fix(podcasts): replace dead Castos search with iTunes Search API

Castos retired its admin-ajax feed lookup (now 405) and moved the
RSS finder behind a Cloudflare Turnstile challenge that backend
requests can't satisfy, so podcast Discover returned no results.
Switch searchPodcasts() to the free, keyless Apple/iTunes Search API.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: ralyodio

src/app/podcasts/podcasts-content.tsx

@@ -5,7 +5,7 @@
  *
  * Podcast discovery and subscription management.
  * Features:
- * - Search podcasts via Castos API
+ * - Search podcasts via the Apple Podcasts / iTunes Search API
  * - Subscribe to podcasts (saved in Supabase)
  * - View subscribed podcasts and episodes
  * - Audio player for podcast episodes (global, persists across routes)

src/lib/podcasts/service.test.ts

@@ -52,30 +52,30 @@ describe('PodcastService', () => {
   });
 
   describe('searchPodcasts', () => {
-    it('should search podcasts using Castos API', async () => {
-      const mockCastosResponse = {
-        success: true,
-        data: [
+    it('should search podcasts using the iTunes Search API', async () => {
+      const mockItunesResponse = {
+        resultCount: 2,
+        results: [
           {
-            title: 'Test Podcast',
-            author: 'Test Author',
-            description: 'A test podcast description',
-            image: 'https://example.com/image.jpg',
-            url: 'https://example.com/feed.xml',
+            collectionName: 'Test Podcast',
+            artistName: 'Test Author',
+            artworkUrl600: 'https://example.com/image.jpg',
+            feedUrl: 'https://example.com/feed.xml',
+            collectionViewUrl: 'https://podcasts.apple.com/test',
           },
           {
-            title: 'Another Podcast',
-            author: 'Another Author',
-            description: 'Another description',
-            image: 'https://example.com/image2.jpg',
-            url: 'https://example.com/feed2.xml',
+            collectionName: 'Another Podcast',
+            artistName: 'Another Author',
+            artworkUrl600: 'https://example.com/image2.jpg',
+            feedUrl: 'https://example.com/feed2.xml',
+            collectionViewUrl: 'https://podcasts.apple.com/another',
           },
         ],
       };
 
       mockFetch.mockResolvedValueOnce({
         ok: true,
-        json: () => Promise.resolve(mockCastosResponse),
+        json: () => Promise.resolve(mockItunesResponse),
       });
 
       const results = await service.searchPodcasts('test');
@@ -84,17 +84,16 @@ describe('PodcastService', () => {
       expect(results[0]).toEqual({
         title: 'Test Podcast',
         author: 'Test Author',
-        description: 'A test podcast description',
+        description: null,
         imageUrl: 'https://example.com/image.jpg',
         feedUrl: 'https://example.com/feed.xml',
-        websiteUrl: null,
+        websiteUrl: 'https://podcasts.apple.com/test',
       });
-      expect(mockFetch).toHaveBeenCalledWith(
-        'https://castos.com/wp-admin/admin-ajax.php',
-        expect.objectContaining({
-          method: 'POST',
-        })
-      );
+      const [calledUrl, calledOptions] = mockFetch.mock.calls[0];
+      expect(calledUrl).toContain('https://itunes.apple.com/search');
+      expect(calledUrl).toContain('media=podcast');
+      expect(calledUrl).toContain('term=test');
+      expect(calledOptions).toMatchObject({ method: 'GET' });
     });
 
     it('should return empty array when search fails', async () => {
@@ -111,7 +110,7 @@ describe('PodcastService', () => {
     it('should handle empty search results', async () => {
       mockFetch.mockResolvedValueOnce({
         ok: true,
-        json: () => Promise.resolve({ success: true, data: [] }),
+        json: () => Promise.resolve({ resultCount: 0, results: [] }),
       });
 
       const results = await service.searchPodcasts('nonexistent');
@@ -122,46 +121,46 @@ describe('PodcastService', () => {
     it('should sanitize search query', async () => {
       mockFetch.mockResolvedValueOnce({
         ok: true,
-        json: () => Promise.resolve({ success: true, data: [] }),
+        json: () => Promise.resolve({ resultCount: 0, results: [] }),
       });
 
       await service.searchPodcasts('test <script>alert("xss")</script>');
 
