client/public/store.js

/**
 * 状态管理
 * 使用简单的 Observable 模式，可替换为 Redux/Vuex/Pinia
 */
import { mockCallSession } from './models.js';
import { Signaling, WebSocketSignaling } from "../../module/signaling.js";// 信令管理
import { RenderStreaming } from "../../module/renderstreaming.js"; // WebRTC连接管理
import { getServerConfig, getRTCConfiguration } from "../js/config.js";//服务器配置和RTC配置
import { showNotification, generateId } from './utils.js'; // 导入通知函数
import chatMessage from './chatmessage.js';
import {
    DEFAULT_PARTICIPANT_AVATAR,
    DEFAULT_PARTICIPANT_NAME,
    buildParticipantsSyncData,
    omitParticipant,
    removeParticipant,
    upsertParticipant
} from './participants.js';
import {
    AUDIO_CONFIG,
    VAD_CONFIG,
    VIDEO_ONLY_CONSTRAINT,
    buildVideoConstraints,
    getAdaptiveVideoBitrate,
    getResolutionLabel,
    getTargetResolutionBitrate
} from './media-config.js';
import { getNetworkQualityFromSummary, summarizeInboundStats } from './webrtc-stats.js';

class CallStateManager {
    constructor() {
        // 核心状态
        this.state = {
            id: generateId(),
            session: {
                ...mockCallSession,
                status: 'idle' // 初始状态为空闲
            },
            localStream: null,  // MediaStream 对象
            remoteStream: null,  // 单路远端流（兼容旧逻辑，participant端使用）
            remoteStreams: {},     // 多路远端流 Map: { connectionId: MediaStream }（host端使用）
            participants: {}     // 多Participant用户信息 Map: { participantId: { id, name, avatar, mediaState, status } }（host端使用）
        };

        // 监听器数组
        this.listeners = [];
        this.socketEventHandlers = {};
        this._socketInviteBound = false;
    }

    // 订阅状态变化
    subscribe(callback) {
        this.listeners.push(callback);
        return () => {
            this.listeners = this.listeners.filter(cb => cb !== callback);
        };
    }

    // 通知所有监听器
    notify(changes) {
        this.listeners.forEach(cb => cb(this.state, changes));
    }

    // 初始化
    async init() {
        // 初始化配置
        await this.setupConfig();
        // 加载用户设置
        this.loadUserSettings();
        // 获取本地摄像头视频流
        await this.getLocalStream();
    }

    // 加载用户设置
    loadUserSettings() {
        const userSettings = localStorage.getItem('userSettings');
        if (userSettings) {
            try {
                const settings = JSON.parse(userSettings);

                // 更新本地用户信息
                if (settings.name || settings.avatar) {
                    this.state.session.localUser = {
                        ...this.state.session.localUser,
                        id: settings.userId || this.state.session.localUser.id,
                        name: settings.name || this.state.session.localUser.name,
                        avatar: settings.avatar || this.state.session.localUser.avatar
                    };

                    // 通知UI更新
                    this.notify({ type: 'USER_SETTINGS_UPDATED', user: this.state.session.localUser });
                }

                // 恢复保存的分辨率设置
                if (settings.resolution) {
                    this._savedResolution = settings.resolution;
                    console.log(`已恢复分辨率设置: ${settings.resolution.width}x${settings.resolution.height}`);
                }
            } catch (error) {
                console.error('Error loading user settings:', error);
            }
        }
    }
    async setupConfig() {
        const res = await getServerConfig();
        this.useWebSocket = res.useWebSocket;
    }
    // 获取本地摄像头视频流
    async getLocalStream() {
        try {
            console.log('Requesting camera permission...');

            // 检查浏览器是否支持getUserMedia
            if (!navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) {
                console.error('getUserMedia is not supported');
                throw new Error('getUserMedia is not supported');
            }

            // 请求摄像头权限并获取媒体流，启用回声消除
            // 使用保存的分辨率（如有），否则使用默认约束
            const videoConstraints = buildVideoConstraints(this._savedResolution);
            const stream = await navigator.mediaDevices.getUserMedia({
                video: videoConstraints,
                audio: AUDIO_CONFIG
            });

            console.log('Stream obtained successfully:', stream);
            console.log('Video tracks:', stream.getVideoTracks());
            console.log('Audio tracks:', stream.getAudioTracks());

            this.state.localStream = stream;
            this.state.session.localUser.mediaState.video = true;
            this.state.session.localUser.mediaState.audio = true;

            console.log('Local stream stored, notifying UI...');

            // 先通知视频流已获取
            this.notify({ type: 'LOCAL_STREAM_OBTAINED', stream });
            // 再通知媒体状态变化
            this.notify({ type: 'LOCAL_MEDIA_CHANGE', mediaType: 'video', value: true });
            this.notify({ type: 'LOCAL_MEDIA_CHANGE', mediaType: 'audio', value: true });

            // 发送媒体状态到服务器
            this.emitMediaStateChange();

            // 启动本地音频活动检测
            this.startActivityDetection(this.state.localStream, { isLocal: true });
        } catch (error) {
            console.error('Error getting local stream:', error);
            // 如果获取视频失败，保持视频关闭状态
            this.state.session.localUser.mediaState.video = false;
            this.state.session.localUser.mediaState.audio = false;

            // 通知媒体状态变化
            this.notify({ type: 'LOCAL_MEDIA_CHANGE', mediaType: 'video', value: false });
            this.notify({ type: 'LOCAL_MEDIA_CHANGE', mediaType: 'audio', value: false });
        }
    }

