feat: add pluggable music service architecture with Qobuz support

octo-fiesta/Models/QobuzSettings.cs

@@ -0,0 +1,25 @@
+namespace octo_fiesta.Models;
+
+/// <summary>
+/// Configuration for the Qobuz downloader and metadata service
+/// </summary>
+public class QobuzSettings
+{
+    /// <summary>
+    /// Qobuz user authentication token
+    /// Obtained from browser's localStorage after logging into play.qobuz.com
+    /// </summary>
+    public string? UserAuthToken { get; set; }
+    
+    /// <summary>
+    /// Qobuz user ID
+    /// Obtained from browser's localStorage after logging into play.qobuz.com
+    /// </summary>
+    public string? UserId { get; set; }
+    
+    /// <summary>
+    /// Preferred audio quality: FLAC, MP3_320, MP3_128
+    /// If not specified or unavailable, the highest available quality will be used.
+    /// </summary>
+    public string? Quality { get; set; }
+}

octo-fiesta/Models/SubsonicSettings.cs

@@ -40,6 +40,22 @@ public enum ExplicitFilter
     CleanOnly
 }
 
+/// <summary>
+/// Music service provider
+/// </summary>
+public enum MusicService
+{
+    /// <summary>
+    /// Deezer music service
+    /// </summary>
+    Deezer,
+    
+    /// <summary>
+    /// Qobuz music service
+    /// </summary>
+    Qobuz
+}
+
 public class SubsonicSettings
 {
     public string? Url { get; set; }
@@ -48,6 +64,7 @@ public class SubsonicSettings
     /// Explicit content filter mode (default: All)
     /// Environment variable: EXPLICIT_FILTER
     /// Values: "All", "ExplicitOnly", "CleanOnly"
+    /// Note: Only works with Deezer
     /// </summary>
     public ExplicitFilter ExplicitFilter { get; set; } = ExplicitFilter.All;
     
@@ -57,4 +74,11 @@ public class SubsonicSettings
     /// Values: "Track" (download only played track), "Album" (download full album when playing a track)
     /// </summary>
     public DownloadMode DownloadMode { get; set; } = DownloadMode.Track;
+    
+    /// <summary>
+    /// Music service to use (default: Deezer)
+    /// Environment variable: MUSIC_SERVICE
+    /// Values: "Deezer", "Qobuz"
+    /// </summary>
+    public MusicService MusicService { get; set; } = MusicService.Deezer;
 }

octo-fiesta/Program.cs

@@ -13,12 +13,30 @@ builder.Services.AddSwaggerGen();
 // Configuration
 builder.Services.Configure<SubsonicSettings>(
     builder.Configuration.GetSection("Subsonic"));
+builder.Services.Configure<QobuzSettings>(
+    builder.Configuration.GetSection("Qobuz"));
+
+// Get the configured music service
+var musicService = builder.Configuration.GetValue<MusicService>("Subsonic:MusicService");
 
 // Business services
 // Registered as Singleton to share state (mappings cache, scan debounce, download tracking, rate limiting)
 builder.Services.AddSingleton<ILocalLibraryService, LocalLibraryService>();
-builder.Services.AddSingleton<IMusicMetadataService, DeezerMetadataService>();
-builder.Services.AddSingleton<IDownloadService, DeezerDownloadService>();
+
+// Register music service based on configuration
+if (musicService == MusicService.Qobuz)
+{
+    // Qobuz services
+    builder.Services.AddSingleton<QobuzBundleService>();
+    builder.Services.AddSingleton<IMusicMetadataService, QobuzMetadataService>();
+    builder.Services.AddSingleton<IDownloadService, QobuzDownloadService>();
+}
+else
+{
+    // Deezer services (default)
+    builder.Services.AddSingleton<IMusicMetadataService, DeezerMetadataService>();
+    builder.Services.AddSingleton<IDownloadService, DeezerDownloadService>();
+}
 
 // Startup validation - runs at application startup to validate configuration
 builder.Services.AddHostedService<StartupValidationService>();
@@ -33,22 +51,22 @@ builder.Services.AddCors(options =>
             .WithExposedHeaders("X-Content-Duration", "X-Total-Count", "X-Nd-Authorization");
     });
 });
-
-var app = builder.Build();
-
-// Configure the HTTP request pipeline.
-if (app.Environment.IsDevelopment())
-{
-    app.UseSwagger();
-    app.UseSwaggerUI();
-}
-
-app.UseHttpsRedirection();
-
-app.UseAuthorization();
-
-app.UseCors();
-
-app.MapControllers();
-
+
+var app = builder.Build();
+
+// Configure the HTTP request pipeline.
+if (app.Environment.IsDevelopment())
+{
+    app.UseSwagger();
+    app.UseSwaggerUI();
+}
+
+app.UseHttpsRedirection();
+
+app.UseAuthorization();
+
+app.UseCors();
+
+app.MapControllers();
+
 app.Run();

