import type { RichContent } from "../../model/interfaces.ts";
import type { RichContentProvider } from "../rich-content-service.ts";
import {
  extractBestIcon,
  extractJsonLd,
  extractLargeImage,
  extractMetaName,
  extractOgTag,
  extractPageTitle,
  fetchWithTimeout,
} from "../rich-content-service.ts";

export const genericProvider: RichContentProvider = {
  name: "generic",

  matches(_url: string): boolean {
    return true; // fallback — always matches
  },

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

    if (!contentType.startsWith("text/html")) {
      return { type: "generic", url };
    }

    const html = await res.text();
    const ld = extractJsonLd(html);

    // Title: og:title → twitter:title → JSON-LD → <title>
    const title = extractOgTag(html, "title") ??
      extractMetaName(html, "twitter:title") ??
      ld.title ??
      extractPageTitle(html);

    // Description: og:description → twitter:description → JSON-LD → <meta name="description">
    const description = extractOgTag(html, "description") ??
      extractMetaName(html, "twitter:description") ??
      ld.description ??
      extractMetaName(html, "description");

    // Image: og:image → twitter:image → JSON-LD → first large <img> → best icon → /favicon.ico
    const thumbnailUrl = extractOgTag(html, "image") ??
      extractMetaName(html, "twitter:image") ??
      ld.thumbnailUrl ??
      extractLargeImage(html, url) ??
      extractBestIcon(html, url) ??
      `${new URL(url).origin}/favicon.ico`;

    // Site name: og:site_name → hostname
    const siteName = extractOgTag(html, "site_name") ??
      new URL(url).hostname.replace(/^www\./, "");

    return {
      type: "generic",
      url,
      title,
      description,
      thumbnailUrl,
      siteName,
    };
  },
};