    // 更新本地媒体状态
    async updateLocalMedia(mediaType, value) {
        await this._updateLocalMediaRefactored(mediaType, value);
        return;
    }

    async _updateLocalMediaRefactored(mediaType, value) {
        if (mediaType === 'video' && value) {
            await this._enableLocalVideo();
            this._notifyUserListUpdate();
            return;
        }

        this.state.session.localUser.mediaState[mediaType] = value;
        this._notifyLocalMediaChange(mediaType, value);
        this.emitMediaStateChange();

        if (mediaType === 'video' && !value) {
            this._disableLocalVideoTracks();
        }

        if (mediaType === 'audio') {
            this._setLocalAudioTrackEnabled(value);
        }

        this._notifyUserListUpdate();
    }

    async _enableLocalVideo() {
        try {
            const newVideoTrack = await this._requestNewVideoTrack();
            this._replaceLocalVideoTrack(newVideoTrack);
            await this._updateOutgoingVideoTrack(newVideoTrack);

            this.state.session.localUser.mediaState.video = true;
            this.notify({ type: 'LOCAL_STREAM_OBTAINED', stream: this.state.localStream });
            this._notifyLocalMediaChange('video', true);
            this.emitMediaStateChange();
            this.startActivityDetection(this.state.localStream, { isLocal: true });
        } catch (error) {
            console.error('Error reopening video:', error);
            this.state.session.localUser.mediaState.video = false;
            this._notifyLocalMediaChange('video', false);
        }
    }

    async _requestNewVideoTrack() {
        const newVideoStream = await navigator.mediaDevices.getUserMedia(VIDEO_ONLY_CONSTRAINT);
        const newVideoTrack = newVideoStream.getVideoTracks()[0];

        if (!newVideoTrack) {
            throw new Error('Failed to get video track');
        }

        return newVideoTrack;
    }

    _replaceLocalVideoTrack(newVideoTrack) {
        if (this.state.localStream) {
            const oldVideoTracks = this.state.localStream.getVideoTracks();
            oldVideoTracks.forEach(track => {
                track.stop();
                this.state.localStream.removeTrack(track);
            });
            this.state.localStream.addTrack(newVideoTrack);
            return;
        }

        this.state.localStream = new MediaStream([newVideoTrack]);
    }

    async _updateOutgoingVideoTrack(newVideoTrack) {
        if (!this.renderstreaming) {
            return;
        }

        console.log('Updating video track in WebRTC connection');

        if (this.role === 'host') {
            const participantIds = Object.keys(this.state.remoteStreams);
            for (const participantId of participantIds) {
                await this._updateVideoTrackForPeer(newVideoTrack, participantId);
            }
            return;
        }

        await this._updateVideoTrackForPeer(newVideoTrack);
    }

    async _updateVideoTrackForPeer(newVideoTrack, participantId = undefined) {
        const transceivers = this.renderstreaming.getTransceivers(participantId);
        if (!transceivers) {
            return;
        }

        const videoTransceivers = transceivers.filter(transceiver =>
            transceiver.sender && transceiver.sender.track && transceiver.sender.track.kind === 'video'
        );

        if (videoTransceivers.length > 0) {
            await this._replaceVideoTrackOnTransceivers(videoTransceivers, newVideoTrack, participantId);
        } else {
            this._addVideoTransceiver(newVideoTrack, participantId);
        }

        this._scheduleVideoSenderUpdate(participantId);
    }

    async _replaceVideoTrackOnTransceivers(videoTransceivers, newVideoTrack, participantId) {
        for (const transceiver of videoTransceivers) {
            try {
                await transceiver.sender.replaceTrack(newVideoTrack);
                console.log(participantId
                    ? `Replaced video track for participant ${participantId}`
                    : 'Successfully replaced video track');
            } catch (error) {
                console.error(
                    participantId
                        ? `Error replacing video track for ${participantId}:`
                        : 'Error replacing video track:',
                    error
                );
            }
        }
    }

    _addVideoTransceiver(newVideoTrack, participantId) {
        try {
            if (participantId) {
                this.renderstreaming.addTransceiver(newVideoTrack, { direction: 'sendonly' }, participantId);
                console.log(`Added new video transceiver for participant ${participantId}`);
                return;
            }

            this.renderstreaming.addTransceiver(newVideoTrack, { direction: 'sendonly' });
            console.log('Added new video transceiver');
        } catch (error) {
            console.error(
                participantId
                    ? `Error adding video transceiver for ${participantId}:`
                    : 'Error adding video transceiver:',
                error
            );
        }
    }

    _scheduleVideoSenderUpdate(participantId) {
        setTimeout(() => { this.setCodecPreferences(participantId); }, 100);
        setTimeout(() => { this.setVideoEncodingParameters(participantId); }, 200);
    }

    _disableLocalVideoTracks() {
        if (!this.state.localStream) {
            return;
        }

        this.state.session.localUser.mediaState.video = false;
        this.state.localStream.getTracks().forEach(track => {
            if (track.kind === 'video') {
                track.stop();
            }
        });
    }

    _setLocalAudioTrackEnabled(value) {
        if (!this.state.localStream) {
            return;
        }

        this.state.session.localUser.mediaState.audio = value;
        this.state.localStream.getTracks().forEach(track => {
            if (track.kind === 'audio') {
                track.enabled = value;
            }
        });
    }

    _notifyLocalMediaChange(mediaType, value) {
        this.notify({ type: 'LOCAL_MEDIA_CHANGE', mediaType, value });
    }

    _notifyUserListUpdate() {
        this.notify({
            type: 'USER_LIST_UPDATE',
            localUser: this.state.session.localUser,
            remoteUser: this.state.session.remoteUser
        });
    }

    /**
     * 早期连接WebSocket信令（在connect视图调用）
     * 仅建立WebSocket连接，不创建/加入房间
     * @async
     * @returns {Promise<WebSocketSignaling|Signaling>} 信令实例
     */
    async connectSignaling() {
        // 先获取配置
        await this.setupConfig();

        if (this._signaling) {
            console.log('Signaling already connected, reusing existing instance');
            return this._signaling;
        }

        // 创建信令实例
        this._signaling = this.useWebSocket ? new WebSocketSignaling() : new Signaling();
        await this._signaling.start();
        this._bindSocketInviteEvents(this._signaling);
        console.log('Signaling connected (WebSocket only, no room yet)');
        return this._signaling;
    }

    _bindSocketInviteEvents(signaling) {
        if (!signaling || this._socketInviteBound || typeof signaling.addEventListener !== 'function') {
            return;
        }