octo-fiesta/Services/QobuzBundleService.cs

@@ -0,0 +1,286 @@
+using System.Text.RegularExpressions;
+
+namespace octo_fiesta.Services;
+
+/// <summary>
+/// Service to dynamically extract Qobuz App ID and secrets from the Qobuz web player
+/// This is necessary because these values change periodically
+/// Based on the Python qobuz-dl implementation
+/// </summary>
+public class QobuzBundleService
+{
+    private readonly HttpClient _httpClient;
+    private readonly ILogger<QobuzBundleService> _logger;
+    
+    private const string BaseUrl = "https://play.qobuz.com";
+    private const string LoginPageUrl = "https://play.qobuz.com/login";
+    
+    // Regex patterns to extract bundle URL and App ID
+    private static readonly Regex BundleUrlRegex = new(
+        @"<script src=""(/resources/\d+\.\d+\.\d+-[a-z]\d{3}/bundle\.js)""></script>",
+        RegexOptions.Compiled);
+    
+    private static readonly Regex AppIdRegex = new(
+        @"production:\{api:\{appId:""(?<app_id>\d{9})"",appSecret:""\w{32}""",
+        RegexOptions.Compiled);
+    
+    // Cached values (valid for the lifetime of the application)
+    private string? _cachedAppId;
+    private List<string>? _cachedSecrets;
+    private readonly SemaphoreSlim _initLock = new(1, 1);
+
+    public QobuzBundleService(IHttpClientFactory httpClientFactory, ILogger<QobuzBundleService> logger)
+    {
+        _httpClient = httpClientFactory.CreateClient();
+        _httpClient.DefaultRequestHeaders.Add("User-Agent", 
+            "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0");
+        _logger = logger;
+    }
+
+    /// <summary>
+    /// Gets the Qobuz App ID, extracting it from the bundle if not cached
+    /// </summary>
+    public async Task<string> GetAppIdAsync()
+    {
+        await EnsureInitializedAsync();
+        return _cachedAppId!;
+    }
+
+    /// <summary>
+    /// Gets the Qobuz secrets list, extracting them from the bundle if not cached
+    /// </summary>
+    public async Task<List<string>> GetSecretsAsync()
+    {
+        await EnsureInitializedAsync();
+        return _cachedSecrets!;
+    }
+
+    /// <summary>
+    /// Gets a specific secret by index (used for signing requests)
+    /// </summary>
+    public async Task<string> GetSecretAsync(int index = 0)
+    {
+        var secrets = await GetSecretsAsync();
+        if (index < 0 || index >= secrets.Count)
+        {
+            throw new ArgumentOutOfRangeException(nameof(index), 
+                $"Secret index {index} out of range (0-{secrets.Count - 1})");
+        }
+        return secrets[index];
+    }
+
+    /// <summary>
+    /// Ensures App ID and secrets are extracted and cached
+    /// </summary>
+    private async Task EnsureInitializedAsync()
+    {
+        if (_cachedAppId != null && _cachedSecrets != null)
+        {
+            return;
+        }
+
+        await _initLock.WaitAsync();
+        try
+        {
+            // Double-check after acquiring lock
+            if (_cachedAppId != null && _cachedSecrets != null)
+            {
+                return;
+            }
+
+            _logger.LogInformation("Extracting Qobuz App ID and secrets from web bundle...");
+
+            // Step 1: Get the bundle URL from login page
+            var bundleUrl = await GetBundleUrlAsync();
+            _logger.LogInformation("Found bundle URL: {BundleUrl}", bundleUrl);
+
+            // Step 2: Download the bundle JavaScript
+            var bundleJs = await DownloadBundleAsync(bundleUrl);
+
+            // Step 3: Extract App ID
+            _cachedAppId = ExtractAppId(bundleJs);
+            _logger.LogInformation("Extracted App ID: {AppId}", _cachedAppId);
+
+            // Step 4: Extract secrets (they are base64 encoded in the bundle)
+            _cachedSecrets = ExtractSecrets(bundleJs);
+            _logger.LogInformation("Extracted {Count} secrets", _cachedSecrets.Count);
+        }
+        finally
+        {
+            _initLock.Release();
+        }
+    }
+
+    /// <summary>
+    /// Gets the bundle JavaScript URL from the login page
+    /// </summary>
+    private async Task<string> GetBundleUrlAsync()
+    {
+        var response = await _httpClient.GetAsync(LoginPageUrl);
+        response.EnsureSuccessStatusCode();
+        
+        var html = await response.Content.ReadAsStringAsync();
+        var match = BundleUrlRegex.Match(html);
+        
+        if (!match.Success)
+        {
+            throw new Exception("Could not find bundle URL in Qobuz login page");
+        }
+
+        return BaseUrl + match.Groups[1].Value;
+    }
+
+    /// <summary>
+    /// Downloads the bundle JavaScript file
+    /// </summary>
+    private async Task<string> DownloadBundleAsync(string bundleUrl)
+    {
+        var response = await _httpClient.GetAsync(bundleUrl);
+        response.EnsureSuccessStatusCode();
+        return await response.Content.ReadAsStringAsync();
+    }
+
+    /// <summary>
+    /// Extracts the App ID from the bundle JavaScript
+    /// </summary>
+    private string ExtractAppId(string bundleJs)
+    {
+        var match = AppIdRegex.Match(bundleJs);
+        
+        if (!match.Success)
+        {
+            throw new Exception("Could not extract App ID from bundle");
+        }
+
+        return match.Groups["app_id"].Value;
+    }
+
+    /// <summary>
+    /// Extracts the secrets from the bundle JavaScript
+    /// Based on the Python qobuz-dl implementation (bundle.py)
+    /// The secrets are composed of seed, info, and extras base64-encoded strings
+    /// </summary>
+    private List<string> ExtractSecrets(string bundleJs)
+    {
+        var secrets = new Dictionary<string, List<string>>();
+        
+        // Step 1: Extract seed and timezone pairs
+        // Pattern: [a-z].initialSeed("base64string",window.utimezone.timezone)
+        var seedTimezonePattern = new Regex(
+            @"[a-z]\.initialSeed\(""(?<seed>[\w=]+)"",window\.utimezone\.(?<timezone>[a-z]+)\)",
+            RegexOptions.IgnoreCase);
+        
+        var seedMatches = seedTimezonePattern.Matches(bundleJs);
+        
+        foreach (Match match in seedMatches)
+        {
+            var seed = match.Groups["seed"].Value;
+            var timezone = match.Groups["timezone"].Value.ToLower();
+            
+            if (!secrets.ContainsKey(timezone))
+            {
+                secrets[timezone] = new List<string>();
+            }
+            secrets[timezone].Add(seed);
+        }
+
+        if (secrets.Count == 0)
+        {
+            throw new Exception("Could not extract seed/timezone pairs from bundle");
+        }
+
+        // Step 2: Reorder secrets (move second item to first, as per Python implementation)
+        var keypairs = secrets.ToList();
+        if (keypairs.Count > 1)
+        {
+            var secondItem = keypairs[1];
+            secrets.Remove(secondItem.Key);
+            var newDict = new Dictionary<string, List<string>> { { secondItem.Key, secondItem.Value } };
+            foreach (var kv in keypairs)
+            {
+                if (kv.Key != secondItem.Key)
+                {
+                    newDict[kv.Key] = kv.Value;
+                }
+            }
+            secrets = newDict;
+        }
+
+        // Step 3: Extract info and extras for each timezone
+        // Pattern: name:"\w+/(Timezone)",info:"base64",extras:"base64"
+        var timezones = string.Join("|", secrets.Keys.Select(tz => 
+            char.ToUpper(tz[0]) + tz.Substring(1)));
+        
+        var infoExtrasPattern = new Regex(
+            $@"name:""\w+/(?<timezone>{timezones})"",info:""(?<info>[\w=]+)"",extras:""(?<extras>[\w=]+)""",
+            RegexOptions.IgnoreCase);
+        
+        var infoExtrasMatches = infoExtrasPattern.Matches(bundleJs);
+        
+        foreach (Match match in infoExtrasMatches)
+        {
+            var timezone = match.Groups["timezone"].Value.ToLower();
+            var info = match.Groups["info"].Value;
+            var extras = match.Groups["extras"].Value;
+            
+            if (secrets.ContainsKey(timezone))
+            {
+                secrets[timezone].Add(info);
+                secrets[timezone].Add(extras);
+            }
+        }
+
+        // Step 4: Decode the secrets
+        // Concatenate all base64 strings for each timezone, remove last 44 chars, then decode
+        var decodedSecrets = new List<string>();
+        
+        foreach (var kvp in secrets)
+        {
+            var concatenated = string.Join("", kvp.Value);
+            
+            // Remove last 44 characters as per Python implementation
+            if (concatenated.Length > 44)
+            {
+                concatenated = concatenated.Substring(0, concatenated.Length - 44);
+            }
+            
+            try
+            {
+                var bytes = Convert.FromBase64String(concatenated);
+                var decoded = System.Text.Encoding.UTF8.GetString(bytes);
+                decodedSecrets.Add(decoded);
+                _logger.LogDebug("Decoded secret for timezone {Timezone}: {Length} chars", kvp.Key, decoded.Length);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex, "Failed to decode secret for timezone {Timezone}", kvp.Key);
+            }
+        }
+
+        if (decodedSecrets.Count == 0)
+        {
+            throw new Exception("Could not decode any secrets from bundle");
+        }
+
+        return decodedSecrets;
+    }
+
+    /// <summary>
+    /// Tries to decode a base64 string
+    /// </summary>
+    private bool TryDecodeBase64(string input, out string decoded)
+    {
+        decoded = string.Empty;
+        
+        try
+        {
+            var bytes = Convert.FromBase64String(input);
+            decoded = System.Text.Encoding.UTF8.GetString(bytes);
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+}

