Prepare Linux deployment with yt-dlp and persistent downloads

TuneRipper.Api/Services/SessionService.cs

@@ -1,21 +1,32 @@
 using System.Collections.Concurrent;
+using Microsoft.Extensions.Options;
+using TuneRipper.Api.Configuration;
 
 namespace TuneRipper.Api.Services;
 
-public class SessionService : ISessionService
+public class SessionService : ISessionService, IDisposable
 {
-    private readonly IWebHostEnvironment _environment;
     private readonly ILogger<SessionService> _logger;
+    private readonly string _downloadsRoot;
     private readonly ConcurrentDictionary<string, DateTime> _sessions = new();
     private readonly Timer _cleanupTimer;
     
     // Session expires after 24 hours of inactivity
     private readonly TimeSpan _sessionTimeout = TimeSpan.FromHours(24);
 
-    public SessionService(IWebHostEnvironment environment, ILogger<SessionService> logger)
+    public SessionService(
+        IWebHostEnvironment environment,
+        IOptions<StorageOptions> options,
+        ILogger<SessionService> logger)
     {
-        _environment = environment;
         _logger = logger;
+        _downloadsRoot = Path.GetFullPath(
+            string.IsNullOrWhiteSpace(options.Value.DownloadsPath)
+                ? Path.Combine(environment.WebRootPath, "downloads")
+                : options.Value.DownloadsPath);
+
+        Directory.CreateDirectory(_downloadsRoot);
+        RestoreSessionsFromDisk();
         
         // Clean up expired sessions every hour
         _cleanupTimer = new Timer(
@@ -46,8 +57,7 @@ public class SessionService : ISessionService
     {
         if (!string.IsNullOrWhiteSpace(sessionId) && IsValidSession(sessionId))
         {
-            // Update last activity time
-            _sessions[sessionId] = DateTime.UtcNow;
+            TouchSession(sessionId);
             return sessionId;
         }
 
@@ -59,7 +69,17 @@ public class SessionService : ISessionService
         if (string.IsNullOrWhiteSpace(sessionId))
             return false;
 
-        if (_sessions.TryGetValue(sessionId, out var lastActivity))
+        if (!_sessions.TryGetValue(sessionId, out var lastActivity))
+        {
+            var sessionPath = GetSessionDownloadsPath(sessionId);
+            if (Directory.Exists(sessionPath))
+            {
+                lastActivity = Directory.GetLastWriteTimeUtc(sessionPath);
+                _sessions.TryAdd(sessionId, lastActivity);
+            }
+        }
+
+        if (_sessions.TryGetValue(sessionId, out lastActivity))
         {
             // Check if session has expired
             if (DateTime.UtcNow - lastActivity > _sessionTimeout)
@@ -118,10 +138,11 @@ public class SessionService : ISessionService
         }
     }
 
+    public string GetDownloadsRootPath() => _downloadsRoot;
+
     public string GetSessionDownloadsPath(string sessionId)
     {
-        var downloadsRoot = Path.Combine(_environment.WebRootPath, "downloads");
-        return Path.Combine(downloadsRoot, sessionId);
+        return Path.Combine(_downloadsRoot, sessionId);
     }
 
     /// <summary>
@@ -150,10 +171,43 @@ public class SessionService : ISessionService
             Directory.CreateDirectory(sessionPath);
             _logger.LogInformation("Created session directory for session: {SessionId} at {Path}", sessionId, sessionPath);
         }
+
+        TouchSession(sessionId);
+    }
+
+    private void RestoreSessionsFromDisk()
+    {
+        foreach (var sessionPath in Directory.EnumerateDirectories(_downloadsRoot))
+        {
+            var sessionId = Path.GetFileName(sessionPath);
+            var lastActivity = Directory.GetLastWriteTimeUtc(sessionPath);
+
+            if (DateTime.UtcNow - lastActivity <= _sessionTimeout)
+            {
+                _sessions[sessionId] = lastActivity;
+            }
+        }
+
+        _logger.LogInformation(
+            "Restored {Count} active sessions from {DownloadsRoot}",
+            _sessions.Count,
+            _downloadsRoot);
+    }
+
+    private void TouchSession(string sessionId)
+    {
+        var now = DateTime.UtcNow;
+        _sessions[sessionId] = now;
+
+        var sessionPath = GetSessionDownloadsPath(sessionId);
+        if (Directory.Exists(sessionPath))
+        {
+            Directory.SetLastWriteTimeUtc(sessionPath, now);
+        }
     }
 
     public void Dispose()
     {
         _cleanupTimer?.Dispose();
     }
-}
+}