        ['invite-call', 'invite-accepted', 'invite-rejected', 'invite-failed'].forEach((eventName) => {
            signaling.addEventListener(eventName, (event) => {
                const handler = this.socketEventHandlers[eventName];
                if (typeof handler === 'function') {
                    handler(event.detail);
                }
            });
        });

        this._socketInviteBound = true;
    }

    onSocketEvent(eventName, handler) {
        this.socketEventHandlers[eventName] = handler;
    }

    getActiveSignaling() {
        if (this._signaling) {
            return this._signaling;
        }

        if (this.renderstreaming && this.renderstreaming._signaling) {
            return this.renderstreaming._signaling;
        }

        return null;
    }

    sendInviteCall(payload) {
        const signaling = this.getActiveSignaling();
        if (!signaling || typeof signaling.sendInviteCall !== 'function') {
            throw new Error('Invite signaling is not ready');
        }
        signaling.sendInviteCall(payload);
    }

    sendInviteAccepted(payload) {
        const signaling = this.getActiveSignaling();
        if (!signaling || typeof signaling.sendInviteAccepted !== 'function') {
            throw new Error('Invite signaling is not ready');
        }
        signaling.sendInviteAccepted(payload);
    }

    sendInviteRejected(payload) {
        const signaling = this.getActiveSignaling();
        if (!signaling || typeof signaling.sendInviteRejected !== 'function') {
            throw new Error('Invite signaling is not ready');
        }
        signaling.sendInviteRejected(payload);
    }

    /**
     * 在仅建立WebSocket连接时同步当前用户信息
     * @param {{ id?: string, name?: string, avatar?: string } | null} userInfo - 用户信息
     */
    syncSocketUserInfo(userInfo = null) {
        const settings = userInfo || (() => {
            try {
                return JSON.parse(localStorage.getItem('userSettings') || '{}');
            } catch (error) {
                console.error('Error parsing user settings:', error);
                return {};
            }
        })();

        const payload = {
            id: settings.id || settings.userId || this.state.session.localUser.id || '',
            name: settings.name || this.state.session.localUser.name || '我',
            avatar: settings.avatar || this.state.session.localUser.avatar || '/images/p1.png'
        };

        this.state.session.localUser = {
            ...this.state.session.localUser,
            id: payload.id,
            name: payload.name,
            avatar: payload.avatar
        };

        if (this._signaling && typeof this._signaling.sendMessage === 'function') {
            this._signaling.sendMessage('', {
                type: 'user-info',
                data: payload
            });
        }
    }

    /**
     * 创建信令和RTC实例
     * @async
     * @param {string} connectionId - 连接ID
     * @returns {Promise<void>}
     */
    async _createSignalingAndRTC(connectionId) {
        this.connectionId = connectionId; // 获取连接ID
        // 设置状态为连接中
        this.state.session.status = 'connecting';
        this.notify({ type: 'CALL_STATUS_CHANGE', status: 'connecting' });

        // 确保本地流已经初始化
        if (!this.state.localStream) {
            console.log('Local stream not available, waiting for initialization...');
            // 等待localStream初始化
            await new Promise((resolve) => {
                const checkStream = () => {
                    if (this.state.localStream) {
                        resolve();
                    } else {
                        setTimeout(checkStream, 100);
                    }
                };
                checkStream();
            });
        }

        // 复用已有信令实例（connectSignaling()已建立WebSocket），或创建新实例
        const signaling = this._signaling || (this.useWebSocket ? new WebSocketSignaling() : new Signaling());
        const config = getRTCConfiguration(); // 获取RTC配置
        this.renderstreaming = new RenderStreaming(signaling, config);
        this._signaling = null; // RenderStreaming 已接管信令，清除引用
    }

    /**
     * 设置WebRTC连接
     * @async
     * @returns {Promise<void>}
     */
    async setUp(connectionId) {
        await this._createSignalingAndRTC(connectionId);
        this._registerCallbacks();
        await this._startConnection(connectionId);
    }

    /**
     * 注册所有WebRTC回调
     */
    _registerCallbacks() {
        this.renderstreaming.onNewPeer = (participantId) => {
            console.log(`New peer created for ${participantId}, adding local tracks`);
            if (this.state.localStream) {
                const tracks = this.state.localStream.getTracks();
                for (const track of tracks) {
                    this.renderstreaming.addTransceiver(track, { direction: 'sendonly' }, participantId);
                }
                this.setCodecPreferences(participantId);
                this.setVideoEncodingParameters(participantId);
            }
        };

        // 连接建立回调
        this.renderstreaming.onConnect = (connectionId, data) => {
            // 保存角色信息（host/participant）
            if (data && data.role) {
                this.role = data.role;
                // 更新localUser的isHost标志
                this.state.session.localUser.isHost = (this.role === 'host');
                // 保存自身的participantId，用于从participants-sync中过滤自身
                if (data.participantId) {
                    this.selfParticipantId = data.participantId;
                }
                console.log(`Connected as ${this.role}, participantId: ${this.selfParticipantId}`);
            }
            // 连接建立后，更新状态为ongoing
            this.state.session.status = 'ongoing';
            this.notify({ type: 'CALL_STATUS_CHANGE', status: 'ongoing' });

            // 参与者加入时默认静音：禁用音频轨道并更新状态
            if (this.role === 'participant') {
                if (this.state.localStream) {
                    this.state.localStream.getAudioTracks().forEach(track => {
                        track.enabled = false;
                    });
                }
                this.state.session.localUser.mediaState.audio = false;
                this.notify({ type: 'LOCAL_MEDIA_CHANGE', mediaType: 'audio', value: false });
                console.log('Participant joined with audio muted by default');
            }

            // 连接建立后发送本地用户信息
            this.sendMessage('user-info', {
                id: this.state.session.localUser.id,
                name: this.state.session.localUser.name,
                avatar: this.state.session.localUser.avatar
            });

