From 0f6920003f64c9f1382f3740290803024838d472 Mon Sep 17 00:00:00 2001
From: ImoutoChan <kirirrin@gmail.com>
Date: Fri, 24 Nov 2023 23:09:03 +0400
Subject: [PATCH] Improve page prediction for yandere history loading

---
 .../Loaders/YandereLoaderTests.cs                  | 14 ++++++++++++++
 .../BooruApiLoaderTagHistoryExtensions.cs          |  9 ++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/Imouto.BooruParser.Tests/Loaders/YandereLoaderTests.cs b/Imouto.BooruParser.Tests/Loaders/YandereLoaderTests.cs
index fdd5b54..2a6ab07 100644
--- a/Imouto.BooruParser.Tests/Loaders/YandereLoaderTests.cs
+++ b/Imouto.BooruParser.Tests/Loaders/YandereLoaderTests.cs
@@ -221,6 +221,20 @@ public async Task ShouldGetTagHistoryFromIdToPresent()
             result.Should().NotBeEmpty();
             result.DistinctBy(x => x.HistoryId).Should().HaveCount(result.Count);
         }
+
+        /// <summary>
+        /// Bug with loading history after 4952686
+        /// </summary>
+        [Fact]
+        public async Task ShouldGetTagHistoryFrom4952686IdToPresent()
+        {
+            var loader = _loaderFixture.GetLoader();
+
+            var result = await loader.GetTagHistoryFromIdToPresentAsync(4952686).ToListAsync();
+
+            result.Should().NotBeEmpty();
+            result.DistinctBy(x => x.HistoryId).Should().HaveCount(result.Count);
+        }
     }
 
     public class GetPopularPostsAsyncMethod : YandereLoaderTests
diff --git a/Imouto.BooruParser/Implementations/BooruApiLoaderTagHistoryExtensions.cs b/Imouto.BooruParser/Implementations/BooruApiLoaderTagHistoryExtensions.cs
index b535612..d2efbca 100644
--- a/Imouto.BooruParser/Implementations/BooruApiLoaderTagHistoryExtensions.cs
+++ b/Imouto.BooruParser/Implementations/BooruApiLoaderTagHistoryExtensions.cs
@@ -44,7 +44,14 @@ public static async IAsyncEnumerable<TagHistoryEntry> GetTagHistoryFromIdToPrese
             var predictedPage = (currentId - afterHistoryId) / 20 + 2;
             
             // validation
-            var page = await loader.GetTagHistoryPageAsync(new SearchToken($"{predictedPage}"), limit, ct);
+            HistorySearchResult<TagHistoryEntry> page;
+            var tries = 10;
+            do
+            {
+                page = await loader.GetTagHistoryPageAsync(new SearchToken($"{predictedPage++}"), limit, ct);
+                tries--;
+            } while (!page.Results.Any() && tries > 0);
+            
             if (page.Results.All(x => x.HistoryId > afterHistoryId))
                 throw new Exception("Prediction failed");