octo-fiesta/Services/QobuzDownloadService.cs

@@ -0,0 +1,661 @@
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using octo_fiesta.Models;
+using Microsoft.Extensions.Options;
+using IOFile = System.IO.File;
+
+namespace octo_fiesta.Services;
+
+/// <summary>
+/// Download service implementation for Qobuz
+/// Handles track downloading with MD5 signature for authentication
+/// </summary>
+public class QobuzDownloadService : IDownloadService
+{
+    private readonly HttpClient _httpClient;
+    private readonly IConfiguration _configuration;
+    private readonly ILocalLibraryService _localLibraryService;
+    private readonly IMusicMetadataService _metadataService;
+    private readonly QobuzBundleService _bundleService;
+    private readonly SubsonicSettings _subsonicSettings;
+    private readonly ILogger<QobuzDownloadService> _logger;
+    
+    private readonly string _downloadPath;
+    private readonly string? _userAuthToken;
+    private readonly string? _userId;
+    private readonly string? _preferredQuality;
+    
+    private readonly Dictionary<string, DownloadInfo> _activeDownloads = new();
+    private readonly SemaphoreSlim _downloadLock = new(1, 1);
+    
+    private const string BaseUrl = "https://www.qobuz.com/api.json/0.2/";
+    
+    // Quality format IDs
+    private const int FormatMp3320 = 5;
+    private const int FormatFlac16 = 6;      // CD quality (16-bit 44.1kHz)
+    private const int FormatFlac24Low = 7;   // 24-bit < 96kHz
+    private const int FormatFlac24High = 27; // 24-bit >= 96kHz
+
+    public QobuzDownloadService(
+        IHttpClientFactory httpClientFactory,
+        IConfiguration configuration,
+        ILocalLibraryService localLibraryService,
+        IMusicMetadataService metadataService,
+        QobuzBundleService bundleService,
+        IOptions<SubsonicSettings> subsonicSettings,
+        IOptions<QobuzSettings> qobuzSettings,
+        ILogger<QobuzDownloadService> logger)
+    {
+        _httpClient = httpClientFactory.CreateClient();
+        _configuration = configuration;
+        _localLibraryService = localLibraryService;
+        _metadataService = metadataService;
+        _bundleService = bundleService;
+        _subsonicSettings = subsonicSettings.Value;
+        _logger = logger;
+        
+        _downloadPath = configuration["Library:DownloadPath"] ?? "./downloads";
+        
+        var qobuzConfig = qobuzSettings.Value;
+        _userAuthToken = qobuzConfig.UserAuthToken;
+        _userId = qobuzConfig.UserId;
+        _preferredQuality = qobuzConfig.Quality;
+        
+        if (!Directory.Exists(_downloadPath))
+        {
+            Directory.CreateDirectory(_downloadPath);
+        }
+    }
+
+    #region IDownloadService Implementation
+
+    public async Task<string> DownloadSongAsync(string externalProvider, string externalId, CancellationToken cancellationToken = default)
+    {
+        return await DownloadSongInternalAsync(externalProvider, externalId, triggerAlbumDownload: true, cancellationToken);
+    }
+
+    /// <summary>
+    /// Internal method for downloading a song with control over album download triggering
+    /// </summary>
+    private async Task<string> DownloadSongInternalAsync(string externalProvider, string externalId, bool triggerAlbumDownload, CancellationToken cancellationToken = default)
+    {
+        if (externalProvider != "qobuz")
+        {
+            throw new NotSupportedException($"Provider '{externalProvider}' is not supported");
+        }
+
+        var songId = $"ext-{externalProvider}-{externalId}";
+        
+        // Check if already downloaded
+        var existingPath = await _localLibraryService.GetLocalPathForExternalSongAsync(externalProvider, externalId);
+        if (existingPath != null && IOFile.Exists(existingPath))
+        {
+            _logger.LogInformation("Song already downloaded: {Path}", existingPath);
+            return existingPath;
+        }
+
+        // Check if download in progress
+        if (_activeDownloads.TryGetValue(songId, out var activeDownload) && activeDownload.Status == DownloadStatus.InProgress)
+        {
+            _logger.LogInformation("Download already in progress for {SongId}", songId);
+            while (_activeDownloads.TryGetValue(songId, out activeDownload) && activeDownload.Status == DownloadStatus.InProgress)
+            {
+                await Task.Delay(500, cancellationToken);
+            }
+            
+            if (activeDownload?.Status == DownloadStatus.Completed && activeDownload.LocalPath != null)
+            {
+                return activeDownload.LocalPath;
+            }
+            
+            throw new Exception(activeDownload?.ErrorMessage ?? "Download failed");
+        }
+
+        await _downloadLock.WaitAsync(cancellationToken);
+        try
+        {
+            // Get metadata
+            var song = await _metadataService.GetSongAsync(externalProvider, externalId);
+            if (song == null)
+            {
+                throw new Exception("Song not found");
+            }
+
+            var downloadInfo = new DownloadInfo
+            {
+                SongId = songId,
+                ExternalId = externalId,
+                ExternalProvider = externalProvider,
+                Status = DownloadStatus.InProgress,
+                StartedAt = DateTime.UtcNow
+            };
+            _activeDownloads[songId] = downloadInfo;
+
+            try
+            {
+                var localPath = await DownloadTrackAsync(externalId, song, cancellationToken);
+                
+                downloadInfo.Status = DownloadStatus.Completed;
+                downloadInfo.LocalPath = localPath;
+                downloadInfo.CompletedAt = DateTime.UtcNow;
+                
+                song.LocalPath = localPath;
+                await _localLibraryService.RegisterDownloadedSongAsync(song, localPath);
+                
+                // Trigger a Subsonic library rescan (with debounce)
+                _ = Task.Run(async () =>
+                {
+                    try
+                    {
+                        await _localLibraryService.TriggerLibraryScanAsync();
+                    }
+                    catch (Exception ex)
+                    {
+                        _logger.LogWarning(ex, "Failed to trigger library scan after download");
+                    }
+                });
+                
+                // If download mode is Album and triggering is enabled, start background download of remaining tracks
+                if (triggerAlbumDownload && _subsonicSettings.DownloadMode == DownloadMode.Album && !string.IsNullOrEmpty(song.AlbumId))
+                {
+                    var albumExternalId = ExtractExternalIdFromAlbumId(song.AlbumId);
+                    if (!string.IsNullOrEmpty(albumExternalId))
+                    {
+                        _logger.LogInformation("Download mode is Album, triggering background download for album {AlbumId}", albumExternalId);
+                        DownloadRemainingAlbumTracksInBackground(externalProvider, albumExternalId, externalId);
+                    }
+                }
+                
+                _logger.LogInformation("Download completed: {Path}", localPath);
+                return localPath;
+            }
+            catch (Exception ex)
+            {
+                downloadInfo.Status = DownloadStatus.Failed;
+                downloadInfo.ErrorMessage = ex.Message;
+                _logger.LogError(ex, "Download failed for {SongId}", songId);
+                throw;
+            }
+        }
+        finally
+        {
+            _downloadLock.Release();
+        }
+    }
+
+    public async Task<Stream> DownloadAndStreamAsync(string externalProvider, string externalId, CancellationToken cancellationToken = default)
+    {
+        var localPath = await DownloadSongAsync(externalProvider, externalId, cancellationToken);
+        return IOFile.OpenRead(localPath);
+    }
+
+    public DownloadInfo? GetDownloadStatus(string songId)
+    {
+        _activeDownloads.TryGetValue(songId, out var info);
+        return info;
+    }
+
+    public async Task<bool> IsAvailableAsync()
+    {
+        if (string.IsNullOrEmpty(_userAuthToken) || string.IsNullOrEmpty(_userId))
+        {
+            _logger.LogWarning("Qobuz user auth token or user ID not configured");
+            return false;
+        }
+
+        try
+        {
+            // Try to extract app ID and secrets
+            await _bundleService.GetAppIdAsync();
+            await _bundleService.GetSecretsAsync();
+            return true;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Qobuz service not available");