            // 发送当前媒体状态，确保远端收到正确的初始状态
            this.emitMediaStateChange();

            if (this.state.localStream) {
                // const tracks = this.state.localStream.getTracks();
                // for (const track of tracks) {
                //     this.renderstreaming.addTransceiver(track, { direction: 'sendonly' });
                // }
                // this.setCodecPreferences();
                this.showStatsMessage();
            } else {
                console.error('Local stream is not available');
                showNotification('本地视频流不可用', 'error');
            }
        };

        // 连接断开回调（收到服务器的 disconnect 消息，通常是 host 离开导致房间关闭）
        this.renderstreaming.onDisconnect = () => {
            console.log('Received disconnect from server, host left or room closed');
            this.hangUp(); // 房间已关闭，挂断连接
        };

        // SDP Answer 接收回调：重新设置编码参数以保障画质
        this.renderstreaming.onGotAnswer = (connectionId) => {
            console.log('SDP Answer received, resetting encoding parameters for connectionId:', connectionId);
            if (this.role === 'host') {
                const allParticipantIds = Object.keys(this.state.remoteStreams || {});
                for (const pid of allParticipantIds) {
                    setTimeout(() => { this.setVideoEncodingParameters(pid); }, 50);
                }
            } else {
                setTimeout(() => { this.setVideoEncodingParameters(); }, 50);
            }
        };

        // participant加入回调（host收到，新participant加入房间）
        this.renderstreaming.onParticipantJoined = (participantId) => {
            console.log(`Participant joined: ${participantId}`);
            this._upsertParticipant(participantId);
            this._notifyParticipantsUpdate();
            this.broadcastParticipantsList();
        };

        // participant离开回调（host收到，房间仍然存在）
        this.renderstreaming.onParticipantLeft = (participantId) => {
            console.log(`Participant left: ${participantId}, room still active`);
            this.updateRemoteUserStatus('offline');
            this.updateRemoteUserNetworkQuality('no_signal');
            showNotification('对方已离开通话', 'warning');
            // 清理该 participant 的远端流
            if (this.state.remoteStreams[participantId]) {
                this.state.remoteStreams[participantId].getTracks().forEach(track => track.stop());
                delete this.state.remoteStreams[participantId];
            }
            if (this.state.remoteStream) {
                this.state.remoteStream.getTracks().forEach(track => track.stop());
                this.state.remoteStream = null;
            }
            // 清理该 participant 的用户信息
            this._removeParticipant(participantId);
            // 通知UI更新，用participantId作为connectionId传给renderer
            this.notify({ type: 'PARTICIPANT_LEFT', connectionId: participantId });
            this._notifyParticipantsUpdate();
            this.broadcastParticipantsList();
        };

        // 轨道事件回调
        this.renderstreaming.onTrackEvent = (data) => {
            this._handleTrackEvent(data);
        };

        this.renderstreaming.onMessage = (data) => {
            this._handleRenderStreamingMessage(data);
        };
    }

    /**
     * 启动WebRTC连接和检测
     * @async
     * @param {string} connectionId - 连接ID
     * @returns {Promise<void>}
     */
    async _startConnection(connectionId) {
        // 启动WebRTC连接
        await this.renderstreaming.start();
        await this.renderstreaming.createConnection(connectionId);

        // 启动网络质量检测
        this.startNetworkQualityDetection();

        // 启动本地音频活动检测
        this.startActivityDetection(this.state.localStream, { isLocal: true });
        //启动远端音频活动检测
        this.startActivityDetection(this.state.remoteStream, { isLocal: false });
    }

    /**
 * 挂断WebRTC连接
 * Host挂断：房间删除，通知所有participants
 * Participant挂断：仅自己离开，房间保留
 * @async
 * @returns {Promise<void>}
 */
    async hangUp() {
        this.clearStatsMessage(); // 清除统计信息
        this.stopNetworkQualityDetection(); // 停止网络质量检测
        // 停止通话时长计时器
        if (this.durationInterval) {
            clearInterval(this.durationInterval);
            this.durationInterval = null;
        }
        // 重置通话时长同步标志
        this.durationSynced = false;

        const isHost = this.role === 'host';
        console.log(`Disconnect peer on ${this.connectionId}. Role: ${this.role}`);

        // 删除连接并停止WebRTC
        if (this.renderstreaming) {
            try {
                // 发送断开连接信令给服务器
                // 服务器会根据角色决定：
                // - host断开：通知所有participants，删除房间
                // - participant断开：仅通知host，保留房间
                await this.renderstreaming.deleteConnection();
                await this.renderstreaming.stop();
            } catch (error) {
                console.error('Error during hangUp:', error);
            }
            this.renderstreaming = null;
        }

        // 更新远程用户状态为离线
        this.updateRemoteUserStatus('offline');
        this.updateRemoteUserNetworkQuality('no_signal');
        // 清理participants
        this.state.participants = {};
        this.selfParticipantId = null;
        this.connectionId = null;
        this.role = null;
        this.state.session.status = 'ended';
        this.notify({ type: 'CALL_ENDED', reason: isHost ? 'host_hangup' : 'participant_hangup' });
    }

    _handleTrackEvent(data) {
        const direction = data.transceiver.direction;

        if (direction === 'sendrecv' || direction === 'recvonly') {
            this._handleIncomingTrack(data);
            return;
        }

        if (direction === 'sendonly' && data.track.kind === 'audio') {
            this.startActivityDetection(this.state.localStream, { isLocal: true });
        }
    }

    _handleIncomingTrack(data) {
        const trackParticipantId = data.participantId || this.connectionId;
        const isHost = this.role === 'host';
        const targetStream = this._getOrCreateRemoteStream(trackParticipantId, isHost);

        this._replaceTrackOfSameKind(targetStream, data.track);
        console.log('Added new track:', data.track.kind, 'for participant:', trackParticipantId);

        if (isHost && !this.state.participants[trackParticipantId]) {
            this._upsertParticipant(trackParticipantId);
            this._notifyParticipantsUpdate();
            this.broadcastParticipantsList();
        }

        this._notifyRemoteStreamUpdate(targetStream, trackParticipantId, isHost, data.track.kind);

        if (this.state.session.remoteUser.status !== 'online') {
            this.updateRemoteUserStatus('online');
            this.updateRemoteUserNetworkQuality('good');
            this.sendMessage('user-info', {
                id: this.state.session.localUser.id,
                name: this.state.session.localUser.name,
                avatar: this.state.session.localUser.avatar
            });
            this._startDurationTimer();
        }

        if (data.track.kind === 'audio') {
            this.startActivityDetection(this.state.remoteStream, { isLocal: false });
        }
    }

