feat: implement DeezerDownloadService with Blowfish decryption

- Port JavaScript DeezerDownloader to C# - Add Deezer API authentication with ARL token - Implement track download via media.deezer.com API - Add Blowfish CBC decryption for encrypted chunks (uses OpenSSL) - Add rate limiting and retry with exponential backoff - Update config for Deezer ARL tokens - Configure Subsonic URL to 192.168.1.12:4533
2026-02-09 23:55:10 -05:00 · 2025-12-08 15:12:16 +01:00
parent 6b07ac7646
commit 8aa9c2d437
11 changed files with 732 additions and 393 deletions
--- a/octo-fiesta/Services/DeezerDownloadService.cs
+++ b/octo-fiesta/Services/DeezerDownloadService.cs
@@ -0,0 +1,582 @@
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using octo_fiesta.Models;
+
+namespace octo_fiesta.Services;
+
+/// <summary>
+/// Configuration pour le téléchargeur Deezer
+/// </summary>
+public class DeezerDownloaderSettings
+{
+    public string? Arl { get; set; }
+    public string? ArlFallback { get; set; }
+    public string DownloadPath { get; set; } = "./downloads";
+}
+
+/// <summary>
+/// Port C# du DeezerDownloader JavaScript
+/// Gère l'authentification Deezer, le téléchargement et le déchiffrement des pistes
+/// </summary>
+public class DeezerDownloadService : IDownloadService
+{
+    private readonly HttpClient _httpClient;
+    private readonly IConfiguration _configuration;
+    private readonly ILocalLibraryService _localLibraryService;
+    private readonly IMusicMetadataService _metadataService;
+    private readonly ILogger<DeezerDownloadService> _logger;
+    
+    private readonly string _downloadPath;
+    private readonly string? _arl;
+    private readonly string? _arlFallback;
+    
+    private string? _apiToken;
+    private string? _licenseToken;
+    private bool _usingFallback;
+    
+    private readonly Dictionary<string, DownloadInfo> _activeDownloads = new();
+    private readonly SemaphoreSlim _downloadLock = new(1, 1);
+    private readonly SemaphoreSlim _requestLock = new(1, 1);
+    
+    private DateTime _lastRequestTime = DateTime.MinValue;
+    private readonly int _minRequestIntervalMs = 200;
+    
+    private const string DeezerApiBase = "https://api.deezer.com";
+    private const string BfSecret = "g4el58wc0zvf9na1";
+
+    public DeezerDownloadService(
+        IHttpClientFactory httpClientFactory,
+        IConfiguration configuration,
+        ILocalLibraryService localLibraryService,
+        IMusicMetadataService metadataService,
+        ILogger<DeezerDownloadService> logger)
+    {
+        _httpClient = httpClientFactory.CreateClient();
+        _configuration = configuration;
+        _localLibraryService = localLibraryService;
+        _metadataService = metadataService;
+        _logger = logger;
+        
+        _downloadPath = configuration["Library:DownloadPath"] ?? "./downloads";
+        _arl = configuration["Deezer:Arl"];
+        _arlFallback = configuration["Deezer:ArlFallback"];
+        
+        if (!Directory.Exists(_downloadPath))
+        {
+            Directory.CreateDirectory(_downloadPath);
+        }
+    }
+
+    #region IDownloadService Implementation
+
+    public async Task<string> DownloadSongAsync(string externalProvider, string externalId, CancellationToken cancellationToken = default)
+    {
+        if (externalProvider != "deezer")
+        {
+            throw new NotSupportedException($"Provider '{externalProvider}' is not supported");
+        }
+
+        var songId = $"ext-{externalProvider}-{externalId}";
+        
+        // Vérifier si déjà téléchargé
+        var existingPath = await _localLibraryService.GetLocalPathForExternalSongAsync(externalProvider, externalId);
+        if (existingPath != null && File.Exists(existingPath))
+        {
+            _logger.LogInformation("Song already downloaded: {Path}", existingPath);
+            return existingPath;
+        }
+
+        // Vérifier si téléchargement en cours
