using System.Data;
using Microsoft.EntityFrameworkCore;
using TrafagSalesExporter.Data;
using TrafagSalesExporter.Models;

namespace TrafagSalesExporter.Services;

public class DatabaseInitializationService : IDatabaseInitializationService
{
    private readonly IDbContextFactory<AppDbContext> _dbFactory;

    public DatabaseInitializationService(IDbContextFactory<AppDbContext> dbFactory)
    {
        _dbFactory = dbFactory;
    }

    public async Task InitializeAsync()
    {
        using var db = await _dbFactory.CreateDbContextAsync();
        await db.Database.EnsureCreatedAsync();
        EnsureSchema(db);
        SeedIfEmpty(db);
    }

    private static void EnsureSchema(AppDbContext db)
    {
        AddColumnIfMissing(db, "HanaServers", "DatabaseName", "TEXT NOT NULL DEFAULT ''");
        AddColumnIfMissing(db, "HanaServers", "UseSsl", "INTEGER NOT NULL DEFAULT 0");
        AddColumnIfMissing(db, "HanaServers", "ValidateCertificate", "INTEGER NOT NULL DEFAULT 0");
        AddColumnIfMissing(db, "HanaServers", "AdditionalParams", "TEXT NOT NULL DEFAULT ''");
        AddColumnIfMissing(db, "Sites", "SourceSystem", "TEXT NOT NULL DEFAULT 'SAP'");
        AddColumnIfMissing(db, "Sites", "UsernameOverride", "TEXT NOT NULL DEFAULT ''");
        AddColumnIfMissing(db, "Sites", "PasswordOverride", "TEXT NOT NULL DEFAULT ''");
        AddColumnIfMissing(db, "ExportSettings", "SapUsername", "TEXT NOT NULL DEFAULT ''");
        AddColumnIfMissing(db, "ExportSettings", "SapPassword", "TEXT NOT NULL DEFAULT ''");
        AddColumnIfMissing(db, "ExportSettings", "Bi1Username", "TEXT NOT NULL DEFAULT ''");
        AddColumnIfMissing(db, "ExportSettings", "Bi1Password", "TEXT NOT NULL DEFAULT ''");
        AddColumnIfMissing(db, "ExportSettings", "SageUsername", "TEXT NOT NULL DEFAULT ''");
        AddColumnIfMissing(db, "ExportSettings", "SagePassword", "TEXT NOT NULL DEFAULT ''");
        EnsureTransformationTable(db);
    }

    private static void AddColumnIfMissing(AppDbContext db, string table, string column, string type)
    {
        var conn = db.Database.GetDbConnection();
        if (conn.State != ConnectionState.Open)
            conn.Open();

        var exists = false;
        using (var cmd = conn.CreateCommand())
        {
            cmd.CommandText = $"PRAGMA table_info({table})";
            using var reader = cmd.ExecuteReader();
            while (reader.Read())
            {
                if (string.Equals(reader["name"]?.ToString(), column, StringComparison.OrdinalIgnoreCase))
                {
                    exists = true;
                    break;
                }
            }
        }

        if (!exists)
        {
            using var alter = conn.CreateCommand();
            alter.CommandText = $"ALTER TABLE {table} ADD COLUMN {column} {type}";
            alter.ExecuteNonQuery();
        }
    }

    private static void EnsureTransformationTable(AppDbContext db)
    {
        var conn = db.Database.GetDbConnection();
        if (conn.State != ConnectionState.Open)
            conn.Open();

        using var cmd = conn.CreateCommand();
        cmd.CommandText = @"
CREATE TABLE IF NOT EXISTS FieldTransformationRules (
    Id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
    SourceSystem TEXT NOT NULL DEFAULT 'SAP',
    SourceField TEXT NOT NULL,
    TargetField TEXT NOT NULL,
    TransformationType TEXT NOT NULL,
    Argument TEXT NOT NULL DEFAULT '',
    SortOrder INTEGER NOT NULL DEFAULT 0,
    IsActive INTEGER NOT NULL DEFAULT 1
);";
        cmd.ExecuteNonQuery();
    }

    private static void SeedIfEmpty(AppDbContext db)
    {
        if (db.HanaServers.Any())
            return;

        var serverInternal = new HanaServer { Name = "Internal", Host = "travtrp0", Port = 30015, Username = "", Password = "" };
        var serverIndia = new HanaServer { Name = "India", Host = "20.197.20.60", Port = 30015, Username = "", Password = "" };
        db.HanaServers.AddRange(serverInternal, serverIndia);
        db.SaveChanges();

        db.Sites.AddRange(
            new Site { HanaServerId = serverInternal.Id, Schema = "fr01_p", TSC = "TRFR", Land = "Frankreich", IsActive = true },
            new Site { HanaServerId = serverInternal.Id, Schema = "it01_p", TSC = "TRIT", Land = "Italien", IsActive = true },
            new Site { HanaServerId = serverInternal.Id, Schema = "us01_p", TSC = "TRUS", Land = "USA", IsActive = true },
            new Site { HanaServerId = serverIndia.Id, Schema = "TRAFAG_LIVE", TSC = "TRIN", Land = "Indien", IsActive = true }
        );

        db.SharePointConfigs.Add(new SharePointConfig
        {
            SiteUrl = "https://trafagag.sharepoint.com/sites/WorldwideBIPlatform",
            ExportFolder = "/Shared Documents/Exports/",
            TenantId = "",
            ClientId = "",
            ClientSecret = ""
        });

        db.ExportSettings.Add(new ExportSettings
        {
            DateFilter = "2025-01-01",
            TimerHour = 3,
            TimerMinute = 0,
            TimerEnabled = true
        });

        db.SaveChanges();
    }
}