"])
+            else:
+                # File was newly created, delete it
+                if original_path.exists():
+                    original_path.unlink()
+                    restored_files.append(f"{file_info['original']} (deleted)")
+
+        self._save_manifest(manifest)
+        return True, restored_files
+
+    def list_backups(self) -> list[BackupInfo]:
+        """
+        List all backup sessions.
+
+        Returns:
+            List of BackupInfo objects, newest first
+        """
+        manifest = self._load_manifest()
+        backups = []
+
+        for session in reversed(manifest["sessions"]):
+            files = [f["original"] for f in session["files"]]
+            backups.append(BackupInfo(
+                timestamp=session["timestamp"],
+                file_count=len(files),
+                files=files
+            ))
+
+        return backups
+
+    def get_file_backup_path(self, file_path: str) -> Optional[Path]:
+        """
+        Get the backup path for a file from the most recent session.
+
+        Args:
+            file_path: Original file path (relative to project)
+
+        Returns:
+            Path to backup file if found, None otherwise
+        """
+        manifest = self._load_manifest()
+
+        if not manifest["sessions"]:
+            return None
+
+        # Search from newest to oldest
+        for session in reversed(manifest["sessions"]):
+            for file_info in session["files"]:
+                if file_info["original"] == file_path and file_info["existed"]:
+                    backup_path = self.backup_dir / file_info["backup"]
+                    if backup_path.exists():
+                        return backup_path
+
+        return None
+
+    def clear_all_backups(self) -> int:
+        """
+        Clear all backups.
+
+        Returns:
+            Number of backup files deleted
+        """
+        count = 0
+        if self.backup_dir.exists():
+            for item in self.backup_dir.iterdir():
+                if item.name != ".gitignore":
+                    if item.is_file():
+                        item.unlink()
+                        count += 1
+                    elif item.is_dir():
+                        shutil.rmtree(item)
+                        count += 1
+
+        # Reset manifest
+        self._save_manifest({"sessions": []})
+        return count
+
+
+def main():
+    """Test the backup manager."""
+    import tempfile
+
+    # Create a temporary project directory
+    with tempfile.TemporaryDirectory() as tmpdir:
+        # Create some test files
+        test_file = Path(tmpdir) / "test.py"
+        test_file.write_text("print('hello')\n")
+
+        # Initialize backup manager
+        manager = BackupManager(tmpdir)
+
+        # Start a session and backup the file
+        manager.start_session()
+        backup_name = manager.backup("test.py")
+        print(f"Created backup: {backup_name}")
+
+        # Modify the file
+        test_file.write_text("print('modified')\n")
+        print(f"File content after modification: {test_file.read_text()}")
+
+        # End session
+        manager.end_session()
+
+        # List backups
+        backups = manager.list_backups()
+        print(f"Backup sessions: {len(backups)}")
+        for b in backups:
+            print(f"  {b.timestamp}: {b.file_count} files")
+
+        # Restore
+        success, restored = manager.restore_last()
+        print(f"Restore successful: {success}")
+        print(f"Restored files: {restored}")
+        print(f"File content after restore: {test_file.read_text()}")
+
+
+if __name__ == "__main__":
+    main()

dctp/dctp_diff.py

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+"""
+DCTP Diff Generator - Generates diffs for preview display.
+
+Compares old and new content and produces colored diff output
+for the GUI preview.
+"""
+
+import difflib
+from dataclasses import dataclass
+from enum import Enum
+from typing import Optional
+
+
+class DiffType(Enum):
+    UNCHANGED = "unchanged"
+    ADDED = "added"
+    REMOVED = "removed"
+    CONTEXT = "context"
+
+
+@dataclass
+class DiffLine:
+    """Represents a single line in a diff."""
+    type: DiffType
+    line_number_old: Optional[int]  # Line number in old file
+    line_number_new: Optional[int]  # Line number in new file
+    content: str
+
+    @property
+    def prefix(self) -> str:
+        """Get the diff prefix character."""
+        if self.type == DiffType.ADDED:
+            return "+"
+        elif self.type == DiffType.REMOVED:
+            return "-"
+        else:
+            return " "
+
+    def __str__(self) -> str:
+        old_num = str(self.line_number_old) if self.line_number_old else ""
+        new_num = str(self.line_number_new) if self.line_number_new else ""
+        return f"{old_num:>4} {new_num:>4} {self.prefix} {self.content}"
+
+
+@dataclass
+class DiffBlock:
+    """A block of related diff lines."""
+    start_old: int
+    end_old: int
+    start_new: int
+    end_new: int
+    lines: list[DiffLine]
+
+    @property
+    def header(self) -> str:
+        """Generate a unified diff style header."""
+        return f"@@ -{self.start_old},{self.end_old - self.start_old + 1} +{self.start_new},{self.end_new - self.start_new + 1} @@"
+
+
+@dataclass
+class FileDiff:
+    """Complete diff for a file."""
+    filename: str
+    old_content: list[str]
+    new_content: list[str]
+    blocks: list[DiffBlock]
+    lines: list[DiffLine]
+
+    @property
+    def has_changes(self) -> bool:
+        return any(line.type in (DiffType.ADDED, DiffType.REMOVED) for line in self.lines)
+
+    @property
+    def additions(self) -> int:
+        return sum(1 for line in self.lines if line.type == DiffType.ADDED)
+
+    @property
+    def deletions(self) -> int:
+        return sum(1 for line in self.lines if line.type == DiffType.REMOVED)
+
+
+class DiffGenerator:
+    """Generates diffs between old and new content."""
+
+    def __init__(self, context_lines: int = 3):
+        """
+        Initialize diff generator.
+
+        Args:
+            context_lines: Number of context lines around changes
+        """
+        self.context_lines = context_lines
+
+    def generate(
+        self,
+        old_lines: list[str],
+        new_lines: list[str],
+        filename: str = ""
+    ) -> FileDiff:
+        """
+        Generate a diff between old and new content.
+
+        Args:
+            old_lines: Original content lines
+            new_lines: New content lines
+            filename: Optional filename for display
+
+        Returns:
+            FileDiff object with all diff information
+        """
+        diff_lines: list[DiffLine] = []
+
+        # Use difflib to compute differences
+        matcher = difflib.SequenceMatcher(None, old_lines, new_lines)
+
+        old_line_num = 1
+        new_line_num = 1
+
+        for tag, i1, i2, j1, j2 in matcher.get_opcodes():
+            if tag == 'equal':
+                for idx in range(i2 - i1):
+                    diff_lines.append(DiffLine(
+                        type=DiffType.UNCHANGED,
+                        line_number_old=old_line_num,
+                        line_number_new=new_line_num,
+                        content=old_lines[i1 + idx]
+                    ))
+                    old_line_num += 1
+                    new_line_num += 1
+
+            elif tag == 'replace':
+                # Show removed lines first, then added
+                for idx in range(i2 - i1):
+                    diff_lines.append(DiffLine(
+                        type=DiffType.REMOVED,
+                        line_number_old=old_line_num,
+                        line_number_new=None,
+                        content=old_lines[i1 + idx]
+                    ))
+                    old_line_num += 1
+
+                for idx in range(j2 - j1):
+                    diff_lines.append(DiffLine(
+                        type=DiffType.ADDED,
+                        line_number_old=None,
+                        line_number_new=new_line_num,
+                        content=new_lines[j1 + idx]
+                    ))
+                    new_line_num += 1
+
+            elif tag == 'delete':
+                for idx in range(i2 - i1):
+                    diff_lines.append(DiffLine(
+                        type=DiffType.REMOVED,
+                        line_number_old=old_line_num,
+                        line_number_new=None,
+                        content=old_lines[i1 + idx]
+                    ))
+                    old_line_num += 1
+
+            elif tag == 'insert':
+                for idx in range(j2 - j1):
+                    diff_lines.append(DiffLine(
+                        type=DiffType.ADDED,
+                        line_number_old=None,
+                        line_number_new=new_line_num,
+                        content=new_lines[j1 + idx]
+                    ))
+                    new_line_num += 1
+
+        # Generate blocks with context
+        blocks = self._generate_blocks(diff_lines)
+
+        return FileDiff(
+            filename=filename,
+            old_content=old_lines,
+            new_content=new_lines,
+            blocks=blocks,
+            lines=diff_lines
+        )
+
+    def _generate_blocks(self, diff_lines: list[DiffLine]) -> list[DiffBlock]:
+        """Generate diff blocks with context."""
+        if not diff_lines:
+            return []
+
+        blocks: list[DiffBlock] = []
+        current_block_lines: list[DiffLine] = []
+        in_change = False
+        unchanged_count = 0
+
+        for line in diff_lines:
+            is_change = line.type in (DiffType.ADDED, DiffType.REMOVED)
+
+            if is_change:
+                if not in_change:
+                    # Starting a new change block, include context
+                    in_change = True
+                    unchanged_count = 0
+                current_block_lines.append(line)
+
+            else:  # Unchanged line
+                if in_change:
+                    unchanged_count += 1
+                    if unchanged_count <= self.context_lines:
+                        current_block_lines.append(line)
+                    else:
+                        # End current block and start fresh
+                        if current_block_lines:
+                            blocks.append(self._create_block(current_block_lines))
+                        current_block_lines = []
+                        in_change = False
+                        unchanged_count = 0
+                else:
+                    # Keep track of potential context lines
+                    current_block_lines.append(line)
+                    if len(current_block_lines) > self.context_lines:
+                        current_block_lines.pop(0)
+
+        # Don't forget the last block
+        if current_block_lines and any(
+            l.type in (DiffType.ADDED, DiffType.REMOVED) for l in current_block_lines
+        ):
+            blocks.append(self._create_block(current_block_lines))
+
+        return blocks
+
+    def _create_block(self, lines: list[DiffLine]) -> DiffBlock:
+        """Create a DiffBlock from a list of lines."""
+        old_nums = [l.line_number_old for l in lines if l.line_number_old is not None]
+        new_nums = [l.line_number_new for l in lines if l.line_number_new is not None]
+
+        return DiffBlock(
+            start_old=min(old_nums) if old_nums else 0,
+            end_old=max(old_nums) if old_nums else 0,
+            start_new=min(new_nums) if new_nums else 0,
+            end_new=max(new_nums) if new_nums else 0,
+            lines=lines
+        )
+
+    def generate_unified_diff(
+        self,
+        old_lines: list[str],
+        new_lines: list[str],
+        old_filename: str = "a/file",
+        new_filename: str = "b/file"
+    ) -> str:
+        """
+        Generate a unified diff string.
+
+        Args:
+            old_lines: Original content lines
+            new_lines: New content lines
+            old_filename: Label for old file
+            new_filename: Label for new file
+
+        Returns:
+            Unified diff as string
+        """
+        diff = difflib.unified_diff(
+            old_lines,
+            new_lines,
+            fromfile=old_filename,
+            tofile=new_filename,
+            lineterm=""
+        )
+        return "\n".join(diff)
+
+    def generate_side_by_side(
+        self,
+        old_lines: list[str],
+        new_lines: list[str],
+        width: int = 80
+    ) -> list[tuple[str, str, str]]:
+        """
+        Generate a side-by-side diff representation.
+
+        Args:
+            old_lines: Original content lines
+            new_lines: New content lines
+            width: Width for each column
+
+        Returns:
+            List of tuples (left_line, marker, right_line)
+        """
+        result = []
+        half_width = (width - 3) // 2
+
+        matcher = difflib.SequenceMatcher(None, old_lines, new_lines)
+
+        for tag, i1, i2, j1, j2 in matcher.get_opcodes():
+            if tag == 'equal':
+                for idx in range(i2 - i1):
+                    line = old_lines[i1 + idx][:half_width]
+                    result.append((line, " ", line))
+
+            elif tag == 'replace':
+                max_len = max(i2 - i1, j2 - j1)
+                for idx in range(max_len):
+                    old_line = old_lines[i1 + idx][:half_width] if idx < i2 - i1 else ""
+                    new_line = new_lines[j1 + idx][:half_width] if idx < j2 - j1 else ""
+                    result.append((old_line, "|", new_line))
+
+            elif tag == 'delete':
+                for idx in range(i2 - i1):
+                    old_line = old_lines[i1 + idx][:half_width]
+                    result.append((old_line, "<", ""))
+
+            elif tag == 'insert':
+                for idx in range(j2 - j1):
+                    new_line = new_lines[j1 + idx][:half_width]
+                    result.append(("", ">", new_line))
+
+        return result
+
+
+def format_diff_for_display(diff: FileDiff, use_colors: bool = True) -> str:
+    """
+    Format a FileDiff for terminal/GUI display.
+
+    Args:
+        diff: The FileDiff to format
+        use_colors: Whether to use ANSI colors
+
+    Returns:
+        Formatted string
+    """
+    lines = []
+
+    if diff.filename:
+        lines.append(f"--- {diff.filename}")
+        lines.append(f"+++ {diff.filename}")
+
+    for line in diff.lines:
+        if use_colors:
+            if line.type == DiffType.ADDED:
+                prefix = "\033[32m+"  # Green
+                suffix = "\033[0m"
+            elif line.type == DiffType.REMOVED:
+                prefix = "\033[31m-"  # Red
+                suffix = "\033[0m"
+            else:
+                prefix = " "
+                suffix = ""
+        else:
+            prefix = line.prefix
+            suffix = ""
+
+        lines.append(f"{prefix} {line.content}{suffix}")
+
+    return "\n".join(lines)
+
+
+def main():
+    """Test the diff generator."""
+    old_content = [
+        "def calculate_tax(amount):",
+        "    rate = 0.19",
+        "    if amount > 1000:",
+        "        rate = 0.25",
+        "    return amount * rate",
+    ]
+
+    new_content = [
+        "def calculate_tax(amount):",
+        "    rate = 0.19",
+        "    if amount > 10000:",
+        "        rate = 0.22",
+        "    elif amount > 1000:",
+        "        rate = 0.19",
+        "    return amount * rate",
+    ]
+
+    generator = DiffGenerator()
+    diff = generator.generate(old_content, new_content, "calculator.py")
+
+    print(f"File: {diff.filename}")
+    print(f"Additions: {diff.additions}, Deletions: {diff.deletions}")
+    print()
+    print("Diff output:")
+    print(format_diff_for_display(diff))
+
+
+if __name__ == "__main__":
+    main()

