class WebRTCAudioProcessor {
    constructor() {
        this.audioContext = null;
        this.scriptProcessor = null;
        this.source = null;
        this.onProcessAudio = null; // 用于外部传入的音频处理回调
    }

    /**
     * 初始化并开始捕获音频流
     * @param {Function} onProcessAudio - 处理 PCM 数据的回调函数
     * @returns {Promise<void>}
     */
    async start(onProcessAudio) {
        if (this.audioContext) {
            console.warn('Audio processor is already running.');
            return;
        }

        if (typeof onProcessAudio !== 'function') {
            throw new Error('onProcessAudio must be a function');
        }

        this.onProcessAudio = onProcessAudio;

        try {
            // 获取用户音频流
            const stream = await navigator.mediaDevices.getUserMedia({ audio: true, video: false });
            this._setupAudioContext(stream);
        } catch (error) {
            console.error('Error accessing microphone:', error);
            throw error;
        }
    }

    /**
     * 设置 AudioContext 和音频处理节点
     * @param {MediaStream} stream - 音频流
     */
    _setupAudioContext(stream) {
        this.audioContext = new (window.AudioContext || window.webkitAudioContext)();
        this.source = this.audioContext.createMediaStreamSource(stream);

        // 创建 ScriptProcessorNode 处理音频数据
        this.scriptProcessor = this.audioContext.createScriptProcessor(4096, 1, 1);
        this.source.connect(this.scriptProcessor);
        this.scriptProcessor.connect(this.audioContext.destination);

        // 处理音频数据
        this.scriptProcessor.onaudioprocess = (event) => {
            const inputBuffer = event.inputBuffer;
            const pcmData = inputBuffer.getChannelData(0); // 获取 PCM 数据
            this.onProcessAudio(pcmData); // 调用外部传入的回调函数
        };
    }

    /**
     * 停止音频处理并释放资源
     */
    stop() {
        if (this.scriptProcessor) {
            this.scriptProcessor.disconnect();
            this.scriptProcessor = null;
        }

        if (this.source) {
            this.source.disconnect();
            this.source = null;
        }

        if (this.audioContext) {
            this.audioContext.close().then(() => {
                this.audioContext = null;
            });
        }

        this.onProcessAudio = null;
    }
}