From 63209cb828ab75db0cacff1dccb59af86d2d5e94 Mon Sep 17 00:00:00 2001
From: Youwes09 <yuvi.shen@outlook.com>
Date: Tue, 28 Apr 2026 22:45:19 -0500
Subject: [PATCH] Fix: Futile Attempt to Implement Image-Dedupe (#55)

---
 .../series/lib => core/cover}/autoLink.ts     |  0
 .../lib => core/cover}/autoLinkWorker.ts      |  2 +-
 src/core/cover/coverHash.ts                   | 54 +++++++++++
 .../lib => core/cover}/coverResolver.ts       | 25 ++---
 src/core/cover/index.ts                       |  4 +
 .../library/components/LibraryGrid.svelte     |  2 +-
 .../series/components/SeriesDetail.svelte     |  2 +-
 .../series/components/SeriesHeader.svelte     |  2 +-
 src/features/series/lib/coverHash.ts          | 89 ------------------
 .../series/panels/CoverPickerPanel.svelte     | 91 ++++++++++---------
 .../series/panels/SeriesLinkPanel.svelte      |  2 +-
 src/shared/manga/MangaPreview.svelte          |  4 +-
 12 files changed, 124 insertions(+), 153 deletions(-)
 rename src/{features/series/lib => core/cover}/autoLink.ts (100%)
 rename src/{features/series/lib => core/cover}/autoLinkWorker.ts (91%)
 create mode 100644 src/core/cover/coverHash.ts
 rename src/{features/series/lib => core/cover}/coverResolver.ts (79%)
 create mode 100644 src/core/cover/index.ts
 delete mode 100644 src/features/series/lib/coverHash.ts

diff --git a/src/features/series/lib/autoLink.ts b/src/core/cover/autoLink.ts
similarity index 100%
rename from src/features/series/lib/autoLink.ts
rename to src/core/cover/autoLink.ts
diff --git a/src/features/series/lib/autoLinkWorker.ts b/src/core/cover/autoLinkWorker.ts
similarity index 91%
rename from src/features/series/lib/autoLinkWorker.ts
rename to src/core/cover/autoLinkWorker.ts
index 132fd6f..b5bae69 100644
--- a/src/features/series/lib/autoLinkWorker.ts
+++ b/src/core/cover/autoLinkWorker.ts
@@ -22,7 +22,7 @@ self.onmessage = (e: MessageEvent<WorkerMsg>) => {
   for (const m of allManga) {
     if (m.id === focalId) continue;
     if (linkedIds.includes(m.id)) continue;
-    if (titleSimilarity(focalTitle, m.title) >= 0.4) matches.push(m.id);
+    if (titleSimilarity(focalTitle, m.title) >= 0.65) matches.push(m.id);
   }
 