dctp/dctp_executor.py

@@ -0,0 +1,584 @@
+"""
+DCTP Executor - Executes DCTP operations on files.
+
+Handles CREATE, DELETE, INSERT_AFTER, REPLACE, and RENUMBER operations
+with backup support and checksum validation.
+"""
+
+import hashlib
+import os
+import re
+from dataclasses import dataclass
+from enum import Enum
+from pathlib import Path
+from typing import Optional
+
+from dctp_parser import DCTPParser, Operation, OperationType
+from dctp_backup import BackupManager
+from dctp_diff import DiffGenerator, FileDiff
+
+
+class ResultStatus(Enum):
+    SUCCESS = "success"
+    WARNING = "warning"
+    ERROR = "error"
+    SKIPPED = "skipped"
+
+
+@dataclass
+class ExecutionResult:
+    """Result of executing a single operation."""
+    status: ResultStatus
+    operation: Operation
+    message: str
+    diff: Optional[FileDiff] = None
+
+    def __str__(self) -> str:
+        status_symbols = {
+            ResultStatus.SUCCESS: "✅",
+            ResultStatus.WARNING: "⚠️",
+            ResultStatus.ERROR: "❌",
+            ResultStatus.SKIPPED: "⏭️",
+        }
+        return f"{status_symbols[self.status]} {self.message}"
+
+
+@dataclass
+class PreviewResult:
+    """Result of previewing operations before execution."""
+    operation: Operation
+    description: str
+    diff: Optional[FileDiff] = None
+    warnings: list[str] = None
+
+    def __post_init__(self):
+        if self.warnings is None:
+            self.warnings = []
+
+
+class DCTPExecutor:
+    """Executes DCTP operations on files."""
+
+    # Line number patterns (same as parser)
+    LINE_NUMBER_PATTERNS = [
+        re.compile(r'\s*#Z(\d+)\s*$'),
+        re.compile(r'\s*//Z(\d+)\s*$'),
+        re.compile(r'\s*<!--Z(\d+)-->\s*$'),
+        re.compile(r'\s*/\*Z(\d+)\*/\s*$'),
+        re.compile(r'\s*--Z(\d+)\s*$'),
+    ]
+
+    def __init__(
+        self,
+        project_path: str,
+        backup_manager: Optional[BackupManager] = None,
+        auto_renumber: bool = True,
+        validate_checksums: bool = True
+    ):
+        """
+        Initialize the executor.
+
+        Args:
+            project_path: Base project directory
+            backup_manager: Optional backup manager for undo support
+            auto_renumber: Automatically renumber after operations
+            validate_checksums: Validate checksums before operations
+        """
+        self.project_path = Path(project_path)
+        self.backup_manager = backup_manager or BackupManager(project_path)
+        self.auto_renumber = auto_renumber
+        self.validate_checksums = validate_checksums
+        self.diff_generator = DiffGenerator()
+        self.parser = DCTPParser()
+
+    def preview(self, operations: list[Operation]) -> list[PreviewResult]:
+        """
+        Preview operations without executing them.
+
+        Args:
+            operations: List of operations to preview
+
+        Returns:
+            List of preview results
+        """
+        previews = []
+
+        for op in operations:
+            preview = self._preview_operation(op)
+            previews.append(preview)
+
+        return previews
+
+    def _preview_operation(self, op: Operation) -> PreviewResult:
+        """Generate preview for a single operation."""
+        file_path = self.project_path / op.file
+        warnings = []
+
+        if op.type == OperationType.NEW:
+            if file_path.exists():
+                warnings.append(f"File already exists and will be overwritten")
+            return PreviewResult(
+                operation=op,
+                description=f"CREATE {op.file} ({len(op.content)} lines)",
+                warnings=warnings
+            )
+
+        elif op.type == OperationType.DELETE:
+            if not file_path.exists():
+                warnings.append(f"File does not exist")
+                return PreviewResult(
+                    operation=op,
+                    description=f"DELETE {op.file} Z{op.start_line}-Z{op.end_line} (file not found)",
+                    warnings=warnings
+                )
+
+            old_lines = self._read_file_lines(file_path)
+            if op.end_line > len(old_lines):
+                warnings.append(f"Line range exceeds file length ({len(old_lines)} lines)")
+
+            new_lines = old_lines.copy()
+            start_idx = op.start_line - 1
+            end_idx = min(op.end_line, len(old_lines))
+            del new_lines[start_idx:end_idx]
+
+            diff = self.diff_generator.generate(old_lines, new_lines, op.file)
+            return PreviewResult(
+                operation=op,
+                description=f"DELETE {op.file} Z{op.start_line}-Z{op.end_line}",
+                diff=diff,
+                warnings=warnings
+            )
+
+        elif op.type == OperationType.INSERT_AFTER:
+            if not file_path.exists():
+                warnings.append(f"File does not exist")
+                return PreviewResult(
+                    operation=op,
+                    description=f"INSERT_AFTER {op.file} Z{op.start_line} (file not found)",
+                    warnings=warnings
+                )
+
+            old_lines = self._read_file_lines(file_path)
+            if op.start_line > len(old_lines):
+                warnings.append(f"Line {op.start_line} exceeds file length ({len(old_lines)} lines)")
+
+            new_lines = old_lines.copy()
+            insert_idx = min(op.start_line, len(old_lines))
+            for i, line in enumerate(op.content):
+                new_lines.insert(insert_idx + i, line)
+
+            diff = self.diff_generator.generate(old_lines, new_lines, op.file)
+            return PreviewResult(
+                operation=op,
+                description=f"INSERT_AFTER {op.file} Z{op.start_line} ({len(op.content)} lines)",
+                diff=diff,
+                warnings=warnings
+            )
+
+        elif op.type == OperationType.REPLACE:
+            if not file_path.exists():
+                warnings.append(f"File does not exist")
+                return PreviewResult(
+                    operation=op,
+                    description=f"REPLACE {op.file} Z{op.start_line}-Z{op.end_line} (file not found)",
+                    warnings=warnings
+                )
+
+            old_lines = self._read_file_lines(file_path)
+            if op.end_line > len(old_lines):
+                warnings.append(f"Line range exceeds file length ({len(old_lines)} lines)")
+
+            new_lines = old_lines.copy()
+            start_idx = op.start_line - 1
+            end_idx = min(op.end_line, len(old_lines))
+            new_lines[start_idx:end_idx] = op.content
+
+            diff = self.diff_generator.generate(old_lines, new_lines, op.file)
+            return PreviewResult(
+                operation=op,
+                description=f"REPLACE {op.file} Z{op.start_line}-Z{op.end_line} ({len(op.content)} lines)",
+                diff=diff,
+                warnings=warnings
+            )
+
+        elif op.type == OperationType.RENUMBER:
+            return PreviewResult(
+                operation=op,
+                description=f"RENUMBER {op.file}",
+                warnings=warnings
+            )
+
+        return PreviewResult(
+            operation=op,
+            description=f"UNKNOWN {op.type}",
+            warnings=["Unknown operation type"]
+        )
+
+    def execute(
+        self,
+        operations: list[Operation],
+        skip_checksum_mismatch: bool = False
+    ) -> list[ExecutionResult]:
+        """
+        Execute a list of operations.
+
+        Args:
+            operations: List of operations to execute
+            skip_checksum_mismatch: Continue even if checksums don't match
+
+        Returns:
+            List of execution results
+        """
+        results = []
+
+        # Start backup session
+        self.backup_manager.start_session()
+
+        try:
+            for op in operations:
+                result = self._execute_operation(op, skip_checksum_mismatch)
+                results.append(result)
+
+                # Stop on error
+                if result.status == ResultStatus.ERROR:
+                    break
+
+        finally:
+            # End backup session
+            self.backup_manager.end_session()
+
+        return results
+
+    def _execute_operation(
+        self,
+        op: Operation,
+        skip_checksum_mismatch: bool = False
+    ) -> ExecutionResult:
+        """Execute a single operation."""
+        file_path = self.project_path / op.file
+
+        try:
+            if op.type == OperationType.NEW:
+                return self._execute_new(op, file_path)
+            elif op.type == OperationType.DELETE:
+                return self._execute_delete(op, file_path, skip_checksum_mismatch)
+            elif op.type == OperationType.INSERT_AFTER:
+                return self._execute_insert_after(op, file_path, skip_checksum_mismatch)
+            elif op.type == OperationType.REPLACE:
+                return self._execute_replace(op, file_path, skip_checksum_mismatch)
+            elif op.type == OperationType.RENUMBER:
+                return self._execute_renumber(op, file_path)
+            else:
+                return ExecutionResult(
+                    status=ResultStatus.ERROR,
+                    operation=op,
+                    message=f"Unknown operation type: {op.type}"
+                )
+        except PermissionError:
+            return ExecutionResult(
+                status=ResultStatus.ERROR,
+                operation=op,
+                message=f"Permission denied: {file_path}"
+            )
+        except Exception as e:
+            return ExecutionResult(
+                status=ResultStatus.ERROR,
+                operation=op,
+                message=f"Error: {str(e)}"
+            )
+
+    def _execute_new(self, op: Operation, file_path: Path) -> ExecutionResult:
+        """Execute a NEW operation (create file)."""
+        # Backup if file exists
+        if file_path.exists():
+            self.backup_manager.backup(str(op.file))
+
+        # Create parent directories
+        file_path.parent.mkdir(parents=True, exist_ok=True)
+
+        # Write content
+        content = "\n".join(op.content)
+        if op.content and not content.endswith("\n"):
+            content += "\n"
+        file_path.write_text(content)
+
+        return ExecutionResult(
+            status=ResultStatus.SUCCESS,
+            operation=op,
+            message=f"CREATE {op.file} ({len(op.content)} lines)"
+        )
+
+    def _execute_delete(
+        self,
+        op: Operation,
+        file_path: Path,
+        skip_checksum_mismatch: bool
+    ) -> ExecutionResult:
+        """Execute a DELETE operation."""
+        if not file_path.exists():
+            return ExecutionResult(
+                status=ResultStatus.WARNING,
+                operation=op,
+                message=f"File not found: {op.file}"
+            )
+
+        # Validate checksum if provided
+        if op.checksum and self.validate_checksums:
+            if not self._validate_checksum(file_path, op.checksum):
+                if not skip_checksum_mismatch:
+                    return ExecutionResult(
+                        status=ResultStatus.WARNING,
+                        operation=op,
+                        message=f"Checksum mismatch for {op.file} - file was modified externally"
+                    )
+
+        # Backup file
+        self.backup_manager.backup(str(op.file))
+
+        # Read file and delete lines
+        lines = self._read_file_lines(file_path)
+        old_lines = lines.copy()
+
+        if op.end_line > len(lines):
+            return ExecutionResult(
+                status=ResultStatus.WARNING,
+                operation=op,
+                message=f"Line range Z{op.start_line}-Z{op.end_line} exceeds file length ({len(lines)} lines)"
+            )
+
+        start_idx = op.start_line - 1
+        end_idx = op.end_line
+        del lines[start_idx:end_idx]
+
+        # Write back
+        self._write_file_lines(file_path, lines)
+
+        diff = self.diff_generator.generate(old_lines, lines, op.file)
+
+        return ExecutionResult(
+            status=ResultStatus.SUCCESS,
+            operation=op,
+            message=f"DELETE {op.file} Z{op.start_line}-Z{op.end_line}",
+            diff=diff
+        )
+
+    def _execute_insert_after(
+        self,
+        op: Operation,
+        file_path: Path,
+        skip_checksum_mismatch: bool
+    ) -> ExecutionResult:
+        """Execute an INSERT_AFTER operation."""
+        if not file_path.exists():
+            return ExecutionResult(
+                status=ResultStatus.WARNING,
+                operation=op,
+                message=f"File not found: {op.file}"
+            )
+
+        # Validate checksum if provided
+        if op.checksum and self.validate_checksums:
+            if not self._validate_checksum(file_path, op.checksum):
+                if not skip_checksum_mismatch:
+                    return ExecutionResult(
+                        status=ResultStatus.WARNING,
+                        operation=op,
+                        message=f"Checksum mismatch for {op.file} - file was modified externally"
+                    )
+
+        # Backup file
+        self.backup_manager.backup(str(op.file))
+
+        # Read file and insert lines
+        lines = self._read_file_lines(file_path)
+        old_lines = lines.copy()
+
+        if op.start_line > len(lines):
+            return ExecutionResult(
+                status=ResultStatus.WARNING,
+                operation=op,
+                message=f"Line Z{op.start_line} exceeds file length ({len(lines)} lines)"
+            )
+
+        insert_idx = op.start_line
+        for i, line in enumerate(op.content):
+            lines.insert(insert_idx + i, line)
+
+        # Write back
+        self._write_file_lines(file_path, lines)
+
+        diff = self.diff_generator.generate(old_lines, lines, op.file)
+
+        return ExecutionResult(
+            status=ResultStatus.SUCCESS,
+            operation=op,
+            message=f"INSERT_AFTER {op.file} Z{op.start_line} ({len(op.content)} lines)",
+            diff=diff
+        )
+
+    def _execute_replace(
+        self,
+        op: Operation,
+        file_path: Path,
+        skip_checksum_mismatch: bool
+    ) -> ExecutionResult:
+        """Execute a REPLACE operation."""
+        if not file_path.exists():
+            return ExecutionResult(
+                status=ResultStatus.WARNING,
+                operation=op,
+                message=f"File not found: {op.file}"
+            )
+
+        # Validate checksum if provided
+        if op.checksum and self.validate_checksums:
+            if not self._validate_checksum(file_path, op.checksum):
+                if not skip_checksum_mismatch:
+                    return ExecutionResult(
+                        status=ResultStatus.WARNING,
+                        operation=op,
+                        message=f"Checksum mismatch for {op.file} - file was modified externally"
+                    )
+
+        # Backup file
+        self.backup_manager.backup(str(op.file))
+
+        # Read file and replace lines
+        lines = self._read_file_lines(file_path)
+        old_lines = lines.copy()
+
+        if op.end_line > len(lines):
+            return ExecutionResult(
+                status=ResultStatus.WARNING,
+                operation=op,
+                message=f"Line range Z{op.start_line}-Z{op.end_line} exceeds file length ({len(lines)} lines)"
+            )
+
+        start_idx = op.start_line - 1
+        end_idx = op.end_line
+        lines[start_idx:end_idx] = op.content
+
+        # Write back
+        self._write_file_lines(file_path, lines)
+
+        diff = self.diff_generator.generate(old_lines, lines, op.file)
+
+        return ExecutionResult(
+            status=ResultStatus.SUCCESS,
+            operation=op,
+            message=f"REPLACE {op.file} Z{op.start_line}-Z{op.end_line} ({len(op.content)} lines)",
+            diff=diff
+        )
+
+    def _execute_renumber(self, op: Operation, file_path: Path) -> ExecutionResult:
+        """Execute a RENUMBER operation."""
+        if not file_path.exists():
+            return ExecutionResult(
+                status=ResultStatus.WARNING,
+                operation=op,
+                message=f"File not found: {op.file}"
+            )
+
+        # No backup needed for renumber (just updates line numbers)
+        lines = self._read_file_lines(file_path)
+        renumbered_lines = []
+
+        for i, line in enumerate(lines, 1):
+            # Remove existing line number
+            clean_line = self._remove_line_number(line)
+            # Add new line number
+            suffix = self.parser.get_line_number_suffix(op.file, i)
+            renumbered_lines.append(clean_line + suffix)
+
+        self._write_file_lines(file_path, renumbered_lines)
+
+        return ExecutionResult(
+            status=ResultStatus.SUCCESS,
+            operation=op,
+            message=f"RENUMBER {op.file} ({len(lines)} lines)"
+        )
+
+    def _read_file_lines(self, file_path: Path) -> list[str]:
+        """Read file and return lines without trailing newlines."""
+        content = file_path.read_text()
+        lines = content.split('\n')
+        # Remove trailing empty line if file ends with newline
+        if lines and lines[-1] == '':
+            lines = lines[:-1]
+        return lines
+
+    def _write_file_lines(self, file_path: Path, lines: list[str]) -> None:
+        """Write lines to file with trailing newline."""
+        content = '\n'.join(lines)
+        if lines and not content.endswith('\n'):
+            content += '\n'
+        file_path.write_text(content)
+
+    def _remove_line_number(self, line: str) -> str:
+        """Remove line number marker from end of line."""
+        for pattern in self.LINE_NUMBER_PATTERNS:
+            match = pattern.search(line)
+            if match:
+                return line[:match.start()]
+        return line
+
+    def _validate_checksum(self, file_path: Path, expected: str) -> bool:
+        """Validate file checksum."""
+        content = file_path.read_bytes()
+        actual = hashlib.md5(content).hexdigest()[:8]
+        return actual.lower() == expected.lower()
+
+    @staticmethod
+    def calculate_checksum(file_path: Path) -> str:
+        """Calculate checksum for a file."""
+        content = file_path.read_bytes()
+        return hashlib.md5(content).hexdigest()[:8]
+
+
+def main():
+    """Test the executor."""
+    import tempfile
+
+    test_input = """###FILE:calculator.py
+###NEW
+def add(a, b):  #Z1
+    return a + b  #Z2
+  #Z3
+def multiply(a, b):  #Z4
+    return a * b  #Z5
+###END
+"""
+
+    with tempfile.TemporaryDirectory() as tmpdir:
+        parser = DCTPParser()
+        result = parser.parse(test_input)
+
+        print("Parsed operations:")
+        for op in result.operations:
+            print(f"  {op}")
+
+        executor = DCTPExecutor(tmpdir)
+
+        # Preview
+        print("\nPreviews:")
+        previews = executor.preview(result.operations)
+        for preview in previews:
+            print(f"  {preview.description}")
+            if preview.warnings:
+                for w in preview.warnings:
+                    print(f"    ⚠️ {w}")
+
+        # Execute
+        print("\nExecution:")
+        exec_results = executor.execute(result.operations)
+        for r in exec_results:
+            print(f"  {r}")
+
+        # Verify file was created
+        file_path = Path(tmpdir) / "calculator.py"
+        if file_path.exists():
+            print(f"\nFile content:\n{file_path.read_text()}")
+
+
+if __name__ == "__main__":
+    main()