+        if (_activeDownloads.TryGetValue(songId, out var activeDownload) && activeDownload.Status == DownloadStatus.InProgress)
+        {
+            _logger.LogInformation("Download already in progress for {SongId}", songId);
+            while (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
+        {
+            // Récupérer les métadonnées
+            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);
+                
+                _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 File.OpenRead(localPath);
+    }
+
+    public DownloadInfo? GetDownloadStatus(string songId)
+    {
+        _activeDownloads.TryGetValue(songId, out var info);
+        return info;
+    }
+
+    public async Task<bool> IsAvailableAsync()
+    {
+        if (string.IsNullOrEmpty(_arl))
+        {
+            _logger.LogWarning("Deezer ARL not configured");
+            return false;
+        }
+
+        try
+        {
+            await InitializeAsync();
+            return true;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Deezer service not available");
+            return false;
+        }
+    }
+
+    #endregion
+
+    #region Deezer API Methods
+
+    private async Task InitializeAsync(string? arlOverride = null)
+    {
+        var arl = arlOverride ?? _arl;
+        if (string.IsNullOrEmpty(arl))
+        {
+            throw new Exception("ARL token required for Deezer downloads");
+        }
+
+        await RetryWithBackoffAsync(async () =>
+        {
+            var request = new HttpRequestMessage(HttpMethod.Post, 
+                "https://www.deezer.com/ajax/gw-light.php?method=deezer.getUserData&input=3&api_version=1.0&api_token=null");
+            
+            request.Headers.Add("Cookie", $"arl={arl}");
+            request.Content = new StringContent("{}", Encoding.UTF8, "application/json");
+
+            var response = await _httpClient.SendAsync(request);
+            response.EnsureSuccessStatusCode();
+
+            var json = await response.Content.ReadAsStringAsync();
+            var doc = JsonDocument.Parse(json);
+
+            if (doc.RootElement.TryGetProperty("results", out var results) &&
+                results.TryGetProperty("checkForm", out var checkForm))
+            {
+                _apiToken = checkForm.GetString();
+                
+                if (results.TryGetProperty("USER", out var user) &&
+                    user.TryGetProperty("OPTIONS", out var options) &&
+                    options.TryGetProperty("license_token", out var licenseToken))
+                {
+                    _licenseToken = licenseToken.GetString();
+                }
+                
+                _logger.LogInformation("Deezer token refreshed: {Token}...", _apiToken?.Substring(0, Math.Min(16, _apiToken?.Length ?? 0)));
+                return true;
+            }
+
+            throw new Exception("Invalid ARL token");
+        });
+    }
+
+    private async Task<DownloadResult> GetTrackDownloadInfoAsync(string trackId, CancellationToken cancellationToken)
+    {
+        var tryDownload = async (string arl) =>
+        {
+            // Refresh token with specific ARL
+            await InitializeAsync(arl);
+
+            return await QueueRequestAsync(async () =>
+            {
+                // Get track info
+                var trackResponse = await _httpClient.GetAsync($"{DeezerApiBase}/track/{trackId}", cancellationToken);
+                trackResponse.EnsureSuccessStatusCode();
+                
+                var trackJson = await trackResponse.Content.ReadAsStringAsync(cancellationToken);
+                var trackDoc = JsonDocument.Parse(trackJson);
+                
+                if (!trackDoc.RootElement.TryGetProperty("track_token", out var trackTokenElement))
+                {
+                    throw new Exception("Track not found or track_token missing");
+                }
+
+                var trackToken = trackTokenElement.GetString();
+                var title = trackDoc.RootElement.GetProperty("title").GetString() ?? "";
