pitch + pitchVariation));
utterance.rate = Math.max(0.3, Math.min(2.0, utterance.rate + rateVariation));
utterance.volume = Math.max(0.3, Math.min(1.0, utterance.volume + volumeVariation));
}

// 生成合成语音（备用方案）
async generateSyntheticSpeech(text, voiceType) {
return new Promise((resolve) => {
// 这里可以使用Web Audio API生成更复杂的语音
// 简化版：播放一个代表语音的音调
const duration = text.length * 0.3; // 根据文本长度估算时长

this.playEmotionalTone(duration, voiceType).then(resolve);
});
}

// 播放情感音调
async playEmotionalTone(duration, voiceType) {
const oscillator = this.audioContext.createOscillator();
const gainNode = this.audioContext.createGain();

// 根据声音类型设置基础频率
const baseFreq = this.getVoiceBaseFrequency(voiceType);

// 根据情感调整频率变化
const emotionVariation = this.calculateEmotionFrequencyVariation();

oscillator.type = 'sawtooth'; // 更接近人声的波形
oscillator.frequency.setValueAtTime(baseFreq, this.audioContext.currentTime);

// 添加频率变化模拟语音语调
for (let i = 0; i < 5; i++) {
const time = this.audioContext.currentTime + (i * duration / 5);
const freq = baseFreq + (emotionVariation * Math.sin(i * 0.5));
oscillator.frequency.exponentialRampToValueAtTime(freq, time);
}

// 配置音量包络
const currentTime = this.audioContext.currentTime;
gainNode.gain.setValueAtTime(0, currentTime);
gainNode.gain.linearRampToValueAtTime(0.2, currentTime + 0.1);
gainNode.gain.exponentialRampToValueAtTime(0.01, currentTime + duration);

oscillator.connect(gainNode);
gainNode.connect(this.audioContext.destination);

oscillator.start();
oscillator.stop(currentTime + duration);

return new Promise(resolve => {
oscillator.onended = () => resolve();
});
}

// 获取声音基础频率
getVoiceBaseFrequency(voiceType) {
const frequencies = {
female1: 440, // A4
female2: 494, // B4
male1: 330, // E4
male2: 294, // D4
child: 523 // C5
};
return frequencies[voiceType] || 440;
}

// 计算情感频率变化
calculateEmotionFrequencyVariation() {
const happiness = this.emotionProfile.happiness / 100;
const sadness = this.emotionProfile.sadness / 100;
const anger = this.emotionProfile.anger / 100;

let variation = 0;
variation += happiness * 50; // 喜悦增加变化
variation -= sadness * 30; // 悲伤减少变化
variation += anger * 40; // 愤怒增加变化

return variation;
}

// 添加背景音乐
async addBackgroundMusic(text) {
const instrument = this.currentInstrument;
const duration = this.calculateLineDuration(text);

// 根据歌曲段落类型选择音乐风格
const currentSection = this.sections[this.currentSectionIndex];
const style = this.getMusicStyleForSection(currentSection.type);

await this.generateBackgroundMusic(instrument, duration, style);
}

// 生成背景音乐
async generateBackgroundMusic(instrument, duration, style) {
return new Promise((resolve) => {
try {
// 创建多个振荡器模拟乐器
const oscillators = [];
const gainNodes = [];

// 根据乐器和风格创建和声
const chords = this.generateChords(style, duration);

chords.forEach((chord, index) => {
chord.notes.forEach(note => {
const oscillator = this.audioContext.createOscillator();
const gainNode = this.audioContext.createGain();

// 配置乐器音色
this.configureInstrument(oscillator, instrument);

oscillator.frequency.value = note.frequency;

// 配置音量包络
const startTime = this.audioContext.currentTime + (index * chord.duration);
gainNode.gain.setValueAtTime(0, startTime);
gainNode.gain.linearRampToValueAtTime(note.volume, startTime + 0.1);
gainNode.gain.exponentialRampToValueAtTime(0.001, startTime + chord.duration);

oscillator.connect(gainNode);
gainNode.connect(this.audioContext.destination);

oscillator.start(startTime);
oscillator.stop(startTime + chord.duration);

oscillators.push(oscillator);
gainNodes.push(gainNode);
});
});

// 设置总时长后resolve
setTimeout(() => {
resolve();
}, duration * 1000);

} catch (error) {
console.error('背景音乐生成错误:', error);
resolve();
}
});
}

// 配置乐器音色
configureInstrument(oscillator, instrument) {
const instrumentConfigs = {
piano: { type: 'sine', detune: 0 },
strings: { type: 'sawtooth', detune: 5 },
guitar: { type: 'square', detune: -3 },
flute: { type: 'sine', detune: 2 },
drums: { type: 'triangle', detune: 0 }
};

const config = instrumentConfigs[instrument] || instrumentConfigs.piano;
oscillator.type = config.type;
if (oscillator.detune) {
oscillator.detune.value = config.detune;
}
}

// 生成和弦进行
generateChords(style, duration) {
const chordProgressions = {
verse: [
{ notes: [{frequency: 261.63, volume: 0.1}, {frequency: 329.63, volume: 0.08}, {frequency: 392.00, volume: 0.06}], duration: duration / 4 },
{ notes: [{frequency: 293.