From ddb22ba6d2a6aacc817b3f81716f4b590d46e923 Mon Sep 17 00:00:00 2001
From: Joseph Milazzo <joseph.v.milazzo@gmail.com>
Date: Sun, 8 Sep 2024 16:12:04 -0500
Subject: [PATCH] Fixed a bug where there could be a duplicate key in OPDS for
 some unique configurations.

---
 API/Controllers/OPDSController.cs | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/API/Controllers/OPDSController.cs b/API/Controllers/OPDSController.cs
index d25321ad8a..b025be4a4a 100644
--- a/API/Controllers/OPDSController.cs
+++ b/API/Controllers/OPDSController.cs
@@ -873,6 +873,7 @@ public async Task<IActionResult> GetSeries(string apiKey, int seriesId)
         feed.Links.Add(CreateLink(FeedLinkRelation.Image, FeedLinkType.Image, $"{baseUrl}api/image/series-cover?seriesId={seriesId}&apiKey={apiKey}"));
 
         var chapterDict = new Dictionary<int, short>();
+        var fileDict = new Dictionary<int, short>();
         var seriesDetail =  await _seriesService.GetSeriesDetail(seriesId, userId);
         foreach (var volume in seriesDetail.Volumes)
         {
@@ -881,12 +882,14 @@ public async Task<IActionResult> GetSeries(string apiKey, int seriesId)
             foreach (var chapter in chaptersForVolume)
             {
                 var chapterId = chapter.Id;
-                if (chapterDict.ContainsKey(chapterId)) continue;
+                if (!chapterDict.TryAdd(chapterId, 0)) continue;
 
                 var chapterDto = _mapper.Map<ChapterDto>(chapter);
                 foreach (var mangaFile in chapter.Files)
                 {
-                    chapterDict.Add(chapterId, 0);
+                    // If a chapter has multiple files that are within one chapter, this dict prevents duplicate key exception
+                    if (!fileDict.TryAdd(mangaFile.Id, 0)) continue;
+
                     feed.Entries.Add(await CreateChapterWithFile(userId, seriesId, volume.Id, chapterId, _mapper.Map<MangaFileDto>(mangaFile), series,
                         chapterDto, apiKey, prefix, baseUrl));
                 }
@@ -905,6 +908,8 @@ public async Task<IActionResult> GetSeries(string apiKey, int seriesId)
             var chapterDto = _mapper.Map<ChapterDto>(chapter);
             foreach (var mangaFile in files)
             {
+                // If a chapter has multiple files that are within one chapter, this dict prevents duplicate key exception
+                if (!fileDict.TryAdd(mangaFile.Id, 0)) continue;
                 feed.Entries.Add(await CreateChapterWithFile(userId, seriesId, chapter.VolumeId, chapter.Id, _mapper.Map<MangaFileDto>(mangaFile), series,
                     chapterDto, apiKey, prefix, baseUrl));
             }
@@ -916,6 +921,9 @@ public async Task<IActionResult> GetSeries(string apiKey, int seriesId)
             var chapterDto = _mapper.Map<ChapterDto>(special);
             foreach (var mangaFile in files)
             {
+                // If a chapter has multiple files that are within one chapter, this dict prevents duplicate key exception
+                if (!fileDict.TryAdd(mangaFile.Id, 0)) continue;
+
                 feed.Entries.Add(await CreateChapterWithFile(userId, seriesId, special.VolumeId, special.Id, _mapper.Map<MangaFileDto>(mangaFile), series,
                     chapterDto, apiKey, prefix, baseUrl));
             }