   self.postMessage(matches);
diff --git a/src/core/cover/coverHash.ts b/src/core/cover/coverHash.ts
new file mode 100644
index 0000000..5dbf7c2
--- /dev/null
+++ b/src/core/cover/coverHash.ts
@@ -0,0 +1,54 @@
+const THUMB_SIZE  = 16;
+const DUPE_THRESH = 0.12;
+
+const hashCache = new Map<string, Uint8ClampedArray>();
+
+function toGray(data: Uint8ClampedArray, pixels: number): Uint8ClampedArray {
+  const gray = new Uint8ClampedArray(pixels);
+  for (let i = 0; i < pixels; i++) {
+    const o = i * 4;
+    gray[i] = (data[o] * 299 + data[o + 1] * 587 + data[o + 2] * 114) / 1000;
+  }
+  return gray;
+}
+
+function loadThumb(url: string): Promise<Uint8ClampedArray> {
+  return new Promise((resolve, reject) => {
+    const img = new Image();
+    img.crossOrigin = "anonymous";
+    img.onload = () => {
+      const canvas = document.createElement("canvas");
+      canvas.width = canvas.height = THUMB_SIZE;
+      const ctx = canvas.getContext("2d")!;
+      ctx.drawImage(img, 0, 0, THUMB_SIZE, THUMB_SIZE);
+      resolve(toGray(ctx.getImageData(0, 0, THUMB_SIZE, THUMB_SIZE).data, THUMB_SIZE * THUMB_SIZE));
+    };
+    img.onerror = reject;
+    img.src = url;
+  });
+}
+
+function similarity(a: Uint8ClampedArray, b: Uint8ClampedArray): number {
+  let diff = 0;
+  for (let i = 0; i < a.length; i++) diff += Math.abs(a[i] - b[i]);
+  return diff / (a.length * 255);
+}
+
+export async function getHash(url: string): Promise<Uint8ClampedArray | null> {
+  if (hashCache.has(url)) return hashCache.get(url)!;
+  try {
+    const thumb = await loadThumb(url);
+    hashCache.set(url, thumb);
+    return thumb;
+  } catch {
+    return null;
+  }
+}
+
+export function areDuplicates(a: Uint8ClampedArray, b: Uint8ClampedArray): boolean {
+  return similarity(a, b) <= DUPE_THRESH;
+}
+
+export function clearHashCache(): void {
+  hashCache.clear();
+}
\ No newline at end of file
diff --git a/src/features/series/lib/coverResolver.ts b/src/core/cover/coverResolver.ts
similarity index 79%
rename from src/features/series/lib/coverResolver.ts
rename to src/core/cover/coverResolver.ts
index fc9e375..9dd3912 100644
--- a/src/features/series/lib/coverResolver.ts
+++ b/src/core/cover/coverResolver.ts
@@ -1,6 +1,6 @@
 import { store }                    from "@store/state.svelte";
 import { searchWithScore }          from "@core/algorithms/search";
-import { getHash, areDuplicates }   from "@features/series/lib/coverHash";
+import { getHash, areDuplicates }   from "@core/cover/coverHash";
 
 type CoverManga = { id: number; thumbnailUrl: string; source?: { displayName: string } | null };
 
@@ -11,7 +11,7 @@ export type CoverCandidate = {
   isActive: boolean;
 };
 
-const FUZZY_SCORE_THRESHOLD = 0.5;
+const FUZZY_SCORE_THRESHOLD = 0.65;
 
 function normalizeUrl(url: string): string {
   try {
@@ -76,19 +76,20 @@ export function coverCandidatesSync(
 export async function dedupeByImage(candidates: CoverCandidate[]): Promise<CoverCandidate[]> {
   const hashes = await Promise.all(candidates.map(c => getHash(c.url)));
 
-  const keptIndices: number[] = [];
+  const groups: number[][] = [];
 
   for (let i = 0; i < candidates.length; i++) {
     const hi = hashes[i];
-    if (!hi) { keptIndices.push(i); continue; }
-
-    const isDupe = keptIndices.some(j => {
-      const hj = hashes[j];
-      return hj ? areDuplicates(hi, hj) : false;
-    });
-
-    if (!isDupe) keptIndices.push(i);
+    const existing = hi
+      ? groups.find(g => { const hj = hashes[g[0]]; return hj ? areDuplicates(hi, hj) : false; })
+      : undefined;
+    if (existing) existing.push(i);
+    else groups.push([i]);
   }
 
-  return keptIndices.map(i => candidates[i]);
+  return groups.map(group => {
+    const active = group.find(i => candidates[i].isActive) ?? group[0];
+    const labels = [...new Set(group.map(i => candidates[i].label))];
+    return { ...candidates[active], label: labels.join(" · ") };
+  });
 }
\ No newline at end of file
diff --git a/src/core/cover/index.ts b/src/core/cover/index.ts
new file mode 100644
index 0000000..130da9f
--- /dev/null
+++ b/src/core/cover/index.ts
@@ -0,0 +1,4 @@
+export { getHash, areDuplicates, clearHashCache } from "./coverHash";
+export { resolvedCover, coverCandidatesSync, dedupeByImage } from "./coverResolver";
+export type { CoverCandidate } from "./coverResolver";
+export { autoLinkLibrary } from "./autoLink";
diff --git a/src/features/library/components/LibraryGrid.svelte b/src/features/library/components/LibraryGrid.svelte
index bea2a3e..7aeac42 100644
--- a/src/features/library/components/LibraryGrid.svelte
+++ b/src/features/library/components/LibraryGrid.svelte
@@ -1,7 +1,7 @@
 <script lang="ts">
   import { Folder, Trash, CheckSquare, Robot } from "phosphor-svelte";
   import Thumbnail from "@shared/manga/Thumbnail.svelte";
-  import { resolvedCover } from "@features/series/lib/coverResolver";
+  import { resolvedCover } from "@core/cover/coverResolver";
   import type { Manga, Category } from "@types";
 