    _getOrCreateRemoteStream(trackParticipantId, isHost) {
        if (isHost) {
            if (!this.state.remoteStreams[trackParticipantId]) {
                this.state.remoteStreams[trackParticipantId] = new MediaStream();
            }
            return this.state.remoteStreams[trackParticipantId];
        }

        if (this.state.remoteStream == null) {
            this.state.remoteStream = new MediaStream();
        }

        return this.state.remoteStream;
    }

    _replaceTrackOfSameKind(targetStream, track) {
        const existingTracks = targetStream.getTracks().filter(existingTrack => existingTrack.kind === track.kind);
        existingTracks.forEach(existingTrack => {
            targetStream.removeTrack(existingTrack);
            console.log('Removed old track:', existingTrack.kind);
        });

        targetStream.addTrack(track);
    }

    _notifyRemoteStreamUpdate(targetStream, trackParticipantId, isHost, trackKind) {
        const notifyStreamUpdate = () => {
            this.notify({
                type: 'REMOTE_STREAM_OBTAINED',
                stream: targetStream,
                connectionId: trackParticipantId,
                isHost
            });
            console.log('Notified UI about remote stream update');
        };

        if (trackKind === 'audio' && targetStream.getVideoTracks().length === 0) {
            console.log('Audio track arrived first, delaying stream notification for video track...');
            setTimeout(() => {
                const nowHasVideo = targetStream.getVideoTracks().length > 0;
                console.log(`After delay, stream has video: ${nowHasVideo}`);
                notifyStreamUpdate();
            }, 200);
            return;
        }

        notifyStreamUpdate();
    }

    _handleRenderStreamingMessage(data) {
        console.log('收到消息:', data);

        switch (data.type) {
            case 'chat-message':
                this._handleChatMessage(data);
                break;
            case 'media-state-changed':
                this._handleMediaStateChangedMessage(data);
                break;
            case 'user-info':
                this._handleUserInfoMessage(data);
                break;
            case 'participants-sync':
                this._handleParticipantsSyncMessage(data);
                break;
            default:
                break;
        }
    }

    _handleChatMessage(data) {
        const chatPayload = data.data || data.message;
        if (!chatPayload) {
            return;
        }

        chatMessage.handleChatMessage(chatPayload);

        if (data.participantId && this.role === 'host' && this.state.participants[data.participantId]) {
            this._upsertParticipant(data.participantId, {
                id: chatPayload.senderId,
                ...(chatPayload.senderName ? { name: chatPayload.senderName } : {}),
                ...(chatPayload.senderAvatar ? { avatar: chatPayload.senderAvatar } : {})
            });
            this._notifyParticipantsUpdate();
            this.broadcastParticipantsList();
            return;
        }

        if (!this.role || this.role !== 'host') {
            if (data.participantId && this.state.participants[data.participantId]) {
                this._upsertParticipant(data.participantId, {
                    ...(chatPayload.senderName ? { name: chatPayload.senderName } : {}),
                    ...(chatPayload.senderAvatar ? { avatar: chatPayload.senderAvatar } : {})
                });
                this._notifyParticipantsUpdate();
            } else if (chatPayload.senderId !== this.state.session.localUser.id) {
                this._updateRemoteUserProfile({
                    id: chatPayload.senderId,
                    name: chatPayload.senderName,
                    avatar: chatPayload.senderAvatar
                });
            }
        }
    }

    _handleMediaStateChangedMessage(data) {
        console.log('收到媒体状态变化:', data.data, 'from participant:', data.participantId);

        if (this.role === 'host') {
            if (data.participantId && this.state.participants[data.participantId]) {
                this._upsertParticipant(data.participantId, {
                    mediaState: data.data
                });
            }

            this.updateRemoteMedia(data.data, data.participantId);
            this._notifyParticipantsUpdate();
            this.broadcastParticipantsList();
            return;
        }

        if (data.participantId && data.participantId !== this.selfParticipantId && this.state.participants[data.participantId]) {
            this._upsertParticipant(data.participantId, {
                mediaState: data.data
            });
            this._notifyParticipantsUpdate();
            return;
        }

        if (data.participantId === this.selfParticipantId) {
            return;
        }

        console.log('Received media-state-changed from Host, updating remoteUser:', data.data);
        this.updateRemoteMedia(data.data, data.participantId);
        this._notifyParticipantsUpdate();
    }

    _handleUserInfoMessage(data) {
        console.log('收到用户信息:', data.data, 'from participant:', data.participantId);
        if (!data.data) {
            return;
        }

        if (data.participantId && this.role === 'host') {
            this._upsertParticipant(data.participantId, {
                id: data.data.id || '',
                name: data.data.name || DEFAULT_PARTICIPANT_NAME,
                avatar: data.data.avatar || DEFAULT_PARTICIPANT_AVATAR
            });
            this._notifyParticipantsUpdate();
            this.broadcastParticipantsList();
            return;
        }

        this._updateRemoteUserProfile({
            id: data.data.id || this.state.session.remoteUser.id,
            name: data.data.name || this.state.session.remoteUser.name,
            avatar: data.data.avatar || this.state.session.remoteUser.avatar
        });
    }

    _handleParticipantsSyncMessage(data) {
        if (this.role === 'host' || !data.data) {
            return;
        }

        console.log('收到成员列表同步:', data.data);
        this.state.participants = omitParticipant(data.data, this.selfParticipantId);
        this._notifyParticipantsUpdate();
        this._syncCallDuration(data.callDuration);
    }

