Add admin access and landing dashboard

TrafagSalesExporter/Services/AccessPasswordSettingsWriter.cs

@@ -0,0 +1,40 @@
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+
+namespace TrafagSalesExporter.Services;
+
+internal static class AccessPasswordSettingsWriter
+{
+    private static readonly object FileLock = new();
+
+    public static string HashPassword(string password)
+        => Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(password)));
+
+    public static void SavePasswordHash(string contentRootPath, string sectionName, string passwordHash)
+    {
+        var path = Path.Combine(contentRootPath, "appsettings.json");
+
+        lock (FileLock)
+        {
+            var json = File.Exists(path)
+                ? File.ReadAllText(path, Encoding.UTF8)
+                : "{}";
+
+            var root = JsonNode.Parse(json)?.AsObject() ?? new JsonObject();
+            var section = root[sectionName] as JsonObject;
+            if (section is null)
+            {
+                section = new JsonObject();
+                root[sectionName] = section;
+            }
+
+            section["PasswordHash"] = passwordHash;
+            section["Password"] = string.Empty;
+
+            var options = new JsonSerializerOptions { WriteIndented = true };
+            File.WriteAllText(path, root.ToJsonString(options), new UTF8Encoding(false));
+        }
+    }
+}