feat: add cache-only storage mode for streaming without library persistence

.env.example

@@ -1,7 +1,7 @@
 # Navidrome/Subsonic server URL
 SUBSONIC_URL=http://localhost:4533
 
-# Path where downloaded songs will be stored on the host
+# Path where downloaded songs will be stored on the host (only applies if STORAGE_MODE=Permanent)
 DOWNLOAD_PATH=./downloads
 
 # Music service to use: Deezer or Qobuz (default: Deezer)
@@ -46,3 +46,15 @@ EXPLICIT_FILTER=All
 # - Album: When playing a track, download the entire album in background
 #          The played track is downloaded first, remaining tracks are queued
 DOWNLOAD_MODE=Track
+
+# Storage mode (optional, default: Permanent)
+# - Permanent: Files are saved to the library permanently and registered in Navidrome
+# - Cache: Files are stored in /tmp and automatically cleaned up after CACHE_DURATION_HOURS
+#          Not registered in Navidrome, ideal for streaming without library bloat
+STORAGE_MODE=Permanent
+
+# Cache duration in hours (optional, default: 1)
+# Files older than this duration will be automatically deleted when STORAGE_MODE=Cache
+# Based on last access time (updated each time the file is streamed)
+# Cache location: /tmp/octo-fiesta-cache (automatic, no configuration needed)
+CACHE_DURATION_HOURS=1

octo-fiesta/Models/Settings/SubsonicSettings.cs

@@ -40,6 +40,23 @@ public enum ExplicitFilter
     CleanOnly
 }
 
+/// <summary>
+/// Storage mode for downloaded tracks
+/// </summary>
+public enum StorageMode
+{
+    /// <summary>
+    /// Files are permanently stored in the library and registered in the database
+    /// </summary>
+    Permanent,
+    
+    /// <summary>
+    /// Files are stored in a temporary cache and automatically cleaned up
+    /// Not registered in the database, no Navidrome scan triggered
+    /// </summary>
+    Cache
+}
+
 /// <summary>
 /// Music service provider
 /// </summary>
@@ -81,4 +98,19 @@ public class SubsonicSettings
     /// Values: "Deezer", "Qobuz"
     /// </summary>
     public MusicService MusicService { get; set; } = MusicService.Deezer;
+    
+    /// <summary>
+    /// Storage mode for downloaded files (default: Permanent)
+    /// Environment variable: STORAGE_MODE
+    /// Values: "Permanent" (files saved to library), "Cache" (temporary files, auto-cleanup)
+    /// </summary>
+    public StorageMode StorageMode { get; set; } = StorageMode.Permanent;
+    
+    /// <summary>
+    /// Cache duration in hours for Cache storage mode (default: 1)
+    /// Environment variable: CACHE_DURATION_HOURS
+    /// Files older than this duration will be automatically deleted
+    /// Only applies when StorageMode is Cache
+    /// </summary>
+    public int CacheDurationHours { get; set; } = 1;
 }

octo-fiesta/Program.cs

@@ -5,6 +5,7 @@ using octo_fiesta.Services.Qobuz;
 using octo_fiesta.Services.Local;
 using octo_fiesta.Services.Validation;
 using octo_fiesta.Services.Subsonic;
+using octo_fiesta.Services.Common;
 using octo_fiesta.Middleware;
 
 var builder = WebApplication.CreateBuilder(args);
@@ -64,6 +65,9 @@ builder.Services.AddSingleton<IStartupValidator, QobuzStartupValidator>();
 // Register orchestrator as hosted service
 builder.Services.AddHostedService<StartupValidationOrchestrator>();
 
