<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>webRTC</title>
</head>

<body>
    <div>
        <h1>webRTC</h1>
        <p>选择音乐使频道内所有设备同步播放 chrome://webrtc-internals/</p>
    </div>
    <script type="module">
        import IndexedDB from './database.js'
        import MusicList from './music.js'
        import ClientList from './client.js'

        // 读取本地音乐列表(本地缓存)
        const store = new IndexedDB('musicDatabase', 1, 'musicObjectStore')
        await store.open()
        const list = await store.getAll()
        //console.log('本地音乐列表:', list)

        // 读取本地用户名(本地缓存)
        const name = localStorage.getItem('username')
        if (!name) {
            localStorage.setItem('username', `user-${Math.random().toString(36).substr(2)}`)
        }

        // 初始化音乐列表(加入本地缓存)
        const musicList = new MusicList({ list })
        musicList.on('remove', item => {
            //console.log('移除音乐', item)
            store.delete(item.id)
        })
        musicList.on('play', item => {
            //console.log('播放音乐', item)
        })
        musicList.on('load', async item => {
            await new Promise((resolve) => {
                //console.log('加载音乐', item)
                // 建立一个专用信道, 用于接收音乐数据(接收方已经准备好摘要信息)
                var buffer = new ArrayBuffer(0)
                var count = 0
                clientList.setChannel(`music-data-${item.id}`, {
                    onmessage: async (event, client) => {
                        buffer = appendBuffer(buffer, event.data)
                        console.log('收到音乐数据 chunk', count, buffer.byteLength)
                        count++
                        if (buffer.byteLength >= item.size) {
                            console.log('音乐数据接收完毕')
                            item.arrayBuffer = buffer
                            event.target.close() // 关闭信道
                            resolve()
                        }
                    }
                })
                // 要求对方从指定信道发送音乐数据
                clientList.send('base', JSON.stringify({ type: 'get_music_data', id: item.id, channel: `music-data-${item.id}` }))
                //store.put(item) // 只有在like时才保存到本地
            })
        })
        musicList.on('add', item => {
            //console.log('添加音乐', item)
            if (item.arrayBuffer) {
                store.add(item)
                // 告知对方音乐列表有更新
                clientList.send('base', JSON.stringify({ type: 'set_music_list', list: musicList.list.map(({ id, name, size, type }) => ({ id, name, size, type })) }))
            }
        })

        // 初始化客户端列表
        console.log('初始化客户端列表', 'name:', name)
        const clientList = new ClientList({ name })

        // 缓冲分片发送
        const CHUNK_SIZE = 1024 * 128 // 每个块的大小为128KB
        const THRESHOLD = 1024 * 1024 // 缓冲区的阈值为1MB
        const DELAY = 100             // 延迟500ms

        // 将两个ArrayBuffer合并成一个
        function appendBuffer(buffer1, buffer2) {
            const tmp = new Uint8Array(buffer1.byteLength + buffer2.byteLength)
            tmp.set(new Uint8Array(buffer1), 0)
            tmp.set(new Uint8Array(buffer2), buffer1.byteLength)
            return tmp.buffer
        }
        // 只有一个基本信道, 用于交换和调度信息
        clientList.setChannel('base', {
            onopen: async event => {
                console.log('打开信道', event.target.label)
                // 要求对方发送音乐列表
                clientList.send('base', JSON.stringify({ type: 'get_music_list' }))
            },
            onmessage: async (event, client) => {
                const { type, id, channel, list } = JSON.parse(event.data)
                if (type === 'get_music_list') {
                    const ms = musicList.list.filter(item => item.arrayBuffer)
                    console.log(client.name, '请求音乐列表:', ms)
                    clientList.send('base', JSON.stringify({
                        type: 'set_music_list',
                        list: ms.map(({ id, name, size, type }) => ({ id, name, size, type }))
                    }))
                    return
                }
                if (type === 'set_music_list') {
                    console.log(client.name, '发来音乐列表:', `x${JSON.parse(event.data).list.length}`)
                    // 将音乐列表添加到本地
                    const ids = musicList.list.map(item => item.id)
                    list.filter(item => !ids.includes(item.id)).forEach(item => {
                        musicList.add(item)
                    })
                    return
                }
                if (type === 'get_music_data') {
                    // 建立一个信道, 用于传输音乐数据(接收方已经准备好摘要信息)
                    console.log(client.name, '建立一个信道, 用于传输音乐数据', musicList.list)
                    musicList.list.filter(item => item.id === id).forEach(item => {
                        const ch = client.webrtc.createDataChannel(channel, { reliable: true })
                        ch.onopen = async event => {
                            console.log(client.name, `打开 ${channel} 信道, 传输音乐数据`)
                            // 将音乐数据分成多个小块,并逐个发送
                            async function sendChunk(dataChannel, data, index = 0, buffer = new ArrayBuffer(0)) {
                                while (index < data.byteLength) {
                                    if (dataChannel.bufferedAmount <= THRESHOLD) {
                                        const chunk = data.slice(index, index + CHUNK_SIZE)
                                        dataChannel.send(chunk)
                                        index += CHUNK_SIZE
                                        buffer = appendBuffer(buffer, chunk)
                                    }
                                    await new Promise((resolve) => setTimeout(resolve, DELAY))
                                }
                                return buffer
                            }
                            await sendChunk(ch, item.arrayBuffer)
                            console.log(`发送 ${channel} 信道数据结束`)
                            ch.close() // 关闭信道
                        }
                    })
                    return
                }
                console.log('未知类型:', type)
            }
        })
        // like对方的条目时亮起(双方高亮)(本地缓存)(可由对比缓存实现)
        // ban对方的条目时灰掉(也禁止对方播放)(并保持ban表)(由插件实现)
        // 只需要在注册时拉取列表, 播放时才需要拉取音乐数据