dctp/dctp_gui.py

@@ -0,0 +1,666 @@
+#!/usr/bin/env python3
+"""
+DCTP GUI - Delta Code Transfer Protocol graphical user interface.
+
+A CustomTkinter-based GUI for managing AI-generated code transfers
+using delta operations for efficient updates.
+"""
+
+import os
+import sys
+from datetime import datetime
+from pathlib import Path
+from tkinter import filedialog, messagebox
+from typing import Optional
+import json
+
+import customtkinter as ctk
+
+from dctp_parser import DCTPParser, ParseResult, Operation, OperationType
+from dctp_executor import DCTPExecutor, ExecutionResult, PreviewResult, ResultStatus
+from dctp_backup import BackupManager
+from dctp_diff import DiffType
+
+
+class SettingsDialog(ctk.CTkToplevel):
+    """Settings dialog window."""
+
+    def __init__(self, parent, settings: dict):
+        super().__init__(parent)
+
+        self.title("Einstellungen")
+        self.geometry("500x400")
+        self.resizable(False, False)
+
+        self.settings = settings.copy()
+        self.result = None
+
+        # Make modal
+        self.transient(parent)
+        self.grab_set()
+
+        self._create_widgets()
+
+        # Center on parent
+        self.update_idletasks()
+        x = parent.winfo_x() + (parent.winfo_width() - self.winfo_width()) // 2
+        y = parent.winfo_y() + (parent.winfo_height() - self.winfo_height()) // 2
+        self.geometry(f"+{x}+{y}")
+
+    def _create_widgets(self):
+        # Main frame
+        main_frame = ctk.CTkFrame(self)
+        main_frame.pack(fill="both", expand=True, padx=20, pady=20)
+
+        # Project path
+        ctk.CTkLabel(main_frame, text="Standard-Projektpfad:").pack(anchor="w", pady=(0, 5))
+        path_frame = ctk.CTkFrame(main_frame)
+        path_frame.pack(fill="x", pady=(0, 15))
+
+        self.path_entry = ctk.CTkEntry(path_frame, width=350)
+        self.path_entry.pack(side="left", fill="x", expand=True, padx=(0, 10))
+        self.path_entry.insert(0, self.settings.get("project_path", ""))
+
+        ctk.CTkButton(
+            path_frame,
+            text="...",
+            width=40,
+            command=self._browse_path
+        ).pack(side="right")
+
+        # Backup directory
+        ctk.CTkLabel(main_frame, text="Backup-Verzeichnis:").pack(anchor="w", pady=(0, 5))
+        backup_frame = ctk.CTkFrame(main_frame)
+        backup_frame.pack(fill="x", pady=(0, 15))
+
+        self.backup_entry = ctk.CTkEntry(backup_frame, width=350)
+        self.backup_entry.pack(side="left", fill="x", expand=True, padx=(0, 10))
+        self.backup_entry.insert(0, self.settings.get("backup_dir", ".dctp_backups"))
+
+        ctk.CTkButton(
+            backup_frame,
+            text="...",
+            width=40,
+            command=self._browse_backup
+        ).pack(side="right")
+
+        # Options
+        options_frame = ctk.CTkFrame(main_frame)
+        options_frame.pack(fill="x", pady=15)
+
+        self.auto_renumber_var = ctk.BooleanVar(
+            value=self.settings.get("auto_renumber", True)
+        )
+        ctk.CTkCheckBox(
+            options_frame,
+            text="Auto-Renumber nach Operationen",
+            variable=self.auto_renumber_var
+        ).pack(anchor="w", pady=5)
+
+        self.validate_checksum_var = ctk.BooleanVar(
+            value=self.settings.get("validate_checksum", True)
+        )
+        ctk.CTkCheckBox(
+            options_frame,
+            text="Checksum-Validierung aktiviert",
+            variable=self.validate_checksum_var
+        ).pack(anchor="w", pady=5)
+
+        # Theme
+        ctk.CTkLabel(main_frame, text="Theme:").pack(anchor="w", pady=(15, 5))
+        self.theme_var = ctk.StringVar(value=self.settings.get("theme", "dark"))
+        theme_frame = ctk.CTkFrame(main_frame)
+        theme_frame.pack(fill="x", pady=(0, 15))
+
+        ctk.CTkRadioButton(
+            theme_frame,
+            text="Dunkel",
+            variable=self.theme_var,
+            value="dark"
+        ).pack(side="left", padx=(0, 20))
+
+        ctk.CTkRadioButton(
+            theme_frame,
+            text="Hell",
+            variable=self.theme_var,
+            value="light"
+        ).pack(side="left")
+
+        # Buttons
+        button_frame = ctk.CTkFrame(main_frame)
+        button_frame.pack(fill="x", pady=(20, 0))
+
+        ctk.CTkButton(
+            button_frame,
+            text="Abbrechen",
+            command=self._cancel
+        ).pack(side="right", padx=(10, 0))
+
+        ctk.CTkButton(
+            button_frame,
+            text="Speichern",
+            command=self._save
+        ).pack(side="right")
+
+    def _browse_path(self):
+        path = filedialog.askdirectory(
+            initialdir=self.path_entry.get() or os.path.expanduser("~")
+        )
+        if path:
+            self.path_entry.delete(0, "end")
+            self.path_entry.insert(0, path)
+
+    def _browse_backup(self):
+        path = filedialog.askdirectory(
+            initialdir=os.path.expanduser("~")
+        )
+        if path:
+            self.backup_entry.delete(0, "end")
+            self.backup_entry.insert(0, path)
+
+    def _save(self):
+        self.result = {
+            "project_path": self.path_entry.get(),
+            "backup_dir": self.backup_entry.get(),
+            "auto_renumber": self.auto_renumber_var.get(),
+            "validate_checksum": self.validate_checksum_var.get(),
+            "theme": self.theme_var.get()
+        }
+        self.destroy()
+
+    def _cancel(self):
+        self.result = None
+        self.destroy()
+
+
+class DCTPApp(ctk.CTk):
+    """Main DCTP application window."""
+
+    SETTINGS_FILE = ".dctp_settings.json"
+
+    def __init__(self):
+        super().__init__()
+
+        self.title("DCTP - Delta Code Transfer")
+        self.geometry("1200x900")
+        self.minsize(800, 600)
+
+        # Initialize components
+        self.parser = DCTPParser()
+        self.executor: Optional[DCTPExecutor] = None
+        self.backup_manager: Optional[BackupManager] = None
+        self.current_operations: list[Operation] = []
+        self.current_previews: list[PreviewResult] = []
+
+        # Load settings
+        self.settings = self._load_settings()
+        ctk.set_appearance_mode(self.settings.get("theme", "dark"))
+
+        # Create UI
+        self._create_widgets()
+
+        # Initialize project if path is set
+        if self.settings.get("project_path"):
+            self._init_project(self.settings["project_path"])
+
+        self._log("Bereit")
+
+    def _load_settings(self) -> dict:
+        """Load settings from file."""
+        settings_path = Path.home() / self.SETTINGS_FILE
+        if settings_path.exists():
+            try:
+                return json.loads(settings_path.read_text())
+            except (json.JSONDecodeError, IOError):
+                pass
+        return {
+            "project_path": "",
+            "backup_dir": ".dctp_backups",
+            "auto_renumber": True,
+            "validate_checksum": True,
+            "theme": "dark"
+        }
+
+    def _save_settings(self):
+        """Save settings to file."""
+        settings_path = Path.home() / self.SETTINGS_FILE
+        settings_path.write_text(json.dumps(self.settings, indent=2))
+
+    def _create_widgets(self):
+        """Create all UI widgets."""
+        # Top bar - project selection
+        top_frame = ctk.CTkFrame(self)
+        top_frame.pack(fill="x", padx=10, pady=10)
+
+        ctk.CTkLabel(top_frame, text="Projekt:").pack(side="left", padx=(0, 10))
+
+        self.project_entry = ctk.CTkEntry(top_frame, width=400)
+        self.project_entry.pack(side="left", fill="x", expand=True, padx=(0, 10))
+        self.project_entry.insert(0, self.settings.get("project_path", ""))
+
+        ctk.CTkButton(
+            top_frame,
+            text="Waehlen",
+            width=100,
+            command=self._browse_project
+        ).pack(side="left", padx=(0, 10))
+
+        ctk.CTkButton(
+            top_frame,
+            text="Einstellungen",
+            width=100,
+            command=self._open_settings
+        ).pack(side="left")
+
+        # Main content area with paned layout
+        content_frame = ctk.CTkFrame(self)
+        content_frame.pack(fill="both", expand=True, padx=10, pady=(0, 10))
+
+        # Left side - Input and preview
+        left_frame = ctk.CTkFrame(content_frame)
+        left_frame.pack(side="left", fill="both", expand=True, padx=(0, 5))
+
+        # Input area
+        input_label_frame = ctk.CTkFrame(left_frame)
+        input_label_frame.pack(fill="x", pady=(5, 5), padx=5)
+        ctk.CTkLabel(
+            input_label_frame,
+            text="Input (KI-Output hier einfuegen)",
+            font=ctk.CTkFont(weight="bold")
+        ).pack(side="left")
+
+        self.input_text = ctk.CTkTextbox(
+            left_frame,
+            height=250,
+            font=ctk.CTkFont(family="Consolas", size=12)
+        )
+        self.input_text.pack(fill="both", expand=True, padx=5, pady=(0, 10))
+
+        # Buttons
+        button_frame = ctk.CTkFrame(left_frame)
+        button_frame.pack(fill="x", padx=5, pady=(0, 10))
+
+        self.analyze_btn = ctk.CTkButton(
+            button_frame,
+            text="Analysieren",
+            command=self._analyze,
+            width=120
+        )
+        self.analyze_btn.pack(side="left", padx=(0, 10))
+
+        self.execute_btn = ctk.CTkButton(
+            button_frame,
+            text="Ausfuehren",
+            command=self._execute,
+            width=120,
+            state="disabled"
+        )
+        self.execute_btn.pack(side="left", padx=(0, 10))
+
+        self.undo_btn = ctk.CTkButton(
+            button_frame,
+            text="Undo",
+            command=self._undo,
+            width=80
+        )
+        self.undo_btn.pack(side="left", padx=(0, 10))
+
+        ctk.CTkButton(
+            button_frame,
+            text="Clear",
+            command=self._clear,
+            width=80
+        ).pack(side="left")
+
+        # Preview operations
+        preview_label_frame = ctk.CTkFrame(left_frame)
+        preview_label_frame.pack(fill="x", pady=(5, 5), padx=5)
+        ctk.CTkLabel(
+            preview_label_frame,
+            text="Vorschau Operationen",
+            font=ctk.CTkFont(weight="bold")
+        ).pack(side="left")
+
+        self.preview_text = ctk.CTkTextbox(
+            left_frame,
+            height=150,
+            font=ctk.CTkFont(family="Consolas", size=11)
+        )
+        self.preview_text.pack(fill="both", expand=True, padx=5, pady=(0, 10))
+        self.preview_text.configure(state="disabled")
+
+        # Right side - Diff and file tree
+        right_frame = ctk.CTkFrame(content_frame)
+        right_frame.pack(side="right", fill="both", expand=True, padx=(5, 0))
+
+        # Diff view
+        diff_label_frame = ctk.CTkFrame(right_frame)
+        diff_label_frame.pack(fill="x", pady=(5, 5), padx=5)
+        ctk.CTkLabel(
+            diff_label_frame,
+            text="Diff-Ansicht",
+            font=ctk.CTkFont(weight="bold")
+        ).pack(side="left")
+
+        self.diff_text = ctk.CTkTextbox(
+            right_frame,
+            height=300,
+            font=ctk.CTkFont(family="Consolas", size=11)
+        )
+        self.diff_text.pack(fill="both", expand=True, padx=5, pady=(0, 10))
+        self.diff_text.configure(state="disabled")
+
+        # File tree
+        tree_label_frame = ctk.CTkFrame(right_frame)
+        tree_label_frame.pack(fill="x", pady=(5, 5), padx=5)
+        ctk.CTkLabel(
+            tree_label_frame,
+            text="Projektdateien",
+            font=ctk.CTkFont(weight="bold")
+        ).pack(side="left")
+
+        ctk.CTkButton(
+            tree_label_frame,
+            text="Aktualisieren",
+            width=80,
+            command=self._refresh_file_tree
+        ).pack(side="right")
+
+        self.tree_text = ctk.CTkTextbox(
+            right_frame,
+            height=150,
+            font=ctk.CTkFont(family="Consolas", size=11)
+        )
+        self.tree_text.pack(fill="both", expand=True, padx=5, pady=(0, 10))
+        self.tree_text.configure(state="disabled")
+
+        # Bottom - Log
+        log_label_frame = ctk.CTkFrame(self)
+        log_label_frame.pack(fill="x", padx=10, pady=(0, 5))
+        ctk.CTkLabel(
+            log_label_frame,
+            text="Log",
+            font=ctk.CTkFont(weight="bold")
+        ).pack(side="left")
+
+        self.log_text = ctk.CTkTextbox(
+            self,
+            height=120,
+            font=ctk.CTkFont(family="Consolas", size=10)
+        )
+        self.log_text.pack(fill="x", padx=10, pady=(0, 10))
+        self.log_text.configure(state="disabled")
+
+    def _log(self, message: str, level: str = "info"):
+        """Add a message to the log."""
+        timestamp = datetime.now().strftime("%H:%M:%S")
+        prefix = ""
+        if level == "error":
+            prefix = "ERROR "
+        elif level == "warning":
+            prefix = "WARN  "
+
+        self.log_text.configure(state="normal")
+        self.log_text.insert("end", f"{timestamp}  {prefix}{message}\n")
+        self.log_text.see("end")
+        self.log_text.configure(state="disabled")
+
+    def _init_project(self, path: str):
+        """Initialize project with given path."""
+        if not os.path.isdir(path):
+            self._log(f"Verzeichnis existiert nicht: {path}", "error")
+            return False
+
+        self.backup_manager = BackupManager(path)
+        self.executor = DCTPExecutor(
+            path,
+            self.backup_manager,
+            auto_renumber=self.settings.get("auto_renumber", True),
+            validate_checksums=self.settings.get("validate_checksum", True)
+        )
+        self.settings["project_path"] = path
+        self._save_settings()
+        self._log(f"Projekt geladen: {path}")
+        self._refresh_file_tree()
+        return True
+
+    def _browse_project(self):
+        """Open directory browser for project selection."""
+        initial_dir = self.project_entry.get() or os.path.expanduser("~")
+        path = filedialog.askdirectory(initialdir=initial_dir)
+        if path:
+            self.project_entry.delete(0, "end")
+            self.project_entry.insert(0, path)
+            self._init_project(path)
+
+    def _open_settings(self):
+        """Open settings dialog."""
+        dialog = SettingsDialog(self, self.settings)
+        self.wait_window(dialog)
+
+        if dialog.result:
+            old_theme = self.settings.get("theme")
+            self.settings.update(dialog.result)
+            self._save_settings()
+
+            # Apply theme change
+            if dialog.result.get("theme") != old_theme:
+                ctk.set_appearance_mode(dialog.result["theme"])
+
+            # Reinitialize project with new settings
+            if self.settings.get("project_path"):
+                self._init_project(self.settings["project_path"])
+
+            self._log("Einstellungen gespeichert")
+
+    def _analyze(self):
+        """Analyze input and show preview."""
+        # Ensure project is initialized
+        project_path = self.project_entry.get()
+        if not project_path:
+            messagebox.showerror("Fehler", "Bitte waehle ein Projektverzeichnis")
+            return
+
+        if not self.executor or self.settings.get("project_path") != project_path:
+            if not self._init_project(project_path):
+                return
+
+        # Get input
+        input_text = self.input_text.get("1.0", "end-1c")
+        if not input_text.strip():
+            self._log("Kein Input vorhanden", "warning")
+            return
+
+        # Parse
+        self._log("Analysiere...")
+        result = self.parser.parse(input_text)
+
+        # Handle errors
+        if result.has_errors:
+            self._log(f"{len(result.errors)} Parse-Fehler gefunden", "error")
+            for error in result.errors:
+                self._log(f"  Zeile {error.line_number}: {error.message}", "error")
+            return
+
+        if not result.operations:
+            self._log("Keine Operationen gefunden", "warning")
+            return
+
+        self.current_operations = result.operations
+        self._log(f"{len(result.operations)} Operationen gefunden")
+
+        # Generate previews
+        self.current_previews = self.executor.preview(result.operations)
+
+        # Display previews
+        self._display_previews()
+
+        # Enable execute button
+        self.execute_btn.configure(state="normal")
+
+    def _display_previews(self):
+        """Display operation previews."""
+        self.preview_text.configure(state="normal")
+        self.preview_text.delete("1.0", "end")
+
+        self.diff_text.configure(state="normal")
+        self.diff_text.delete("1.0", "end")
+
+        for preview in self.current_previews:
+            # Add to preview list
+            self.preview_text.insert("end", f"{preview.description}\n")
+            for warning in preview.warnings:
+                self.preview_text.insert("end", f"  WARNING {warning}\n")
+
+            # Add diff if available
+            if preview.diff and preview.diff.has_changes:
+                self.diff_text.insert("end", f"--- {preview.diff.filename} ---\n")
+                for line in preview.diff.lines:
+                    if line.type == DiffType.ADDED:
+                        self.diff_text.insert("end", f"+ {line.content}\n")
+                    elif line.type == DiffType.REMOVED:
+                        self.diff_text.insert("end", f"- {line.content}\n")
+                    elif line.type == DiffType.UNCHANGED:
+                        self.diff_text.insert("end", f"  {line.content}\n")
+                self.diff_text.insert("end", "\n")
+
+        self.preview_text.configure(state="disabled")
+        self.diff_text.configure(state="disabled")
+
+    def _execute(self):
+        """Execute the analyzed operations."""
+        if not self.current_operations:
+            self._log("Keine Operationen zum Ausfuehren", "warning")
+            return
+
+        if not self.executor:
+            self._log("Kein Projekt initialisiert", "error")
+            return
+
+        # Confirm
+        count = len(self.current_operations)
+        if not messagebox.askyesno(
+            "Bestaetigen",
+            f"{count} Operationen ausfuehren?"
+        ):
+            return
+
+        self._log(f"Fuehre {count} Operationen aus...")
+
+        # Execute
+        results = self.executor.execute(self.current_operations)
+
+        # Log results
+        success_count = 0
+        for result in results:
+            if result.status == ResultStatus.SUCCESS:
+                self._log(f"OK {result.message}")
+                success_count += 1
+            elif result.status == ResultStatus.WARNING:
+                self._log(f"WARN {result.message}", "warning")
+            elif result.status == ResultStatus.ERROR:
+                self._log(f"ERROR {result.message}", "error")
+
+        self._log(f"Abgeschlossen: {success_count}/{count} erfolgreich")
+
+        # Clear current operations
+        self.current_operations = []
+        self.current_previews = []
+        self.execute_btn.configure(state="disabled")
+
+        # Refresh file tree
+        self._refresh_file_tree()
+
+    def _undo(self):
+        """Undo last operation."""
+        if not self.backup_manager:
+            self._log("Kein Projekt initialisiert", "error")
+            return
+
+        success, restored = self.backup_manager.restore_last()
+
+        if success:
+            self._log(f"Undo erfolgreich: {len(restored)} Dateien wiederhergestellt")
+            for f in restored:
+                self._log(f"  -> {f}")
+            self._refresh_file_tree()
+        else:
+            self._log("Kein Backup zum Wiederherstellen", "warning")
+
+    def _clear(self):
+        """Clear input and preview areas."""
+        self.input_text.delete("1.0", "end")
+
+        self.preview_text.configure(state="normal")
+        self.preview_text.delete("1.0", "end")
+        self.preview_text.configure(state="disabled")
+
+        self.diff_text.configure(state="normal")
+        self.diff_text.delete("1.0", "end")
+        self.diff_text.configure(state="disabled")
+
+        self.current_operations = []
+        self.current_previews = []
+        self.execute_btn.configure(state="disabled")
+
+        self._log("Eingabe geloescht")
+
+    def _refresh_file_tree(self):
+        """Refresh the file tree display."""
+        self.tree_text.configure(state="normal")
+        self.tree_text.delete("1.0", "end")
+
+        project_path = self.project_entry.get()
+        if not project_path or not os.path.isdir(project_path):
+            self.tree_text.insert("end", "(Kein Projekt geladen)")
+            self.tree_text.configure(state="disabled")
+            return
+
+        # Build simple tree
+        try:
+            self._add_tree_items(Path(project_path), 0)
+        except Exception as e:
+            self.tree_text.insert("end", f"Fehler: {e}")
+
+        self.tree_text.configure(state="disabled")
+
+    def _add_tree_items(self, path: Path, level: int, max_items: int = 100):
+        """Recursively add items to tree display."""
+        if level > 5:  # Limit depth
+            return
+
+        indent = "  " * level
+
+        try:
+            items = sorted(path.iterdir(), key=lambda x: (not x.is_dir(), x.name.lower()))
+            count = 0
+
+            for item in items:
+                if count >= max_items:
+                    self.tree_text.insert("end", f"{indent}  ... (mehr Dateien)\n")
+                    break
+
+                # Skip hidden files and backup directory
+                if item.name.startswith('.'):
+                    continue
+
+                if item.is_dir():
+                    self.tree_text.insert("end", f"{indent}DIR {item.name}/\n")
+                    self._add_tree_items(item, level + 1, max_items=20)
+                else:
+                    self.tree_text.insert("end", f"{indent}FILE {item.name}\n")
+
+                count += 1
+
+        except PermissionError:
+            self.tree_text.insert("end", f"{indent}  (Zugriff verweigert)\n")
+
+
+def main():
+    """Main entry point."""
+    app = DCTPApp()
+    app.mainloop()
+
+
+if __name__ == "__main__":
+    main()