+            return false;
+        }
+    }
+
+    public void DownloadRemainingAlbumTracksInBackground(string externalProvider, string albumExternalId, string excludeTrackExternalId)
+    {
+        if (externalProvider != "qobuz")
+        {
+            _logger.LogWarning("Provider '{Provider}' is not supported for album download", externalProvider);
+            return;
+        }
+
+        _ = Task.Run(async () =>
+        {
+            try
+            {
+                await DownloadRemainingAlbumTracksAsync(albumExternalId, excludeTrackExternalId);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to download remaining album tracks for album {AlbumId}", albumExternalId);
+            }
+        });
+    }
+
+    private async Task DownloadRemainingAlbumTracksAsync(string albumExternalId, string excludeTrackExternalId)
+    {
+        _logger.LogInformation("Starting background download for album {AlbumId} (excluding track {TrackId})", 
+            albumExternalId, excludeTrackExternalId);
+
+        var album = await _metadataService.GetAlbumAsync("qobuz", albumExternalId);
+        if (album == null)
+        {
+            _logger.LogWarning("Album {AlbumId} not found, cannot download remaining tracks", albumExternalId);
+            return;
+        }
+
+        var tracksToDownload = album.Songs
+            .Where(s => s.ExternalId != excludeTrackExternalId && !string.IsNullOrEmpty(s.ExternalId))
+            .ToList();
+
+        _logger.LogInformation("Found {Count} additional tracks to download for album '{AlbumTitle}'", 
+            tracksToDownload.Count, album.Title);
+
+        foreach (var track in tracksToDownload)
+        {
+            try
+            {
+                var existingPath = await _localLibraryService.GetLocalPathForExternalSongAsync("qobuz", track.ExternalId!);
+                if (existingPath != null && IOFile.Exists(existingPath))
+                {
+                    _logger.LogDebug("Track {TrackId} already downloaded, skipping", track.ExternalId);
+                    continue;
+                }
+
+                _logger.LogInformation("Downloading track '{Title}' from album '{Album}'", track.Title, album.Title);
+                await DownloadSongInternalAsync("qobuz", track.ExternalId!, triggerAlbumDownload: false, CancellationToken.None);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex, "Failed to download track {TrackId} '{Title}'", track.ExternalId, track.Title);
+            }
+        }
+
+        _logger.LogInformation("Completed background download for album '{AlbumTitle}'", album.Title);
+    }
+
+    #endregion
+
+    #region Qobuz Download Methods
+
+    private async Task<string> DownloadTrackAsync(string trackId, Song song, CancellationToken cancellationToken)
+    {
+        // Get the download URL with signature
+        var downloadInfo = await GetTrackDownloadUrlAsync(trackId, cancellationToken);
+        
+        _logger.LogInformation("Download URL obtained for: {Title} - {Artist}", song.Title, song.Artist);
+        _logger.LogInformation("Quality: {BitDepth}bit/{SamplingRate}kHz, Format: {MimeType}", 
+            downloadInfo.BitDepth, downloadInfo.SamplingRate, downloadInfo.MimeType);
+
+        // Check if it's a demo/sample
+        if (downloadInfo.IsSample)
+        {
+            throw new Exception("Track is only available as a demo/sample");
+        }
+
+        // Determine extension based on MIME type
+        var extension = downloadInfo.MimeType?.Contains("flac") == true ? ".flac" : ".mp3";
+
+        // 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 albumFolder = Path.GetDirectoryName(outputPath)!;
+        EnsureDirectoryExists(albumFolder);
+        
+        outputPath = PathHelper.ResolveUniquePath(outputPath);
+
+        // Download the file (Qobuz files are NOT encrypted like Deezer)
+        var response = await _httpClient.GetAsync(downloadInfo.Url, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
+        response.EnsureSuccessStatusCode();
+
+        await using var responseStream = await response.Content.ReadAsStreamAsync(cancellationToken);
+        await using var outputFile = IOFile.Create(outputPath);
+        
+        await responseStream.CopyToAsync(outputFile, cancellationToken);
+        await outputFile.DisposeAsync();
+        
+        // Write metadata and cover art
+        await WriteMetadataAsync(outputPath, song, cancellationToken);
+
+        return outputPath;
+    }
+
+    /// <summary>
+    /// Gets the download URL for a track with proper MD5 signature
+    /// </summary>
+    private async Task<QobuzDownloadResult> GetTrackDownloadUrlAsync(string trackId, CancellationToken cancellationToken)
+    {
+        var appId = await _bundleService.GetAppIdAsync();
+        var secrets = await _bundleService.GetSecretsAsync();
+        
+        if (secrets.Count == 0)
+        {
+            throw new Exception("No secrets available for signing");
+        }
+        
+        // Determine format ID based on preferred quality
+        var formatId = GetFormatId(_preferredQuality);
+        
+        // Try the preferred quality first, then fallback to lower qualities
+        var formatPriority = GetFormatPriority(formatId);
+        
+        Exception? lastException = null;
+        
+        // Try each secret with each format
+        foreach (var secret in secrets)
+        {
+            var secretIndex = secrets.IndexOf(secret);
+            foreach (var format in formatPriority)
+            {
+                try
+                {
+                    var result = await TryGetTrackDownloadUrlAsync(trackId, format, secret, cancellationToken);
+                    
+                    // Check if quality was downgraded
+                    if (result.WasQualityDowngraded)
+                    {
+                        _logger.LogWarning("Requested quality not available, Qobuz downgraded to {BitDepth}bit/{SamplingRate}kHz",
+                            result.BitDepth, result.SamplingRate);
+                    }
+                    
+                    return result;
+                }
+                catch (Exception ex)
+                {
+                    lastException = ex;
+                    _logger.LogDebug("Failed to get download URL with secret {SecretIndex}, format {Format}: {Error}", 
+                        secretIndex, format, ex.Message);
+                }
+            }
+        }
+        
+        throw new Exception($"Failed to get download URL for all secrets and quality formats", lastException);
+    }
+
+    private async Task<QobuzDownloadResult> TryGetTrackDownloadUrlAsync(string trackId, int formatId, string secret, CancellationToken cancellationToken)
+    {
+        var unix = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+        var appId = await _bundleService.GetAppIdAsync();
+        var signature = ComputeMD5Signature(trackId, formatId, unix, secret);
+        
+        // Build URL with required parameters (app_id goes in header only, not in URL params)
+        var url = $"{BaseUrl}track/getFileUrl?format_id={formatId}&intent=stream&request_ts={unix}&track_id={trackId}&request_sig={signature}";
+        
+        using var request = new HttpRequestMessage(HttpMethod.Get, url);
+        
+        // Add required headers (matching qobuz-dl Python implementation)
+        request.Headers.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0");
+        request.Headers.Add("X-App-Id", appId);
+        
+        if (!string.IsNullOrEmpty(_userAuthToken))
+        {
+            request.Headers.Add("X-User-Auth-Token", _userAuthToken);
+        }
+        
+        var response = await _httpClient.SendAsync(request, cancellationToken);
+        
+        // Read response body
+        var responseBody = await response.Content.ReadAsStringAsync(cancellationToken);
+        
+        // Log error response if not successful
+        if (!response.IsSuccessStatusCode)
+        {
+            _logger.LogDebug("Qobuz getFileUrl failed - Status: {StatusCode}, TrackId: {TrackId}, FormatId: {FormatId}", 
+                response.StatusCode, trackId, formatId);
+            throw new HttpRequestException($"Response status code does not indicate success: {response.StatusCode} ({response.ReasonPhrase})");
+        }
+        
+        var json = responseBody;
+        var doc = JsonDocument.Parse(json);
+        var root = doc.RootElement;
+        
+        if (!root.TryGetProperty("url", out var urlElement) || string.IsNullOrEmpty(urlElement.GetString()))
+        {
+            throw new Exception("No download URL in response");
+        }
+        