+                var artist = trackDoc.RootElement.TryGetProperty("artist", out var artistEl) 
+                    ? artistEl.GetProperty("name").GetString() ?? "" 
+                    : "";
+
+                // Get download URL via media API
+                var mediaRequest = new
+                {
+                    license_token = _licenseToken,
+                    media = new[]
+                    {
+                        new
+                        {
+                            type = "FULL",
+                            formats = new[]
+                            {
+                                new { cipher = "BF_CBC_STRIPE", format = "MP3_128" },
+                                new { cipher = "BF_CBC_STRIPE", format = "MP3_320" },
+                                new { cipher = "BF_CBC_STRIPE", format = "FLAC" }
+                            }
+                        }
+                    },
+                    track_tokens = new[] { trackToken }
+                };
+
+                var mediaHttpRequest = new HttpRequestMessage(HttpMethod.Post, "https://media.deezer.com/v1/get_url");
+                mediaHttpRequest.Content = new StringContent(
+                    JsonSerializer.Serialize(mediaRequest), 
+                    Encoding.UTF8, 
+                    "application/json");
+
+                var mediaResponse = await _httpClient.SendAsync(mediaHttpRequest, cancellationToken);
+                mediaResponse.EnsureSuccessStatusCode();
+
+                var mediaJson = await mediaResponse.Content.ReadAsStringAsync(cancellationToken);
+                var mediaDoc = JsonDocument.Parse(mediaJson);
+
+                if (!mediaDoc.RootElement.TryGetProperty("data", out var data) || 
+                    data.GetArrayLength() == 0)
+                {
+                    throw new Exception("No download URL available");
+                }
+
+                var firstData = data[0];
+                if (!firstData.TryGetProperty("media", out var media) || 
+                    media.GetArrayLength() == 0)
+                {
+                    throw new Exception("No media sources available - track may be unavailable in your region");
+                }
+
+                string? downloadUrl = null;
+                string? format = null;
+
+                foreach (var mediaItem in media.EnumerateArray())
+                {
+                    if (mediaItem.TryGetProperty("sources", out var sources) && 
+                        sources.GetArrayLength() > 0)
+                    {
+                        downloadUrl = sources[0].GetProperty("url").GetString();
+                        format = mediaItem.GetProperty("format").GetString();
+                        break;
+                    }
+                }
+
+                if (string.IsNullOrEmpty(downloadUrl))
+                {
+                    throw new Exception("No download URL found in media sources - track may be region locked");
+                }
+
+                return new DownloadResult
+                {
+                    DownloadUrl = downloadUrl,
+                    Format = format ?? "MP3_128",
+                    Title = title,
+                    Artist = artist
+                };
+            });
+        };
+
+        try
+        {
+            return await tryDownload(_arl!);
+        }
+        catch (Exception ex)
+        {
+            if (!string.IsNullOrEmpty(_arlFallback))
+            {
+                _logger.LogWarning(ex, "Primary ARL failed, trying fallback ARL...");
+                _usingFallback = true;
+                return await tryDownload(_arlFallback);
+            }
+            throw;
+        }
+    }
+
+    private async Task<string> DownloadTrackAsync(string trackId, Song song, CancellationToken cancellationToken)
+    {
+        var downloadInfo = await GetTrackDownloadInfoAsync(trackId, cancellationToken);
+        
+        _logger.LogInformation("Track token obtained for: {Title} - {Artist}", downloadInfo.Title, downloadInfo.Artist);
