import {
  PDFDocument,
  PDFPage,
  rgb,
} from "https://cdn.skypack.dev/pdf-lib@^1.11.1?dts";
import fontkit from "https://cdn.skypack.dev/@pdf-lib/fontkit@^1.0.0?dts";

type Result = {
  id: number;
  word: string;
  answer: string;
};

async function generateVoca(level: number, day: number) {
  const re =
    /<p class="word">(?<id>\d+?)\. (?<word>.+?)<\/p>.*?<span class="af_answer">(?<answer>.+?)<\/span>/gis;
  const res = await fetch(
    `https://www.hackers.co.kr/?c=s_toeic/new_voca_toeic_testpaper/toeic_study/new_paper&mode=new_view&level=${level}&level_type=&lang_text=2&question=1000&day3=${day}&day4=${day}&day_auto=N&index=1`,
  );

  const body = (await res.text());
  const matches = [...body.matchAll(re)].map((m) => ({
    ...m.groups as unknown as Result,
    id: Number.parseInt(m.groups?.id as string),
  }));

  const pdfDoc = await PDFDocument.create();

  const fontBytes = await Deno.readFile("./NanumGothic.ttf");
  pdfDoc.registerFontkit(fontkit);
  const customFont = await pdfDoc.embedFont(fontBytes);

  const fontSize = 12;
  const margin = 20;
  const perColumn = 25;
  const perPage = 50;

  let page!: PDFPage;
  let col = -1;
  let yCursor = 1;

  // 문제 생성
  for (let i = 0; i < matches.length; ++i) {
    const data = matches[i];
    if (i % perPage === 0) {
      page = pdfDoc.addPage();
      yCursor = 1;
      col = -1;
    }
    if (i % perColumn === 0) {
      col++;
      yCursor = 1;
    }
    page.drawText(`${data.id}. ${data.word}`, {
      x: margin + (page.getWidth() / 2 * col),
      y: page.getHeight() - (fontSize + margin) * (yCursor),
      size: fontSize,
      font: customFont,
      color: rgb(0, 0, 0),
    });
    page.drawText("_________________", {
      x: margin + (page.getWidth() / 2 * col) + 140,
      y: page.getHeight() - (fontSize + margin) * (yCursor) - 3,
      size: fontSize,
      font: customFont,
      color: rgb(0, 0, 0),
    });
    yCursor++;
  }

  // 답 생성
  for (let i = 0; i < matches.length; ++i) {
    const data = matches[i];
    if (i % perPage === 0) {
      page = pdfDoc.addPage();
      yCursor = 1;
      col = -1;
    }
    if (i % perColumn === 0) {
      col++;
      yCursor = 1;
    }
    page.drawText(`${data.id}. ${data.word}`, {
      x: margin + (page.getWidth() / 2 * col),
      y: page.getHeight() - (fontSize + margin) * (yCursor),
      size: fontSize,
      font: customFont,
      color: rgb(0, 0, 0),
    });
    page.drawText("_________________", {
      x: margin + (page.getWidth() / 2 * col) + 140,
      y: page.getHeight() - (fontSize + margin) * (yCursor) - 3,
      size: fontSize,
      font: customFont,
      color: rgb(0, 0, 0),
    });
    page.drawText(data.answer, {
      x: margin + (page.getWidth() / 2 * col) + 140,
      y: page.getHeight() - (fontSize + margin) * (yCursor),
      size: fontSize,
      font: customFont,
      color: rgb(1, 0, 0),
    });
    yCursor++;
  }

  const pdfBytes = await pdfDoc.save();
  return pdfBytes;
}

const port = 8055;
const server = Deno.listen({ port });
console.log(
  `HTTP webserver running.  Access it at:  http://localhost:${port}/`,
);

for await (const conn of server) {
  serveHttp(conn);
}

async function serveHttp(conn: Deno.Conn) {
  const httpConn = Deno.serveHttp(conn);
  for await (const requestEvent of httpConn) {
    const url = new URL(requestEvent.request.url);

    if (!url.searchParams.has("level") || !url.searchParams.has("day")) {
      requestEvent.respondWith(
        new Response("Not Found", {
          status: 404,
        }),
      );
      return;
    }

    const level = Number.parseInt(url.searchParams.get("level")!) ?? 7;
    const day = Number.parseInt(url.searchParams.get("day")!) ?? 1;
    const data = await generateVoca(level, day);

    requestEvent.respondWith(
      new Response(data, {
        status: 200,
      }),
    );
  }
}