class NHentai {
  constructor() {
    this.baseUrl = "https://nhentai.net";
    this.type = "book-board";
    this.version = "1.1";
    this.mediaType = "manga";
  }

  shortenTitle(title) {
    return title.replace(/(\[[^]]*]|[({][^)}]*[)}])/g, "").trim();
  }

  parseId(str) {
    return str.replace(/\D/g, "");
  }

  extractJson(scriptText) {
    const m = scriptText.match(/JSON\.parse\("([\s\S]*?)"\)/);
    if (!m) throw new Error("JSON.parse no encontrado");

    const unicodeFixed = m[1].replace(
        /\\u([0-9A-Fa-f]{4})/g,
        (_, h) => String.fromCharCode(parseInt(h, 16))
    );

    return JSON.parse(unicodeFixed);
  }

  async search({ query = "", page = 1 }) {
    if (query.startsWith("id:") || (!isNaN(query) && query.length <= 7)) {
      return [await this.getMetadata(this.parseId(query))];
    }

    const url = `${this.baseUrl}/search/?q=${encodeURIComponent(query)}&page=${page}`;
    const { result } = await this.scrape(
        url,
        page =>
            page.evaluate(() => document.documentElement.innerHTML),
        { waitSelector: ".gallery" }
    );

    const $ = this.cheerio.load(result);
    return $(".gallery").map((_, el) => ({
      id: this.parseId($(el).find("a").attr("href")),
      image: $(el).find("img").attr("data-src") || $(el).find("img").attr("src"),
      title: this.shortenTitle($(el).find(".caption").text()),
      type: "book"
    })).get();
  }

  async getMetadata(id) {
    const url = `${this.baseUrl}/g/${id}/`;

    const { result } = await this.scrape(
        url,
        page =>
            page.evaluate(() => {
              const html = document.documentElement.innerHTML;

              const script = [...document.querySelectorAll("script")]
                  .find(s =>
                      s.textContent.includes("JSON.parse") &&
                      !s.textContent.includes("media_server") &&
                      !s.textContent.includes("avatar_url")
                  )?.textContent || null;

              const thumbMatch = html.match(/thumb_cdn_urls:\s*(\[[^\]]*])/);
              const thumbCdns = thumbMatch ? JSON.parse(thumbMatch[1]) : [];

              return { script, thumbCdns };
            })
    );

    if (!result?.script) {
      throw new Error("Script de datos no encontrado");
    }

    const data = this.extractJson(result.script);
    const cdn = result.thumbCdns[0] || "t3.nhentai.net";

    return {
      id: id.toString(),
      title: data.title.pretty || data.title.english,
      format: "MANGA",
      status: "completed",
      genres: data.tags
          .filter(t => t.type === "tag")
          .map(t => t.name),
      published: new Date(data.upload_date * 1000).toLocaleDateString(),
      summary: `Pages: ${data.images.pages.length}\nFavorites: ${data.num_favorites}`,
      chapters: 1,
      image: `https://${cdn}/galleries/${data.media_id}/cover.webp`
    };
  }

  async findChapters(mangaId) {
    return [{
      id: mangaId.toString(),
      title: "Chapter",
      number: 1,
      index: 0
    }];
  }

  async findChapterPages(chapterId) {
    const url = `${this.baseUrl}/g/${chapterId}/`;
    const { result } = await this.scrape(
        url,
        page =>
            page.evaluate(() => {
              const html = document.documentElement.innerHTML;
              const cdnMatch = html.match(/image_cdn_urls:\s*(\[[^\]]*])/);
              const s = [...document.querySelectorAll("script")]
                  .find(x =>
                      x.textContent.includes("JSON.parse") &&
                      !x.textContent.includes("media_server") &&
                      !x.textContent.includes("avatar_url")
                  );
              return {
                script: s?.textContent || null,
                cdns: cdnMatch ? JSON.parse(cdnMatch[1]) : ["i.nhentai.net"]
              };
            })
    );

    if (!result?.script) throw new Error("Datos no encontrados");
    const data = this.extractJson(result.script);
    const cdn = result.cdns[0];

    return data.images.pages.map((p, i) => {
      const ext = p.t === "j" ? "jpg" : p.t === "p" ? "png" : "webp";
      return {
        index: i,
        url: `https://${cdn}/galleries/${data.media_id}/${i + 1}.${ext}`
      };
    });
  }
}

module.exports = NHentai;