feat: implement iTunes API for release year detection and bulk refresh

lib/itunes.ts

@@ -0,0 +1,79 @@
+
+/**
+ * iTunes Search API integration for fetching release years
+ * API Documentation: https://performance-partners.apple.com/search-api
+ */
+
+interface ItunesResult {
+    wrapperType: string;
+    kind: string;
+    artistName: string;
+    collectionName: string;
+    trackName: string;
+    releaseDate: string;
+    primaryGenreName: string;
+}
+
+interface ItunesResponse {
+    resultCount: number;
+    results: ItunesResult[];
+}
+
+/**
+ * Get the earliest release year for a song from iTunes
+ * @param artist Artist name
+ * @param title Song title
+ * @returns Release year or null if not found
+ */
+export async function getReleaseYearFromItunes(artist: string, title: string): Promise<number | null> {
+    try {
+        // Construct search URL
+        // entity=song ensures we get individual tracks
+        // limit=10 to get a good range of potential matches (originals, remasters, best ofs)
+        const term = encodeURIComponent(`${artist} ${title}`);
+        const url = `https://itunes.apple.com/search?term=${term}&entity=song&limit=10`;
+
+        const response = await fetch(url);
+
+        if (!response.ok) {
+            console.error(`iTunes API error: ${response.status} ${response.statusText}`);
+            return null;
+        }
+
+        const data: ItunesResponse = await response.json();
+
+        if (data.resultCount === 0) {
+            return null;
+        }
+
+        // Filter for exact(ish) matches to avoid wrong songs
+        // and find the earliest release date
+        let earliestYear: number | null = null;
+        const normalizedTitle = title.toLowerCase().replace(/[^\w\s]/g, '');
+        const normalizedArtist = artist.toLowerCase().replace(/[^\w\s]/g, '');
+
+        for (const result of data.results) {
+            // Basic validation that it's the right song
+            const resTitle = result.trackName.toLowerCase().replace(/[^\w\s]/g, '');
+            const resArtist = result.artistName.toLowerCase().replace(/[^\w\s]/g, '');
+
+            // Check if title and artist are contained in the result (fuzzy match)
+            if (resTitle.includes(normalizedTitle) && resArtist.includes(normalizedArtist)) {
+                if (result.releaseDate) {
+                    const year = new Date(result.releaseDate).getFullYear();
+                    if (!isNaN(year)) {
+                        if (earliestYear === null || year < earliestYear) {
+                            earliestYear = year;
+                        }
+                    }
+                }
+            }
+        }
+
+        return earliestYear;
+
+    } catch (error) {
+        console.error(`Error fetching release year from iTunes for "${title}" by "${artist}":`, error);
+        return null;
+    }
+}