// @ts-check
import { WebSocketServer } from 'ws';
import { readFileSync, mkdirSync, writeFileSync } from "fs";
import { join as joinPath } from 'path'
import matter from 'gray-matter';

const PORT = 8080

const wss = new WebSocketServer({ port: PORT });

console.log(`WebSocket server running on ws://localhost:${PORT}`);

wss.on('connection', (ws) => {
  console.log('New client connected');

  let filename = ''
  const ROOT_DIR = 'docs';

  ws.on('message', (message, isBinary) => {
    if (message instanceof Buffer && isBinary) {
      writeFileSync(joinPath(ROOT_DIR, filename), message);

      return;
    }

    const { name, ...payload } = JSON.parse(message.toString('utf-8'));

    switch (name) {
      case 'download_q': {
        const { q, duration } = payload;
        console.log(`Start ${q}`)

        const q_stem = q.replace(/\.[a-z0-9]+$/, "").replace(/\[.+?\]/g, '').trim();

        try {
          mkdirSync(joinPath(ROOT_DIR, q_stem));
        } catch (e) {}

        let isChanged = false;

        const ts = [];

        let { data, content } = matter(readFileSync(joinPath(ROOT_DIR, `${q_stem}.md`), 'utf-8'));
        data.video = '/' + q;

        const interval = data.interval;
        if (typeof interval === 'number') {
          for (let t = 0; t < duration; t += interval) {
            const min = Math.floor(t / 60)
            const sec = Math.floor(t - min * 60)

            content += `\n${min}:${sec.toString().padStart(2, '0')}\n`;
          }
        }

        const re = /^(?<min>\d{1,2}):(?<sec>\d{2})\s*$/;
        const lines = content.split('\n')
        content = ''
        for (const line of lines) {
          const m = re.exec(line);
          if (m?.groups) {
            const { min, sec } = m.groups;
            const t = `${min}_${sec}`;
            ts.push(t);
            content += `\n![${line}](./${q_stem}/${t}.png)\n\n`;
            isChanged = true;
          } else {
            content += `${line}\n`;
          }
        }

        if (isChanged){
          writeFileSync(joinPath(ROOT_DIR, `${q_stem}.md`), matter.stringify(content, data));
          ws.send(JSON.stringify({ name: "seek_q_ts", q, ts }));
        }
      } break;
      case 'timed_q' : {
        const { q, t } = payload;
        const q_stem = q.replace(/\.[a-z0-9]+$/, "").replace(/\[.+?\]/g, '').trim();
        filename = t ? joinPath(q_stem, `${t}.png`) : '';
      } break;
      case 'done' : {
        const { q } = payload
        console.log(`Done ${q}`)
      } break;
    }
  });

  ws.on('close', () => {
    console.log('Client disconnected');
  });
});