import Yakamoz from "yakamoz";
import { Parser } from "m3u8-parser";
import muxjs from "mux.js";

(async () => {
  //You can change these parts or you can connect it to indexedDB if you want!
  const baseURL = `http://localhost:5501/anime_uploads/weathering-with-you/1`;

  const m3u8File = `/1-7054810786387988481-1080p.m3u8`;
  const parser = new Parser();

  //fetching and parsing our m3u8 manifest
  async function fetchAndParseM3U8() {
    const f = await fetch(baseURL + m3u8File);
    const resp = await f.text();
    parser.push(resp);
    parser.end();
    return parser.manifest.segments;
  }

  const parsedSegments = await fetchAndParseM3U8();

  const request = (url) =>
    fetch(url).then((response) => response.arrayBuffer());

  //Transmuxer to convert mp2t buffers to fragmented mp4 buffers
  let transmuxer = new muxjs.mp4.Transmuxer();
  async function transmux(chunk, giveAsSourceBuffer) {
    return new Promise((resolve) => {
      transmuxer.off("data");
      transmuxer.on("data", (segment) => {
        if (giveAsSourceBuffer) {
          let data = new Uint8Array(
            segment.initSegment.byteLength + segment.data.byteLength
          );
          data.set(segment.initSegment, 0);
          data.set(segment.data, segment.initSegment.byteLength);
          resolve(data.buffer);
        } else {
          resolve(segment.data.buffer);
        }
      });

      transmuxer.push(new Uint8Array(chunk));
      transmuxer.flush();
    });
  }

  const yakamoz = new Yakamoz();

  //append the first buffer
  yakamoz.addEventListener("NEED_SOURCEBUFFER", async (e) => {
    const { append } = e.detail;
    const getNewBuffer = await request(`${baseURL}/${parsedSegments[0].uri}`);
    const buffer = await transmux(getNewBuffer, true);
    append(buffer);
  });

  //append proper segments when needed
  yakamoz.addEventListener("NEW_SEGMENT", async (e) => {
    const { append, targetSegment } = e.detail;
    const getNewBuffer = await request(
      `${baseURL}/${parsedSegments[targetSegment].uri}`
    );
    const buffer = await transmux(getNewBuffer);
    append(buffer);
  });

  //Do not forget to create a video element and mime property should match with the playing video.
  yakamoz.init({
    video: document.querySelector("video"),
    segments: parsedSegments,
    mime: 'video/mp4; codecs="avc1.640028,mp4a.40.2"; profiles="isom,iso2,avc1,mp41""',
  });

  //No need to clear unnecessary buffers. Yakamoz will clear them by default 😉
})();