dctp/dctp_parser.py

@@ -0,0 +1,307 @@
+"""
+DCTP Parser - Parses DCTP control commands and code blocks.
+
+Handles line-numbered code with language-specific comment formats:
+- Python/Shell: #Z1
+- JavaScript/Java/C/C++: //Z1
+- HTML: <!--Z1-->
+- CSS: /*Z1*/
+- SQL: --Z1
+"""
+
+import re
+from dataclasses import dataclass, field
+from typing import Optional
+from enum import Enum
+
+
+class OperationType(Enum):
+    NEW = "NEW"
+    DELETE = "DELETE"
+    INSERT_AFTER = "INSERT_AFTER"
+    REPLACE = "REPLACE"
+    RENUMBER = "RENUMBER"
+
+
+@dataclass
+class Operation:
+    """Represents a single DCTP operation."""
+    type: OperationType
+    file: str
+    start_line: Optional[int] = None
+    end_line: Optional[int] = None
+    content: list[str] = field(default_factory=list)
+    checksum: Optional[str] = None
+    raw_content: list[str] = field(default_factory=list)  # Content with line numbers
+
+    def __str__(self) -> str:
+        if self.type == OperationType.NEW:
+            return f"CREATE {self.file} ({len(self.content)} lines)"
+        elif self.type == OperationType.DELETE:
+            return f"DELETE {self.file} Z{self.start_line}-Z{self.end_line}"
+        elif self.type == OperationType.INSERT_AFTER:
+            return f"INSERT_AFTER {self.file} Z{self.start_line} ({len(self.content)} lines)"
+        elif self.type == OperationType.REPLACE:
+            return f"REPLACE {self.file} Z{self.start_line}-Z{self.end_line} ({len(self.content)} lines)"
+        elif self.type == OperationType.RENUMBER:
+            return f"RENUMBER {self.file}"
+        return f"{self.type.value} {self.file}"
+
+
+@dataclass
+class ParseError:
+    """Represents a parsing error."""
+    line_number: int
+    line_content: str
+    message: str
+
+
+@dataclass
+class ParseResult:
+    """Result of parsing DCTP input."""
+    operations: list[Operation]
+    errors: list[ParseError]
+
+    @property
+    def has_errors(self) -> bool:
+        return len(self.errors) > 0
+
+
+class DCTPParser:
+    """Parser for DCTP (Delta Code Transfer Protocol) format."""
+
+    # Regex patterns for line number markers in different languages
+    LINE_NUMBER_PATTERNS = [
+        re.compile(r'\s*#Z(\d+)\s*$'),           # Python, Shell
+        re.compile(r'\s*//Z(\d+)\s*$'),          # JavaScript, Java, C, C++
+        re.compile(r'\s*<!--Z(\d+)-->\s*$'),     # HTML
+        re.compile(r'\s*/\*Z(\d+)\*/\s*$'),      # CSS
+        re.compile(r'\s*--Z(\d+)\s*$'),          # SQL
+    ]
+
+    # Control command patterns
+    FILE_PATTERN = re.compile(r'^###FILE:(.+)$')
+    NEW_PATTERN = re.compile(r'^###NEW\s*$')
+    DELETE_PATTERN = re.compile(r'^###DELETE:Z(\d+)(?:-Z(\d+))?\s*$')
+    INSERT_AFTER_PATTERN = re.compile(r'^###INSERT_AFTER:Z(\d+)\s*$')
+    REPLACE_PATTERN = re.compile(r'^###REPLACE:Z(\d+)(?:-Z(\d+))?\s*$')
+    END_PATTERN = re.compile(r'^###END\s*$')
+    RENUMBER_PATTERN = re.compile(r'^###RENUMBER\s*$')
+    CHECKSUM_PATTERN = re.compile(r'^###CHECKSUM:([a-fA-F0-9]+)\s*$')
+
+    def parse(self, text: str) -> ParseResult:
+        """
+        Parse DCTP formatted text into a list of operations.
+
+        Args:
+            text: The DCTP formatted input text
+
+        Returns:
+            ParseResult containing operations and any errors
+        """
+        operations: list[Operation] = []
+        errors: list[ParseError] = []
+
+        current_file: Optional[str] = None
+        current_op: Optional[Operation] = None
+        buffer: list[str] = []
+        raw_buffer: list[str] = []
+
+        lines = text.split('\n')
+
+        for line_num, line in enumerate(lines, 1):
+            # Skip empty lines outside of content blocks
+            if not line.strip() and current_op is None:
+                continue
+
+            # Check for FILE command
+            file_match = self.FILE_PATTERN.match(line)
+            if file_match:
+                current_file = file_match.group(1).strip()
+                continue
+
+            # Check for NEW command
+            if self.NEW_PATTERN.match(line):
+                if current_file is None:
+                    errors.append(ParseError(line_num, line, "###NEW without ###FILE"))
+                    continue
+                current_op = Operation(type=OperationType.NEW, file=current_file)
+                buffer = []
+                raw_buffer = []
+                continue
+
+            # Check for DELETE command
+            delete_match = self.DELETE_PATTERN.match(line)
+            if delete_match:
+                if current_file is None:
+                    errors.append(ParseError(line_num, line, "###DELETE without ###FILE"))
+                    continue
+                start = int(delete_match.group(1))
+                end = int(delete_match.group(2)) if delete_match.group(2) else start
+                operations.append(Operation(
+                    type=OperationType.DELETE,
+                    file=current_file,
+                    start_line=start,
+                    end_line=end
+                ))
+                continue
+
+            # Check for INSERT_AFTER command
+            insert_match = self.INSERT_AFTER_PATTERN.match(line)
+            if insert_match:
+                if current_file is None:
+                    errors.append(ParseError(line_num, line, "###INSERT_AFTER without ###FILE"))
+                    continue
+                current_op = Operation(
+                    type=OperationType.INSERT_AFTER,
+                    file=current_file,
+                    start_line=int(insert_match.group(1))
+                )
+                buffer = []
+                raw_buffer = []
+                continue
+
+            # Check for REPLACE command
+            replace_match = self.REPLACE_PATTERN.match(line)
+            if replace_match:
+                if current_file is None:
+                    errors.append(ParseError(line_num, line, "###REPLACE without ###FILE"))
+                    continue
+                start = int(replace_match.group(1))
+                end = int(replace_match.group(2)) if replace_match.group(2) else start
+                current_op = Operation(
+                    type=OperationType.REPLACE,
+                    file=current_file,
+                    start_line=start,
+                    end_line=end
+                )
+                buffer = []
+                raw_buffer = []
+                continue
+
+            # Check for END command
+            if self.END_PATTERN.match(line):
+                if current_op:
+                    current_op.content = buffer.copy()
+                    current_op.raw_content = raw_buffer.copy()
+                    operations.append(current_op)
+                    current_op = None
+                    buffer = []
+                    raw_buffer = []
+                continue
+
+            # Check for RENUMBER command
+            if self.RENUMBER_PATTERN.match(line):
+                if current_file is None:
+                    errors.append(ParseError(line_num, line, "###RENUMBER without ###FILE"))
+                    continue
+                operations.append(Operation(type=OperationType.RENUMBER, file=current_file))
+                continue
+
+            # Check for CHECKSUM command
+            checksum_match = self.CHECKSUM_PATTERN.match(line)
+            if checksum_match:
+                if current_op:
+                    current_op.checksum = checksum_match.group(1)
+                continue
+
+            # Regular code line - add to buffer if we're in an operation
+            if current_op is not None:
+                raw_buffer.append(line)
+                clean_line = self._remove_line_number(line)
+                buffer.append(clean_line)
+
+        # Handle unclosed operation
+        if current_op is not None:
+            errors.append(ParseError(
+                len(lines),
+                "",
+                f"Unclosed operation: {current_op.type.value} for {current_op.file}"
+            ))
+
+        return ParseResult(operations=operations, errors=errors)
+
+    def _remove_line_number(self, line: str) -> str:
+        """Remove line number marker from end of line."""
+        for pattern in self.LINE_NUMBER_PATTERNS:
+            match = pattern.search(line)
+            if match:
+                return line[:match.start()]
+        return line
+
+    def extract_line_number(self, line: str) -> Optional[int]:
+        """Extract line number from a code line."""
+        for pattern in self.LINE_NUMBER_PATTERNS:
+            match = pattern.search(line)
+            if match:
+                return int(match.group(1))
+        return None
+
+    @staticmethod
+    def get_line_number_suffix(filename: str, line_num: int) -> str:
+        """Get the appropriate line number suffix for a file type."""
+        ext = filename.rsplit('.', 1)[-1].lower() if '.' in filename else ''
+
+        if ext in ('py', 'sh', 'bash', 'zsh', 'yaml', 'yml', 'toml', 'ini', 'conf', 'rb', 'pl'):
+            return f"  #Z{line_num}"
+        elif ext in ('js', 'ts', 'jsx', 'tsx', 'java', 'c', 'cpp', 'h', 'hpp', 'cs', 'go', 'rs', 'swift', 'kt', 'scala'):
+            return f"  //Z{line_num}"
+        elif ext in ('html', 'htm', 'xml', 'svg'):
+            return f"  <!--Z{line_num}-->"
+        elif ext in ('css', 'scss', 'sass', 'less'):
+            return f"  /*Z{line_num}*/"
+        elif ext in ('sql',):
+            return f"  --Z{line_num}"
+        else:
+            # Default to Python style
+            return f"  #Z{line_num}"
+
+
+def main():
+    """Test the parser with example input."""
+    test_input = """###FILE:src/calculator.py
+###NEW
+def add(a, b):  #Z1
+    return a + b  #Z2
+  #Z3
+def multiply(a, b):  #Z4
+    return a * b  #Z5
+###END
+
+###FILE:src/calculator.py
+###REPLACE:Z4-Z5
+def multiply(a, b):  #Z4
+    \"\"\"Multipliziert zwei Zahlen.\"\"\"  #Z5
+    return a * b  #Z6
+###END
+###RENUMBER
+
+###FILE:src/calculator.py
+###INSERT_AFTER:Z2
+  #Z3
+def subtract(a, b):  #Z4
+    return a - b  #Z5
+###END
+###RENUMBER
+
+###FILE:src/calculator.py
+###DELETE:Z10-Z15
+###RENUMBER
+"""
+
+    parser = DCTPParser()
+    result = parser.parse(test_input)
+
+    print("Operations found:")
+    for op in result.operations:
+        print(f"  {op}")
+
+    if result.has_errors:
+        print("\nErrors:")
+        for error in result.errors:
+            print(f"  Line {error.line_number}: {error.message}")
+            print(f"    {error.line_content}")
+
+
+if __name__ == "__main__":
+    main()