        // 延迟1500ms
        //await new Promise((resolve) => setTimeout(resolve, 100))

        // 设置自己的主机名
        const nameInput = document.createElement('input')
        nameInput.type = 'text'
        nameInput.placeholder = '请设置你的名字'
        nameInput.value = name
        nameInput.onchange = event => {
            localStorage.setItem('username', event.target.value)
            window.location.reload() // 简单刷新页面
        }
        document.body.appendChild(nameInput)
    </script>

    <!--script type="module">

        // webRTC 传递音乐(分别传输文件和操作事件能更流畅)
        const music = async function () {
            const clients = [] // 客户端列表

            // 对端设备
            const ul = document.createElement('ul')
            document.body.appendChild(ul)
            const protocol = window.location.protocol === 'https:' ? 'wss' : 'ws'
            const host = window.location.host
            const ws = new WebSocket(`${protocol}://${host}/webrtc/music`)
            const pc = new RTCPeerConnection()

            var audioSource = null
            // 监听音乐列表播放事件
            musicList.on('play', async item => {
                audioSource?.stop() // 先停止可能在播放的音乐
                console.log('播放音乐', item.arrayBuffer)
                // 复制一份 item.arrayBuffer
                const arrayBuffer = item.arrayBuffer.slice(0)
                // 传输音乐文件向远程端
                const audioContext = new AudioContext()
                audioContext.decodeAudioData(arrayBuffer, async audioBuffer => {
                    // 将音乐流添加到 RTCPeerConnection
                    const mediaStreamDestination = audioContext.createMediaStreamDestination()
                    mediaStreamDestination.stream.getAudioTracks().forEach(function (track) {
                        pc.addTrack(track, mediaStreamDestination.stream)
                    })
                    // 播放音乐(远程)
                    audioSource = audioContext.createBufferSource()
                    audioSource.buffer = audioBuffer
                    audioSource.connect(mediaStreamDestination)
                    audioSource.start()
                    // 创建SDP offer并将其设置为本地描述, 发送给指定的远程端
                    const id = clients[0].id
                    await pc.setLocalDescription(await pc.createOffer())     // 设置本地描述为 offer
                    ws.send(JSON.stringify({ id, offer: pc.localDescription }))  // 发送给远程终端 offer
                })
            })
            // 监听音乐列表停止事件
            musicList.on('stop', async () => {
                audioSource?.stop()
                audioSource = null
            })
            // 监听 ICE 候选事件
            pc.onicecandidate = event => {
                if (event.candidate) {
                    const id = clients[0].id
                    ws.send(JSON.stringify({ id, candidate: event.candidate }))  // 发送 ICE 候选到远程终端
                }
            }
            // 监听远程流事件
            pc.ontrack = function (event) {
                console.log('pc ontrack:', event)
                const audio = document.createElement('audio')
                audio.srcObject = event.streams[0]
                audio.play()
            }
            ws.onmessage = async (event) => {
                const data = JSON.parse(event.data)
                if (data.type === 'push') {
                    console.log('收到 type:push 将设备增加', data.id)
                    clients.push({ id: data.id, channel: data.channel })
                    const li = document.createElement('li')
                    li.innerText = `id:${data.id} channel:${data.channel}`
                    li.id = data.id
                    li.onclick = async () => {
                        console.log('点击设备', data.id)
                        // 清理所有选中状态
                        clients.forEach(client => {
                            const li = document.getElementById(client.id)
                            if (data.id === client.id) {
                                li.style.backgroundColor = 'red'
                                console.log('设置选中状态', data.id)
                                return
                            }
                            li.style.backgroundColor = 'transparent'
                            console.log('清理选中状态', client.id)
                        })
                    }
                    ul.appendChild(li)
                    return
                }
                if (data.type === 'pull') {
                    console.log('收到 type:pull 将设备删除', data.id)
                    const index = clients.findIndex(client => client.id === data.id)
