// audio.js — 音频管理器 + 合成 UI 音效

class AudioManager {
  constructor() {
    this._ctx = null;
    this._master = null;
    this._voiceQueue = [];
    this._voiceEl = null;
    this._ringEl = null;
    this._bgmEl = null;
    this._ambEl = null;
    this._preloaded = {};
  }

  // ── 初始化（必须在用户手势后调用）──
  async init() {
    this._ctx = new (window.AudioContext || window.webkitAudioContext)();
    if (this._ctx.state === 'suspended') await this._ctx.resume();
    this._master = this._ctx.createGain();
    this._master.gain.value = 1.0;
    this._master.connect(this._ctx.destination);
  }

  // ── 合成短音（UI 反馈音效）──
  synth({ freq = 440, freq2 = null, dur = 100, type = 'sine', vol = 0.3 } = {}) {
    if (!this._ctx) return;
    const t = this._ctx.currentTime;
    const d = dur / 1000;

    const osc = this._ctx.createOscillator();
    const gain = this._ctx.createGain();

    osc.type = type;
    osc.frequency.setValueAtTime(freq, t);
    if (freq2 != null) {
      osc.frequency.linearRampToValueAtTime(freq2, t + d);
    }

    gain.gain.setValueAtTime(vol, t);
    gain.gain.setValueAtTime(vol, t + d * 0.75);
    gain.gain.linearRampToValueAtTime(0, t + d);

    osc.connect(gain);
    gain.connect(this._master);
    osc.start(t);
    osc.stop(t + d + 0.05);
  }

  // ── 预加载短音效 ──
  async preload(key, url) {
    if (this._preloaded[key]) return;
    try {
      const res = await fetch(url);
      const buf = await res.arrayBuffer();
      this._preloaded[key] = await this._ctx.decodeAudioData(buf);
    } catch (e) {
      console.warn('[Audio] preload failed:', key, e);
    }
  }

  // ── 播放预加载音效 ──
  playFX(key, { vol = 1.0, loop = false } = {}) {
    const buf = this._preloaded[key];
    if (!buf) return null;
    const src = this._ctx.createBufferSource();
    src.buffer = buf;
    src.loop = loop;
    const gain = this._ctx.createGain();
    gain.gain.value = vol;
    src.connect(gain);
    gain.connect(this._master);
    src.start();
    return { src, gain, stop: () => { try { src.stop(); } catch (_) {} } };
  }

  // ── 铃声（循环）──
  async startRingtone(url) {
    this.stopRingtone();
    if (typeof TEST !== 'undefined' && TEST) return;
    this._ringEl = new Audio(url);
    this._ringEl.loop = true;
    this._ringEl.volume = 1.0;
    try { await this._ringEl.play(); } catch (e) { console.warn('[Audio] ring error', e); }
  }

  stopRingtone() {
    if (this._ringEl) {
      this._ringEl.pause();
      this._ringEl.src = '';
      this._ringEl = null;
    }
  }

  // ── 语音播放（多段顺序）──
  playVoice(urls, { vol = 1.0, onEnd = null } = {}) {
    this.stopVoice();
    if (typeof TEST !== 'undefined' && TEST) {
      if (onEnd) onEnd();
      return;
    }
    this._voiceQueue = [...urls];
    this._playNext(vol, onEnd);
  }

  _playNext(vol, onEnd) {
    if (this._voiceQueue.length === 0) {
      this._voiceEl = null;
      if (onEnd) onEnd();
      return;
    }
    const url = this._voiceQueue.shift();
    const el = new Audio(url);
    el.volume = vol;
    this._voiceEl = el;
    el.onended = () => this._playNext(vol, onEnd);
    el.onerror = () => {
      console.warn('[Audio] voice error:', url);
      this._playNext(vol, onEnd);
    };
    el.play().catch(e => console.warn('[Audio] play error', e));
  }

  stopVoice() {
    this._voiceQueue = [];
    if (this._voiceEl) {
      this._voiceEl.onended = null;
      this._voiceEl.pause();
      this._voiceEl = null;
    }
  }

  isVoicePlaying() {
    return !!(this._voiceEl && !this._voiceEl.paused);
  }

  // ── BGM（淡入淡出切换）──
  async startBGM(url, { vol = 0.35, fade = 2000 } = {}) {
    if (this._bgmEl) {
      const old = this._bgmEl;
      this._fadeOut(old, fade / 2).then(() => { old.pause(); old.src = ''; });
    }
    const el = new Audio(url);
    el.loop = true;
    el.volume = 0;
    this._bgmEl = el;
    try {
      await el.play();
      this._fadeTo(el, vol, fade);
    } catch (e) { console.warn('[Audio] BGM error', e); }
  }

  stopBGM(fade = 2000) {
    if (this._bgmEl) {
      const el = this._bgmEl;
      this._bgmEl = null;
      this._fadeOut(el, fade).then(() => { el.pause(); el.src = ''; });
    }
  }