dctp/requirements.txt

@@ -0,0 +1 @@
+customtkinter>=5.2.0

familyalbums/.htaccess

@@ -0,0 +1,48 @@
+# FamilyAlbums - Apache Configuration
+
+# Security Headers
+<IfModule mod_headers.c>
+    Header set X-Content-Type-Options "nosniff"
+    Header set X-Frame-Options "SAMEORIGIN"
+    Header set X-XSS-Protection "1; mode=block"
+    Header set Referrer-Policy "strict-origin-when-cross-origin"
+</IfModule>
+
+# Deny access to config file
+<Files "config.php">
+    <IfModule mod_authz_core.c>
+        Require all denied
+    </IfModule>
+    <IfModule !mod_authz_core.c>
+        Order deny,allow
+        Deny from all
+    </IfModule>
+</Files>
+
+# Deny access to hidden files
+<FilesMatch "^\.">
+    <IfModule mod_authz_core.c>
+        Require all denied
+    </IfModule>
+    <IfModule !mod_authz_core.c>
+        Order deny,allow
+        Deny from all
+    </IfModule>
+</FilesMatch>
+
+# Enable compression
+<IfModule mod_deflate.c>
+    AddOutputFilterByType DEFLATE text/html text/plain text/css application/json application/javascript
+</IfModule>
+
+# Cache static assets
+<IfModule mod_expires.c>
+    ExpiresActive On
+    ExpiresByType image/jpeg "access plus 1 month"
+    ExpiresByType image/png "access plus 1 month"
+    ExpiresByType image/gif "access plus 1 month"
+    ExpiresByType image/webp "access plus 1 month"
+</IfModule>
+
+# Default charset
+AddDefaultCharset UTF-8

familyalbums/README.md

@@ -0,0 +1,131 @@
+# FamilyAlbums - Familien-Fotoalbum-Portal
+
+Ein einfaches, PHP-basiertes Portal zur Verwaltung und Anzeige von Familien-Fotoalben mit Links zu Nextcloud.
+
+## Features
+
+- Öffentliche Galerie-Ansicht mit Jahr/Monat-Filter
+- Stichwortsuche über Titel, Tags und Beschreibung
+- Kommentarfunktion für Familienmitglieder
+- Admin-Interface zur Albumverwaltung
+- Responsive Design (Tailwind CSS)
+- Flat-File Datenbank (JSON) - kein MySQL erforderlich
+- Spam-Schutz (Honeypot + Rate-Limiting)
+- CSRF-Schutz für Admin-Aktionen
+
+## Installation
+
+### 1. Dateien kopieren
+
+```bash
+# Auf den Webserver kopieren
+sudo cp -r familyalbums /var/www/
+
+# Berechtigungen setzen
+sudo chown -R www-data:www-data /var/www/familyalbums
+sudo chmod -R 755 /var/www/familyalbums
+sudo chmod 770 /var/www/familyalbums/data
+sudo chmod 770 /var/www/familyalbums/thumbnails
+```
+
+### 2. Admin-Passwort ändern
+
+**WICHTIG:** Das Standard-Passwort muss vor dem produktiven Einsatz geändert werden!
+
+```bash
+# Neuen Passwort-Hash generieren
+php -r "echo password_hash('DeinSicheresPasswort', PASSWORD_DEFAULT);"
+```
+
+Den generierten Hash in `config.php` eintragen:
+
+```php
+define('ADMIN_PASSWORD_HASH', '$2y$10$DEIN_GENERIERTER_HASH_HIER');
+```
+
+### 3. Apache Virtual Host (optional)
+
+```apache
+<VirtualHost *:80>
+    ServerName familyalbums.example.com
+    DocumentRoot /var/www/familyalbums
+
+    <Directory /var/www/familyalbums>
+        AllowOverride All
+        Require all granted
+    </Directory>
+</VirtualHost>
+```
+
+## Verwendung
+
+### Öffentliche Galerie
+
+- URL: `https://deine-domain.ch/`
+- Filter nach Jahr und Monat
+- Stichwortsuche
+- Kommentare zu Alben hinterlassen
+
+### Admin-Bereich
+
+- URL: `https://deine-domain.ch/admin.php`
+- Login mit dem konfigurierten Passwort
+- Alben hinzufügen, bearbeiten, löschen
+- Optional: Vorschaubilder hochladen
+- Kommentare moderieren
+
+## Datenstruktur
+
+### albums.json
+
+```json
+{
+  "albums": [
+    {
+      "id": "uuid",
+      "title": "Albumtitel",
+      "url": "https://nextcloud.../apps/photos/public/...",
+      "date": "2024-12-25",
+      "tags": ["tag1", "tag2"],
+      "description": "Beschreibung",
+      "thumbnail": "thumbnails/bild.jpg",
+      "created_at": "2024-12-26T10:00:00+01:00"
+    }
+  ]
+}
+```
+
+### comments.json
+
+```json
+{
+  "comments": [
+    {
+      "id": "uuid",
+      "album_id": "album-uuid",
+      "author": "Name",
+      "text": "Kommentar",
+      "created_at": "2024-12-27T14:30:00+01:00"
+    }
+  ]
+}
+```
+
+## Sicherheit
+
+- Admin-Passwort mit bcrypt gehasht
+- CSRF-Token für alle Admin-Aktionen
+- XSS-Schutz durch `htmlspecialchars()`
+- Rate-Limiting für Kommentare (5/Minute pro IP)
+- Honeypot-Feld gegen Spam-Bots
+- `.htaccess` schützt config.php und data/
+
+## Anforderungen
+
+- PHP 8.0+
+- Apache mit mod_rewrite (optional)
+- Schreibrechte für data/ und thumbnails/
+
+## Lizenz
+
+Privates Projekt für Familien-Nutzung.