+// Register cache cleanup service (only runs when StorageMode is Cache)
+builder.Services.AddHostedService<CacheCleanupService>();
+
 builder.Services.AddCors(options =>
 {
     options.AddDefaultPolicy(policy =>

octo-fiesta/Services/Common/BaseDownloadService.cs

@@ -23,6 +23,7 @@ public abstract class BaseDownloadService : IDownloadService
     protected readonly ILogger Logger;
     
     protected readonly string DownloadPath;
+    protected readonly string CachePath;
     
     protected readonly Dictionary<string, DownloadInfo> ActiveDownloads = new();
     protected readonly SemaphoreSlim DownloadLock = new(1, 1);
@@ -46,11 +47,17 @@ public abstract class BaseDownloadService : IDownloadService
         Logger = logger;
         
         DownloadPath = configuration["Library:DownloadPath"] ?? "./downloads";
+        CachePath = Path.Combine(Path.GetTempPath(), "octo-fiesta-cache");
         
         if (!Directory.Exists(DownloadPath))
         {
             Directory.CreateDirectory(DownloadPath);
         }
+        
+        if (!Directory.Exists(CachePath))
+        {
+            Directory.CreateDirectory(CachePath);
+        }
     }
     
     #region IDownloadService Implementation
@@ -62,7 +69,7 @@ public abstract class BaseDownloadService : IDownloadService
     
     public async Task<Stream> DownloadAndStreamAsync(string externalProvider, string externalId, CancellationToken cancellationToken = default)
     {
-        var localPath = await DownloadSongAsync(externalProvider, externalId, cancellationToken);
+        var localPath = await DownloadSongInternalAsync(externalProvider, externalId, triggerAlbumDownload: true, cancellationToken);
         return IOFile.OpenRead(localPath);
     }
     
@@ -130,14 +137,30 @@ public abstract class BaseDownloadService : IDownloadService
         }
 
         var songId = $"ext-{externalProvider}-{externalId}";
+        var isCache = SubsonicSettings.StorageMode == StorageMode.Cache;
         
-        // Check if already downloaded
+        // Check if already downloaded (skip for cache mode as we want to check cache folder)
+        if (!isCache)
+        {
             var existingPath = await LocalLibraryService.GetLocalPathForExternalSongAsync(externalProvider, externalId);
             if (existingPath != null && IOFile.Exists(existingPath))
             {
                 Logger.LogInformation("Song already downloaded: {Path}", existingPath);
                 return existingPath;
             }
+        }
+        else
+        {
+            // For cache mode, check if file exists in cache directory
+            var cachedPath = GetCachedFilePath(externalProvider, externalId);
+            if (cachedPath != null && IOFile.Exists(cachedPath))
+            {
+                Logger.LogInformation("Song found in cache: {Path}", cachedPath);
+                // Update file access time for cache cleanup logic
+                IOFile.SetLastAccessTime(cachedPath, DateTime.UtcNow);
+                return cachedPath;
+            }
+        }
 
         // Check if download in progress
         if (ActiveDownloads.TryGetValue(songId, out var activeDownload) && activeDownload.Status == DownloadStatus.InProgress)
@@ -185,6 +208,10 @@ public abstract class BaseDownloadService : IDownloadService
                 downloadInfo.CompletedAt = DateTime.UtcNow;
                 
                 song.LocalPath = localPath;
+                
+                // Only register and scan if NOT in cache mode
+                if (!isCache)
+                {
                     await LocalLibraryService.RegisterDownloadedSongAsync(song, localPath);
                     
                     // Trigger a Subsonic library rescan (with debounce)
@@ -210,6 +237,11 @@ public abstract class BaseDownloadService : IDownloadService
                             DownloadRemainingAlbumTracksInBackground(externalProvider, albumExternalId, externalId);
                         }
                     }
+                }
+                else
+                {
+                    Logger.LogInformation("Cache mode: skipping library registration and scan");
+                }
                 
                 Logger.LogInformation("Download completed: {Path}", localPath);
                 return localPath;
@@ -401,5 +433,31 @@ public abstract class BaseDownloadService : IDownloadService
         }
     }
     