+        _logger.LogInformation("Using format: {Format}", downloadInfo.Format);
+
+        // Déterminer l'extension basée sur le format
+        var extension = downloadInfo.Format?.ToUpper() switch
+        {
+            "FLAC" => ".flac",
+            _ => ".mp3"
+        };
+
+        // Générer le nom de fichier
+        var safeTitle = SanitizeFileName(song.Title);
+        var safeArtist = SanitizeFileName(song.Artist);
+        var fileName = $"{safeArtist} - {safeTitle}{extension}";
+        var outputPath = Path.Combine(_downloadPath, fileName);
+
+        // Éviter les conflits
+        var counter = 1;
+        while (File.Exists(outputPath))
+        {
+            fileName = $"{safeArtist} - {safeTitle} ({counter}){extension}";
+            outputPath = Path.Combine(_downloadPath, fileName);
+            counter++;
+        }
+
+        // Télécharger le fichier chiffré
+        var response = await RetryWithBackoffAsync(async () =>
+        {
+            var request = new HttpRequestMessage(HttpMethod.Get, downloadInfo.DownloadUrl);
+            request.Headers.Add("User-Agent", "Mozilla/5.0");
+            request.Headers.Add("Accept", "*/*");
+            
+            return await _httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
+        });
+
+        response.EnsureSuccessStatusCode();
+
+        // Télécharger et déchiffrer
+        await using var responseStream = await response.Content.ReadAsStreamAsync(cancellationToken);
+        await using var outputFile = File.Create(outputPath);
+        
+        await DecryptAndWriteStreamAsync(responseStream, outputFile, trackId, cancellationToken);
+
+        return outputPath;
+    }
+
+    #endregion
+
+    #region Decryption
+
+    private byte[] GetBlowfishKey(string trackId)
+    {
+        var hash = MD5.HashData(Encoding.UTF8.GetBytes(trackId));
+        var hashHex = Convert.ToHexString(hash).ToLower();
+        
+        var bfKey = new byte[16];
+        for (int i = 0; i < 16; i++)
+        {
+            bfKey[i] = (byte)(hashHex[i] ^ hashHex[i + 16] ^ BfSecret[i]);
+        }
+        
+        return bfKey;
+    }
+
+    private async Task DecryptAndWriteStreamAsync(
+        Stream input, 
+        Stream output, 
+        string trackId, 
+        CancellationToken cancellationToken)
+    {
+        var bfKey = GetBlowfishKey(trackId);
+        var iv = new byte[] { 0, 1, 2, 3, 4, 5, 6, 7 };
+        
+        var buffer = new byte[2048];
+        int chunkIndex = 0;
+        
+        while (true)
+        {
+            var bytesRead = await ReadExactAsync(input, buffer, cancellationToken);
+            if (bytesRead == 0) break;
+
+            var chunk = buffer.AsSpan(0, bytesRead).ToArray();
+
+            // Chaque 3ème chunk (index % 3 == 0) est chiffré
+            if (chunkIndex % 3 == 0 && bytesRead == 2048)
+            {
+                chunk = DecryptBlowfishCbc(chunk, bfKey, iv);
+            }
+
+            await output.WriteAsync(chunk, cancellationToken);
+            chunkIndex++;
+        }
+    }
+
+    private async Task<int> ReadExactAsync(Stream stream, byte[] buffer, CancellationToken cancellationToken)
+    {
+        int totalRead = 0;
+        while (totalRead < buffer.Length)
+        {
+            var bytesRead = await stream.ReadAsync(buffer.AsMemory(totalRead, buffer.Length - totalRead), cancellationToken);
+            if (bytesRead == 0) break;
+            totalRead += bytesRead;
+        }
+        return totalRead;
+    }
+
+    private byte[] DecryptBlowfishCbc(byte[] data, byte[] key, byte[] iv)
+    {
+        // Note: .NET ne supporte pas nativement Blowfish
+        // On utilise BouncyCastle ou une implémentation custom
+        // Pour l'instant, on utilise un appel à OpenSSL via Process (comme le JS)
+        
+        using var process = new System.Diagnostics.Process();
+        process.StartInfo.FileName = "openssl";