familyalbums/admin.php

@@ -0,0 +1,658 @@
+<?php
+/**
+ * FamilyAlbums - Admin Interface
+ */
+
+require_once __DIR__ . '/config.php';
+session_start();
+
+$pageTitle = SITE_TITLE . ' - Administration';
+?>
+<!DOCTYPE html>
+<html lang="de">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title><?= e($pageTitle) ?></title>
+    <script src="https://cdn.tailwindcss.com"></script>
+    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css">
+    <style>
+        .tag-input { display: flex; flex-wrap: wrap; gap: 0.5rem; padding: 0.5rem; border: 1px solid #d1d5db; border-radius: 0.5rem; }
+        .tag-item { background: #dbeafe; color: #1d4ed8; padding: 0.25rem 0.5rem; border-radius: 9999px; display: flex; align-items: center; gap: 0.25rem; }
+        .tag-item button { color: #1d4ed8; cursor: pointer; }
+        .tag-input input { flex: 1; min-width: 100px; border: none; outline: none; }
+        .suggestions { position: absolute; top: 100%; left: 0; right: 0; background: white; border: 1px solid #d1d5db; border-radius: 0.5rem; max-height: 200px; overflow-y: auto; z-index: 10; }
+        .suggestions div { padding: 0.5rem 1rem; cursor: pointer; }
+        .suggestions div:hover { background: #f3f4f6; }
+    </style>
+</head>
+<body class="bg-gray-100 min-h-screen">
+    <!-- Login-Bereich (wird per JS gesteuert) -->
+    <div id="login-section" class="hidden min-h-screen flex items-center justify-center">
+        <div class="bg-white p-8 rounded-xl shadow-lg w-full max-w-md">
+            <h1 class="text-2xl font-bold text-center mb-6">
+                <i class="fas fa-lock mr-2 text-blue-600"></i>Admin Login
+            </h1>
+            <form id="login-form">
+                <div class="mb-4">
+                    <label class="block text-gray-700 mb-2">Passwort</label>
+                    <input type="password" id="login-password" required
+                           class="w-full px-4 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500"
+                           placeholder="Admin-Passwort eingeben">
+                </div>
+                <div id="login-error" class="hidden text-red-500 text-sm mb-4"></div>
+                <button type="submit" class="w-full bg-blue-600 text-white py-2 rounded-lg hover:bg-blue-700 transition">
+                    <i class="fas fa-sign-in-alt mr-2"></i>Anmelden
+                </button>
+            </form>
+            <p class="mt-4 text-center">
+                <a href="index.php" class="text-blue-600 hover:underline">
+                    <i class="fas fa-arrow-left mr-1"></i>Zurück zur Galerie
+                </a>
+            </p>
+        </div>
+    </div>
+
+    <!-- Admin-Bereich -->
+    <div id="admin-section" class="hidden">
+        <!-- Header -->
+        <header class="bg-gradient-to-r from-gray-800 to-gray-900 text-white shadow-lg">
+            <div class="container mx-auto px-4 py-4">
+                <div class="flex items-center justify-between">
+                    <h1 class="text-xl font-bold">
+                        <i class="fas fa-cog mr-2"></i><?= e($pageTitle) ?>
+                    </h1>
+                    <div class="flex items-center gap-4">
+                        <a href="index.php" class="text-white/80 hover:text-white">
+                            <i class="fas fa-eye mr-1"></i>Galerie
+                        </a>
+                        <button onclick="logout()" class="text-white/80 hover:text-white">
+                            <i class="fas fa-sign-out-alt mr-1"></i>Logout
+                        </button>
+                    </div>
+                </div>
+            </div>
+        </header>
+
+        <!-- Tabs -->
+        <div class="bg-white shadow">
+            <div class="container mx-auto px-4">
+                <nav class="flex gap-4">
+                    <button onclick="showTab('albums')" id="tab-albums"
+                            class="tab-btn py-4 px-2 border-b-2 border-blue-600 text-blue-600 font-medium">
+                        <i class="fas fa-images mr-1"></i>Alben
+                    </button>
+                    <button onclick="showTab('comments')" id="tab-comments"
+                            class="tab-btn py-4 px-2 border-b-2 border-transparent text-gray-500 hover:text-gray-700">
+                        <i class="fas fa-comments mr-1"></i>Kommentare
+                    </button>
+                </nav>
+            </div>
+        </div>
+
+        <!-- Content -->
+        <main class="container mx-auto px-4 py-8">
+            <!-- Alben-Tab -->
+            <div id="content-albums">
+                <!-- Album hinzufügen -->
+                <div class="bg-white rounded-xl shadow-md p-6 mb-8">
+                    <h2 class="text-xl font-semibold mb-4">
+                        <i class="fas fa-plus-circle mr-2 text-green-600"></i>
+                        <span id="form-title">Neues Album hinzufügen</span>
+                    </h2>
+                    <form id="album-form" class="grid grid-cols-1 md:grid-cols-2 gap-4">
+                        <input type="hidden" id="album-id">
+
+                        <div>
+                            <label class="block text-gray-700 mb-1">Titel *</label>
+                            <input type="text" id="album-title" required
+                                   class="w-full px-3 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500"
+                                   placeholder="z.B. Weihnachten bei Oma">
+                        </div>
+
+                        <div>
+                            <label class="block text-gray-700 mb-1">Datum *</label>
+                            <input type="date" id="album-date" required
+                                   class="w-full px-3 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500">
+                        </div>
+
+                        <div class="md:col-span-2">
+                            <label class="block text-gray-700 mb-1">Nextcloud-Link *</label>
+                            <input type="url" id="album-url" required
+                                   class="w-full px-3 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500"
+                                   placeholder="https://nextcloud.example.com/apps/photos/public/...">
+                        </div>
+
+                        <div class="md:col-span-2">
+                            <label class="block text-gray-700 mb-1">Beschreibung</label>
+                            <textarea id="album-description" rows="2"
+                                      class="w-full px-3 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500"
+                                      placeholder="Kurze Beschreibung des Albums"></textarea>
+                        </div>
+
+                        <div class="md:col-span-2 relative">
+                            <label class="block text-gray-700 mb-1">Tags</label>
+                            <div class="tag-input" id="tags-container">
+                                <input type="text" id="tag-input" placeholder="Tag eingeben und Enter drücken">
+                            </div>
+                            <div id="tag-suggestions" class="suggestions hidden"></div>
+                            <input type="hidden" id="album-tags">
+                        </div>
+
+                        <div class="md:col-span-2">
+                            <label class="block text-gray-700 mb-1">Vorschaubild (optional)</label>
+                            <div class="flex gap-2">
+                                <input type="file" id="thumbnail-file" accept="image/*"
+                                       class="flex-1 px-3 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500">
+                                <button type="button" onclick="uploadThumbnail()" class="px-4 py-2 bg-gray-200 rounded-lg hover:bg-gray-300">
+                                    <i class="fas fa-upload"></i>
+                                </button>
+                            </div>
+                            <input type="hidden" id="album-thumbnail">
+                            <div id="thumbnail-preview" class="mt-2"></div>
+                        </div>
+
+                        <div class="md:col-span-2 flex gap-2">
+                            <button type="submit" class="bg-green-600 text-white px-6 py-2 rounded-lg hover:bg-green-700 transition">
+                                <i class="fas fa-save mr-2"></i><span id="submit-text">Speichern</span>
+                            </button>
+                            <button type="button" onclick="resetForm()" class="bg-gray-200 px-6 py-2 rounded-lg hover:bg-gray-300 transition">
+                                <i class="fas fa-times mr-2"></i>Abbrechen
+                            </button>
+                        </div>
+                    </form>
+                </div>
+
+                <!-- Album-Liste -->
+                <div class="bg-white rounded-xl shadow-md p-6">
+                    <h2 class="text-xl font-semibold mb-4">
+                        <i class="fas fa-list mr-2 text-blue-600"></i>Alle Alben
+                    </h2>
+                    <div id="albums-list" class="overflow-x-auto">
+                        <table class="w-full">
+                            <thead class="bg-gray-50">
+                                <tr>
+                                    <th class="px-4 py-3 text-left text-gray-600">Titel</th>
+                                    <th class="px-4 py-3 text-left text-gray-600">Datum</th>
+                                    <th class="px-4 py-3 text-left text-gray-600">Tags</th>
+                                    <th class="px-4 py-3 text-right text-gray-600">Aktionen</th>
+                                </tr>
+                            </thead>
+                            <tbody id="albums-table-body">
+                                <!-- Wird per JS befüllt -->
+                            </tbody>
+                        </table>
+                    </div>
+                </div>
+            </div>
+
+            <!-- Kommentare-Tab -->
+            <div id="content-comments" class="hidden">
+                <div class="bg-white rounded-xl shadow-md p-6">
+                    <h2 class="text-xl font-semibold mb-4">
+                        <i class="fas fa-comments mr-2 text-blue-600"></i>Alle Kommentare
+                    </h2>
+                    <div id="comments-list" class="space-y-4">
+                        <!-- Wird per JS befüllt -->
+                    </div>
+                </div>
+            </div>
+        </main>
+    </div>
+
+    <!-- Bestätigungs-Modal -->
+    <div id="confirm-modal" class="hidden fixed inset-0 bg-black/50 z-50 flex items-center justify-center p-4">
+        <div class="bg-white rounded-xl shadow-2xl max-w-md w-full p-6">
+            <h3 class="text-lg font-semibold mb-4" id="confirm-title">Bestätigung</h3>
+            <p id="confirm-message" class="text-gray-600 mb-6"></p>
+            <div class="flex justify-end gap-2">
+                <button onclick="closeConfirm()" class="px-4 py-2 bg-gray-200 rounded-lg hover:bg-gray-300">
+                    Abbrechen
+                </button>
+                <button id="confirm-btn" class="px-4 py-2 bg-red-600 text-white rounded-lg hover:bg-red-700">
+                    Löschen
+                </button>
+            </div>
+        </div>
+    </div>
+
+    <script>
+    // === State ===
+    let csrfToken = '';
+    let allTags = [];
+    let currentTags = [];
+    let editingAlbumId = null;
+    let confirmCallback = null;
+
+    // === Auth ===
+    async function checkAuth() {
+        const response = await fetch('api.php?action=check_auth');
+        const data = await response.json();
+
+        if (data.authenticated) {
+            csrfToken = data.csrf;
+            document.getElementById('login-section').classList.add('hidden');
+            document.getElementById('admin-section').classList.remove('hidden');
+            loadAlbums();
+            loadAllTags();
+        } else {
+            document.getElementById('login-section').classList.remove('hidden');
+            document.getElementById('admin-section').classList.add('hidden');
+        }
+    }
+
+    document.getElementById('login-form').addEventListener('submit', async (e) => {
+        e.preventDefault();
+        const password = document.getElementById('login-password').value;
+        const errorDiv = document.getElementById('login-error');
+
+        try {
+            const response = await fetch('api.php?action=login', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ password })
+            });
+            const data = await response.json();
+
+            if (data.success) {
+                csrfToken = data.csrf;
+                document.getElementById('login-section').classList.add('hidden');
+                document.getElementById('admin-section').classList.remove('hidden');
+                loadAlbums();
+                loadAllTags();
+            } else {
+                errorDiv.textContent = data.error || 'Login fehlgeschlagen';
+                errorDiv.classList.remove('hidden');
+            }
+        } catch (err) {
+            errorDiv.textContent = 'Verbindungsfehler';
+            errorDiv.classList.remove('hidden');
+        }
+    });
+
+    async function logout() {
+        await fetch('api.php?action=logout', { method: 'POST' });
+        location.reload();
+    }
+
+    // === Tabs ===
+    function showTab(tab) {
+        document.querySelectorAll('.tab-btn').forEach(btn => {
+            btn.classList.remove('border-blue-600', 'text-blue-600');
+            btn.classList.add('border-transparent', 'text-gray-500');
+        });
+        document.getElementById(`tab-${tab}`).classList.add('border-blue-600', 'text-blue-600');
+        document.getElementById(`tab-${tab}`).classList.remove('border-transparent', 'text-gray-500');
+
+        document.getElementById('content-albums').classList.add('hidden');
+        document.getElementById('content-comments').classList.add('hidden');
+        document.getElementById(`content-${tab}`).classList.remove('hidden');
+
+        if (tab === 'comments') {
+            loadAllComments();
+        }
+    }
+
+    // === Albums ===
+    async function loadAlbums() {
+        const response = await fetch('api.php?action=albums');
+        const data = await response.json();
+        renderAlbumsTable(data.albums || []);
+    }
+
+    function renderAlbumsTable(albums) {
+        const tbody = document.getElementById('albums-table-body');
+
+        if (albums.length === 0) {
+            tbody.innerHTML = '<tr><td colspan="4" class="text-center py-8 text-gray-500">Noch keine Alben vorhanden</td></tr>';
+            return;
+        }
+
+        tbody.innerHTML = albums.map(album => `
+            <tr class="border-t hover:bg-gray-50">
+                <td class="px-4 py-3">
+                    <div class="font-medium">${escapeHtml(album.title)}</div>
+                    <div class="text-sm text-gray-500 truncate max-w-xs">${escapeHtml(album.url)}</div>
+                </td>
+                <td class="px-4 py-3 text-gray-600">${album.date}</td>
+                <td class="px-4 py-3">
+                    <div class="flex flex-wrap gap-1">
+                        ${album.tags.slice(0, 3).map(tag =>
+                            `<span class="bg-blue-100 text-blue-700 text-xs px-2 py-0.5 rounded-full">${escapeHtml(tag)}</span>`
+                        ).join('')}
+                        ${album.tags.length > 3 ? `<span class="text-gray-400 text-xs">+${album.tags.length - 3}</span>` : ''}
+                    </div>
+                </td>
+                <td class="px-4 py-3 text-right">
+                    <button onclick='editAlbum(${JSON.stringify(album).replace(/'/g, "&#39;")})' class="text-blue-600 hover:text-blue-800 mr-2">
+                        <i class="fas fa-edit"></i>
+                    </button>
+                    <button onclick="confirmDelete('album', '${album.id}', '${escapeHtml(album.title)}')" class="text-red-600 hover:text-red-800">
+                        <i class="fas fa-trash"></i>
+                    </button>
+                </td>
+            </tr>
+        `).join('');
+    }
+
+    async function loadAllTags() {
+        const response = await fetch('api.php?action=tags');
+        const data = await response.json();
+        allTags = data.tags || [];
+    }
+
+    // === Album Form ===
+    document.getElementById('album-form').addEventListener('submit', async (e) => {
+        e.preventDefault();
+
+        const album = {
+            csrf: csrfToken,
+            title: document.getElementById('album-title').value,
+            url: document.getElementById('album-url').value,
+            date: document.getElementById('album-date').value,
+            description: document.getElementById('album-description').value,
+            tags: currentTags,
+            thumbnail: document.getElementById('album-thumbnail').value
+        };
+
+        let url = 'api.php?action=album';
+        let method = 'POST';
+
+        if (editingAlbumId) {
+            album.id = editingAlbumId;
+            method = 'PUT';
+        }
+
+        try {
+            const response = await fetch(url, {
+                method: method,
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify(album)
+            });
+            const data = await response.json();
+
+            if (data.success) {
+                resetForm();
+                loadAlbums();
+                loadAllTags();
+            } else {
+                alert(data.error || 'Fehler beim Speichern');
+            }
+        } catch (err) {
+            alert('Verbindungsfehler');
+        }
+    });
+
+    function editAlbum(album) {
+        editingAlbumId = album.id;
+        document.getElementById('album-id').value = album.id;
+        document.getElementById('album-title').value = album.title;
+        document.getElementById('album-url').value = album.url;
+        document.getElementById('album-date').value = album.date;
+        document.getElementById('album-description').value = album.description || '';
+        document.getElementById('album-thumbnail').value = album.thumbnail || '';
+
+        // Tags
+        currentTags = [...album.tags];
+        renderTags();
+
+        // Thumbnail preview
+        if (album.thumbnail) {
+            document.getElementById('thumbnail-preview').innerHTML =
+                `<img src="${escapeHtml(album.thumbnail)}" class="h-20 rounded">`;
+        }
+
+        document.getElementById('form-title').textContent = 'Album bearbeiten';
+        document.getElementById('submit-text').textContent = 'Aktualisieren';
+
+        // Scroll to form
+        document.getElementById('album-form').scrollIntoView({ behavior: 'smooth' });
+    }
+
+    function resetForm() {
+        editingAlbumId = null;
+        document.getElementById('album-form').reset();
+        document.getElementById('album-thumbnail').value = '';
+        document.getElementById('thumbnail-preview').innerHTML = '';
+        currentTags = [];
+        renderTags();
+        document.getElementById('form-title').textContent = 'Neues Album hinzufügen';
+        document.getElementById('submit-text').textContent = 'Speichern';
+    }
+
+    async function deleteAlbum(id) {
+        try {
+            const response = await fetch('api.php?action=album', {
+                method: 'DELETE',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ id, csrf: csrfToken })
+            });
+            const data = await response.json();
+
+            if (data.success) {
+                loadAlbums();
+            } else {
+                alert(data.error || 'Fehler beim Löschen');
+            }
+        } catch (err) {
+            alert('Verbindungsfehler');
+        }
+    }
+
+    // === Tags ===
+    function renderTags() {
+        const container = document.getElementById('tags-container');
+        const input = document.getElementById('tag-input');
+
+        // Remove existing tag items
+        container.querySelectorAll('.tag-item').forEach(el => el.remove());
+
+        // Add tag items before input
+        currentTags.forEach((tag, index) => {
+            const span = document.createElement('span');
+            span.className = 'tag-item';
+            span.innerHTML = `${escapeHtml(tag)}<button type="button" onclick="removeTag(${index})">&times;</button>`;
+            container.insertBefore(span, input);
+        });
+    }
+
+    function removeTag(index) {
+        currentTags.splice(index, 1);
+        renderTags();
+    }
+
+    document.getElementById('tag-input').addEventListener('keydown', (e) => {
+        if (e.key === 'Enter' || e.key === ',') {
+            e.preventDefault();
+            const value = e.target.value.trim();
+            if (value && !currentTags.includes(value)) {
+                currentTags.push(value);
+                renderTags();
+            }
+            e.target.value = '';
+            document.getElementById('tag-suggestions').classList.add('hidden');
+        }
+    });
+
+    document.getElementById('tag-input').addEventListener('input', (e) => {
+        const value = e.target.value.toLowerCase();
+        const suggestions = document.getElementById('tag-suggestions');
+
+        if (value.length < 1) {
+            suggestions.classList.add('hidden');
+            return;
+        }
+
+        const matches = allTags.filter(tag =>
+            tag.toLowerCase().includes(value) && !currentTags.includes(tag)
+        ).slice(0, 5);
+
+        if (matches.length === 0) {
+            suggestions.classList.add('hidden');
+            return;
+        }
+
+        suggestions.innerHTML = matches.map(tag =>
+            `<div onclick="selectTag('${escapeHtml(tag)}')">${escapeHtml(tag)}</div>`
+        ).join('');
+        suggestions.classList.remove('hidden');
+    });
+
+    function selectTag(tag) {
+        if (!currentTags.includes(tag)) {
+            currentTags.push(tag);
+            renderTags();
+        }
+        document.getElementById('tag-input').value = '';
+        document.getElementById('tag-suggestions').classList.add('hidden');
+    }
+
+    // === Thumbnail Upload ===
+    async function uploadThumbnail() {
+        const fileInput = document.getElementById('thumbnail-file');
+        if (!fileInput.files[0]) {
+            alert('Bitte wähle zuerst ein Bild aus');
+            return;
+        }
+
+        const formData = new FormData();
+        formData.append('thumbnail', fileInput.files[0]);
+        formData.append('csrf', csrfToken);
+
+        try {
+            const response = await fetch('api.php?action=upload_thumbnail', {
+                method: 'POST',
+                body: formData
+            });
+            const data = await response.json();
+
+            if (data.success) {
+                document.getElementById('album-thumbnail').value = data.path;
+                document.getElementById('thumbnail-preview').innerHTML =
+                    `<img src="${escapeHtml(data.path)}" class="h-20 rounded">`;
+                fileInput.value = '';
+            } else {
+                alert(data.error || 'Upload fehlgeschlagen');
+            }
+        } catch (err) {
+            alert('Verbindungsfehler');
+        }
+    }
+
+    // === Comments ===
+    async function loadAllComments() {
+        const albumsResponse = await fetch('api.php?action=albums');
+        const albumsData = await albumsResponse.json();
+        const albums = albumsData.albums || [];
+
+        const commentsContainer = document.getElementById('comments-list');
+        commentsContainer.innerHTML = '<p class="text-center"><i class="fas fa-spinner fa-spin"></i> Lade Kommentare...</p>';
+
+        // Kommentare für alle Alben laden
+        const allComments = [];
+        for (const album of albums) {
+            const response = await fetch(`api.php?action=comments&album_id=${album.id}`);
+            const data = await response.json();
+            (data.comments || []).forEach(comment => {
+                comment.albumTitle = album.title;
+                allComments.push(comment);
+            });
+        }
+
+        // Nach Datum sortieren
+        allComments.sort((a, b) => b.created_at.localeCompare(a.created_at));
+
+        if (allComments.length === 0) {
+            commentsContainer.innerHTML = '<p class="text-center text-gray-500 py-8">Noch keine Kommentare vorhanden</p>';
+            return;
+        }
+
+        commentsContainer.innerHTML = allComments.map(comment => `
+            <div class="bg-gray-50 p-4 rounded-lg">
+                <div class="flex justify-between items-start mb-2">
+                    <div>
+                        <span class="font-semibold">${escapeHtml(comment.author)}</span>
+                        <span class="text-gray-400 text-sm ml-2">${formatDateTime(comment.created_at)}</span>
+                    </div>
+                    <button onclick="confirmDelete('comment', '${comment.id}', 'diesen Kommentar')" class="text-red-600 hover:text-red-800">
+                        <i class="fas fa-trash"></i>
+                    </button>
+                </div>
+                <p class="text-gray-700 mb-2">${escapeHtml(comment.text)}</p>
+                <p class="text-sm text-gray-500">
+                    <i class="fas fa-images mr-1"></i>${escapeHtml(comment.albumTitle)}
+                </p>
+            </div>
+        `).join('');
+    }
+
+    async function deleteComment(id) {
+        try {
+            const response = await fetch('api.php?action=comment', {
+                method: 'DELETE',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ id, csrf: csrfToken })
+            });
+            const data = await response.json();
+
+            if (data.success) {
+                loadAllComments();
+            } else {
+                alert(data.error || 'Fehler beim Löschen');
+            }
+        } catch (err) {
+            alert('Verbindungsfehler');
+        }
+    }
+
+    // === Confirm Modal ===
+    function confirmDelete(type, id, name) {
+        document.getElementById('confirm-message').textContent =
+            `Möchtest du "${name}" wirklich löschen?`;
+
+        confirmCallback = () => {
+            if (type === 'album') {
+                deleteAlbum(id);
+            } else if (type === 'comment') {
+                deleteComment(id);
+            }
+        };
+
+        document.getElementById('confirm-modal').classList.remove('hidden');
+    }
+
+    function closeConfirm() {
+        document.getElementById('confirm-modal').classList.add('hidden');
+        confirmCallback = null;
+    }
+
+    document.getElementById('confirm-btn').addEventListener('click', () => {
+        if (confirmCallback) {
+            confirmCallback();
+        }
+        closeConfirm();
+    });
+
+    // === Helpers ===
+    function escapeHtml(text) {
+        const div = document.createElement('div');
+        div.textContent = text;
+        return div.innerHTML;
+    }
+
+    function formatDateTime(isoStr) {
+        const date = new Date(isoStr);
+        return date.toLocaleDateString('de-CH', {
+            day: 'numeric',
+            month: 'long',
+            year: 'numeric',
+            hour: '2-digit',
+            minute: '2-digit'
+        });
+    }
+
+    // === Init ===
+    checkAuth();
+    </script>
+</body>
+</html>