+    /// <summary>
+    /// Gets the cached file path for a given provider and external ID
+    /// Returns null if no cached file exists
+    /// </summary>
+    protected string? GetCachedFilePath(string provider, string externalId)
+    {
+        try
+        {
+            // Search for cached files matching the pattern: {provider}_{externalId}.*
+            var pattern = $"{provider}_{externalId}.*";
+            var files = Directory.GetFiles(CachePath, pattern, SearchOption.AllDirectories);
+            
+            if (files.Length > 0)
+            {
+                return files[0]; // Return first match
+            }
+            
+            return null;
+        }
+        catch (Exception ex)
+        {
+            Logger.LogWarning(ex, "Failed to search for cached file: {Provider}_{ExternalId}", provider, externalId);
+            return null;
+        }
+    }
+    
     #endregion
 }

octo-fiesta/Services/Common/CacheCleanupService.cs

@@ -0,0 +1,163 @@
+using Microsoft.Extensions.Options;
+using octo_fiesta.Models.Settings;
+
+namespace octo_fiesta.Services.Common;
+
+/// <summary>
+/// Background service that periodically cleans up old cached files
+/// Only runs when StorageMode is set to Cache
+/// </summary>
+public class CacheCleanupService : BackgroundService
+{
+    private readonly IConfiguration _configuration;
+    private readonly SubsonicSettings _subsonicSettings;
+    private readonly ILogger<CacheCleanupService> _logger;
+    private readonly TimeSpan _cleanupInterval = TimeSpan.FromHours(1);
+
+    public CacheCleanupService(
+        IConfiguration configuration,
+        IOptions<SubsonicSettings> subsonicSettings,
+        ILogger<CacheCleanupService> logger)
+    {
+        _configuration = configuration;
+        _subsonicSettings = subsonicSettings.Value;
+        _logger = logger;
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        // Only run if storage mode is Cache
+        if (_subsonicSettings.StorageMode != StorageMode.Cache)
+        {
+            _logger.LogInformation("CacheCleanupService disabled: StorageMode is not Cache");
+            return;
+        }
+
+        _logger.LogInformation("CacheCleanupService started with cleanup interval of {Interval} and retention of {Hours} hours",
+            _cleanupInterval, _subsonicSettings.CacheDurationHours);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                await CleanupOldCachedFilesAsync(stoppingToken);
+                await Task.Delay(_cleanupInterval, stoppingToken);
+            }
+            catch (OperationCanceledException)
+            {
+                // Service is stopping, exit gracefully
+                break;
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Error during cache cleanup");
+                // Continue running even if cleanup fails
+                await Task.Delay(_cleanupInterval, stoppingToken);
+            }
+        }
+
+        _logger.LogInformation("CacheCleanupService stopped");
+    }
+
+    private async Task CleanupOldCachedFilesAsync(CancellationToken cancellationToken)
+    {
+        var cachePath = Path.Combine(Path.GetTempPath(), "octo-fiesta-cache");
+
+        if (!Directory.Exists(cachePath))
+        {
+            _logger.LogDebug("Cache directory does not exist: {Path}", cachePath);
+            return;
+        }
+
+        var cutoffTime = DateTime.UtcNow.AddHours(-_subsonicSettings.CacheDurationHours);
+        var deletedCount = 0;
+        var totalSize = 0L;
+
+        _logger.LogInformation("Starting cache cleanup: deleting files older than {CutoffTime}", cutoffTime);
+
+        try
+        {
+            // Get all files in cache directory and subdirectories
+            var files = Directory.GetFiles(cachePath, "*.*", SearchOption.AllDirectories);
+
+            foreach (var filePath in files)
+            {
+                if (cancellationToken.IsCancellationRequested)
+                    break;
+
+                try
+                {
+                    var fileInfo = new FileInfo(filePath);
+
+                    // Use last access time to determine if file should be deleted
+                    // This gets updated when a cached file is streamed
+                    if (fileInfo.LastAccessTimeUtc < cutoffTime)
+                    {
+                        var size = fileInfo.Length;
+                        File.Delete(filePath);
+                        deletedCount++;
+                        totalSize += size;
+                        _logger.LogDebug("Deleted cached file: {Path} (last accessed: {LastAccess})",
+                            filePath, fileInfo.LastAccessTimeUtc);
+                    }
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogWarning(ex, "Failed to delete cached file: {Path}", filePath);
+                }
+            }
+
+            // Clean up empty directories
+            await CleanupEmptyDirectoriesAsync(cachePath, cancellationToken);
+
+            if (deletedCount > 0)
+            {
+                var sizeMB = totalSize / (1024.0 * 1024.0);
+                _logger.LogInformation("Cache cleanup completed: deleted {Count} files, freed {Size:F2} MB",
+                    deletedCount, sizeMB);
+            }
+            else
+            {
+                _logger.LogDebug("Cache cleanup completed: no files to delete");
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Error during cache cleanup");
+        }
+    }
+
+    private async Task CleanupEmptyDirectoriesAsync(string rootPath, CancellationToken cancellationToken)
+    {
+        try
+        {
+            var directories = Directory.GetDirectories(rootPath, "*", SearchOption.AllDirectories)
+                .OrderByDescending(d => d.Length); // Process deepest directories first
+
+            foreach (var directory in directories)
+            {
+                if (cancellationToken.IsCancellationRequested)
+                    break;
+
+                try
+                {
+                    if (!Directory.EnumerateFileSystemEntries(directory).Any())
+                    {
+                        Directory.Delete(directory);
+                        _logger.LogDebug("Deleted empty directory: {Path}", directory);
+                    }
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogWarning(ex, "Failed to delete empty directory: {Path}", directory);
+                }
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Error cleaning up empty directories");
+        }
+
+        await Task.CompletedTask;
+    }
+}

