const languages = new Set(["en", "fr", "es", "it", "pl", "tr", "ja", "zh", "sv"]);
const contentTypes = new Set(["sfw", "nsfw"]);
const urlBase = "https://api.comick.fun/chapter/";
const genreBase = "https://api.comick.io/genre/";
const cache = new Map();
const genreCache = new Map();

export default {
  async fetch(request) {
    const url = new URL(request.url);
    const path = url.pathname;

    if (path === "/info") {
      return getInfoResponse();
    }

    try {
      const language = findLanguage(url);
      const contentType = findContentType(url);
      const cacheKey = `${language}-${contentType}`;

      let data;
      if (cache.has(cacheKey)) {
        data = cache.get(cacheKey);
      } else {
        const apiUrl = `${urlBase}?lang=${language}&page=1&order=new&accept_erotic_content=${contentType === 'nsfw'}`;
        data = await fetchData(apiUrl);
        cache.set(cacheKey, data); // Cache the response
      }

      // Fetch genres if not already cached
      if (!genreCache.size) {
        const genres = await fetchData(genreBase);
        const genreMap = genres.reduce((acc, genre) => {
          acc[genre.id] = genre.name;
          return acc;
        }, {});
        genreCache.set('allGenres', genreMap);
      }

      const rssData = generateRSS(data, language, contentType, url);
      return new Response(rssData, {
        headers: {
          "Content-Type": "application/rss+xml",
        },
      });
    } catch (error) {
      console.error("Error processing request:", error);
      return new Response("Internal Server Error", {
        status: 500,
        headers: {
          "Content-Type": "text/plain",
        },
      });
    }
  },
};

function getInfoResponse() {
  return new Response(`
    <html>
      <head>
        <title>Worker Info</title>
      </head>
      <body>
        <h1>Welcome to Manga-RSS!</h1>
        <p>Unfortunately, the GitHub repo was taken down and the python script stopped working, but after rewriting the project in JavaScript, I was able to bring it back. To use this new version with even more supported languages, you just append /[language] to the base url and either /sfw or /nsfw for the content rating.</p>
      </body>
    </html>`, {
    headers: {
      "Content-Type": "text/html",
    },
  });
}

async function fetchData(apiUrl) {
  const init = {
    headers: {
      "content-type": "application/json;charset=UTF-8",
      "User-Agent": "Mozilla/5.0",
    },
  };

  try {
    const responseFromApi = await fetch(apiUrl, init);
    if (!responseFromApi.ok) {
      throw new Error(`Failed to fetch data from API (${responseFromApi.status} ${responseFromApi.statusText})`);
    }

    const contentType = (responseFromApi.headers.get("content-type") || "").toLowerCase();
    return contentType.includes("application/json") ? responseFromApi.json() : responseFromApi.text();
  } catch (error) {
    console.error("Error fetching data:", error);
    throw new Error("Failed to fetch data from the API");
  }
}

function findLanguage(url) {
  for (const lang of languages) {
    if (url.pathname.includes(`/${lang}`)) {
      return lang;
    }
  }
  return "en";
}

function findContentType(url) {
  for (const type of contentTypes) {
    if (url.pathname.includes(`/${type}`)) {
      return type;
    }
  }
  return "sfw";
}

function encodeHTML(text) {
  return text.replace(/</g, '').replace(/>/g, '');
}

function getGenreNames(genreIds) {
  const allGenres = genreCache.get('allGenres');
  return genreIds.map(id => `<li>${encodeHTML(allGenres[id] || 'Unknown Genre')}</li>`).join('');
}

function generateRSS(data, language, contentType, url) {
  const rssHeader = `<?xml version="1.0" encoding="UTF-8" ?>
    <rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
    <channel>
    <title>ComicK - ${language} ${contentType.toUpperCase()} RSS Feed</title>
    <link>https://github.com/ld3z/manga-rss</link>
    <description>A simple RSS feed for ComicK!</description>
    <atom:link href="${url.origin + url.pathname}" rel="self" type="application/rss+xml"/>`;

  const rssItems = data.map(comicData => {
    const comic = comicData.md_comics;

    const title = `<![CDATA[${encodeHTML(`${comic.title} - Chapter ${comicData.chap}`)}]]>`;

    // Embed the image in the description as an <img> tag
    const coverImageURL = comic.md_covers[0] ? `https://meo.comick.pictures/${comic.md_covers[0].b2key}` : '';
    const description = coverImageURL ? `<![CDATA[Chapter ${comicData.chap} of ${comic.title} is now available on ComicK!<br><strong>Genres:</strong><ul>${getGenreNames(comic.genres)}</ul><br><img src="${coverImageURL}" alt="Cover Image" width="200" height="300" />]]>` :
      `<![CDATA[Chapter ${comicData.chap} of ${comic.title} is now available on ComicK!<br><strong>Genres:</strong><ul>${getGenreNames(comic.genres)}</ul>]]>`;

    // Extract and format the 'updated_at' field from the API response
    const pubDate = comicData.updated_at ? new Date(comicData.updated_at).toUTCString() : new Date().toUTCString();

    return `
      <item>
        <guid>https://comick.io/comic/${comic.slug}</guid>
        <title>${title}</title>
        <link>https://comick.io/comic/${comic.slug}</link>
        <description>${description}</description>
        <pubDate>${pubDate}</pubDate>
      </item>`;
  }).join('');

  const rssFooter = `
    </channel>
    </rss>`;

  return `${rssHeader}${rssItems}${rssFooter}`;
}