familyalbums/api.php

@@ -0,0 +1,350 @@
+<?php
+/**
+ * FamilyAlbums - API Endpunkte
+ */
+
+require_once __DIR__ . '/config.php';
+
+session_start();
+
+header('Content-Type: application/json; charset=utf-8');
+
+$method = $_SERVER['REQUEST_METHOD'];
+$action = $_GET['action'] ?? '';
+
+// Hilfsfunktion: JSON Response
+function json_response(array $data, int $code = 200): void {
+    http_response_code($code);
+    echo json_encode($data, JSON_UNESCAPED_UNICODE);
+    exit;
+}
+
+// Hilfsfunktion: Admin-Check
+function require_admin(): void {
+    if (empty($_SESSION['admin_logged_in'])) {
+        json_response(['error' => 'Nicht autorisiert'], 401);
+    }
+}
+
+// === ALBEN ===
+
+if ($action === 'albums' && $method === 'GET') {
+    // Alle Alben abrufen (öffentlich)
+    $data = read_json(ALBUMS_FILE);
+    $albums = $data['albums'] ?? [];
+
+    // Filter: Jahr
+    if (!empty($_GET['year'])) {
+        $year = $_GET['year'];
+        $albums = array_filter($albums, fn($a) => substr($a['date'], 0, 4) === $year);
+    }
+
+    // Filter: Monat
+    if (!empty($_GET['month'])) {
+        $month = $_GET['month'];
+        $albums = array_filter($albums, fn($a) => substr($a['date'], 5, 2) === $month);
+    }
+
+    // Filter: Suche
+    if (!empty($_GET['search'])) {
+        $search = mb_strtolower($_GET['search']);
+        $albums = array_filter($albums, function($a) use ($search) {
+            $haystack = mb_strtolower($a['title'] . ' ' . $a['description'] . ' ' . implode(' ', $a['tags']));
+            return str_contains($haystack, $search);
+        });
+    }
+
+    // Sortierung
+    $sort = $_GET['sort'] ?? 'newest';
+    usort($albums, function($a, $b) use ($sort) {
+        if ($sort === 'oldest') {
+            return strcmp($a['date'], $b['date']);
+        }
+        return strcmp($b['date'], $a['date']); // newest first
+    });
+
+    json_response(['albums' => array_values($albums)]);
+}
+
+if ($action === 'album' && $method === 'POST') {
+    // Album erstellen (Admin)
+    require_admin();
+
+    $input = json_decode(file_get_contents('php://input'), true);
+
+    if (!csrf_validate($input['csrf'] ?? '')) {
+        json_response(['error' => 'Ungültiges CSRF-Token'], 403);
+    }
+
+    if (empty($input['title']) || empty($input['url']) || empty($input['date'])) {
+        json_response(['error' => 'Titel, URL und Datum sind Pflichtfelder'], 400);
+    }
+
+    $album = [
+        'id' => generate_uuid(),
+        'title' => trim($input['title']),
+        'url' => trim($input['url']),
+        'date' => $input['date'],
+        'tags' => array_map('trim', $input['tags'] ?? []),
+        'description' => trim($input['description'] ?? ''),
+        'thumbnail' => $input['thumbnail'] ?? '',
+        'created_at' => date('c')
+    ];
+
+    $data = read_json(ALBUMS_FILE);
+    $data['albums'][] = $album;
+    write_json(ALBUMS_FILE, $data);
+
+    json_response(['success' => true, 'album' => $album]);
+}
+
+if ($action === 'album' && $method === 'PUT') {
+    // Album bearbeiten (Admin)
+    require_admin();
+
+    $input = json_decode(file_get_contents('php://input'), true);
+
+    if (!csrf_validate($input['csrf'] ?? '')) {
+        json_response(['error' => 'Ungültiges CSRF-Token'], 403);
+    }
+
+    $id = $input['id'] ?? '';
+
+    $data = read_json(ALBUMS_FILE);
+    $found = false;
+
+    foreach ($data['albums'] as &$album) {
+        if ($album['id'] === $id) {
+            $album['title'] = trim($input['title'] ?? $album['title']);
+            $album['url'] = trim($input['url'] ?? $album['url']);
+            $album['date'] = $input['date'] ?? $album['date'];
+            $album['tags'] = array_map('trim', $input['tags'] ?? $album['tags']);
+            $album['description'] = trim($input['description'] ?? $album['description']);
+            $album['thumbnail'] = $input['thumbnail'] ?? $album['thumbnail'];
+            $found = true;
+            break;
+        }
+    }
+
+    if (!$found) {
+        json_response(['error' => 'Album nicht gefunden'], 404);
+    }
+
+    write_json(ALBUMS_FILE, $data);
+    json_response(['success' => true]);
+}
+
+if ($action === 'album' && $method === 'DELETE') {
+    // Album löschen (Admin)
+    require_admin();
+
+    $input = json_decode(file_get_contents('php://input'), true);
+
+    if (!csrf_validate($input['csrf'] ?? '')) {
+        json_response(['error' => 'Ungültiges CSRF-Token'], 403);
+    }
+
+    $id = $input['id'] ?? '';
+
+    $data = read_json(ALBUMS_FILE);
+    $data['albums'] = array_filter($data['albums'], fn($a) => $a['id'] !== $id);
+    $data['albums'] = array_values($data['albums']);
+    write_json(ALBUMS_FILE, $data);
+
+    // Zugehörige Kommentare löschen
+    $comments = read_json(COMMENTS_FILE);
+    $comments['comments'] = array_filter($comments['comments'], fn($c) => $c['album_id'] !== $id);
+    $comments['comments'] = array_values($comments['comments']);
+    write_json(COMMENTS_FILE, $comments);
+
+    json_response(['success' => true]);
+}
+
+// === KOMMENTARE ===
+
+if ($action === 'comments' && $method === 'GET') {
+    // Kommentare für Album abrufen (öffentlich)
+    $album_id = $_GET['album_id'] ?? '';
+
+    $data = read_json(COMMENTS_FILE);
+    $comments = array_filter($data['comments'] ?? [], fn($c) => $c['album_id'] === $album_id);
+
+    // Nach Datum sortieren (neueste zuerst)
+    usort($comments, fn($a, $b) => strcmp($b['created_at'], $a['created_at']));
+
+    json_response(['comments' => array_values($comments)]);
+}
+
+if ($action === 'comment' && $method === 'POST') {
+    // Kommentar erstellen (öffentlich)
+    $input = json_decode(file_get_contents('php://input'), true);
+
+    if (empty($input['album_id']) || empty($input['author']) || empty($input['text'])) {
+        json_response(['error' => 'Album-ID, Name und Text sind Pflichtfelder'], 400);
+    }
+
+    // Honeypot-Check (Spam-Schutz)
+    if (!empty($input['website'])) {
+        json_response(['success' => true]); // Fake-Erfolg für Bots
+    }
+
+    // Rate-Limiting: Max 5 Kommentare pro Minute pro IP
+    $ip = $_SERVER['REMOTE_ADDR'];
+    $rate_file = DATA_PATH . 'rate_' . md5($ip) . '.json';
+    $rate_data = read_json($rate_file);
+    $now = time();
+    $rate_data['times'] = array_filter($rate_data['times'] ?? [], fn($t) => $t > $now - 60);
+
+    if (count($rate_data['times']) >= 5) {
+        json_response(['error' => 'Zu viele Kommentare. Bitte warte eine Minute.'], 429);
+    }
+
+    $rate_data['times'][] = $now;
+    write_json($rate_file, $rate_data);
+
+    $comment = [
+        'id' => generate_uuid(),
+        'album_id' => $input['album_id'],
+        'author' => trim($input['author']),
+        'text' => trim($input['text']),
+        'created_at' => date('c')
+    ];
+
+    $data = read_json(COMMENTS_FILE);
+    $data['comments'][] = $comment;
+    write_json(COMMENTS_FILE, $data);
+
+    json_response(['success' => true, 'comment' => $comment]);
+}
+
+if ($action === 'comment' && $method === 'DELETE') {
+    // Kommentar löschen (Admin)
+    require_admin();
+
+    $input = json_decode(file_get_contents('php://input'), true);
+
+    if (!csrf_validate($input['csrf'] ?? '')) {
+        json_response(['error' => 'Ungültiges CSRF-Token'], 403);
+    }
+
+    $id = $input['id'] ?? '';
+
+    $data = read_json(COMMENTS_FILE);
+    $data['comments'] = array_filter($data['comments'], fn($c) => $c['id'] !== $id);
+    $data['comments'] = array_values($data['comments']);
+    write_json(COMMENTS_FILE, $data);
+
+    json_response(['success' => true]);
+}
+
+// === TAGS ===
+
+if ($action === 'tags' && $method === 'GET') {
+    // Alle verwendeten Tags abrufen (für Vorschläge)
+    $data = read_json(ALBUMS_FILE);
+    $tags = [];
+
+    foreach ($data['albums'] ?? [] as $album) {
+        foreach ($album['tags'] ?? [] as $tag) {
+            $tags[$tag] = ($tags[$tag] ?? 0) + 1;
+        }
+    }
+
+    arsort($tags);
+    json_response(['tags' => array_keys($tags)]);
+}
+
+// === JAHRE/MONATE ===
+
+if ($action === 'dates' && $method === 'GET') {
+    // Verfügbare Jahre und Monate
+    $data = read_json(ALBUMS_FILE);
+    $years = [];
+
+    foreach ($data['albums'] ?? [] as $album) {
+        $year = substr($album['date'], 0, 4);
+        $month = substr($album['date'], 5, 2);
+
+        if (!isset($years[$year])) {
+            $years[$year] = [];
+        }
+        if (!in_array($month, $years[$year])) {
+            $years[$year][] = $month;
+        }
+    }
+
+    // Sortieren
+    krsort($years);
+    foreach ($years as &$months) {
+        sort($months);
+    }
+
+    json_response(['dates' => $years]);
+}
+
+// === AUTH ===
+
+if ($action === 'login' && $method === 'POST') {
+    $input = json_decode(file_get_contents('php://input'), true);
+    $password = $input['password'] ?? '';
+
+    if (password_verify($password, ADMIN_PASSWORD_HASH)) {
+        $_SESSION['admin_logged_in'] = true;
+        $_SESSION['csrf_token'] = bin2hex(random_bytes(32));
+        json_response(['success' => true, 'csrf' => $_SESSION['csrf_token']]);
+    }
+
+    // Verzögerung gegen Brute-Force
+    sleep(1);
+    json_response(['error' => 'Falsches Passwort'], 401);
+}
+
+if ($action === 'logout' && $method === 'POST') {
+    session_destroy();
+    json_response(['success' => true]);
+}
+
+if ($action === 'check_auth' && $method === 'GET') {
+    json_response([
+        'authenticated' => !empty($_SESSION['admin_logged_in']),
+        'csrf' => $_SESSION['csrf_token'] ?? ''
+    ]);
+}
+
+// === THUMBNAIL UPLOAD ===
+
+if ($action === 'upload_thumbnail' && $method === 'POST') {
+    require_admin();
+
+    if (empty($_POST['csrf']) || !csrf_validate($_POST['csrf'])) {
+        json_response(['error' => 'Ungültiges CSRF-Token'], 403);
+    }
+
+    if (empty($_FILES['thumbnail']) || $_FILES['thumbnail']['error'] !== UPLOAD_ERR_OK) {
+        json_response(['error' => 'Kein Bild hochgeladen'], 400);
+    }
+
+    $file = $_FILES['thumbnail'];
+    $allowed = ['image/jpeg', 'image/png', 'image/gif', 'image/webp'];
+
+    if (!in_array($file['type'], $allowed)) {
+        json_response(['error' => 'Nur JPG, PNG, GIF und WebP erlaubt'], 400);
+    }
+
+    if ($file['size'] > 5 * 1024 * 1024) {
+        json_response(['error' => 'Maximale Dateigrösse: 5MB'], 400);
+    }
+
+    $ext = pathinfo($file['name'], PATHINFO_EXTENSION);
+    $filename = generate_uuid() . '.' . $ext;
+    $path = THUMBNAIL_PATH . $filename;
+
+    if (!move_uploaded_file($file['tmp_name'], $path)) {
+        json_response(['error' => 'Upload fehlgeschlagen'], 500);
+    }
+
+    json_response(['success' => true, 'path' => THUMBNAIL_URL . $filename]);
+}
+
+// Unbekannte Aktion
+json_response(['error' => 'Unbekannte Aktion'], 404);

familyalbums/config.php

@@ -0,0 +1,91 @@
+<?php
+/**
+ * FamilyAlbums - Konfiguration
+ *
+ * WICHTIG: Nach erster Installation Passwort ändern!
+ * Neuen Hash generieren: php -r "echo password_hash('deinPasswort', PASSWORD_DEFAULT);"
+ */
+
+// Standard-Passwort: "familie2024" - BITTE ÄNDERN!
+define('ADMIN_PASSWORD_HASH', '$2y$10$YxQx8B7GkDqNmPrC4VzKH.qN4tQ8WvX5kF7mZ3hJ9aE1bC2dR6uYO');
+
+define('SITE_TITLE', 'Familien-Fotoalben');
+define('DATA_PATH', __DIR__ . '/data/');
+define('THUMBNAIL_PATH', __DIR__ . '/thumbnails/');
+define('THUMBNAIL_URL', 'thumbnails/');
+
+define('ALBUMS_FILE', DATA_PATH . 'albums.json');
+define('COMMENTS_FILE', DATA_PATH . 'comments.json');
+
+// Session-Einstellungen
+define('SESSION_LIFETIME', 3600); // 1 Stunde
+
+// Zeitzone
+date_default_timezone_set('Europe/Zurich');
+
+/**
+ * JSON-Datei lesen
+ */
+function read_json(string $file): array {
+    if (!file_exists($file)) {
+        return [];
+    }
+    $content = file_get_contents($file);
+    return json_decode($content, true) ?? [];
+}
+
+/**
+ * JSON-Datei schreiben
+ */
+function write_json(string $file, array $data): bool {
+    $dir = dirname($file);
+    if (!is_dir($dir)) {
+        mkdir($dir, 0770, true);
+    }
+    return file_put_contents($file, json_encode($data, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE)) !== false;
+}
+
+/**
+ * UUID generieren
+ */
+function generate_uuid(): string {
+    return sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
+        mt_rand(0, 0xffff), mt_rand(0, 0xffff),
+        mt_rand(0, 0xffff),
+        mt_rand(0, 0x0fff) | 0x4000,
+        mt_rand(0, 0x3fff) | 0x8000,
+        mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
+    );
+}
+
+/**
+ * XSS-sichere Ausgabe
+ */
+function e(string $str): string {
+    return htmlspecialchars($str, ENT_QUOTES, 'UTF-8');
+}
+
+/**
+ * CSRF-Token generieren
+ */
+function csrf_token(): string {
+    if (empty($_SESSION['csrf_token'])) {
+        $_SESSION['csrf_token'] = bin2hex(random_bytes(32));
+    }
+    return $_SESSION['csrf_token'];
+}
+
+/**
+ * CSRF-Token validieren
+ */
+function csrf_validate(string $token): bool {
+    return isset($_SESSION['csrf_token']) && hash_equals($_SESSION['csrf_token'], $token);
+}
+
+// Initialisiere Daten-Dateien falls nicht vorhanden
+if (!file_exists(ALBUMS_FILE)) {
+    write_json(ALBUMS_FILE, ['albums' => []]);
+}
+if (!file_exists(COMMENTS_FILE)) {
+    write_json(COMMENTS_FILE, ['comments' => []]);
+}

familyalbums/data/.htaccess

@@ -0,0 +1,8 @@
+# Deny access to all files in this directory
+<IfModule mod_authz_core.c>
+    Require all denied
+</IfModule>
+<IfModule !mod_authz_core.c>
+    Order deny,allow
+    Deny from all
+</IfModule>

familyalbums/data/albums.json

@@ -0,0 +1,14 @@
+{
+    "albums": [
+        {
+            "id": "demo-001",
+            "title": "Weihnachten 2024",
+            "url": "https://nextcloud.example.com/apps/photos/public/demo",
+            "date": "2024-12-25",
+            "tags": ["weihnachten", "familie", "2024"],
+            "description": "Bescherung und Festessen bei der Familie",
+            "thumbnail": "",
+            "created_at": "2024-12-26T10:00:00+01:00"
+        }
+    ]
+}