+        process.StartInfo.Arguments = $"enc -d -bf-cbc -K {Convert.ToHexString(key).ToLower()} -iv {Convert.ToHexString(iv).ToLower()} -nopad -provider legacy -provider default";
+        process.StartInfo.RedirectStandardInput = true;
+        process.StartInfo.RedirectStandardOutput = true;
+        process.StartInfo.RedirectStandardError = true;
+        process.StartInfo.UseShellExecute = false;
+        process.StartInfo.CreateNoWindow = true;
+
+        process.Start();
+        
+        using var stdin = process.StandardInput.BaseStream;
+        stdin.Write(data, 0, data.Length);
+        stdin.Close();
+
+        using var stdout = process.StandardOutput.BaseStream;
+        using var ms = new MemoryStream();
+        stdout.CopyTo(ms);
+        
+        process.WaitForExit();
+        
+        if (process.ExitCode != 0)
+        {
+            var error = process.StandardError.ReadToEnd();
+            throw new Exception($"OpenSSL decryption failed: {error}");
+        }
+
+        return ms.ToArray();
+    }
+
+    #endregion
+
+    #region Utility Methods
+
+    private async Task<T> RetryWithBackoffAsync<T>(Func<Task<T>> action, int maxRetries = 3, int initialDelayMs = 1000)
+    {
+        Exception? lastException = null;
+        
+        for (int attempt = 0; attempt < maxRetries; attempt++)
+        {
+            try
+            {
+                return await action();
+            }
+            catch (HttpRequestException ex) when (ex.StatusCode == System.Net.HttpStatusCode.ServiceUnavailable ||
+                                                   ex.StatusCode == System.Net.HttpStatusCode.TooManyRequests)
+            {
+                lastException = ex;
+                if (attempt < maxRetries - 1)
+                {
+                    var delay = initialDelayMs * (int)Math.Pow(2, attempt);
+                    _logger.LogWarning("Retry attempt {Attempt}/{MaxRetries} after {Delay}ms ({Message})", 
+                        attempt + 1, maxRetries, delay, ex.Message);
+                    await Task.Delay(delay);
+                }
+            }
+            catch
+            {
+                throw;
+            }
+        }
+
+        throw lastException!;
+    }
+
+    private async Task RetryWithBackoffAsync(Func<Task<bool>> action, int maxRetries = 3, int initialDelayMs = 1000)
+    {
+        await RetryWithBackoffAsync<bool>(action, maxRetries, initialDelayMs);
+    }
+
+    private async Task<T> QueueRequestAsync<T>(Func<Task<T>> action)
+    {
+        await _requestLock.WaitAsync();
+        try
+        {
+            var now = DateTime.UtcNow;
+            var timeSinceLastRequest = (now - _lastRequestTime).TotalMilliseconds;
+            
+            if (timeSinceLastRequest < _minRequestIntervalMs)
+            {
+                await Task.Delay((int)(_minRequestIntervalMs - timeSinceLastRequest));
+            }
+
+            _lastRequestTime = DateTime.UtcNow;
+            return await action();
+        }
+        finally
+        {
+            _requestLock.Release();
+        }
+    }
+
+    private string SanitizeFileName(string fileName)
+    {
+        var invalidChars = Path.GetInvalidFileNameChars();
+        var sanitized = new string(fileName
+            .Select(c => invalidChars.Contains(c) ? '_' : c)
+            .ToArray());
+        
+        if (sanitized.Length > 100)
+        {
+            sanitized = sanitized.Substring(0, 100);
+        }
+        
+        return sanitized.Trim();
+    }
+
+    #endregion
+
+    private class DownloadResult
+    {
+        public string DownloadUrl { get; set; } = string.Empty;
+        public string Format { get; set; } = string.Empty;
+        public string Title { get; set; } = string.Empty;
+        public string Artist { get; set; } = string.Empty;
+    }
+}
--- a/octo-fiesta/Services/DeezspotDownloadService.cs
+++ b/octo-fiesta/Services/DeezspotDownloadService.cs
@@ -1,244 +0,0 @@
-using octo_fiesta.Models;
-using System.Diagnostics;
-
-namespace octo_fiesta.Services;
-
