From 876ec968bd6883dccec2a0a3fb839fd06cdd4063 Mon Sep 17 00:00:00 2001
From: Hazelnoot <acomputerdog@gmail.com>
Date: Fri, 30 May 2025 12:58:35 -0400
Subject: [PATCH] consider duplicate previews where one URL can't be resolved,
 but another URL resolves to a local copy of the same note

---
 .../src/components/SkUrlPreviewGroup.vue      | 26 +++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/packages/frontend/src/components/SkUrlPreviewGroup.vue b/packages/frontend/src/components/SkUrlPreviewGroup.vue
index beba20f783..5175e16cfc 100644
--- a/packages/frontend/src/components/SkUrlPreviewGroup.vue
+++ b/packages/frontend/src/components/SkUrlPreviewGroup.vue
@@ -35,6 +35,7 @@ import { extractUrlFromMfm } from '@/utility/extract-url-from-mfm';
 import { $i } from '@/i';
 import { misskeyApi } from '@/utility/misskey-api';
 import MkUrlPreview from '@/components/MkUrlPreview.vue';
+import { getNoteUrls } from '@/utility/getNoteUrls';
 
 type Summary = Awaited<ReturnType<typeof summaly>> & {
 	haveNoteLocally?: boolean;
@@ -265,6 +266,31 @@ function deduplicatePreviews(previews: Summary[]): Summary[] {
 			return true;
 		}));
 
+	// eslint-disable-next-line no-param-reassign
+	previews = previews
+		// Remove any previews where the note duplicates url
+		.filter((preview, index) => !previews.some((p, i) => {
+			// Skip the current preview (don't count self as duplicate).
+			if (p === preview) return false;
+
+			// Skip if we have a note
+			if (preview.note) return false;
+
+			// Skip if other does not have a note
+			if (!p.note) return false;
+
+			// Skip later previews (keep the earliest instance)
+			if (i > index) return false;
+
+			const noteUrls = getNoteUrls(p.note);
+
+			// Remove if other duplicates our AP URL
+			if (preview.activityPub && noteUrls.includes(preview.activityPub)) return true;
+
+			// Remove if other duplicates our main URL
+			return noteUrls.includes(preview.url);
+		}));
+
 	return previews;
 }