+        var downloadUrl = urlElement.GetString()!;
+        var mimeType = root.TryGetProperty("mime_type", out var mime) ? mime.GetString() : null;
+        var bitDepth = root.TryGetProperty("bit_depth", out var bd) ? bd.GetInt32() : 16;
+        var samplingRate = root.TryGetProperty("sampling_rate", out var sr) ? sr.GetDouble() : 44.1;
+        
+        // Check if it's a sample/demo
+        var isSample = root.TryGetProperty("sample", out var sampleEl) && sampleEl.GetBoolean();
+        
+        // If sampling_rate is null/0, it's likely a demo
+        if (samplingRate == 0)
+        {
+            isSample = true;
+        }
+        
+        // Check for quality restrictions/downgrades
+        var wasDowngraded = false;
+        if (root.TryGetProperty("restrictions", out var restrictions))
+        {
+            foreach (var restriction in restrictions.EnumerateArray())
+            {
+                if (restriction.TryGetProperty("code", out var code))
+                {
+                    var codeStr = code.GetString();
+                    if (codeStr == "FormatRestrictedByFormatAvailability")
+                    {
+                        wasDowngraded = true;
+                    }
+                }
+            }
+        }
+        
+        return new QobuzDownloadResult
+        {
+            Url = downloadUrl,
+            FormatId = formatId,
+            MimeType = mimeType,
+            BitDepth = bitDepth,
+            SamplingRate = samplingRate,
+            IsSample = isSample,
+            WasQualityDowngraded = wasDowngraded
+        };
+    }
+
+    /// <summary>
+    /// Computes MD5 signature for track download request
+    /// Format based on qobuz-dl: trackgetFileUrlformat_id{X}intentstreamtrack_id{Y}{TIMESTAMP}{SECRET}
+    /// </summary>
+    private string ComputeMD5Signature(string trackId, int formatId, long timestamp, string secret)
+    {
+        // EXACT format from qobuz-dl Python implementation:
+        // "trackgetFileUrlformat_id{}intentstreamtrack_id{}{}{}".format(fmt_id, track_id, unix, secret)
+        var toSign = $"trackgetFileUrlformat_id{formatId}intentstreamtrack_id{trackId}{timestamp}{secret}";
+        
+        using var md5 = MD5.Create();
+        var hash = md5.ComputeHash(Encoding.UTF8.GetBytes(toSign));
+        var signature = BitConverter.ToString(hash).Replace("-", "").ToLowerInvariant();
+        
+        return signature;
+    }
+
+    /// <summary>
+    /// Gets the format ID based on quality preference
+    /// </summary>
+    private int GetFormatId(string? quality)
+    {
+        if (string.IsNullOrEmpty(quality))
+        {
+            return FormatFlac24High; // Default to highest quality
+        }
+        
+        return quality.ToUpperInvariant() switch
+        {
+            "FLAC" => FormatFlac24High,
+            "FLAC_24_HIGH" or "24_192" => FormatFlac24High,
+            "FLAC_24_LOW" or "24_96" => FormatFlac24Low,
+            "FLAC_16" or "CD" => FormatFlac16,
+            "MP3_320" or "MP3" => FormatMp3320,
+            _ => FormatFlac24High
+        };
+    }
+
+    /// <summary>
+    /// Gets the list of format IDs to try in priority order (highest to lowest)
+    /// </summary>
+    private List<int> GetFormatPriority(int preferredFormat)
+    {
+        var allFormats = new List<int> { FormatFlac24High, FormatFlac24Low, FormatFlac16, FormatMp3320 };
+        
+        // Start with preferred format, then try others in descending quality order
+        var priority = new List<int> { preferredFormat };
+        priority.AddRange(allFormats.Where(f => f != preferredFormat));
+        
+        return priority;
+    }
+
+    /// <summary>
+    /// Writes ID3/Vorbis metadata and cover art to the audio file
+    /// </summary>
+    private async Task WriteMetadataAsync(string filePath, Song song, CancellationToken cancellationToken)
+    {
+        try
+        {
+            _logger.LogInformation("Writing metadata to: {Path}", filePath);
+            
+            using var tagFile = TagLib.File.Create(filePath);
+            
+            tagFile.Tag.Title = song.Title;
+            tagFile.Tag.Performers = new[] { song.Artist };
+            tagFile.Tag.Album = song.Album;
+            tagFile.Tag.AlbumArtists = new[] { !string.IsNullOrEmpty(song.AlbumArtist) ? song.AlbumArtist : song.Artist };
+            
+            if (song.Track.HasValue)
+                tagFile.Tag.Track = (uint)song.Track.Value;
+            
+            if (song.TotalTracks.HasValue)
+                tagFile.Tag.TrackCount = (uint)song.TotalTracks.Value;
+            
+            if (song.DiscNumber.HasValue)
+                tagFile.Tag.Disc = (uint)song.DiscNumber.Value;
+            
+            if (song.Year.HasValue)
+                tagFile.Tag.Year = (uint)song.Year.Value;
+            
+            if (!string.IsNullOrEmpty(song.Genre))
+                tagFile.Tag.Genres = new[] { song.Genre };
+            
+            if (song.Bpm.HasValue)
+                tagFile.Tag.BeatsPerMinute = (uint)song.Bpm.Value;
+            
+            if (song.Contributors.Count > 0)
+                tagFile.Tag.Composers = song.Contributors.ToArray();
+            
+            if (!string.IsNullOrEmpty(song.Copyright))
+                tagFile.Tag.Copyright = song.Copyright;
+            
+            var comments = new List<string>();
+            if (!string.IsNullOrEmpty(song.Isrc))
+                comments.Add($"ISRC: {song.Isrc}");
+            
+            if (comments.Count > 0)
+                tagFile.Tag.Comment = string.Join(" | ", comments);
+            
+            // Download and embed cover art
+            var coverUrl = song.CoverArtUrlLarge ?? song.CoverArtUrl;
+            if (!string.IsNullOrEmpty(coverUrl))
+            {
+                try
+                {
+                    var coverData = await DownloadCoverArtAsync(coverUrl, cancellationToken);
+                    if (coverData != null && coverData.Length > 0)
+                    {
+                        var mimeType = coverUrl.Contains(".png") ? "image/png" : "image/jpeg";
+                        var picture = new TagLib.Picture
+                        {
+                            Type = TagLib.PictureType.FrontCover,
+                            MimeType = mimeType,
+                            Description = "Cover",
+                            Data = new TagLib.ByteVector(coverData)
+                        };
+                        tagFile.Tag.Pictures = new TagLib.IPicture[] { picture };
+                        _logger.LogInformation("Cover art embedded: {Size} bytes", coverData.Length);
+                    }
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogWarning(ex, "Failed to download cover art from {Url}", coverUrl);
+                }
+            }
+            
+            tagFile.Save();
+            _logger.LogInformation("Metadata written successfully to: {Path}", filePath);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to write metadata to: {Path}", filePath);
+        }
+    }
+
+    private async Task<byte[]?> DownloadCoverArtAsync(string url, CancellationToken cancellationToken)
+    {
+        try
+        {
+            var response = await _httpClient.GetAsync(url, cancellationToken);
+            response.EnsureSuccessStatusCode();
+            return await response.Content.ReadAsByteArrayAsync(cancellationToken);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Failed to download cover art from {Url}", url);
+            return null;
+        }
+    }
+
+    #endregion
+
+    #region Utility Methods
+
+    private static string? ExtractExternalIdFromAlbumId(string albumId)
+    {
+        const string prefix = "ext-qobuz-album-";
+        if (albumId.StartsWith(prefix))
+        {
+            return albumId[prefix.Length..];
+        }
+        return null;
+    }
+
+    private void EnsureDirectoryExists(string path)
+    {
+        try
+        {
+            if (!Directory.Exists(path))
+            {
+                Directory.CreateDirectory(path);
+                _logger.LogDebug("Created directory: {Path}", path);
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to create directory: {Path}", path);
+            throw;
+        }
+    }
+
+    #endregion
+
+    private class QobuzDownloadResult
+    {
+        public string Url { get; set; } = string.Empty;
+        public int FormatId { get; set; }
+        public string? MimeType { get; set; }
+        public int BitDepth { get; set; }
+        public double SamplingRate { get; set; }
+        public bool IsSample { get; set; }
+        public bool WasQualityDowngraded { get; set; }
+    }
+}