    _updateRemoteUserProfile(profile) {
        this.state.session.remoteUser = {
            ...this.state.session.remoteUser,
            ...profile
        };
        this.notify({ type: 'REMOTE_MEDIA_CHANGE', mediaState: this.state.session.remoteUser.mediaState });
    }

    _syncCallDuration(callDuration) {
        if (this.durationSynced || typeof callDuration !== 'number') {
            return;
        }

        this.state.session.duration = callDuration;
        this.durationSynced = true;
        this._startDurationTimer();
        this.notify({ type: 'DURATION_UPDATE', duration: this.state.session.duration });
        console.log(`通话时长已同步，当前时长: ${callDuration}秒`);
    }

    _startDurationTimer() {
        if (this.durationInterval) {
            return;
        }

        this.durationInterval = setInterval(() => {
            this.state.session.duration++;
            this.notify({ type: 'DURATION_UPDATE', duration: this.state.session.duration });
        }, 1000);
    }

    /**
     * 发送消息
     * @param {string} type - 消息类型
     * @param {Object} data - 消息数据
     */
    sendMessage(type, data) {
        if (this.renderstreaming) {
            this.renderstreaming.sendMessage({
                type: type,
                data: data
            });
        }
    }

    /**
     * Participant state helpers
     */
    _notifyParticipantsUpdate() {
        this.notify({ type: 'PARTICIPANTS_UPDATE', participants: this.state.participants });
    }

    _upsertParticipant(participantId, patch = {}) {
        return upsertParticipant(this.state.participants, participantId, patch);
    }

    _removeParticipant(participantId) {
        return removeParticipant(this.state.participants, participantId);
    }

    /**
     * Host端广播完整成员列表给所有Participant
     * 包含Host自身信息 + 所有Participant信息
     * Participant收到后可展示完整通话成员列表
     */
    broadcastParticipantsList() {
        if (this.role !== 'host' || !this.renderstreaming) return;

        const memberList = buildParticipantsSyncData(this.state.session.localUser, this.state.participants);

        this.renderstreaming.sendMessage({
            type: 'participants-sync',
            data: memberList,
            callDuration: this.state.session.duration
        });
        console.log('Broadcast participants list:', Object.keys(memberList));
    }

    /**
     * 设置编解码器偏好
     * 优先选择 VP9/AV1（更高效的压缩），回退到 H264 High Profile
     */
    setCodecPreferences(participantId) {
        const capabilities = RTCRtpSender.getCapabilities('video');
        if (!capabilities || !capabilities.codecs || capabilities.codecs.length === 0) return;
        const { codecs } = capabilities;

        // 构建多codec优先级列表（而非只选一个）
        let selectedCodecs = [];

        const av1Codec = codecs.find(c => c.mimeType === 'video/AV1');
        const vp9Codec = codecs.find(c => c.mimeType === 'video/VP9');
        const h264HighCodec = codecs.find(c =>
            c.mimeType === 'video/H264' &&
            c.sdpFmtpLine && c.sdpFmtpLine.includes('profile-level-id=6400')
        );
        const h264Codec = codecs.find(c => c.mimeType === 'video/H264');

        if (av1Codec) selectedCodecs.push(av1Codec);
        if (vp9Codec) selectedCodecs.push(vp9Codec);
        if (h264HighCodec) selectedCodecs.push(h264HighCodec);
        if (h264Codec && (!h264HighCodec || h264Codec !== h264HighCodec)) selectedCodecs.push(h264Codec);

        if (selectedCodecs.length === 0) return;

        if (this.renderstreaming) {
            const transceivers = this.renderstreaming.getTransceivers(participantId);
            if (transceivers && transceivers.length > 0) {
                const videoTransceivers = transceivers.filter(t => {
                    if (t.sender && t.sender.track) {
                        return t.sender.track.kind === 'video';
                    }
                    return t.mid !== null && t.receiver && t.receiver.track && t.receiver.track.kind === 'video';
                });
                if (videoTransceivers && videoTransceivers.length > 0) {
                    videoTransceivers.forEach(t => {
                        try {
                            t.setCodecPreferences(selectedCodecs);
                        } catch(e) {
                            console.error('Error setting codec preferences:', e);
                        }
                    });
                    console.log(`Codec preferences set: ${selectedCodecs.map(c => c.mimeType).join(' > ')}`);
                }
            }
        }
    }

    /**
     * 设置视频发送编码参数
     * 提升 maxBitrate 以改善远端视频画质
     * @param {string} [participantId] - 目标participant（host端使用）
     */
    setVideoEncodingParameters(participantId) {
        if (!this.renderstreaming) return;

        const transceivers = this.renderstreaming.getTransceivers(participantId);
        if (!transceivers || transceivers.length === 0) return;

        const videoTransceivers = transceivers.filter(t =>
            t.sender && t.sender.track && t.sender.track.kind === 'video'
        );

        for (const transceiver of videoTransceivers) {
            try {
                const sender = transceiver.sender;
                const params = sender.getParameters();

                if (!params.encodings || params.encodings.length === 0) {
                    params.encodings = [{}];
                }

                // 根据实际采集分辨率动态设置maxBitrate
                const videoTrack = sender.track;
                const settings = videoTrack ? videoTrack.getSettings() : {};
                const height = settings.height || 1080;

                const maxBitrate = getAdaptiveVideoBitrate(height);

                params.encodings[0].maxBitrate = maxBitrate;
                params.encodings[0].scaleResolutionDownBy = 1.0;
                params.encodings[0].xGoogleMinBitrate = Math.floor(maxBitrate * 0.5);

                // 优先保持分辨率，降低帧率来适应带宽
                // 'maintain-resolution' 在带宽不足时保持清晰度
                if (params.degradationPreference !== undefined) {
                    params.degradationPreference = 'maintain-resolution';
                }

                sender.setParameters(params);
                console.log(`Set video encoding: maxBitrate=${maxBitrate / 1000000}Mbps, scaleResolutionDownBy=1.0, xGoogleMinBitrate=${Math.floor(maxBitrate * 0.5)}${participantId ? ` for ${participantId}` : ''}`);
            } catch (error) {
                console.error('Error setting video encoding parameters:', error);
            }
        }
    }


