Fix: Futile Attempt to Implement Image-Dedupe (#55)

src/core/cover/autoLink.ts

@@ -0,0 +1,27 @@
+import { store, linkManga } from "@store/state.svelte";
+import type { Manga } from "@types";
+
+export function autoLinkLibrary(focal: Manga, allManga: Manga[]): Promise<number> {
+  return new Promise((resolve) => {
+    const worker = new Worker(
+      new URL("./autoLinkWorker.ts", import.meta.url),
+      { type: "module" },
+    );
+
+    worker.onmessage = (e: MessageEvent<number[]>) => {
+      const matches = e.data;
+      for (const id of matches) linkManga(focal.id, id);
+      worker.terminate();
+      resolve(matches.length);
+    };
+
+    worker.onerror = () => { worker.terminate(); resolve(0); };
+
+    worker.postMessage({
+      focalTitle: focal.title,
+      focalId:    focal.id,
+      allManga:   allManga.map(m => ({ id: m.id, title: m.title })),
+      linkedIds:  store.settings.mangaLinks?.[focal.id] ?? [],
+    });
+  });
+}

src/core/cover/autoLinkWorker.ts

@@ -0,0 +1,29 @@
+interface WorkerMsg {
+  focalTitle: string;
+  focalId: number;
+  allManga: { id: number; title: string }[];
+  linkedIds: number[];
+}
+
+function titleSimilarity(a: string, b: string): number {
+  const norm = (s: string) =>
+    s.toLowerCase().replace(/[^a-z0-9\s]/g, "").split(/\s+/).filter(Boolean);
+  const wa = new Set(norm(a));
+  const wb = new Set(norm(b));
+  if (!wa.size || !wb.size) return 0;
+  const intersection = [...wa].filter(w => wb.has(w)).length;
+  return intersection / new Set([...wa, ...wb]).size;
+}
+
+self.onmessage = (e: MessageEvent<WorkerMsg>) => {
+  const { focalTitle, focalId, allManga, linkedIds } = e.data;
+  const matches: number[] = [];
+
+  for (const m of allManga) {
+    if (m.id === focalId) continue;
+    if (linkedIds.includes(m.id)) continue;
+    if (titleSimilarity(focalTitle, m.title) >= 0.65) matches.push(m.id);
+  }
+
+  self.postMessage(matches);
+};

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();
+}

src/core/cover/coverResolver.ts

@@ -0,0 +1,95 @@
+import { store }                    from "@store/state.svelte";
+import { searchWithScore }          from "@core/algorithms/search";
+import { getHash, areDuplicates }   from "@core/cover/coverHash";
+
+type CoverManga = { id: number; thumbnailUrl: string; source?: { displayName: string } | null };
+
+export type CoverCandidate = {
+  mangaId:  number;
+  url:      string;
+  label:    string;
+  isActive: boolean;
+};
+
+const FUZZY_SCORE_THRESHOLD = 0.65;
+
+function normalizeUrl(url: string): string {
+  try {
+    const u = new URL(url);
+    u.search = "";
+    return u.href.toLowerCase();
+  } catch {
+    return url.toLowerCase();
+  }
+}
+
+export function resolvedCover(mangaId: number, ownUrl: string): string {
+  return store.settings.mangaPrefs?.[mangaId]?.coverUrl ?? ownUrl;
+}
+
+function fuzzyMatchIds(
+  mangaId:  number,
+  title:    string,
+  mangaById: Map<number, CoverManga & { title: string }>,
+): number[] {
+  const results = searchWithScore(
+    [...mangaById.values()].filter(m => m.id !== mangaId),
+    title,
+    m => m.title,
+  );
+  return results
+    .filter(r => r.score >= FUZZY_SCORE_THRESHOLD)
+    .map(r => r.item.id);
+}
+
+export function coverCandidatesSync(
+  mangaId:   number,
+  title:     string,
+  ownUrl:    string,
+  mangaById: Map<number, CoverManga & { title: string }>,
+): CoverCandidate[] {
+  const linkedIds  = store.getLinkedMangaIds(mangaId);
+  const fuzzyIds   = fuzzyMatchIds(mangaId, title, mangaById);
+  const current    = store.settings.mangaPrefs?.[mangaId]?.coverUrl ?? ownUrl;
+
+  const allIds = Array.from(new Set([...linkedIds, ...fuzzyIds]));
+
+  const raw: { mangaId: number; url: string; label: string }[] = [
+    { mangaId, url: ownUrl, label: "This source" },
+    ...allIds.flatMap(id => {
+      const m = mangaById.get(id);
+      return m ? [{ mangaId: m.id, url: m.thumbnailUrl, label: m.source?.displayName ?? `ID ${m.id}` }] : [];
+    }),
+  ];
+
+  const seen = new Set<string>();
+  return raw
+    .filter(c => {
+      const key = normalizeUrl(c.url);
+      if (seen.has(key)) return false;
+      seen.add(key);
+      return true;
+    })
+    .map(c => ({ ...c, isActive: normalizeUrl(c.url) === normalizeUrl(current) }));
+}
+
+export async function dedupeByImage(candidates: CoverCandidate[]): Promise<CoverCandidate[]> {
+  const hashes = await Promise.all(candidates.map(c => getHash(c.url)));
+
+  const groups: number[][] = [];
+
+  for (let i = 0; i < candidates.length; i++) {
+    const hi = hashes[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 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(" · ") };
+  });
+}

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";