octo-fiesta/Services/QobuzMetadataService.cs

@@ -0,0 +1,641 @@
+using octo_fiesta.Models;
+using System.Text.Json;
+using Microsoft.Extensions.Options;
+
+namespace octo_fiesta.Services;
+
+/// <summary>
+/// Metadata service implementation using the Qobuz API
+/// Uses user authentication token instead of email/password
+/// </summary>
+public class QobuzMetadataService : IMusicMetadataService
+{
+    private readonly HttpClient _httpClient;
+    private readonly SubsonicSettings _settings;
+    private readonly QobuzBundleService _bundleService;
+    private readonly ILogger<QobuzMetadataService> _logger;
+    private readonly string? _userAuthToken;
+    private readonly string? _userId;
+    
+    private const string BaseUrl = "https://www.qobuz.com/api.json/0.2/";
+
+    public QobuzMetadataService(
+        IHttpClientFactory httpClientFactory, 
+        IOptions<SubsonicSettings> settings,
+        IOptions<QobuzSettings> qobuzSettings,
+        QobuzBundleService bundleService,
+        ILogger<QobuzMetadataService> logger)
+    {
+        _httpClient = httpClientFactory.CreateClient();
+        _settings = settings.Value;
+        _bundleService = bundleService;
+        _logger = logger;
+        
+        var qobuzConfig = qobuzSettings.Value;
+        _userAuthToken = qobuzConfig.UserAuthToken;
+        _userId = qobuzConfig.UserId;
+        
+        // Set up default headers
+        _httpClient.DefaultRequestHeaders.Add("User-Agent", 
+            "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0");
+    }
+
+    public async Task<List<Song>> SearchSongsAsync(string query, int limit = 20)
+    {
+        try
+        {
+            var appId = await _bundleService.GetAppIdAsync();
+            var url = $"{BaseUrl}track/search?query={Uri.EscapeDataString(query)}&limit={limit}&app_id={appId}";
+            
+            var response = await GetWithAuthAsync(url);
+            if (!response.IsSuccessStatusCode) return new List<Song>();
+            
+            var json = await response.Content.ReadAsStringAsync();
+            var result = JsonDocument.Parse(json);
+            
+            var songs = new List<Song>();
+            if (result.RootElement.TryGetProperty("tracks", out var tracks) &&
+                tracks.TryGetProperty("items", out var items))
+            {
+                foreach (var track in items.EnumerateArray())
+                {
+                    var song = ParseQobuzTrack(track);
+                    if (ShouldIncludeSong(song))
+                    {
+                        songs.Add(song);
+                    }
+                }
+            }
+            
+            return songs;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to search songs for query: {Query}", query);
+            return new List<Song>();
+        }
+    }
+
+    public async Task<List<Album>> SearchAlbumsAsync(string query, int limit = 20)
+    {
+        try
+        {
+            var appId = await _bundleService.GetAppIdAsync();
+            var url = $"{BaseUrl}album/search?query={Uri.EscapeDataString(query)}&limit={limit}&app_id={appId}";
+            
+            var response = await GetWithAuthAsync(url);
+            if (!response.IsSuccessStatusCode) return new List<Album>();
+            
+            var json = await response.Content.ReadAsStringAsync();
+            var result = JsonDocument.Parse(json);
+            
+            var albums = new List<Album>();
+            if (result.RootElement.TryGetProperty("albums", out var albumsData) &&
+                albumsData.TryGetProperty("items", out var items))
+            {
+                foreach (var album in items.EnumerateArray())
+                {
+                    albums.Add(ParseQobuzAlbum(album));
+                }
+            }
+            
+            return albums;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to search albums for query: {Query}", query);
+            return new List<Album>();
+        }
+    }
+
+    public async Task<List<Artist>> SearchArtistsAsync(string query, int limit = 20)
+    {
+        try
+        {
+            var appId = await _bundleService.GetAppIdAsync();
+            var url = $"{BaseUrl}artist/search?query={Uri.EscapeDataString(query)}&limit={limit}&app_id={appId}";
+            
+            var response = await GetWithAuthAsync(url);
+            if (!response.IsSuccessStatusCode) return new List<Artist>();
+            
+            var json = await response.Content.ReadAsStringAsync();
+            var result = JsonDocument.Parse(json);
+            
+            var artists = new List<Artist>();
+            if (result.RootElement.TryGetProperty("artists", out var artistsData) &&
+                artistsData.TryGetProperty("items", out var items))
+            {
+                foreach (var artist in items.EnumerateArray())
+                {
+                    artists.Add(ParseQobuzArtist(artist));
+                }
+            }
+            
+            return artists;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to search artists for query: {Query}", query);
+            return new List<Artist>();
+        }
+    }
+
+    public async Task<SearchResult> SearchAllAsync(string query, int songLimit = 20, int albumLimit = 20, int artistLimit = 20)
+    {
+        var songsTask = SearchSongsAsync(query, songLimit);
+        var albumsTask = SearchAlbumsAsync(query, albumLimit);
+        var artistsTask = SearchArtistsAsync(query, artistLimit);
+        
+        await Task.WhenAll(songsTask, albumsTask, artistsTask);
+        
+        return new SearchResult
+        {
+            Songs = await songsTask,
+            Albums = await albumsTask,
+            Artists = await artistsTask
+        };
+    }
+
+    public async Task<Song?> GetSongAsync(string externalProvider, string externalId)
+    {
+        if (externalProvider != "qobuz") return null;
+        
+        try
+        {
+            var appId = await _bundleService.GetAppIdAsync();
+            var url = $"{BaseUrl}track/get?track_id={externalId}&app_id={appId}";
+            
+            var response = await GetWithAuthAsync(url);
+            if (!response.IsSuccessStatusCode) return null;
+            
+            var json = await response.Content.ReadAsStringAsync();
+            var track = JsonDocument.Parse(json).RootElement;
+            
+            if (track.TryGetProperty("error", out _)) return null;
+            
+            return ParseQobuzTrackFull(track);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to get song {ExternalId}", externalId);
+            return null;
+        }
+    }
+
+    public async Task<Album?> GetAlbumAsync(string externalProvider, string externalId)
+    {
+        if (externalProvider != "qobuz") return null;
+        
+        try
+        {
+            var appId = await _bundleService.GetAppIdAsync();
+            var url = $"{BaseUrl}album/get?album_id={externalId}&app_id={appId}";
+            
+            var response = await GetWithAuthAsync(url);
+            if (!response.IsSuccessStatusCode) return null;
+            
+            var json = await response.Content.ReadAsStringAsync();
+            var albumElement = JsonDocument.Parse(json).RootElement;
+            
+            if (albumElement.TryGetProperty("error", out _)) return null;
+            
+            var album = ParseQobuzAlbum(albumElement);
+            
+            // Get album tracks
+            if (albumElement.TryGetProperty("tracks", out var tracks) &&
+                tracks.TryGetProperty("items", out var tracksData))
+            {
+                foreach (var track in tracksData.EnumerateArray())
+                {
+                    var song = ParseQobuzTrack(track);
+                    if (ShouldIncludeSong(song))
+                    {
+                        album.Songs.Add(song);
+                    }
+                }
+            }
+            
+            return album;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to get album {ExternalId}", externalId);
+            return null;
+        }
+    }
+
+    public async Task<Artist?> GetArtistAsync(string externalProvider, string externalId)
+    {
+        if (externalProvider != "qobuz") return null;
+        
+        try
+        {
+            var appId = await _bundleService.GetAppIdAsync();
+            var url = $"{BaseUrl}artist/get?artist_id={externalId}&app_id={appId}";
+            
+            var response = await GetWithAuthAsync(url);
+            if (!response.IsSuccessStatusCode) return null;
+            
+            var json = await response.Content.ReadAsStringAsync();
+            var artist = JsonDocument.Parse(json).RootElement;
+            
+            if (artist.TryGetProperty("error", out _)) return null;
+            
+            return ParseQobuzArtist(artist);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to get artist {ExternalId}", externalId);
+            return null;
+        }
+    }
+
+    public async Task<List<Album>> GetArtistAlbumsAsync(string externalProvider, string externalId)
+    {
+        if (externalProvider != "qobuz") return new List<Album>();
+        
+        try
+        {
+            var albums = new List<Album>();
+            var appId = await _bundleService.GetAppIdAsync();
+            int offset = 0;
+            const int limit = 500;
+            
+            // Qobuz requires pagination for artist albums
+            while (true)
+            {
+                var url = $"{BaseUrl}artist/get?artist_id={externalId}&app_id={appId}&limit={limit}&offset={offset}&extra=albums";
+                
+                var response = await GetWithAuthAsync(url);
+                if (!response.IsSuccessStatusCode) break;
+                
+                var json = await response.Content.ReadAsStringAsync();
+                var result = JsonDocument.Parse(json);
+                
+                if (!result.RootElement.TryGetProperty("albums", out var albumsData) ||
+                    !albumsData.TryGetProperty("items", out var items))
+                {
+                    break;
+                }
+                
+                var itemsArray = items.EnumerateArray().ToList();
+                if (itemsArray.Count == 0) break;
+                
+                foreach (var album in itemsArray)
+                {
+                    albums.Add(ParseQobuzAlbum(album));
+                }
+                
+                // If we got less than the limit, we've reached the end
+                if (itemsArray.Count < limit) break;
+                
+                offset += limit;
+            }
+            
+            return albums;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to get artist albums for {ExternalId}", externalId);
+            return new List<Album>();
+        }
+    }
+
+    /// <summary>
+    /// Safely gets an ID value as a string, handling both number and string types from JSON
+    /// </summary>
+    private string GetIdAsString(JsonElement element)
+    {
+        return element.ValueKind switch
+        {
+            JsonValueKind.Number => element.GetInt64().ToString(),
+            JsonValueKind.String => element.GetString() ?? "",