octo-fiesta/Services/Deezer/DeezerDownloadService.cs

@@ -109,7 +109,8 @@ public class DeezerDownloadService : BaseDownloadService
 
         // Build organized folder structure: Artist/Album/Track using AlbumArtist (fallback to Artist for singles)
         var artistForPath = song.AlbumArtist ?? song.Artist;
-        var outputPath = PathHelper.BuildTrackPath(DownloadPath, artistForPath, song.Album, song.Title, song.Track, extension);
+        var basePath = SubsonicSettings.StorageMode == StorageMode.Cache ? CachePath : DownloadPath;
+        var outputPath = PathHelper.BuildTrackPath(basePath, artistForPath, song.Album, song.Title, song.Track, extension);
         
         // Create directories if they don't exist
         var albumFolder = Path.GetDirectoryName(outputPath)!;

octo-fiesta/Services/Qobuz/QobuzDownloadService.cs

@@ -108,7 +108,8 @@ public class QobuzDownloadService : BaseDownloadService
 
         // Build organized folder structure using AlbumArtist (fallback to Artist for singles)
         var artistForPath = song.AlbumArtist ?? song.Artist;
-        var outputPath = PathHelper.BuildTrackPath(DownloadPath, artistForPath, song.Album, song.Title, song.Track, extension);
+        var basePath = SubsonicSettings.StorageMode == StorageMode.Cache ? CachePath : DownloadPath;
+        var outputPath = PathHelper.BuildTrackPath(basePath, artistForPath, song.Album, song.Title, song.Track, extension);
         
         var albumFolder = Path.GetDirectoryName(outputPath)!;
         EnsureDirectoryExists(albumFolder);

octo-fiesta/appsettings.json

@@ -9,7 +9,9 @@
   "Subsonic": {
     "Url": "http://localhost:4533",
     "ExplicitFilter": "All",
-    "DownloadMode": "Track"
+    "DownloadMode": "Track",
+    "StorageMode": "Permanent",
+    "CacheDurationHours": 1
   },
   "Library": {
     "DownloadPath": "./downloads"