                    if (index !== -1) {
                        clients.splice(index, 1)
                        const li = document.getElementById(data.id)
                        li.remove()
                    }
                    return
                }
                if (data.type === 'error') {
                    console.log('收到 type:error 没什么可操作的', data.id)
                    return
                }
                if (data.offer) {
                    const id = clients[0].id
                    console.log('收到 offer 并将其设置为远程描述', data.offer)
                    await pc.setRemoteDescription(new RTCSessionDescription(data.offer)) // 设置远程描述为 offer
                    await pc.setLocalDescription(await pc.createAnswer())                // 设置本地描述为 answer
                    ws.send(JSON.stringify({ id, answer: pc.localDescription }))         // 发送给远程终端 answer
                    return
                }
                if (data.answer) {
                    console.log('收到 answer 并将其设置为远程描述', data.answer)
                    await pc.setRemoteDescription(new RTCSessionDescription(data.answer))
                    return
                }
                if (data.candidate) {
                    console.log('收到 candidate 并将其添加到远程端', data.candidate)
                    await pc.addIceCandidate(new RTCIceCandidate(data.candidate))
                    return
                }
            }
        }
        //music()
    </script-->
    <!--script type="module">
        // 创建 RTCPeerConnection
        const pc = new RTCPeerConnection()
        // webSocket 连接服务器
        const protocol = window.location.protocol === 'https:' ? 'wss' : 'ws'
        const host = window.location.host
        const ws = new WebSocket(`${protocol}://${host}/webrtc/default`)
        ws.onopen = function () {
            console.log('video ws open')
        }
        ws.onmessage = function (event) {
            const data = JSON.parse(event.data)
            console.log('ws message:', data)
            if (data.offer) {
                console.log('收到 offer 并将其设置为远程描述')
                pc.setRemoteDescription(new RTCSessionDescription(data.offer))
                // 创建SDP answer并将其设置为本地描述, 发送给远程端
                pc.createAnswer().then(function (answer) {
                    pc.setLocalDescription(answer)
                    ws.send(JSON.stringify({ answer }))
                })
                return
            }
            if (data.answer) {
                console.log('收到 answer 并将其设置为远程描述')
                pc.setRemoteDescription(new RTCSessionDescription(data.answer))
                return
            }
            if (data.candidate) {
                console.log('收到 candidate 并将其添加到远程端')
                pc.addIceCandidate(new RTCIceCandidate(data.candidate))
            }
        }
        ws.onclose = function () {
            console.log('ws close')
        }

        setTimeout(() => {

            // 获取本地视频流
            navigator.mediaDevices.getUserMedia({ audio: false, video: true }).then(stream => {
                // 创建本地视频元素
                const localVideo = document.createElement('video')
                localVideo.srcObject = stream
                localVideo.autoplay = true
                localVideo.muted = true
                document.body.appendChild(localVideo)

                // 添加本地视频流到 RTCPeerConnection
                stream.getTracks().forEach(function (track) {
                    pc.addTrack(track, stream)
                })

                // 监听 ICE candidate 事件
                pc.onicecandidate = function (event) {
                    if (event.candidate) {
                        // 发送 ICE candidate 到远程端
                        ws.send(JSON.stringify({ candidate: event.candidate }))
                    }
                }

                // 监听远程视频流事件
                pc.ontrack = function (event) {
                    // 创建远程视频元素
                    var remoteVideo = document.createElement('video')
                    remoteVideo.srcObject = event.streams[0]
                    remoteVideo.autoplay = true
                    document.body.appendChild(remoteVideo)
                }

                // 创建SDP offer并将其设置为本地描述, 发送给远程端
                pc.createOffer().then(function (offer) {
                    pc.setLocalDescription(offer)
                    ws.send(JSON.stringify({ offer }))
                })

            }).catch(error => {
                console.log(error)
            })

        }, 1000)
    </script-->
</body>

</html>