   interface Props {
diff --git a/src/features/series/components/SeriesDetail.svelte b/src/features/series/components/SeriesDetail.svelte
index 18c23cc..7e7df88 100644
--- a/src/features/series/components/SeriesDetail.svelte
+++ b/src/features/series/components/SeriesDetail.svelte
@@ -35,7 +35,7 @@
   import ChapterList     from "./ChapterList.svelte";
   import { buildChapterList, chaptersAscending } from "../lib/chapterList";
   import { getPref, setPref } from "../lib/mangaPrefs";
-  import { autoLinkLibrary } from "@features/series/lib/autoLink";
+  import { autoLinkLibrary } from "@core/cover/autoLink";
 
   const CHAPTERS_PER_PAGE = 25;
   const MANGA_TTL_MS      = 5 * 60 * 1000;
diff --git a/src/features/series/components/SeriesHeader.svelte b/src/features/series/components/SeriesHeader.svelte
index ad32056..f8d6aae 100644
--- a/src/features/series/components/SeriesHeader.svelte
+++ b/src/features/series/components/SeriesHeader.svelte
@@ -5,7 +5,7 @@
     MapPin, Gear, Trash, Image,
   } from "phosphor-svelte";
   import Thumbnail   from "@shared/manga/Thumbnail.svelte";
-  import { resolvedCover } from "@features/series/lib/coverResolver";
+  import { resolvedCover } from "@core/cover/coverResolver";
   import type { Manga, Chapter, Category } from "@types";
   import type { MangaPrefs } from "@store/state.svelte";
   import { store, setActiveManga, setGenreFilter, setNavPage, setPreviewManga, linkManga, unlinkManga } from "@store/state.svelte";
diff --git a/src/features/series/lib/coverHash.ts b/src/features/series/lib/coverHash.ts
deleted file mode 100644
index d8a5ceb..0000000
--- a/src/features/series/lib/coverHash.ts
+++ /dev/null
@@ -1,89 +0,0 @@
-import { getBlobUrl } from "@core/cache/imageCache";
-
-const HASH_SIZE    = 8;
-const HASH_PIXELS  = HASH_SIZE * HASH_SIZE;
-const CANVAS_SIZE  = 32;
-const DUPE_THRESH  = 10;
-
-const hashCache = new Map<string, Uint8Array>();
-
-async function loadGrayscale(blobUrl: string): Promise<Uint8ClampedArray> {
-  return new Promise((resolve, reject) => {
-    const img = new Image();
-    img.onload = () => {
-      const canvas = document.createElement("canvas");
-      canvas.width = canvas.height = CANVAS_SIZE;
-      const ctx = canvas.getContext("2d")!;
-      ctx.drawImage(img, 0, 0, CANVAS_SIZE, CANVAS_SIZE);
-      const { data } = ctx.getImageData(0, 0, CANVAS_SIZE, CANVAS_SIZE);
-      const gray = new Uint8ClampedArray(CANVAS_SIZE * CANVAS_SIZE);
-      for (let i = 0; i < gray.length; i++) {
-        const o = i * 4;
-        gray[i] = (data[o] * 299 + data[o + 1] * 587 + data[o + 2] * 114) / 1000;