-      // Verify the FormData was created with sanitized input
-      expect(mockFetch).toHaveBeenCalled();
+      // The query is sanitized (script tags/special chars stripped) before being
+      // placed in the request URL.
+      const [calledUrl] = mockFetch.mock.calls[0];
+      expect(calledUrl).not.toContain('script');
+      expect(calledUrl).not.toContain('%3C'); // no encoded '<'
     });
 
-    it('should filter out results without url', async () => {
-      const mockCastosResponse = {
-        success: true,
-        data: [
+    it('should filter out results without a feed url', async () => {
+      const mockItunesResponse = {
+        resultCount: 3,
+        results: [
           {
-            title: 'Valid Podcast',
-            author: 'Author',
-            description: 'Description',
-            image: 'https://example.com/image.jpg',
-            url: 'https://example.com/feed.xml',
+            collectionName: 'Valid Podcast',
+            artistName: 'Author',
+            artworkUrl600: 'https://example.com/image.jpg',
+            feedUrl: 'https://example.com/feed.xml',
           },
           {
-            title: 'Invalid Podcast - No URL',
-            author: 'Author',
-            description: 'Description',
-            image: 'https://example.com/image2.jpg',
-            // Missing url
+            collectionName: 'Invalid Podcast - No feedUrl',
+            artistName: 'Author',
+            artworkUrl600: 'https://example.com/image2.jpg',
+            // Missing feedUrl
           },
           {
-            title: 'Invalid Podcast - Empty URL',
-            author: 'Author',
-            description: 'Description',
-            image: 'https://example.com/image3.jpg',
-            url: '',
+            collectionName: 'Invalid Podcast - Empty feedUrl',
+            artistName: 'Author',
+            artworkUrl600: 'https://example.com/image3.jpg',
+            feedUrl: '',
           },
         ],
       };
 
       mockFetch.mockResolvedValueOnce({
         ok: true,
-        json: () => Promise.resolve(mockCastosResponse),
+        json: () => Promise.resolve(mockItunesResponse),
       });
 
       const results = await service.searchPodcasts('test');
@@ -171,29 +170,34 @@ describe('PodcastService', () => {
       expect(results[0].feedUrl).toBe('https://example.com/feed.xml');
     });
 
-    it('should handle url field from Castos API', async () => {
-      const mockCastosResponse = {
-        success: true,
-        data: [
+    it('should fall back to trackName and artworkUrl100 when collection fields are absent', async () => {
+      const mockItunesResponse = {
+        resultCount: 1,
+        results: [
           {
-            title: 'Podcast with url',
-            author: 'Author',
-            description: 'Description',
-            image: 'https://example.com/image.jpg',
-            url: 'https://example.com/feed.xml',
+            trackName: 'Track-named Podcast',
+            artworkUrl100: 'https://example.com/image100.jpg',
+            feedUrl: 'https://example.com/feed.xml',
           },
         ],
       };
 
       mockFetch.mockResolvedValueOnce({
         ok: true,
-        json: () => Promise.resolve(mockCastosResponse),
+        json: () => Promise.resolve(mockItunesResponse),
       });
 
       const results = await service.searchPodcasts('test');
 
       expect(results).toHaveLength(1);
-      expect(results[0].feedUrl).toBe('https://example.com/feed.xml');
+      expect(results[0]).toEqual({
+        title: 'Track-named Podcast',
+        author: null,
+        description: null,
+        imageUrl: 'https://example.com/image100.jpg',
+        feedUrl: 'https://example.com/feed.xml',
+        websiteUrl: null,
+      });
     });
   });
 

src/lib/podcasts/service.ts

@@ -120,7 +120,11 @@ export interface PodcastService {
 // Constants
 // ============================================================================
 
