'use client'

import { FFmpeg } from '@ffmpeg/ffmpeg'
import { fetchFile, toBlobURL } from '@ffmpeg/util'
import { useRef, useState } from 'react'

export default function Home() {
  const [loaded, setLoaded] = useState(false)
  const [isLoading, setIsLoading] = useState(false)
  const ffmpegRef = useRef(new FFmpeg())
  const videoRef = useRef<HTMLVideoElement | null>(null)
  const messageRef = useRef<HTMLParagraphElement | null>(null)

  const load = async () => {
    setIsLoading(true)
    const baseURL = 'https://unpkg.com/@ffmpeg/core@0.12.6/dist/umd'
    const ffmpeg = ffmpegRef.current
    ffmpeg.on('log', ({ message }) => {
      if (messageRef.current) messageRef.current.innerHTML = message
    })
    // toBlobURL is used to bypass CORS issue, urls with the same
    // domain can be used directly.
    await ffmpeg.load({
      coreURL: await toBlobURL(`${baseURL}/ffmpeg-core.js`, 'text/javascript'),
      wasmURL: await toBlobURL(`${baseURL}/ffmpeg-core.wasm`, 'application/wasm')
    })
    setLoaded(true)
    setIsLoading(false)
  }

  const transcode = async () => {
    const ffmpeg = ffmpegRef.current
    // u can use 'https://ffmpegwasm.netlify.app/video/video-15s.avi' to download the video to public folder for testing
    await ffmpeg.writeFile('input.avi', await fetchFile('https://raw.githubusercontent.com/ffmpegwasm/testdata/master/video-15s.avi'))
    await ffmpeg.exec(['-i', 'input.avi', 'output.mp4'])
    const data = (await ffmpeg.readFile('output.mp4')) as any
    if (videoRef.current)
      videoRef.current.src = URL.createObjectURL(new Blob([data.buffer], { type: 'video/mp4' }))
  }

  return loaded ? (
    <div className="fixed top-[50%] left-[50%] translate-x-[-50%] translate-y-[-50%]">
      <video ref={videoRef} controls></video>
      <br />
      <button
        onClick={transcode}
        className="bg-green-500 hover:bg-green-700 text-white py-3 px-6 rounded"
      >
        Transcode avi to mp4
      </button>
      <p ref={messageRef}></p>
    </div>
  ) : (
    <button
      className="fixed top-[50%] left-[50%] translate-x-[-50%] translate-y-[-50%] flex items-center bg-blue-500 hover:bg-blue-700 text-white py-2 px-4 rounded"
      onClick={load}
    >
      Load ffmpeg-core
      {isLoading && (
        <span className="animate-spin ml-3">
          <svg
            viewBox="0 0 1024 1024"
            focusable="false"
            data-icon="loading"
            width="1em"
            height="1em"
            fill="currentColor"
            aria-hidden="true"
          >
            <path d="M988 548c-19.9 0-36-16.1-36-36 0-59.4-11.6-117-34.6-171.3a440.45 440.45 0 00-94.3-139.9 437.71 437.71 0 00-139.9-94.3C629 83.6 571.4 72 512 72c-19.9 0-36-16.1-36-36s16.1-36 36-36c69.1 0 136.2 13.5 199.3 40.3C772.3 66 827 103 874 150c47 47 83.9 101.8 109.7 162.7 26.7 63.1 40.2 130.2 40.2 199.3.1 19.9-16 36-35.9 36z"></path>
          </svg>
        </span>
      )}
    </button>
  )
}