-      }
-      resolve(gray);
-    };
-    img.onerror = reject;
-    img.src = blobUrl;
-  });
-}
-
-function dct8x8(gray: Uint8ClampedArray): number[] {
-  const N    = CANVAS_SIZE;
-  const step = N / HASH_SIZE;
-  const block: number[] = [];
-
-  for (let by = 0; by < HASH_SIZE; by++) {
-    for (let bx = 0; bx < HASH_SIZE; bx++) {
-      let sum = 0, count = 0;
-      for (let dy = 0; dy < step; dy++) {
-        for (let dx = 0; dx < step; dx++) {
-          sum += gray[(by * step + dy) * N + (bx * step + dx)];
-          count++;
-        }
-      }
-      block.push(sum / count);
-    }
-  }
-  return block;
-}
-
-function pHash(block: number[]): Uint8Array {
-  const mean = block.reduce((a, b) => a + b, 0) / HASH_PIXELS;
-  const bits = new Uint8Array(Math.ceil(HASH_PIXELS / 8));
-  for (let i = 0; i < HASH_PIXELS; i++) {
-    if (block[i] >= mean) bits[i >> 3] |= 1 << (i & 7);
-  }
-  return bits;
-}
-
-function hammingDistance(a: Uint8Array, b: Uint8Array): number {
-  let dist = 0;
-  for (let i = 0; i < a.length; i++) {
-    let x = a[i] ^ b[i];
-    while (x) { dist += x & 1; x >>= 1; }
-  }
-  return dist;
-}
-
-export async function getHash(url: string, priority = -1): Promise<Uint8Array | null> {
-  if (hashCache.has(url)) return hashCache.get(url)!;
-  try {
-    const blob  = await getBlobUrl(url, priority);
-    const gray  = await loadGrayscale(blob);
-    const block = dct8x8(gray);
-    const hash  = pHash(block);
-    hashCache.set(url, hash);
-    return hash;
-  } catch {
-    return null;
-  }
-}
-
-export function areDuplicates(a: Uint8Array, b: Uint8Array): boolean {
-  return hammingDistance(a, b) <= DUPE_THRESH;
-}
-
-export function clearHashCache(): void {
-  hashCache.clear();
-}
\ No newline at end of file
diff --git a/src/features/series/panels/CoverPickerPanel.svelte b/src/features/series/panels/CoverPickerPanel.svelte
index 6a68588..ecd25cb 100644
--- a/src/features/series/panels/CoverPickerPanel.svelte
+++ b/src/features/series/panels/CoverPickerPanel.svelte
@@ -1,7 +1,7 @@
 <script lang="ts">
-  import { X, CaretLeft, CaretRight } from "phosphor-svelte";
+  import { X, CaretLeft, CaretRight, CircleNotch } from "phosphor-svelte";
   import { setPref }                  from "@features/series/lib/mangaPrefs";
-  import { coverCandidatesSync, dedupeByImage } from "@features/series/lib/coverResolver";
+  import { coverCandidatesSync, dedupeByImage } from "@core/cover/coverResolver";
   import Thumbnail                    from "@shared/manga/Thumbnail.svelte";
   import type { Manga }               from "@types";
 