-const CASTOS_API_URL = 'https://castos.com/wp-admin/admin-ajax.php';
+// Apple Podcasts / iTunes Search API — free, keyless, server-friendly.
+// Replaced the Castos lookup tool, which moved behind a Cloudflare Turnstile
+// challenge that backend (server-to-server) requests cannot satisfy.
+const ITUNES_SEARCH_API_URL = 'https://itunes.apple.com/search';
+const PODCAST_SEARCH_LIMIT = 25;
 const COMPLETION_THRESHOLD = 0.95; // 95% = completed
 
 // ============================================================================
@@ -337,25 +341,29 @@ function parseRssFeed(xml: string): ParsedPodcastFeed | null {
 export function createPodcastService(repository: PodcastRepository): PodcastService {
   return {
     /**
-     * Search podcasts using Castos API
+     * Search podcasts using the Apple Podcasts / iTunes Search API.
+     *
+     * The iTunes Search API is free, requires no API key, and returns the RSS
+     * `feedUrl` we need to subscribe. It does not return a description, so that
+     * field is null here and gets populated from the RSS feed on subscribe.
      */
     async searchPodcasts(query: string): Promise<PodcastSearchResult[]> {
       const sanitizedQuery = sanitizeQuery(query);
       if (!sanitizedQuery) return [];
 
       try {
-        const formData = new FormData();
-        formData.append('search', sanitizedQuery);
-        formData.append('action', 'feed_url_lookup_search');
+        const params = new URLSearchParams({
+          media: 'podcast',
+          entity: 'podcast',
+          limit: String(PODCAST_SEARCH_LIMIT),
+          term: sanitizedQuery,
+        });
 
-        const response = await fetch(CASTOS_API_URL, {
-          method: 'POST',
-          body: formData,
+        const response = await fetch(`${ITUNES_SEARCH_API_URL}?${params.toString()}`, {
+          method: 'GET',
           headers: {
-            'Accept': '*/*',
+            'Accept': 'application/json',
             'User-Agent': 'podcast-search/1.0',
-            'Referer': 'https://castos.com/tools/find-podcast-rss-feed/',
-            'Origin': 'https://castos.com',
           },
         });
 
@@ -364,37 +372,32 @@ export function createPodcastService(repository: PodcastRepository): PodcastServ
         }
 
         const data = await response.json() as {
-          success: boolean;
-          data: Array<{
-            title: string;
-            author?: string;
-            description?: string;
-            image?: string;
-            url?: string;
-            feed_url?: string;
+          resultCount: number;
+          results: Array<{
+            collectionName?: string;
+            trackName?: string;
+            artistName?: string;
             feedUrl?: string;
-            website?: string;
+            artworkUrl600?: string;
+            artworkUrl100?: string;
+            collectionViewUrl?: string;
           }>;
         };
 
-        if (!data.success || !Array.isArray(data.data)) {
+        if (!Array.isArray(data.results)) {
           return [];
         }
 
-        // Filter out results without a valid feed URL and map to our format
-        // Castos API returns 'url' field for the RSS feed URL
-        return data.data
-          .filter(item => {
-            const feedUrl = item.url ?? item.feed_url ?? item.feedUrl;
-            return typeof feedUrl === 'string' && feedUrl.length > 0;
-          })
+        // Only results with a usable RSS feed URL can be subscribed to.
+        return data.results
+          .filter(item => typeof item.feedUrl === 'string' && item.feedUrl.length > 0)
           .map(item => ({
-            title: item.title,
-            author: item.author ?? null,
-            description: item.description ?? null,
-            imageUrl: item.image ?? null,
-            feedUrl: (item.url ?? item.feed_url ?? item.feedUrl) as string,
-            websiteUrl: item.website ?? null,
+            title: item.collectionName ?? item.trackName ?? 'Untitled Podcast',
+            author: item.artistName ?? null,
+            description: null,
+            imageUrl: item.artworkUrl600 ?? item.artworkUrl100 ?? null,
+            feedUrl: item.feedUrl as string,
+            websiteUrl: item.collectionViewUrl ?? null,
           }));
       } catch {
         return [];