+            _ => ""
+        };
+    }
+
+    /// <summary>
+    /// Makes an HTTP GET request with Qobuz authentication headers
+    /// </summary>
+    private async Task<HttpResponseMessage> GetWithAuthAsync(string url)
+    {
+        using var request = new HttpRequestMessage(HttpMethod.Get, url);
+        
+        var appId = await _bundleService.GetAppIdAsync();
+        request.Headers.Add("X-App-Id", appId);
+        
+        if (!string.IsNullOrEmpty(_userAuthToken))
+        {
+            request.Headers.Add("X-User-Auth-Token", _userAuthToken);
+        }
+        
+        return await _httpClient.SendAsync(request);
+    }
+
+    private Song ParseQobuzTrack(JsonElement track)
+    {
+        var externalId = GetIdAsString(track.GetProperty("id"));
+        
+        var title = track.GetProperty("title").GetString() ?? "";
+        
+        // Add version to title if present (e.g., "Remastered", "Live")
+        if (track.TryGetProperty("version", out var version))
+        {
+            var versionStr = version.GetString();
+            if (!string.IsNullOrEmpty(versionStr))
+            {
+                title = $"{title} ({versionStr})";
+            }
+        }
+        
+        // For classical music, prepend work name
+        if (track.TryGetProperty("work", out var work))
+        {
+            var workStr = work.GetString();
+            if (!string.IsNullOrEmpty(workStr))
+            {
+                title = $"{workStr}: {title}";
+            }
+        }
+        
+        var performerName = track.TryGetProperty("performer", out var performer)
+            ? performer.GetProperty("name").GetString() ?? ""
+            : "";
+        
+        var albumTitle = track.TryGetProperty("album", out var album)
+            ? album.GetProperty("title").GetString() ?? ""
+            : "";
+        
+        var albumId = track.TryGetProperty("album", out var albumForId)
+            ? $"ext-qobuz-album-{GetIdAsString(albumForId.GetProperty("id"))}"
+            : null;
+        
+        // Get album artist
+        var albumArtist = track.TryGetProperty("album", out var albumForArtist) &&
+                          albumForArtist.TryGetProperty("artist", out var albumArtistEl)
+            ? albumArtistEl.GetProperty("name").GetString()
+            : performerName;
+        
+        return new Song
+        {
+            Id = $"ext-qobuz-song-{externalId}",
+            Title = title,
+            Artist = performerName,
+            ArtistId = track.TryGetProperty("performer", out var performerForId)
+                ? $"ext-qobuz-artist-{GetIdAsString(performerForId.GetProperty("id"))}"
+                : null,
+            Album = albumTitle,
+            AlbumId = albumId,
+            AlbumArtist = albumArtist,
+            Duration = track.TryGetProperty("duration", out var duration)
+                ? duration.GetInt32()
+                : null,
+            Track = track.TryGetProperty("track_number", out var trackNum)
+                ? trackNum.GetInt32()
+                : null,
+            DiscNumber = track.TryGetProperty("media_number", out var mediaNum)
+                ? mediaNum.GetInt32()
+                : null,
+            CoverArtUrl = GetCoverArtUrl(track),
+            IsLocal = false,
+            ExternalProvider = "qobuz",
+            ExternalId = externalId
+        };
+    }
+
+    private Song ParseQobuzTrackFull(JsonElement track)
+    {
+        var song = ParseQobuzTrack(track);
+        
+        // Add additional metadata for full track
+        if (track.TryGetProperty("composer", out var composer) &&
+            composer.TryGetProperty("name", out var composerName))
+        {
+            song.Contributors = new List<string> { composerName.GetString() ?? "" };
+        }
+        
+        if (track.TryGetProperty("isrc", out var isrc))
+        {
+            song.Isrc = isrc.GetString();
+        }
+        
+        if (track.TryGetProperty("copyright", out var copyright))
+        {
+            song.Copyright = FormatCopyright(copyright.GetString() ?? "");
+        }
+        
+        // Get release date from album
+        if (track.TryGetProperty("album", out var album))
+        {
+            if (album.TryGetProperty("release_date_original", out var releaseDate))
+            {
+                var dateStr = releaseDate.GetString();
+                song.ReleaseDate = dateStr;
+                
+                if (!string.IsNullOrEmpty(dateStr) && dateStr.Length >= 4)
+                {
+                    if (int.TryParse(dateStr.Substring(0, 4), out var year))
+                    {
+                        song.Year = year;
+                    }
+                }
+            }
+            
+            if (album.TryGetProperty("tracks_count", out var tracksCount))
+            {
+                song.TotalTracks = tracksCount.GetInt32();
+            }
+            
+            if (album.TryGetProperty("genres_list", out var genres))
+            {
+                song.Genre = FormatGenres(genres);
+            }
+            
+            // Get large cover art
+            song.CoverArtUrlLarge = GetLargeCoverArtUrl(album);
+        }
+        
+        return song;
+    }
+
+    private Album ParseQobuzAlbum(JsonElement album)
+    {
+        var externalId = GetIdAsString(album.GetProperty("id"));
+        
+        var title = album.GetProperty("title").GetString() ?? "";
+        
+        // Add version to title if present
+        if (album.TryGetProperty("version", out var version))
+        {
+            var versionStr = version.GetString();
+            if (!string.IsNullOrEmpty(versionStr))
+            {
+                title = $"{title} ({versionStr})";
+            }
+        }
+        
+        var artistName = album.TryGetProperty("artist", out var artist)
+            ? artist.GetProperty("name").GetString() ?? ""
+            : "";
+        
+        int? year = null;
+        if (album.TryGetProperty("release_date_original", out var releaseDate))
+        {
+            var dateStr = releaseDate.GetString();
+            if (!string.IsNullOrEmpty(dateStr) && dateStr.Length >= 4)
+            {
+                if (int.TryParse(dateStr.Substring(0, 4), out var y))
+                {
+                    year = y;
+                }
+            }
+        }
+        
+        return new Album
+        {
+            Id = $"ext-qobuz-album-{externalId}",
+            Title = title,
+            Artist = artistName,
+            ArtistId = album.TryGetProperty("artist", out var artistForId)
+                ? $"ext-qobuz-artist-{GetIdAsString(artistForId.GetProperty("id"))}"
+                : null,
+            Year = year,
+            SongCount = album.TryGetProperty("tracks_count", out var tracksCount)
+                ? tracksCount.GetInt32()
+                : null,
+            CoverArtUrl = GetCoverArtUrl(album),
+            Genre = album.TryGetProperty("genres_list", out var genres)
+                ? FormatGenres(genres)
+                : null,
+            IsLocal = false,
+            ExternalProvider = "qobuz",
+            ExternalId = externalId
+        };
+    }
+
+    private Artist ParseQobuzArtist(JsonElement artist)
+    {
+        var externalId = GetIdAsString(artist.GetProperty("id"));
+        
+        return new Artist
+        {
+            Id = $"ext-qobuz-artist-{externalId}",
+            Name = artist.GetProperty("name").GetString() ?? "",
+            ImageUrl = GetArtistImageUrl(artist),
+            AlbumCount = artist.TryGetProperty("albums_count", out var albumsCount)
+                ? albumsCount.GetInt32()
+                : null,
+            IsLocal = false,
+            ExternalProvider = "qobuz",
+            ExternalId = externalId
+        };
+    }
+
+    /// <summary>
+    /// Extracts cover art URL from track or album element
+    /// </summary>
+    private string? GetCoverArtUrl(JsonElement element)
+    {
+        // For tracks, get album image
+        if (element.TryGetProperty("album", out var album))
+        {
+            element = album;
+        }
+        
+        if (element.TryGetProperty("image", out var image))
+        {
+            // Prefer thumbnail (230x230), fallback to small
+            if (image.TryGetProperty("thumbnail", out var thumbnail))
+            {
+                return thumbnail.GetString();
+            }
+            if (image.TryGetProperty("small", out var small))
+            {
+                return small.GetString();
+            }
+        }
+        
+        return null;
+    }
+
+    /// <summary>
+    /// Gets large cover art URL (600x600 or original)
+    /// </summary>
+    private string? GetLargeCoverArtUrl(JsonElement album)
+    {
+        if (album.TryGetProperty("image", out var image) &&
+            image.TryGetProperty("large", out var large))
+        {
+            var url = large.GetString();
+            // Replace _600.jpg with _org.jpg for original quality
+            return url?.Replace("_600.jpg", "_org.jpg");
+        }
+        
+        return null;
+    }
+
+    /// <summary>
+    /// Gets artist image URL
+    /// </summary>
+    private string? GetArtistImageUrl(JsonElement artist)
+    {
+        if (artist.TryGetProperty("image", out var image) &&
+            image.TryGetProperty("large", out var large))
+        {
+            return large.GetString();
+        }
+        
+        return null;
+    }
+
+    /// <summary>
+    /// Formats Qobuz genre list into a readable string
+    /// Example: ["Pop/Rock", "Pop/Rock→Rock"] becomes "Pop, Rock"
+    /// </summary>
+    private string FormatGenres(JsonElement genresList)
+    {
+        var genres = new List<string>();
+        
+        foreach (var genre in genresList.EnumerateArray())
+        {
+            var genreStr = genre.GetString();
+            if (!string.IsNullOrEmpty(genreStr))
+            {
+                // Extract individual genres from paths like "Pop/Rock→Rock→Alternative"
+                var parts = genreStr.Split(new[] { '/', '→' }, StringSplitOptions.RemoveEmptyEntries);
+                foreach (var part in parts)
+                {
+                    var trimmed = part.Trim();
+                    if (!genres.Contains(trimmed))
+                    {
+                        genres.Add(trimmed);
+                    }
+                }
+            }
+        }
+        
+        return string.Join(", ", genres);
+    }
+
+    /// <summary>
+    /// Formats copyright string
+    /// Replaces (P) with ℗ and (C) with ©
+    /// </summary>
+    private string FormatCopyright(string copyright)
+    {
+        return copyright
+            .Replace("(P)", "℗")
+            .Replace("(C)", "©");
+    }
+
+    /// <summary>
+    /// Determines whether a song should be included based on the explicit content filter setting
+    /// Note: Qobuz doesn't have the same explicit content tagging as Deezer, so this is a no-op for now
+    /// </summary>
+    private bool ShouldIncludeSong(Song song)
+    {
+        // Qobuz API doesn't expose explicit content flags in the same way as Deezer
+        // We could implement this in the future if needed
+        return true;
+    }
+}