@@ -21,22 +21,19 @@
     coverCandidatesSync(manga.id, manga.title, manga.thumbnailUrl, mangaById)
   );
 
-  let candidates  = $state(syncCandidates);
+  let candidates  = $state<typeof syncCandidates>([]);
   let hashingDone = $state(false);
   let index       = $state(0);
 
   $effect(() => {
     const snap = syncCandidates;
-    candidates  = snap;
+    candidates  = [];
     hashingDone = false;
-    index       = Math.max(0, snap.findIndex(c => c.isActive));
+    index       = 0;
 
-    dedupeByImage(snap).then(deduped => {
-      const activeInDeduped = deduped.some(c => c.isActive);
-      candidates = activeInDeduped
-        ? deduped
-        : (() => { const a = snap.find(c => c.isActive); return a ? [a, ...deduped.filter(c => !c.isActive)] : deduped; })();
-      index       = Math.max(0, candidates.findIndex(c => c.isActive));
+    dedupeByImage(snap).then(merged => {
+      candidates  = merged;
+      index       = Math.max(0, merged.findIndex(c => c.isActive));
       hashingDone = true;
     });
   });
@@ -70,41 +67,44 @@
   <div class="modal" role="dialog" aria-label="Choose cover image" onkeydown={onKeydown}>
     <div class="header">
       <span class="title">Cover Image</span>
-      {#if !hashingDone}
-        <span class="comparing">Comparing…</span>
+<button class="close-btn" onclick={onClose}><X size={14} weight="light" /></button>
+    </div>
+
+    {#if !hashingDone}
+      <div class="loading">
+        <CircleNotch size={24} weight="light" class="anim-spin" style="color:var(--text-faint)" />
+      </div>
+    {:else}
+      <div class="stage">
+        <button class="arrow" onclick={prev} disabled={candidates.length <= 1} aria-label="Previous">
+          <CaretLeft size={18} weight="bold" />
+        </button>
+
+        <div class="cover-wrap">
+          {#if current}
+            <Thumbnail src={current.url} alt="" class="cover-img" />
+          {/if}
+        </div>
+
+        <button class="arrow" onclick={next} disabled={candidates.length <= 1} aria-label="Next">
+          <CaretRight size={18} weight="bold" />
+        </button>
+      </div>
+
+      {#if candidates.length > 1}
+        <div class="filmstrip">
+          {#each candidates as c, i (c.url)}
+            <button
+              class="film-thumb"
+              class:film-active={i === index}
+              onclick={() => index = i}
+              aria-label="Cover {i + 1}"
+            >
+              <Thumbnail src={c.url} alt="" class="film-img" />
+            </button>
+          {/each}
+        </div>
       {/if}
-      <button class="close-btn" onclick={onClose}><X size={14} weight="light" /></button>
-    </div>
-
-    <div class="stage">
-      <button class="arrow" onclick={prev} disabled={candidates.length <= 1} aria-label="Previous">
-        <CaretLeft size={18} weight="bold" />
-      </button>
-
-      <div class="cover-wrap">
-        {#if current}
-          <Thumbnail src={current.url} alt="" class="cover-img" />
-        {/if}
-      </div>
-
-      <button class="arrow" onclick={next} disabled={candidates.length <= 1} aria-label="Next">
-        <CaretRight size={18} weight="bold" />
-      </button>
-    </div>
-
-    {#if candidates.length > 1}
-      <div class="filmstrip">
-        {#each candidates as c, i (c.url)}
-          <button
-            class="film-thumb"
-            class:film-active={i === index}
-            onclick={() => index = i}
-            aria-label="Cover {i + 1}"
-          >
-            <Thumbnail src={c.url} alt="" class="film-img" />
-          </button>
-        {/each}
-      </div>
     {/if}
 
     <div class="footer">
@@ -209,6 +209,7 @@
     transition: opacity var(--t-base);
   }
   .confirm-btn:hover { opacity: 0.88; }
+  .loading { display: flex; align-items: center; justify-content: center; padding: var(--sp-10) 0; }
   @keyframes fadeIn  { from { opacity: 0 }                         to { opacity: 1 } }
   @keyframes scaleIn { from { opacity: 0; transform: scale(0.97) } to { opacity: 1; transform: scale(1) } }
   @keyframes pulse   { 0%, 100% { opacity: 0.4 }                  50% { opacity: 1 } }
diff --git a/src/features/series/panels/SeriesLinkPanel.svelte b/src/features/series/panels/SeriesLinkPanel.svelte
index 36ffb4d..d46031f 100644
--- a/src/features/series/panels/SeriesLinkPanel.svelte
+++ b/src/features/series/panels/SeriesLinkPanel.svelte
@@ -33,7 +33,7 @@
     return others
       .filter(m => !linkedIds.includes(m.id))
       .map(m => ({ manga: m, score: titleSimilarity(manga.title, m.title) }))
-      .filter(r => r.score >= 0.4)
+      .filter(r => r.score >= 0.65)
       .sort((a, b) => b.score - a.score)
       .slice(0, 8);
   });
diff --git a/src/shared/manga/MangaPreview.svelte b/src/shared/manga/MangaPreview.svelte
index 953eb7b..a588f54 100644
--- a/src/shared/manga/MangaPreview.svelte
+++ b/src/shared/manga/MangaPreview.svelte
@@ -14,10 +14,10 @@
     setPreviewManga, setActiveManga, setNavPage, setGenreFilter,
     checkAndMarkCompleted as storeCheckAndMarkCompleted, addBookmark,
   } from "@store/state.svelte";
-  import { resolvedCover } from "@features/series/lib/coverResolver";
+  import { resolvedCover } from "@core/cover/coverResolver";
   import CoverPickerPanel  from "@features/series/panels/CoverPickerPanel.svelte";
   import SeriesLinkPanel   from "@features/series/panels/SeriesLinkPanel.svelte";
-  import { autoLinkLibrary } from "@features/series/lib/autoLink";
+  import { autoLinkLibrary } from "@core/cover/autoLink";
   import type { Manga, Chapter, Category } from "@types/index";