/**
 * Previews Bandcamp links from their page's OG tags, for
 * `rich-content-service.ts`.
 *
 * @module
 */

import type { RichContent } from "../../../shared/dump.ts";
import type { RichContentProvider } from "./provider.ts";
import { extractOgTag } from "../html.ts";
import { fetchWithTimeout, readTextCapped } from "../fetch.ts";
import { BANDCAMP_HOST_RE } from "../bandcamp-tralbum.ts";

/**
 * Claims bandcamp.com and its subdomains, where artists have their pages. Takes
 * the embed player's URL from the page's `og:video`. The native player fetches the page's streams
 * itself at play time, through `GET /api/bandcamp/tracks`.
 */
export const bandcampProvider: RichContentProvider = {
  name: "bandcamp",

  matches(url: string): boolean {
    try {
      return BANDCAMP_HOST_RE.test(new URL(url).hostname);
    } catch {
      return false;
    }
  },

  async fetch(url: string): Promise<RichContent> {
    const res = await fetchWithTimeout(url);
    const contentType = res.headers.get("content-type") ?? "";

    if (!contentType.startsWith("text/html")) {
      await res.body?.cancel();
      return { type: "bandcamp", siteName: "Bandcamp", url };
    }

    const html = await readTextCapped(res);

    return {
      type: "bandcamp",
      siteName: "Bandcamp",
      url,
      title: extractOgTag(html, "title"),
      description: extractOgTag(html, "description"),
      thumbnailUrl: extractOgTag(html, "image"),
      embedUrl: extractOgTag(html, "video") ?? undefined,
    };
  },
};