-/// <summary>
-/// Implémentation du service de téléchargement utilisant Deezspot (ou similaire)
-/// Cette implémentation est un placeholder - à adapter selon l'outil de téléchargement choisi
-/// </summary>
-public class DeezspotDownloadService : IDownloadService
-{
-    private readonly IConfiguration _configuration;
-    private readonly ILocalLibraryService _localLibraryService;
-    private readonly IMusicMetadataService _metadataService;
-    private readonly ILogger<DeezspotDownloadService> _logger;
-    private readonly Dictionary<string, DownloadInfo> _activeDownloads = new();
-    private readonly SemaphoreSlim _downloadLock = new(1, 1);
-    private readonly string _downloadPath;
-    private readonly string? _deezspotPath;
-
-    public DeezspotDownloadService(
-        IConfiguration configuration,
-        ILocalLibraryService localLibraryService,
-        IMusicMetadataService metadataService,
-        ILogger<DeezspotDownloadService> logger)
-    {
-        _configuration = configuration;
-        _localLibraryService = localLibraryService;
-        _metadataService = metadataService;
-        _logger = logger;
-        _downloadPath = configuration["Library:DownloadPath"] ?? Path.Combine(Directory.GetCurrentDirectory(), "downloads");
-        _deezspotPath = configuration["Deezspot:ExecutablePath"];
-        
-        if (!Directory.Exists(_downloadPath))
-        {
-            Directory.CreateDirectory(_downloadPath);
-        }
-    }
-
-    public async Task<string> DownloadSongAsync(string externalProvider, string externalId, CancellationToken cancellationToken = default)
-    {
-        var songId = $"ext-{externalProvider}-{externalId}";
-        
-        // Vérifier si déjà téléchargé
-        var existingPath = await _localLibraryService.GetLocalPathForExternalSongAsync(externalProvider, externalId);
-        if (existingPath != null && File.Exists(existingPath))
-        {
-            return existingPath;
-        }
-
-        // Vérifier si téléchargement en cours
-        if (_activeDownloads.TryGetValue(songId, out var activeDownload) && activeDownload.Status == DownloadStatus.InProgress)
-        {
-            // Attendre la fin du téléchargement en cours
-            while (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
-        {
-            // Récupérer les métadonnées pour le nom de fichier
-            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 ExecuteDownloadAsync(externalProvider, externalId, song, cancellationToken);
-                
-                downloadInfo.Status = DownloadStatus.Completed;
-                downloadInfo.LocalPath = localPath;
-                downloadInfo.CompletedAt = DateTime.UtcNow;
-                
-                // Enregistrer dans la bibliothèque locale
-                song.LocalPath = localPath;
-                await _localLibraryService.RegisterDownloadedSongAsync(song, localPath);
-                
-                return localPath;
-            }
-            catch (Exception ex)
-            {
-                downloadInfo.Status = DownloadStatus.Failed;
-                downloadInfo.ErrorMessage = ex.Message;
-                throw;
-            }
-        }
-        finally
-        {
-            _downloadLock.Release();
-        }
-    }
-
-    public async Task<Stream> DownloadAndStreamAsync(string externalProvider, string externalId, CancellationToken cancellationToken = default)
-    {
-        // Pour le streaming à la volée, on télécharge d'abord le fichier puis on le stream
-        // Une implémentation plus avancée pourrait utiliser des pipes pour streamer pendant le téléchargement
-        var localPath = await DownloadSongAsync(externalProvider, externalId, cancellationToken);
-        return File.OpenRead(localPath);
-    }
-
-    public DownloadInfo? GetDownloadStatus(string songId)
-    {
-        _activeDownloads.TryGetValue(songId, out var info);
-        return info;
-    }
-
-    public async Task<bool> IsAvailableAsync()
-    {
