Add feed discovery plugin

plugins/feed-discovery/src/providers/podcastindex.ts

@@ -0,0 +1,76 @@
+import { createHash } from "node:crypto";
+import type { DiscoveredFeed, FeedDiscoveryConfig, FeedDiscoveryProvider, FeedDiscoveryQuery } from "../types.js";
+
+interface PodcastIndexFeed {
+  title?: string;
+  description?: string;
+  url?: string;
+  link?: string;
+  image?: string;
+  language?: string;
+  newestItemPublishTime?: number;
+  categories?: Record<string, string>;
+}
+
+export class PodcastIndexProvider implements FeedDiscoveryProvider {
+  id = "podcastindex";
+  name = "PodcastIndex";
+  enabledByDefault = false;
+  requiresApiKey = true;
+
+  constructor(private readonly config: FeedDiscoveryConfig) {}
+
+  async search(query: FeedDiscoveryQuery) {
+    if (!this.config.podcastIndexApiKey || !this.config.podcastIndexApiSecret) {
+      return [];
+    }
+    if (query.type && query.type !== "all" && query.type !== "podcast") {
+      return [];
+    }
+
+    const authDate = Math.floor(Date.now() / 1000).toString();
+    const auth = createHash("sha1")
+      .update(this.config.podcastIndexApiKey + this.config.podcastIndexApiSecret + authDate)
+      .digest("hex");
+
+    const url = new URL("https://api.podcastindex.org/api/1.0/search/byterm");
+    url.searchParams.set("q", query.q);
+    url.searchParams.set("max", String(Math.min(query.limit ?? 25, 100)));
+
+    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,
+          "X-Auth-Date": authDate,
+          "X-Auth-Key": this.config.podcastIndexApiKey,
+          Authorization: auth
+        }
+      });
+      if (!response.ok) {
+        throw new Error(`PodcastIndex HTTP ${response.status}`);
+      }
+      const body = await response.json() as { feeds?: PodcastIndexFeed[] };
+      return (body.feeds ?? [])
+        .filter((feed) => feed.url)
+        .map((feed): DiscoveredFeed => ({
+          title: feed.title ?? feed.url ?? "Untitled podcast",
+          description: feed.description,
+          homepageUrl: feed.link,
+          feedUrl: feed.url as string,
+          kind: "podcast",
+          provider: this.id,
+          language: feed.language,
+          imageUrl: feed.image,
+          lastPublishedAt: feed.newestItemPublishTime ? new Date(feed.newestItemPublishTime * 1000).toISOString() : undefined,
+          score: 0,
+          confidence: 0.9,
+          tags: [...Object.values(feed.categories ?? {}), "podcast"]
+        }));
+    } finally {
+      clearTimeout(timeout);
+    }
+  }
+}