v3: added opengraph support to the app, wrote README instructions incl. a Docker image

api/services/providers/self.ts

@@ -0,0 +1,83 @@
+import type { RichContent } from "../../model/interfaces.ts";
+import type { RichContentProvider } from "../rich-content-service.ts";
+import { getDump } from "../dump-service.ts";
+import { getUserByUsername } from "../user-service.ts";
+import { getPlaylistById } from "../playlist-service.ts";
+import { BASE_URL } from "../../config.ts";
+
+const DUMP_RE = /^\/dumps\/([^/]+)$/;
+const USER_RE = /^\/users\/([^/]+)$/;
+const PLAYLIST_RE = /^\/playlists\/([^/]+)$/;
+
+export const selfProvider: RichContentProvider = {
+  name: "self",
+
+  matches(url: string): boolean {
+    try {
+      const { pathname } = new URL(url);
+      return DUMP_RE.test(pathname) ||
+        USER_RE.test(pathname) ||
+        PLAYLIST_RE.test(pathname);
+    } catch {
+      return false;
+    }
+  },
+
+  fetch(url: string): Promise<RichContent> {
+    const { pathname } = new URL(url);
+
+    const dumpMatch = pathname.match(DUMP_RE);
+    if (dumpMatch) {
+      const dump = getDump(dumpMatch[1]);
+      let thumbnailUrl: string | undefined;
+      if (dump.kind === "file" && dump.fileMime?.startsWith("image/")) {
+        thumbnailUrl = `${BASE_URL}/api/files/${dump.id}`;
+      } else if (dump.richContent?.thumbnailUrl) {
+        thumbnailUrl = dump.richContent.thumbnailUrl;
+      }
+      return Promise.resolve({
+        type: "generic",
+        url,
+        siteName: "gerbeur",
+        title: dump.title,
+        description: dump.comment,
+        thumbnailUrl,
+      });
+    }
+
+    const userMatch = pathname.match(USER_RE);
+    if (userMatch) {
+      const user = getUserByUsername(userMatch[1]);
+      const thumbnailUrl = user.avatarMime
+        ? `${BASE_URL}/api/avatars/${user.id}`
+        : undefined;
+      return Promise.resolve({
+        type: "generic",
+        url,
+        siteName: "gerbeur",
+        title: user.username,
+        description: user.description,
+        thumbnailUrl,
+      });
+    }
+
+    const playlistMatch = pathname.match(PLAYLIST_RE);
+    if (playlistMatch) {
+      const playlist = getPlaylistById(playlistMatch[1]);
+      const thumbnailUrl = playlist.imageMime
+        ? `${BASE_URL}/api/playlists/${playlist.id}/image`
+        : undefined;
+      return Promise.resolve({
+        type: "generic",
+        url,
+        siteName: "gerbeur",
+        title: playlist.title,
+        description: playlist.description,
+        thumbnailUrl,
+      });
+    }
+
+    // Should not reach here if matches() is correct
+    return Promise.resolve({ type: "generic", url });
+  },
+};