familyalbums/data/comments.json

@@ -0,0 +1,3 @@
+{
+    "comments": []
+}

familyalbums/index.php

@@ -0,0 +1,449 @@
+<?php
+/**
+ * FamilyAlbums - Öffentliche Ansicht
+ */
+
+require_once __DIR__ . '/config.php';
+
+$pageTitle = SITE_TITLE;
+?>
+<!DOCTYPE html>
+<html lang="de">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title><?= e($pageTitle) ?></title>
+    <script src="https://cdn.tailwindcss.com"></script>
+    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css">
+    <style>
+        .album-card:hover { transform: translateY(-4px); }
+        .tag { transition: all 0.2s; }
+        .tag:hover { transform: scale(1.05); }
+        .modal { transition: opacity 0.3s; }
+        .modal.hidden { opacity: 0; pointer-events: none; }
+        .gradient-placeholder {
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        }
+    </style>
+</head>
+<body class="bg-gray-100 min-h-screen">
+    <!-- Header -->
+    <header class="bg-gradient-to-r from-blue-600 to-purple-600 text-white shadow-lg">
+        <div class="container mx-auto px-4 py-6">
+            <div class="flex flex-col md:flex-row md:items-center md:justify-between gap-4">
+                <h1 class="text-2xl md:text-3xl font-bold">
+                    <i class="fas fa-images mr-2"></i><?= e($pageTitle) ?>
+                </h1>
+                <a href="admin.php" class="text-white/80 hover:text-white text-sm">
+                    <i class="fas fa-lock mr-1"></i>Admin
+                </a>
+            </div>
+        </div>
+    </header>
+
+    <!-- Filter-Bereich -->
+    <div class="bg-white shadow-md sticky top-0 z-10">
+        <div class="container mx-auto px-4 py-4">
+            <div class="flex flex-col md:flex-row gap-4">
+                <!-- Suche -->
+                <div class="flex-1">
+                    <div class="relative">
+                        <input type="text" id="search" placeholder="Album suchen..."
+                               class="w-full pl-10 pr-4 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-blue-500">
+                        <i class="fas fa-search absolute left-3 top-3 text-gray-400"></i>
+                    </div>
+                </div>
+
+                <!-- Jahr -->
+                <select id="filter-year" class="px-4 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500">
+                    <option value="">Alle Jahre</option>
+                </select>
+
+                <!-- Monat -->
+                <select id="filter-month" class="px-4 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500" disabled>
+                    <option value="">Alle Monate</option>
+                </select>
+
+                <!-- Sortierung -->
+                <select id="sort" class="px-4 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500">
+                    <option value="newest">Neueste zuerst</option>
+                    <option value="oldest">Älteste zuerst</option>
+                </select>
+            </div>
+        </div>
+    </div>
+
+    <!-- Album-Grid -->
+    <main class="container mx-auto px-4 py-8">
+        <div id="albums-container" class="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-6">
+            <!-- Alben werden per JS geladen -->
+        </div>
+
+        <div id="no-results" class="hidden text-center py-12 text-gray-500">
+            <i class="fas fa-search text-4xl mb-4"></i>
+            <p class="text-xl">Keine Alben gefunden</p>
+        </div>
+
+        <div id="loading" class="text-center py-12">
+            <i class="fas fa-spinner fa-spin text-4xl text-blue-500"></i>
+        </div>
+    </main>
+
+    <!-- Album-Detail Modal -->
+    <div id="album-modal" class="modal hidden fixed inset-0 bg-black/50 z-50 flex items-center justify-center p-4">
+        <div class="bg-white rounded-xl shadow-2xl max-w-2xl w-full max-h-[90vh] overflow-y-auto">
+            <div class="p-6">
+                <div class="flex justify-between items-start mb-4">
+                    <h2 id="modal-title" class="text-2xl font-bold text-gray-800"></h2>
+                    <button onclick="closeModal()" class="text-gray-400 hover:text-gray-600">
+                        <i class="fas fa-times text-xl"></i>
+                    </button>
+                </div>
+
+                <div id="modal-thumbnail" class="mb-4 rounded-lg overflow-hidden"></div>
+
+                <p id="modal-date" class="text-gray-500 mb-2"></p>
+                <p id="modal-description" class="text-gray-700 mb-4"></p>
+
+                <div id="modal-tags" class="flex flex-wrap gap-2 mb-6"></div>
+
+                <a id="modal-link" href="#" target="_blank"
+                   class="inline-block bg-blue-600 text-white px-6 py-3 rounded-lg hover:bg-blue-700 transition mb-6">
+                    <i class="fas fa-external-link-alt mr-2"></i>Album öffnen
+                </a>
+
+                <!-- Kommentare -->
+                <div class="border-t pt-6">
+                    <h3 class="text-lg font-semibold mb-4">
+                        <i class="fas fa-comments mr-2"></i>Kommentare
+                    </h3>
+
+                    <div id="comments-list" class="space-y-4 mb-6"></div>
+
+                    <!-- Kommentar-Formular -->
+                    <form id="comment-form" class="bg-gray-50 p-4 rounded-lg">
+                        <input type="hidden" id="comment-album-id">
+                        <!-- Honeypot -->
+                        <input type="text" name="website" id="comment-website" class="hidden" tabindex="-1" autocomplete="off">
+
+                        <div class="mb-3">
+                            <input type="text" id="comment-author" placeholder="Dein Name" required
+                                   class="w-full px-3 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500">
+                        </div>
+                        <div class="mb-3">
+                            <textarea id="comment-text" placeholder="Dein Kommentar..." required rows="3"
+                                      class="w-full px-3 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500"></textarea>
+                        </div>
+                        <button type="submit" class="bg-green-600 text-white px-4 py-2 rounded-lg hover:bg-green-700 transition">
+                            <i class="fas fa-paper-plane mr-2"></i>Absenden
+                        </button>
+                    </form>
+                </div>
+            </div>
+        </div>
+    </div>
+
+    <!-- Footer -->
+    <footer class="bg-gray-800 text-white py-6 mt-12">
+        <div class="container mx-auto px-4 text-center">
+            <p>&copy; <?= date('Y') ?> <?= e($pageTitle) ?></p>
+        </div>
+    </footer>
+
+    <script>
+    // === State ===
+    let allDates = {};
+    let currentAlbumId = null;
+    let debounceTimer = null;
+
+    // === Monatsnamen ===
+    const monthNames = {
+        '01': 'Januar', '02': 'Februar', '03': 'März', '04': 'April',
+        '05': 'Mai', '06': 'Juni', '07': 'Juli', '08': 'August',
+        '09': 'September', '10': 'Oktober', '11': 'November', '12': 'Dezember'
+    };
+
+    // === Helpers ===
+    function escapeHtml(text) {
+        const div = document.createElement('div');
+        div.textContent = text;
+        return div.innerHTML;
+    }
+
+    function formatDate(dateStr) {
+        const [year, month, day] = dateStr.split('-');
+        return `${parseInt(day)}. ${monthNames[month]} ${year}`;
+    }
+
+    function formatDateTime(isoStr) {
+        const date = new Date(isoStr);
+        return date.toLocaleDateString('de-CH', {
+            day: 'numeric',
+            month: 'long',
+            year: 'numeric',
+            hour: '2-digit',
+            minute: '2-digit'
+        });
+    }
+
+    // === API Calls ===
+    async function fetchAlbums() {
+        const params = new URLSearchParams();
+
+        const year = document.getElementById('filter-year').value;
+        const month = document.getElementById('filter-month').value;
+        const search = document.getElementById('search').value;
+        const sort = document.getElementById('sort').value;
+
+        if (year) params.append('year', year);
+        if (month) params.append('month', month);
+        if (search) params.append('search', search);
+        params.append('sort', sort);
+
+        const response = await fetch(`api.php?action=albums&${params}`);
+        return response.json();
+    }
+
+    async function fetchDates() {
+        const response = await fetch('api.php?action=dates');
+        return response.json();
+    }
+
+    async function fetchComments(albumId) {
+        const response = await fetch(`api.php?action=comments&album_id=${encodeURIComponent(albumId)}`);
+        return response.json();
+    }
+
+    async function postComment(albumId, author, text, website) {
+        const response = await fetch('api.php?action=comment', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ album_id: albumId, author, text, website })
+        });
+        return response.json();
+    }
+
+    // === Rendering ===
+    function renderAlbums(albums) {
+        const container = document.getElementById('albums-container');
+        const noResults = document.getElementById('no-results');
+        const loading = document.getElementById('loading');
+
+        loading.classList.add('hidden');
+
+        if (albums.length === 0) {
+            container.innerHTML = '';
+            noResults.classList.remove('hidden');
+            return;
+        }
+
+        noResults.classList.add('hidden');
+
+        container.innerHTML = albums.map(album => `
+            <div class="album-card bg-white rounded-xl shadow-md overflow-hidden cursor-pointer transition-all duration-300 hover:shadow-xl"
+                 data-album='${JSON.stringify(album).replace(/'/g, "&#39;")}'
+                 onclick="openModalFromCard(this)">
+                <div class="aspect-video gradient-placeholder flex items-center justify-center">
+                    ${album.thumbnail
+                        ? `<img src="${escapeHtml(album.thumbnail)}" alt="${escapeHtml(album.title)}" class="w-full h-full object-cover" onerror="this.parentElement.innerHTML='<i class=\\'fas fa-images text-4xl text-white/50\\'></i>'">`
+                        : `<i class="fas fa-images text-4xl text-white/50"></i>`
+                    }
+                </div>
+                <div class="p-4">
+                    <h3 class="font-semibold text-lg text-gray-800 mb-1 line-clamp-2">${escapeHtml(album.title)}</h3>
+                    <p class="text-gray-500 text-sm mb-3">
+                        <i class="fas fa-calendar mr-1"></i>${formatDate(album.date)}
+                    </p>
+                    <div class="flex flex-wrap gap-1">
+                        ${album.tags.slice(0, 3).map(tag => `
+                            <span class="tag bg-blue-100 text-blue-700 text-xs px-2 py-1 rounded-full">${escapeHtml(tag)}</span>
+                        `).join('')}
+                        ${album.tags.length > 3 ? `<span class="text-gray-400 text-xs">+${album.tags.length - 3}</span>` : ''}
+                    </div>
+                </div>
+            </div>
+        `).join('');
+    }
+
+    function renderDateFilters(dates) {
+        allDates = dates;
+        const yearSelect = document.getElementById('filter-year');
+
+        yearSelect.innerHTML = '<option value="">Alle Jahre</option>' +
+            Object.keys(dates).map(year => `<option value="${year}">${year}</option>`).join('');
+    }
+
+    function updateMonthFilter() {
+        const year = document.getElementById('filter-year').value;
+        const monthSelect = document.getElementById('filter-month');
+
+        if (!year || !allDates[year]) {
+            monthSelect.innerHTML = '<option value="">Alle Monate</option>';
+            monthSelect.disabled = true;
+            return;
+        }
+
+        monthSelect.disabled = false;
+        monthSelect.innerHTML = '<option value="">Alle Monate</option>' +
+            allDates[year].map(month => `<option value="${month}">${monthNames[month]}</option>`).join('');
+    }
+
+    function renderComments(comments) {
+        const container = document.getElementById('comments-list');
+
+        if (comments.length === 0) {
+            container.innerHTML = '<p class="text-gray-500 text-center italic">Noch keine Kommentare. Sei der Erste!</p>';
+            return;
+        }
+
+        container.innerHTML = comments.map(comment => `
+            <div class="bg-white p-3 rounded-lg border">
+                <div class="flex justify-between items-start mb-1">
+                    <span class="font-semibold text-gray-800">${escapeHtml(comment.author)}</span>
+                    <span class="text-gray-400 text-xs">${formatDateTime(comment.created_at)}</span>
+                </div>
+                <p class="text-gray-700">${escapeHtml(comment.text)}</p>
+            </div>
+        `).join('');
+    }
+
+    // === Modal ===
+    function openModalFromCard(element) {
+        const album = JSON.parse(element.dataset.album);
+        openModal(album.id, album);
+    }
+
+    function openModal(id, album) {
+        currentAlbumId = id;
+
+        document.getElementById('modal-title').textContent = album.title;
+        document.getElementById('modal-date').innerHTML = `<i class="fas fa-calendar mr-1"></i>${formatDate(album.date)}`;
+        document.getElementById('modal-description').textContent = album.description || 'Keine Beschreibung';
+        document.getElementById('modal-link').href = album.url;
+        document.getElementById('comment-album-id').value = id;
+
+        // Thumbnail
+        const thumbnailContainer = document.getElementById('modal-thumbnail');
+        if (album.thumbnail) {
+            thumbnailContainer.innerHTML = `<img src="${escapeHtml(album.thumbnail)}" alt="${escapeHtml(album.title)}" class="w-full max-h-64 object-cover">`;
+        } else {
+            thumbnailContainer.innerHTML = '';
+        }
+
+        // Tags
+        document.getElementById('modal-tags').innerHTML = album.tags.map(tag =>
+            `<span class="bg-blue-100 text-blue-700 text-sm px-3 py-1 rounded-full">${escapeHtml(tag)}</span>`
+        ).join('');
+
+        // Modal anzeigen
+        document.getElementById('album-modal').classList.remove('hidden');
+        document.body.style.overflow = 'hidden';
+
+        // Kommentare laden
+        loadComments(id);
+    }
+
+    function closeModal() {
+        document.getElementById('album-modal').classList.add('hidden');
+        document.body.style.overflow = '';
+        currentAlbumId = null;
+    }
+
+    async function loadComments(albumId) {
+        document.getElementById('comments-list').innerHTML = '<p class="text-center"><i class="fas fa-spinner fa-spin"></i></p>';
+        const data = await fetchComments(albumId);
+        renderComments(data.comments || []);
+    }
+
+    // === Event Listeners ===
+    document.getElementById('search').addEventListener('input', () => {
+        clearTimeout(debounceTimer);
+        debounceTimer = setTimeout(async () => {
+            const data = await fetchAlbums();
+            renderAlbums(data.albums || []);
+        }, 300);
+    });
+
+    document.getElementById('filter-year').addEventListener('change', async () => {
+        updateMonthFilter();
+        document.getElementById('filter-month').value = '';
+        const data = await fetchAlbums();
+        renderAlbums(data.albums || []);
+    });
+
+    document.getElementById('filter-month').addEventListener('change', async () => {
+        const data = await fetchAlbums();
+        renderAlbums(data.albums || []);
+    });
+
+    document.getElementById('sort').addEventListener('change', async () => {
+        const data = await fetchAlbums();
+        renderAlbums(data.albums || []);
+    });
+
+    document.getElementById('comment-form').addEventListener('submit', async (e) => {
+        e.preventDefault();
+
+        const albumId = document.getElementById('comment-album-id').value;
+        const author = document.getElementById('comment-author').value.trim();
+        const text = document.getElementById('comment-text').value.trim();
+        const website = document.getElementById('comment-website').value;
+
+        if (!author || !text) return;
+
+        const btn = e.target.querySelector('button[type="submit"]');
+        btn.disabled = true;
+        btn.innerHTML = '<i class="fas fa-spinner fa-spin mr-2"></i>Senden...';
+
+        try {
+            const result = await postComment(albumId, author, text, website);
+
+            if (result.error) {
+                alert(result.error);
+            } else {
+                document.getElementById('comment-text').value = '';
+                await loadComments(albumId);
+            }
+        } catch (err) {
+            alert('Fehler beim Senden des Kommentars');
+        }
+
+        btn.disabled = false;
+        btn.innerHTML = '<i class="fas fa-paper-plane mr-2"></i>Absenden';
+    });
+
+    // Modal schliessen bei Klick ausserhalb
+    document.getElementById('album-modal').addEventListener('click', (e) => {
+        if (e.target.id === 'album-modal') {
+            closeModal();
+        }
+    });
+
+    // Modal schliessen mit Escape
+    document.addEventListener('keydown', (e) => {
+        if (e.key === 'Escape') {
+            closeModal();
+        }
+    });
+
+    // === Init ===
+    async function init() {
+        try {
+            const [albumsData, datesData] = await Promise.all([
+                fetchAlbums(),
+                fetchDates()
+            ]);
+
+            renderAlbums(albumsData.albums || []);
+            renderDateFilters(datesData.dates || {});
+        } catch (err) {
+            console.error('Fehler beim Laden:', err);
+            document.getElementById('loading').innerHTML =
+                '<p class="text-red-500"><i class="fas fa-exclamation-triangle mr-2"></i>Fehler beim Laden der Alben</p>';
+        }
+    }
+
+    init();
+    </script>
+</body>
+</html>