Add feed discovery plugin

plugins/feed-discovery/src/providers/itunes-podcast.ts

@@ -0,0 +1,64 @@
+import type { DiscoveredFeed, FeedDiscoveryConfig, FeedDiscoveryProvider, FeedDiscoveryQuery } from "../types.js";
+
+interface ITunesPodcast {
+  collectionName?: string;
+  artistName?: string;
+  feedUrl?: string;
+  collectionViewUrl?: string;
+  artworkUrl600?: string;
+  primaryGenreName?: string;
+  releaseDate?: string;
+}
+
+export class ITunesPodcastProvider implements FeedDiscoveryProvider {
+  id = "itunes-podcast";
+  name = "iTunes Podcast Search";
+  enabledByDefault = true;
+  requiresApiKey = false;
+
+  constructor(private readonly config: Pick<FeedDiscoveryConfig, "requestTimeoutMs" | "userAgent">) {}
+
+  async search(query: FeedDiscoveryQuery) {
+    if (query.type && query.type !== "all" && query.type !== "podcast") {
+      return [];
+    }
+
+    const url = new URL("https://itunes.apple.com/search");
+    url.searchParams.set("term", query.q);
+    url.searchParams.set("entity", "podcast");
+    url.searchParams.set("limit", String(Math.min(query.limit ?? 25, 50)));
+    if (query.locale) {
+      url.searchParams.set("country", query.locale.toUpperCase());
+    }
+
+    const controller = new AbortController();
+    const timeout = setTimeout(() => controller.abort(), this.config.requestTimeoutMs);
+    try {
+      const response = await fetch(url, {
+        signal: controller.signal,
+        headers: { "user-agent": this.config.userAgent }
+      });
+      if (!response.ok) {
+        throw new Error(`iTunes HTTP ${response.status}`);
+      }
+      const body = await response.json() as { results?: ITunesPodcast[] };
+      return (body.results ?? [])
+        .filter((item) => item.feedUrl)
+        .map((item): DiscoveredFeed => ({
+          title: item.collectionName ?? item.feedUrl ?? "Untitled podcast",
+          description: item.artistName,
+          homepageUrl: item.collectionViewUrl,
+          feedUrl: item.feedUrl as string,
+          kind: "podcast",
+          provider: this.id,
+          imageUrl: item.artworkUrl600,
+          lastPublishedAt: item.releaseDate,
+          score: 0,
+          confidence: 0.85,
+          tags: [item.primaryGenreName, "podcast"].filter((tag): tag is string => Boolean(tag))
+        }));
+    } finally {
+      clearTimeout(timeout);
+    }
+  }
+}