-        if (string.IsNullOrEmpty(_deezspotPath))
-        {
-            _logger.LogWarning("Deezspot path not configured");
-            return false;
-        }
-
-        if (!File.Exists(_deezspotPath))
-        {
-            _logger.LogWarning("Deezspot executable not found at {Path}", _deezspotPath);
-            return false;
-        }
-
-        await Task.CompletedTask;
-        return true;
-    }
-
-    private async Task<string> ExecuteDownloadAsync(string provider, string externalId, Song song, CancellationToken cancellationToken)
-    {
-        // Générer un nom de fichier sécurisé
-        var safeTitle = SanitizeFileName(song.Title);
-        var safeArtist = SanitizeFileName(song.Artist);
-        var fileName = $"{safeArtist} - {safeTitle}.mp3";
-        var outputPath = Path.Combine(_downloadPath, fileName);
-
-        // Éviter les conflits de noms
-        var counter = 1;
-        while (File.Exists(outputPath))
-        {
-            fileName = $"{safeArtist} - {safeTitle} ({counter}).mp3";
-            outputPath = Path.Combine(_downloadPath, fileName);
-            counter++;
-        }
-
-        if (string.IsNullOrEmpty(_deezspotPath))
-        {
-            throw new InvalidOperationException("Deezspot executable path not configured. Set 'Deezspot:ExecutablePath' in configuration.");
-        }
-
-        // Construire la commande Deezspot
-        // Note: La syntaxe exacte dépend de la version de Deezspot utilisée
-        var trackUrl = provider == "deezer" 
-            ? $"https://www.deezer.com/track/{externalId}"
-            : $"https://open.spotify.com/track/{externalId}";
-
-        var processInfo = new ProcessStartInfo
-        {
-            FileName = _deezspotPath,
-            Arguments = $"download \"{trackUrl}\" -o \"{_downloadPath}\"",
-            RedirectStandardOutput = true,
-            RedirectStandardError = true,
-            UseShellExecute = false,
-            CreateNoWindow = true
-        };
-
-        _logger.LogInformation("Starting download: {Command} {Args}", processInfo.FileName, processInfo.Arguments);
-
-        using var process = new Process { StartInfo = processInfo };
-        process.Start();
-
-        var outputTask = process.StandardOutput.ReadToEndAsync();
-        var errorTask = process.StandardError.ReadToEndAsync();
-
-        await process.WaitForExitAsync(cancellationToken);
-
-        var output = await outputTask;
-        var error = await errorTask;
-
-        if (process.ExitCode != 0)
-        {
-            _logger.LogError("Download failed: {Error}", error);
-            throw new Exception($"Download failed: {error}");
-        }
-
-        // Chercher le fichier téléchargé (Deezspot peut utiliser son propre nommage)
-        var downloadedFiles = Directory.GetFiles(_downloadPath, "*.mp3")
-            .OrderByDescending(f => File.GetCreationTime(f))
-            .ToList();
-
-        if (downloadedFiles.Any())
-        {
-            var latestFile = downloadedFiles.First();
-            
-            // Si le fichier a un nom différent, on peut le renommer
-            if (latestFile != outputPath && File.GetCreationTime(latestFile) > DateTime.UtcNow.AddMinutes(-5))
-            {
-                _logger.LogInformation("Downloaded file: {File}", latestFile);
-                return latestFile;
-            }
-        }
-
-        if (File.Exists(outputPath))
-        {
-            return outputPath;
-        }
-
-        throw new Exception("Download completed but file not found");
-    }
-
-    private string SanitizeFileName(string fileName)
-    {
-        var invalidChars = Path.GetInvalidFileNameChars();
-        var sanitized = new string(fileName
-            .Select(c => invalidChars.Contains(c) ? '_' : c)
-            .ToArray());
-        
-        // Limiter la longueur
-        if (sanitized.Length > 100)
-        {
-            sanitized = sanitized.Substring(0, 100);
-        }
-        
-        return sanitized.Trim();
-    }
-}