bsky-social-app/src/components/Post/Embed/VideoEmbed/VideoEmbedInner/web-controls/utils.tsx

import {type RefObject, useCallback, useEffect, useRef, useState} from 'react'

import {logger} from '#/logger'
import {useVideoVolumeState} from '#/components/Post/Embed/VideoEmbed/VideoVolumeContext'
import {IS_WEB_SAFARI} from '#/env'

export function useVideoElement(ref: RefObject<HTMLVideoElement | null>) {
  const [playing, setPlaying] = useState(false)
  const [muted, setMuted] = useState(true)
  const [currentTime, setCurrentTime] = useState(0)
  const [volume, setVolume] = useVideoVolumeState()
  const [duration, setDuration] = useState(0)
  const [buffering, setBuffering] = useState(false)
  const [error, setError] = useState(false)
  const [canPlay, setCanPlay] = useState(false)
  const playWhenReadyRef = useRef(false)

  useEffect(() => {
    if (!ref.current) return
    ref.current.volume = volume
  }, [ref, volume])

  useEffect(() => {
    if (!ref.current) return

    let bufferingTimeout: ReturnType<typeof setTimeout> | undefined

    function round(num: number) {
      return Math.round(num * 100) / 100
    }

    // Initial values
    setCurrentTime(round(ref.current.currentTime) || 0)
    setDuration(round(ref.current.duration) || 0)
    setMuted(ref.current.muted)
    setPlaying(!ref.current.paused)
    setVolume(ref.current.volume)

    const handleTimeUpdate = () => {
      if (!ref.current) return
      setCurrentTime(round(ref.current.currentTime) || 0)
      // HACK: Safari randomly fires `stalled` events when changing between segments
      // let's just clear the buffering state if the video is still progressing -sfn
      if (IS_WEB_SAFARI) {
        if (bufferingTimeout) clearTimeout(bufferingTimeout)
        setBuffering(false)
      }
    }

    const handleDurationChange = () => {
      if (!ref.current) return
      setDuration(round(ref.current.duration) || 0)
    }

    const handlePlay = () => {
      setPlaying(true)
    }

    const handlePause = () => {
      setPlaying(false)
    }

    const handleVolumeChange = () => {
      if (!ref.current) return
      setMuted(ref.current.muted)
    }

    const handleError = () => {
      setError(true)
    }

    const handleCanPlay = async () => {
      if (bufferingTimeout) clearTimeout(bufferingTimeout)
      setBuffering(false)
      setCanPlay(true)

      if (!ref.current) return
      if (playWhenReadyRef.current) {
        try {
          await ref.current.play()
        } catch (e: any) {
          if (
            !e.message?.includes(
              `The request is not allowed by the user agent`,
            ) &&
            !e.message?.includes(
              `The play() request was interrupted by a call to pause()`,
            )
          ) {
            throw e
          }
        }
        playWhenReadyRef.current = false
      }
    }

    const handleCanPlayThrough = () => {
      if (bufferingTimeout) clearTimeout(bufferingTimeout)
      setBuffering(false)
    }

    const handleWaiting = () => {
      if (bufferingTimeout) clearTimeout(bufferingTimeout)
      bufferingTimeout = setTimeout(() => {
        setBuffering(true)
      }, 500) // Delay to avoid frequent buffering state changes
    }

    const handlePlaying = () => {
      if (bufferingTimeout) clearTimeout(bufferingTimeout)
      setBuffering(false)
      setError(false)
    }

    const handleStalled = () => {
      if (bufferingTimeout) clearTimeout(bufferingTimeout)
      bufferingTimeout = setTimeout(() => {
        setBuffering(true)
      }, 500) // Delay to avoid frequent buffering state changes
    }

    const handleEnded = () => {
      setPlaying(false)
      setBuffering(false)
      setError(false)
    }

    const abortController = new AbortController()

    ref.current.addEventListener('timeupdate', handleTimeUpdate, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('durationchange', handleDurationChange, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('play', handlePlay, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('pause', handlePause, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('volumechange', handleVolumeChange, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('error', handleError, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('canplay', handleCanPlay, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('canplaythrough', handleCanPlayThrough, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('waiting', handleWaiting, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('playing', handlePlaying, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('stalled', handleStalled, {
      signal: abortController.signal,
    })
    ref.current.addEventListener('ended', handleEnded, {
      signal: abortController.signal,
    })

    return () => {
      abortController.abort()
      clearTimeout(bufferingTimeout)
    }
  }, [ref, setVolume])

  const play = useCallback(() => {
    if (!ref.current) return

    if (ref.current.ended) {
      ref.current.currentTime = 0
    }

    if (ref.current.readyState < HTMLMediaElement.HAVE_FUTURE_DATA) {
      playWhenReadyRef.current = true
    } else {
      const promise = ref.current.play()
      if (promise !== undefined) {
        promise.catch((err: any) => {
          if (
            // ignore this common error. it's fine
            !err.message?.includes(
              `The play() request was interrupted by a call to pause()`,
            )
          ) {
            logger.error('Error playing video:', {message: err})
          }
        })
      }
    }
  }, [ref])

  const pause = useCallback(() => {
    if (!ref.current) return

    ref.current.pause()
    playWhenReadyRef.current = false
  }, [ref])

  const togglePlayPause = useCallback(() => {
    if (!ref.current) return

    if (ref.current.paused) {
      play()
    } else {
      pause()
    }
  }, [ref, play, pause])

  const changeMuted = useCallback(
    (newMuted: boolean | ((prev: boolean) => boolean)) => {
      if (!ref.current) return

      const value =
        typeof newMuted === 'function' ? newMuted(ref.current.muted) : newMuted
      ref.current.muted = value
    },
    [ref],
  )

  return {
    play,
    pause,
    togglePlayPause,
    duration,
    currentTime,
    playing,
    muted,
    changeMuted,
    buffering,
    error,
    canPlay,
  }
}

export function formatTime(time: number) {
  if (isNaN(time)) {
    return '--'
  }

  time = Math.round(time)

  const minutes = Math.floor(time / 60)
  const seconds = String(time % 60).padStart(2, '0')

  return `${minutes}:${seconds}`
}