chore: migrated context + series-detail + migrate

src/lib/util.ts

@@ -1,5 +1,59 @@
 import { clsx, type ClassValue } from "clsx";
+import type { Source } from "./types";
 
 export function cn(...inputs: ClassValue[]) {
   return clsx(inputs);
-}
+}
+
+// ── Source deduplication ──────────────────────────────────────────────────────
+
+/**
+ * Deduplicates sources by name, preferring the given language.
+ * This prevents fetching MangaDex EN + MangaDex ES + MangaDex FR separately —
+ * only the preferred-lang variant (or alphabetically first fallback) is kept.
+ */
+export function dedupeSources(sources: Source[], preferredLang: string): Source[] {
+  const byName = new Map<string, Source[]>();
+  for (const src of sources) {
+    if (src.id === "0") continue;
+    if (!byName.has(src.name)) byName.set(src.name, []);
+    byName.get(src.name)!.push(src);
+  }
+  const picked: Source[] = [];
+  for (const group of byName.values()) {
+    const preferred = group.find((s) => s.lang === preferredLang);
+    picked.push(preferred ?? group.sort((a, b) => a.lang.localeCompare(b.lang))[0]);
+  }
+  return picked;
+}
+
+// ── Manga deduplication ───────────────────────────────────────────────────────
+
+/**
+ * Deduplicates manga by title (case-insensitive), keeping the first occurrence.
+ * Use this when merging results across sources — eliminates the same series
+ * appearing multiple times in grids from different source variants.
+ */
+export function dedupeMangaByTitle<T extends { id: number; title: string }>(items: T[]): T[] {
+  const seen = new Set<string>();
+  const out: T[] = [];
+  for (const m of items) {
+    const key = m.title.toLowerCase().trim();
+    if (!seen.has(key)) { seen.add(key); out.push(m); }
+  }
+  return out;
+}
+
+/**
+ * Deduplicates manga by id only (lossless — use when sources are already deduped).
+ * Use this when merging library results with source results for the same query,
+ * where the same manga id may appear in both sets.
+ */
+export function dedupeMangaById<T extends { id: number }>(items: T[]): T[] {
+  const seen = new Set<number>();
+  const out: T[] = [];
+  for (const m of items) {
+    if (!seen.has(m.id)) { seen.add(m.id); out.push(m); }
+  }
+  return out;
+}