Torrent

Aberwyn/Data/TorrentService.cs

@@ -0,0 +1,159 @@
+using BencodeNET.Parsing;
+using BencodeNET.Torrents;
+using BencodeNET.Objects;
+using System.Text;
+
+public interface ITorrentService
+{
+    Task<TorrentInfo> ParseTorrentAsync(IFormFile file);
+    Task<TorrentInfo> FetchTrackerStatsAsync(TorrentInfo info);
+}
+
+public class TorrentService : ITorrentService
+{
+    private readonly HttpClient _httpClient;
+    private readonly ILogger<TorrentService> _logger;
+    
+    // Kända trackers och deras egenskaper
+    private readonly Dictionary<string, TrackerInfo> _knownTrackers = new()
+    {
+        ["hdts-announce.ru"] = new TrackerInfo 
+        { 
+            Name = "HD-Torrents", 
+            SupportsScraping = true, // Ändrat till true
+            RequiresAuth = false, // Kan fungera utan auth för scraping
+            IsPrivate = true,
+            Notes = "Privat tracker, scraping kan fungera utan inloggning"
+        }
+    };
+
+    public TorrentService(HttpClient httpClient, ILogger<TorrentService> logger)
+    {
+        _httpClient = httpClient;
+        _logger = logger;
+        _httpClient.Timeout = TimeSpan.FromSeconds(10);
+    }
+
+    public async Task<TorrentInfo> ParseTorrentAsync(IFormFile file)
+    {
+        try
+        {
+            using var stream = new MemoryStream();
+            await file.CopyToAsync(stream);
+            stream.Position = 0;
+
+            var parser = new TorrentParser();
+            var torrent = parser.Parse(stream);
+            var infoHash = torrent.GetInfoHashBytes();
+            var announceUrl = torrent.Trackers?.FirstOrDefault()?.FirstOrDefault()?.ToString();
+            
+            return new TorrentInfo
+            {
+                FileName = torrent.DisplayName ?? file.FileName,
+                AnnounceUrl = announceUrl,
+                ScrapeUrl = ConvertAnnounceToScrape(announceUrl),
+                InfoHash = UrlEncodeInfoHash(infoHash),
+                InfoHashBytes = infoHash,
+                Size = torrent.TotalSize
+            };
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Fel vid parsing av torrent-fil");
+            return new TorrentInfo
+            {
+                FileName = file.FileName,
+                ErrorMessage = $"Kunde inte parsa torrent-filen: {ex.Message}"
+            };
+        }
+    }
+
+    public async Task<TorrentInfo> FetchTrackerStatsAsync(TorrentInfo info)
+    {
+        if (string.IsNullOrWhiteSpace(info.ScrapeUrl))
+        {
+            info.ErrorMessage = "Ingen scrape URL tillgänglig";
+            return info;
+        }
+
+        var url = $"{info.ScrapeUrl}?info_hash={info.InfoHash}";
+        _logger.LogInformation("Scraping tracker: {Url}", url);
+
+        try
+        {
+            var data = await _httpClient.GetByteArrayAsync(url);
+            var parser = new BencodeParser();
+            var bdict = parser.Parse<BDictionary>(data);
+
+            if (bdict.TryGetValue("files", out var filesValue) && filesValue is BDictionary files)
+            {
+                if (TryGetStatsFromFiles(files, info.InfoHash, info) ||
+                    TryGetStatsFromFiles(files, Encoding.UTF8.GetString(info.InfoHashBytes), info))
+                {
+                    info.HasTrackerData = true;
+                    return info;
+                }
+                info.ErrorMessage = "Info hash hittades inte i tracker-svaret";
+            }
+            else
+            {
+                info.ErrorMessage = "Inget 'files' objekt i tracker-svaret";
+            }
+        }
+        catch (HttpRequestException ex)
+        {
+            info.ErrorMessage = $"HTTP fel: {ex.Message}";
+            _logger.LogWarning(ex, "HTTP fel vid tracker scraping");
+        }
+        catch (TaskCanceledException)
+        {
+            info.ErrorMessage = "Timeout vid anslutning till tracker";
+            _logger.LogWarning("Timeout vid tracker scraping");
+        }
+        catch (Exception ex)
+        {
+            info.ErrorMessage = $"Fel vid parsing: {ex.Message}";
+            _logger.LogError(ex, "Fel vid tracker scraping");
+        }
+
+        return info;
+    }
+
+    private bool TryGetStatsFromFiles(BDictionary files, string hashKey, TorrentInfo info)
+    {
+        if (files.TryGetValue(hashKey, out var hashEntry) && hashEntry is BDictionary stats)
+        {
+            info.Seeders = stats.TryGetInt("complete") ?? 0;
+            info.Leechers = stats.TryGetInt("incomplete") ?? 0;
+            info.Completed = stats.TryGetInt("downloaded") ?? 0;
+            return true;
+        }
+        return false;
+    }
+
+    private string ConvertAnnounceToScrape(string announceUrl)
+    {
+        if (string.IsNullOrEmpty(announceUrl))
+            return null;
+
+        return announceUrl.Replace("/announce", "/scrape");
+    }
+
+    private string UrlEncodeInfoHash(byte[] infoHash)
+    {
+        var sb = new StringBuilder();
+        foreach (byte b in infoHash)
+        {
+            sb.AppendFormat("%{0:x2}", b);
+        }
+        return sb.ToString();
+    }
+}
+
+public static class BDictionaryExtensions
+{
+    public static int? TryGetInt(this BDictionary dict, string key)
+    {
+        return dict.TryGetValue(key, out var value) && value is BNumber num ? (int?)num.Value : null;
+    }
+}