    /**
     * 动态切换视频分辨率
     * 使用 MediaStreamTrack.applyConstraints() 在通话中实时调整
     * 同时根据分辨率调整编码比特率
     * @param {number} width - 目标宽度
     * @param {number} height - 目标高度
     */
    async changeResolution(width, height) {
        if (!this.state.localStream) {
            showNotification('本地视频流不可用', 'error');
            return;
        }

        const videoTracks = this.state.localStream.getVideoTracks();
        if (videoTracks.length === 0) {
            showNotification('视频轨道不可用', 'error');
            return;
        }

        const track = videoTracks[0];
        const label = getResolutionLabel(height);

        try {
            // 使用 applyConstraints 在不重新获取流的情况下调整分辨率
            await track.applyConstraints({
                width: { ideal: width, max: width },
                height: { ideal: height, max: height },
                frameRate: { ideal: 30, max: 30 }
            });

            console.log(`分辨率已切换为 ${width}x${height}`);

            // 根据分辨率调整编码比特率
            // 480p: ~1Mbps, 720p: ~2.5Mbps, 1080p: ~4Mbps, 2K: ~6Mbps
            const maxBitrate = getTargetResolutionBitrate(height);
            this._applyMaxBitrate(maxBitrate);

            // 保存当前分辨率设置到本地存储
            const userSettings = JSON.parse(localStorage.getItem('userSettings') || '{}');
            userSettings.resolution = { width, height };
            localStorage.setItem('userSettings', JSON.stringify(userSettings));

            // 通知 UI 更新
            this.notify({ type: 'RESOLUTION_CHANGED', resolution: { width, height, label } });
            showNotification(`已切换为 ${label}`, 'success');
        } catch (error) {
            console.error('切换分辨率失败:', error);
            showNotification('切换分辨率失败，摄像头不支持该分辨率', 'error');
        }
    }

    /**
     * 对所有视频 sender 应用 maxBitrate
     * @param {number} maxBitrate - 最大比特率（bps）
     */
    _applyMaxBitrate(maxBitrate) {
        if (!this.renderstreaming) return;

        const isHost = this.role === 'host';
        const participantIds = isHost ? Object.keys(this.state.participants) : [null];

        for (const pid of participantIds) {
            const transceivers = this.renderstreaming.getTransceivers(pid);
            if (!transceivers) continue;

            const videoTransceivers = transceivers.filter(t =>
                t.sender && t.sender.track && t.sender.track.kind === 'video'
            );

            for (const transceiver of videoTransceivers) {
                try {
                    const sender = transceiver.sender;
                    const params = sender.getParameters();
                    if (!params.encodings || params.encodings.length === 0) {
                        params.encodings = [{}];
                    }
                    params.encodings[0].maxBitrate = maxBitrate;
                    sender.setParameters(params);
                    console.log(`Updated maxBitrate to ${maxBitrate} for ${pid || 'self'}`);
                } catch (error) {
                    console.error('Error updating maxBitrate:', error);
                }
            }
        }
    }

    // 更新远端媒体状态 (由 WebSocket 触发)
    updateRemoteMedia(mediaState, participantId) {
        this.state.session.remoteUser.mediaState = {
            ...this.state.session.remoteUser.mediaState,
            ...mediaState
        };
        this.notify({ type: 'REMOTE_MEDIA_CHANGE', mediaState, participantId });
        // 通知UI更新用户列表
        this.notify({ type: 'USER_LIST_UPDATE', localUser: this.state.session.localUser, remoteUser: this.state.session.remoteUser });
    }

    // 更新远端用户状态
    updateRemoteUserStatus(status) {
        this.state.session.remoteUser.status = status;
        this.notify({ type: 'REMOTE_MEDIA_CHANGE', localUser: this.state.session.localUser, remoteUser: this.state.session.remoteUser });
    }
    updateRemoteUserNetworkQuality(networkQuality) {
        this.state.session.remoteUser.networkQuality = networkQuality;
        this.notify({ type: 'REMOTE_MEDIA_CHANGE', localUser: this.state.session.localUser, remoteUser: this.state.session.remoteUser });
    }
    // 结束通话（用户主动点击挂断按钮）
    async endCall() {
        console.log(`endCall called. Role: ${this.role}`);
        // 调用 hangUp() 正确关闭 WebRTC 连接并发送断开信令
        // hangUp 内部会根据角色区分：
        // - host: 通知所有participants，删除房间
        // - participant: 仅自己离开，房间保留
        await this.hangUp();
    }

    // 加入通话
    async joinCall(connectionId) {
        this.state.session.status = 'connecting';
        this.notify({ type: 'CALL_STATUS_CHANGE', status: 'connecting' });
        showNotification(`正在加入通话 (${connectionId})`);

        // 初始化
        await this.init();

        // 保存连接ID
        this.connectionId = connectionId;
    }

    // 创建通话
    async createCall() {
        this.state.session.status = 'connecting';
        this.notify({ type: 'CALL_STATUS_CHANGE', status: 'connecting' });
        showNotification('正在创建通话...');

        // 初始化
        await this.init();
    }

    // 真实网络质量检测
    async detectNetworkQuality() {
        if (!this.renderstreaming) {
            return;
        }

        try {
            const stats = await this.renderstreaming.getStats();
            if (!stats) {
                return;
            }

            const summary = summarizeInboundStats(stats);
            const quality = getNetworkQualityFromSummary(summary);

            // 更新网络质量状态
            if (this.state.session.remoteUser.networkQuality !== quality) {
                this.state.session.remoteUser.networkQuality = quality;
                this.notify({ type: 'NETWORK_CHANGE', quality });
            }

