import React, { useEffect, useRef, useState } from 'react'
import Hls from 'hls.js'
import { whepUrl, hlsUrl } from './api.js'
import { audio, effectiveMuted } from './useAudio.js'

// WebRTC (WHEP) first, HLS fallback. Mute/volume come from the shared audio store.
export default function Player({ params, api }) {
  const { id, user, title } = params
  const videoRef = useRef(null)
  const [status, setStatus] = useState('connecting…')
  const [viewers, setViewers] = useState(params.viewers ?? 0)
  const state = audio.use()
  const muted = effectiveMuted(state, id)
  const volume = state.streams[id]?.volume ?? 0.8
  const override = state.streams[id]?.override
  const focused = state.focused === id

  useEffect(() => { audio.ensure(id) }, [id])
  useEffect(() => { const d = api.onDidActiveChange?.(() => {}) ; return () => d?.dispose?.() }, [api])
  useEffect(() => { const t = setInterval(() => setViewers(params.viewers ?? 0), 2000); return () => clearInterval(t) }, [params.viewers])

  // apply audio state to the element
  useEffect(() => {
    const v = videoRef.current; if (!v) return
    v.muted = muted; v.volume = volume
    if (!muted && v.paused) v.play().catch(() => {})
  }, [muted, volume])

  // connect
  useEffect(() => {
    const v = videoRef.current; if (!v) return
    let pc, hls, cancelled = false
    const startHls = () => {
      if (cancelled) return
      setStatus('hls')
      if (Hls.isSupported()) {
        hls = new Hls({ lowLatencyMode: true, liveSyncDurationCount: 2, enableWorker: true })
        hls.loadSource(hlsUrl(id)); hls.attachMedia(v)
        hls.on(Hls.Events.MANIFEST_PARSED, () => v.play().catch(() => {}))
        hls.on(Hls.Events.ERROR, (_, d) => { if (d.fatal) setStatus('hls error: ' + d.details) })
      } else if (v.canPlayType('application/vnd.apple.mpegurl')) {
        v.src = hlsUrl(id); v.play().catch(() => {})
      } else setStatus('no playback method')
    }
    const startWhep = async () => {
      try {
        pc = new RTCPeerConnection({ iceServers: [{ urls: 'stun:stun.l.google.com:19302' }] })
        pc.addTransceiver('video', { direction: 'recvonly' })
        pc.addTransceiver('audio', { direction: 'recvonly' })
        pc.ontrack = e => { if (v.srcObject !== e.streams[0]) { v.srcObject = e.streams[0]; v.play().catch(() => {}) } }
        pc.onconnectionstatechange = () => {
          if (pc.connectionState === 'connected') setStatus('')
          if (['failed', 'disconnected', 'closed'].includes(pc.connectionState) && !cancelled) { pc.close(); startHls() }
        }
        const offer = await pc.createOffer()
        await pc.setLocalDescription(offer)
        await new Promise(res => { if (pc.iceGatheringState === 'complete') return res(); const t = setTimeout(res, 1500); pc.onicegatheringstatechange = () => { if (pc.iceGatheringState === 'complete') { clearTimeout(t); res() } } })
        const r = await fetch(whepUrl(id), { method: 'POST', headers: { 'Content-Type': 'application/sdp' }, body: pc.localDescription.sdp, credentials: 'same-origin' })
        if (!r.ok) throw new Error('whep ' + r.status)
        await pc.setRemoteDescription({ type: 'answer', sdp: await r.text() })
        setStatus('webrtc')
      } catch (e) {
        if (cancelled) return
        try { pc?.close() } catch {}
        startHls()
      }
    }
    startWhep()
    return () => { cancelled = true; try { pc?.close() } catch {}; try { hls?.destroy() } catch {}; v.srcObject = null; v.removeAttribute('src') }
  }, [id])

  const icon = muted ? '🔇' : volume === 0 ? '🔈' : volume < 0.5 ? '🔉' : '🔊'
  return (
    <div className={'player' + (focused ? ' focused' : '')} onMouseDown={() => api.setActive?.()}>
      <video ref={videoRef} autoPlay playsInline muted />
      {status && <div className="status">{status}</div>}
      <div className="bar">
        <span className="live">LIVE</span>
        <span className="who">{user}</span>
        <span className="title" title={title}>{title}</span>
        <span className="viewers">👁 {viewers}</span>
        <button className={'mute' + (!muted ? ' on' : '') + (override === 'unmuted' && !focused ? ' pinned' : '')}
                title={override ? (override === 'unmuted' ? 'audio pinned on (click to mute)' : 'muted (click to unmute)') : (focused ? 'focused: audio on (click to mute)' : 'muted: click to pin audio on')}
                onMouseDown={e => e.stopPropagation()} onClick={() => audio.toggleMute(id)}>{icon}</button>
        <input type="range" min="0" max="1" step="0.02" value={volume} onMouseDown={e => e.stopPropagation()}
               onChange={e => audio.setVolume(id, parseFloat(e.target.value))} />
      </div>
    </div>
  )
}