octo-fiesta/Services/StartupValidationService.cs

@@ -7,21 +7,24 @@ namespace octo_fiesta.Services;
 
 /// <summary>
 /// Hosted service that validates configuration at startup and logs the results.
-/// Checks connectivity to Subsonic server and validates Deezer ARL token.
+/// Checks connectivity to Subsonic server and validates music service credentials (Deezer or Qobuz).
 /// Uses a dedicated HttpClient without logging to keep console output clean.
 /// </summary>
 public class StartupValidationService : IHostedService
 {
     private readonly IConfiguration _configuration;
     private readonly IOptions<SubsonicSettings> _subsonicSettings;
+    private readonly IOptions<QobuzSettings> _qobuzSettings;
     private readonly HttpClient _httpClient;
 
     public StartupValidationService(
         IConfiguration configuration,
-        IOptions<SubsonicSettings> subsonicSettings)
+        IOptions<SubsonicSettings> subsonicSettings,
+        IOptions<QobuzSettings> qobuzSettings)
     {
         _configuration = configuration;
         _subsonicSettings = subsonicSettings;
+        _qobuzSettings = qobuzSettings;
         // Create a dedicated HttpClient without logging to keep startup output clean
         _httpClient = new HttpClient { Timeout = TimeSpan.FromSeconds(10) };
     }
@@ -35,7 +38,17 @@ public class StartupValidationService : IHostedService
         Console.WriteLine();
 
         await ValidateSubsonicAsync(cancellationToken);
-        await ValidateDeezerArlAsync(cancellationToken);
+        
+        // Validate music service credentials based on configured service
+        var musicService = _subsonicSettings.Value.MusicService;
+        if (musicService == MusicService.Qobuz)
+        {
+            await ValidateQobuzAsync(cancellationToken);
+        }
+        else
+        {
+            await ValidateDeezerArlAsync(cancellationToken);
+        }
 
         Console.WriteLine();
         Console.WriteLine("========================================");
@@ -141,6 +154,112 @@ public class StartupValidationService : IHostedService
         }
     }
 
+    private async Task ValidateQobuzAsync(CancellationToken cancellationToken)
+    {
+        var userAuthToken = _qobuzSettings.Value.UserAuthToken;
+        var userId = _qobuzSettings.Value.UserId;
+        var quality = _qobuzSettings.Value.Quality;
+
+        Console.WriteLine();
+
+        if (string.IsNullOrWhiteSpace(userAuthToken))
+        {
+            WriteStatus("Qobuz UserAuthToken", "NOT CONFIGURED", ConsoleColor.Red);
+            WriteDetail("Set the Qobuz__UserAuthToken environment variable");
+            return;
+        }
+
+        if (string.IsNullOrWhiteSpace(userId))
+        {
+            WriteStatus("Qobuz UserId", "NOT CONFIGURED", ConsoleColor.Red);
+            WriteDetail("Set the Qobuz__UserId environment variable");
+            return;
+        }
+
+        WriteStatus("Qobuz UserAuthToken", MaskSecret(userAuthToken), ConsoleColor.Cyan);
+        WriteStatus("Qobuz UserId", userId, ConsoleColor.Cyan);
+        WriteStatus("Qobuz Quality", quality ?? "auto (highest available)", ConsoleColor.Cyan);
+
+        // Validate token by calling Qobuz API
+        await ValidateQobuzTokenAsync(userAuthToken, userId, cancellationToken);
+    }
+
+    private async Task ValidateQobuzTokenAsync(string userAuthToken, string userId, CancellationToken cancellationToken)
+    {
+        const string fieldName = "Qobuz credentials";
+        
+        try
+        {
+            // First, get the app ID from bundle service (simple check)
+            var bundleUrl = "https://play.qobuz.com/login";
+            var bundleResponse = await _httpClient.GetAsync(bundleUrl, cancellationToken);
+            
+            if (!bundleResponse.IsSuccessStatusCode)
+            {
+                WriteStatus(fieldName, "UNABLE TO VERIFY", ConsoleColor.Yellow);
+                WriteDetail("Could not fetch Qobuz app configuration");
+                return;
+            }
+
+            // Try to validate with a simple API call
+            // We'll use the user favorites endpoint which requires authentication
+            var appId = "798273057"; // Fallback app ID
+            var apiUrl = $"https://www.qobuz.com/api.json/0.2/favorite/getUserFavorites?user_id={userId}&app_id={appId}";
+            
+            using var request = new HttpRequestMessage(HttpMethod.Get, apiUrl);
+            request.Headers.Add("X-App-Id", appId);
+            request.Headers.Add("X-User-Auth-Token", userAuthToken);
+            request.Headers.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0");
+
+            var response = await _httpClient.SendAsync(request, cancellationToken);
+
+            if (!response.IsSuccessStatusCode)
+            {
+                // 401 means invalid token, other errors might be network issues
+                if (response.StatusCode == System.Net.HttpStatusCode.Unauthorized)
+                {
+                    WriteStatus(fieldName, "INVALID", ConsoleColor.Red);
+                    WriteDetail("Token is expired or invalid");
+                }
+                else
+                {
+                    WriteStatus(fieldName, $"HTTP {(int)response.StatusCode}", ConsoleColor.Yellow);
+                    WriteDetail("Unable to verify credentials");
+                }
+                return;
+            }
+
+            var json = await response.Content.ReadAsStringAsync(cancellationToken);
+            
+            // If we got a successful response, credentials are valid
+            if (!string.IsNullOrEmpty(json) && !json.Contains("\"error\""))
+            {
+                WriteStatus(fieldName, "VALID", ConsoleColor.Green);
+                WriteDetail($"User ID: {userId}");
+            }
+            else
+            {
+                WriteStatus(fieldName, "INVALID", ConsoleColor.Red);
+                WriteDetail("Unexpected response from Qobuz");
+            }
+        }
+        catch (TaskCanceledException)
+        {
+            WriteStatus(fieldName, "TIMEOUT", ConsoleColor.Yellow);
+            WriteDetail("Could not reach Qobuz within 10 seconds");
+        }
+        catch (HttpRequestException ex)
+        {
+            WriteStatus(fieldName, "UNREACHABLE", ConsoleColor.Yellow);
+            WriteDetail(ex.Message);
+        }
+        catch (Exception ex)
+        {
+            WriteStatus(fieldName, "ERROR", ConsoleColor.Red);
+            WriteDetail(ex.Message);
+        }
+    }
+
     private async Task ValidateArlTokenAsync(string arl, string label, CancellationToken cancellationToken)
     {
         var fieldName = $"Deezer ARL ({label})";