        } catch (error) {
            console.error('Error detecting network quality:', error);
        }
    }
    // 音频活动检测
    startActivityDetection(stream, { isLocal = false } = {}) {
        if (!stream) {
            return;
        }

        const audioTracks = stream.getAudioTracks();
        if (audioTracks.length === 0) {
            return;
        }

        try {
            const { threshold, debounceTime, fftSize } = VAD_CONFIG;

            const audioContext = new (window.AudioContext || window.webkitAudioContext)();
            const source = audioContext.createMediaStreamSource(stream);
            const analyser = audioContext.createAnalyser();
            analyser.fftSize = fftSize;

            source.connect(analyser);

            const dataArray = new Uint8Array(analyser.frequencyBinCount);
            let isSpeaking = false;
            let lastActivityTime = 0;

            const detectActivity = () => {
                if (!stream || !this.renderstreaming) {
                    return;
                }

                analyser.getByteTimeDomainData(dataArray);

                let sum = 0;
                for (let i = 0; i < dataArray.length; i++) {
                    const amplitude = dataArray[i] - 128;
                    sum += amplitude * amplitude;
                }
                const rms = Math.sqrt(sum / dataArray.length);
                const level = rms / 128;

                const currentTime = Date.now();
                if (level > threshold / 100) {
                    lastActivityTime = currentTime;
                    if (!isSpeaking) {
                        isSpeaking = true;
                        if (isLocal) {
                            this.state.session.localUser.mediaState.isSpeaking = true;
                            this.notify({ type: 'LOCAL_MEDIA_CHANGE', mediaType: 'isSpeaking', value: true });
                            this.emitMediaStateChange();
                        } else {
                            this.updateRemoteMedia({ isSpeaking: true });
                        }
                    }
                } else if (isSpeaking && currentTime - lastActivityTime > debounceTime) {
                    isSpeaking = false;
                    if (isLocal) {
                        this.state.session.localUser.mediaState.isSpeaking = false;
                        this.notify({ type: 'LOCAL_MEDIA_CHANGE', mediaType: 'isSpeaking', value: false });
                        this.emitMediaStateChange();
                    } else {
                        this.updateRemoteMedia({ isSpeaking: false });
                    }
                }

                if (this.state.session.status === 'ongoing') {
                    requestAnimationFrame(detectActivity);
                }
            };

            detectActivity();

            console.log(`${isLocal ? 'Local' : 'Remote'} activity detection started`);

        } catch (error) {
            console.error(`Error starting ${isLocal ? 'local' : 'remote'} activity detection:`, error);
        }
    }
    // 启动网络质量检测
    startNetworkQualityDetection() {
        // 每3秒检测一次网络质量
        this.networkQualityInterval = setInterval(() => {
            this.detectNetworkQuality();
        }, 3000);
    }

    // 停止网络质量检测
    stopNetworkQualityDetection() {
        if (this.networkQualityInterval) {
            clearInterval(this.networkQualityInterval);
            this.networkQualityInterval = null;
        }
    }


    // 发送媒体状态到服务器
    emitMediaStateChange() {
        const payload = {
            userId: this.state.session.localUser.id,
            ...this.state.session.localUser.mediaState
        };
        console.log('[WebSocket Emit] media-state-changed:', payload);
        // 使用WebRTC发送媒体状态变化
        if (this.renderstreaming) {
            this.renderstreaming.sendMessage({
                type: 'media-state-changed',
                data: payload
            });
        }
    }

    // 显示统计信息
    async showStatsMessage() {
        console.log('Showing stats message');

        // 立即执行一次网络质量检测
        await this.detectNetworkQuality();

        // 定期显示详细统计信息
        this.statsInterval = setInterval(async () => {
            if (!this.renderstreaming) {
                return;
            }

            try {
                const stats = await this.renderstreaming.getStats();
                if (!stats) {
                    return;
                }

                const statsSummary = summarizeInboundStats(stats);

                // 输出详细统计信息
                console.log('=== WebRTC Statistics ===');
                console.log(`Network Quality: ${this.state.session.remoteUser.networkQuality}`);
                console.log('Video Stats:', {
                    'Packets Lost': statsSummary.video.packetsLost,
                    'Packets Received': statsSummary.video.packetsReceived,
                    'Packet Loss Rate': statsSummary.video.packetsReceived > 0 ?
                        `${((statsSummary.video.packetsLost / (statsSummary.video.packetsLost + statsSummary.video.packetsReceived)) * 100).toFixed(2)}%` : '0%',
                    'Jitter': `${(statsSummary.video.jitter * 1000).toFixed(2)}ms`,
                    'Round Trip Time': `${(statsSummary.video.roundTripTime * 1000).toFixed(2)}ms`,
                    'FPS': statsSummary.video.fps.toFixed(1),
                    'Bitrate': `${statsSummary.video.bitrate}kbps`
                });
                console.log('Audio Stats:', {
                    'Packets Lost': statsSummary.audio.packetsLost,
                    'Packets Received': statsSummary.audio.packetsReceived,
                    'Packet Loss Rate': statsSummary.audio.packetsReceived > 0 ?
                        `${((statsSummary.audio.packetsLost / (statsSummary.audio.packetsLost + statsSummary.audio.packetsReceived)) * 100).toFixed(2)}%` : '0%',
                    'Jitter': `${(statsSummary.audio.jitter * 1000).toFixed(2)}ms`
                });
                console.log('========================');

            } catch (error) {
                console.error('Error showing stats message:', error);
            }
        }, 5000); // 每5秒更新一次统计信息
    }

    // 清除统计信息
    clearStatsMessage() {
        console.log('Clearing stats message');

        // 清理统计信息定时器
        if (this.statsInterval) {
            clearInterval(this.statsInterval);
            this.statsInterval = null;
        }
    }

    // Getters
    getState() { return this.state; }
    getLocalUser() { return this.state.session.localUser; }
    getRemoteUser() { return this.state.session.remoteUser; }

    getConnectionId() { return this.connectionId; }

    getRenderStreaming() { return this.renderstreaming; }
}

// 创建单例实例
const store = new CallStateManager();

// 页面卸载前清理
window.addEventListener('beforeunload', async () => {
    if (!store.renderstreaming)
        return;
    await store.renderstreaming.stop(); // 停止WebRTC连接
}, true);
export default store;