Initial commit: Futonizer MKV track stripper

Services/HistoryService.cs

@@ -0,0 +1,65 @@
+using System.IO;
+using System.Text.Json;
+using Futonizer.Models;
+
+namespace Futonizer.Services;
+
+/// <summary>
+/// Persists a rolling history of previously processed files (newest first,
+/// capped at <see cref="MaxEntries"/>) as a JSON file stored next to the
+/// application executable.
+/// </summary>
+public static class HistoryService
+{
+    private const int MaxEntries = 1000;
+    private static readonly string HistoryFilePath =
+        Path.Combine(AppContext.BaseDirectory, "history.json");
+    private static readonly object FileLock = new();
+
+    public static List<HistoryEntry> Load()
+    {
+        lock (FileLock)
+        {
+            try
+            {
+                if (!File.Exists(HistoryFilePath)) return new List<HistoryEntry>();
+                string json = File.ReadAllText(HistoryFilePath);
+                var list = JsonSerializer.Deserialize<List<HistoryEntry>>(json);
+                return list ?? new List<HistoryEntry>();
+            }
+            catch
+            {
+                return new List<HistoryEntry>();
+            }
+        }
+    }
+
+    /// <summary>
+    /// Adds a new entry at the front of the history and trims it down to
+    /// <see cref="MaxEntries"/> items. Safe to call concurrently from
+    /// multiple in-flight strip jobs.
+    /// </summary>
+    public static void Add(HistoryEntry entry)
+    {
+        lock (FileLock)
+        {
+            try
+            {
+                var list = File.Exists(HistoryFilePath)
+                    ? JsonSerializer.Deserialize<List<HistoryEntry>>(File.ReadAllText(HistoryFilePath)) ?? new List<HistoryEntry>()
+                    : new List<HistoryEntry>();
+
+                list.Insert(0, entry);
+                if (list.Count > MaxEntries)
+                    list.RemoveRange(MaxEntries, list.Count - MaxEntries);
+
+                string json = JsonSerializer.Serialize(list, new JsonSerializerOptions { WriteIndented = true });
+                File.WriteAllText(HistoryFilePath, json);
+            }
+            catch
+            {
+                // Best effort — history is a convenience feature, never worth failing a strip job over.
+            }
+        }
+    }
+}