  // ── 环境音 ──
  async startAmbience(url, { vol = 0.25 } = {}) {
    if (this._ambEl) { this._ambEl.pause(); this._ambEl.src = ''; }
    const el = new Audio(url);
    el.loop = true;
    el.volume = vol;
    this._ambEl = el;
    try { await el.play(); } catch (e) { console.warn('[Audio] ambience error', e); }
  }

  stopAmbience() {
    if (this._ambEl) { this._ambEl.pause(); this._ambEl.src = ''; this._ambEl = null; }
  }

  // ── 音量渐变 ──
  _fadeTo(el, target, duration) {
    const start = el.volume;
    const steps = 30;
    const dt = duration / steps;
    const dv = (target - start) / steps;
    let i = 0;
    const t = setInterval(() => {
      el.volume = Math.max(0, Math.min(1, start + dv * i));
      if (++i >= steps) clearInterval(t);
    }, dt);
  }

  _fadeOut(el, duration) {
    return new Promise(resolve => {
      const start = el.volume;
      const steps = 20;
      const dt = duration / steps;
      const dv = start / steps;
      let i = 0;
      const t = setInterval(() => {
        el.volume = Math.max(0, start - dv * i);
        if (++i >= steps) { clearInterval(t); resolve(); }
      }, dt);
    });
  }
}

const Snd = new AudioManager();

// ══════════════════════════════════════════════════
//  SFX_UI — 合成 UI 音效（不依赖音频文件）
// ══════════════════════════════════════════════════

const SFX_UI = {
  // 确认操作（单击）
  tap() {
    Snd.synth({ freq: 880, dur: 45, vol: 0.2 });
  },

  // 滑动确认
  swipe() {
    Snd.synth({ freq: 660, dur: 60, vol: 0.18 });
  },

  // 无效操作
  error() {
    Snd.synth({ freq: 200, dur: 100, type: 'square', vol: 0.1 });
  },

  // 新消息到达
  notify() {
    Snd.synth({ freq: 523, dur: 100, vol: 0.25 });
    setTimeout(() => Snd.synth({ freq: 659, dur: 130, vol: 0.2 }), 130);
  },

  // 进入选择模式（三音上行）
  choiceReady() {
    Snd.synth({ freq: 440, dur: 80, type: 'triangle', vol: 0.18 });
    setTimeout(() => Snd.synth({ freq: 523, dur: 80, type: 'triangle', vol: 0.18 }), 100);
    setTimeout(() => Snd.synth({ freq: 659, dur: 120, type: 'triangle', vol: 0.18 }), 200);
  },

  // 选择：温暖/接受（右滑）— 上行音
  choiceWarm() {
    Snd.synth({ freq: 440, freq2: 659, dur: 140, vol: 0.22 });
  },

  // 选择：冷淡/拒绝（左滑）— 下行音
  choiceCold() {
    Snd.synth({ freq: 523, freq2: 349, dur: 140, vol: 0.22 });
  },

  // 选择：好奇/追问（上滑）— 快速上行
  choiceCurious() {
    Snd.synth({ freq: 523, freq2: 784, dur: 120, vol: 0.22 });
  },

  // 选择：沉默/退缩（下滑）— 极轻低音
  choiceSilent() {
    Snd.synth({ freq: 330, dur: 200, vol: 0.08 });
  },

  // 跳过 / 忽略
  skip() {
    Snd.synth({ freq: 587, freq2: 392, dur: 80, vol: 0.12 });
  },

  // 下一条消息即将到来
  next() {
    Snd.synth({ freq: 440, dur: 80, vol: 0.1 });
    setTimeout(() => Snd.synth({ freq: 523, dur: 100, vol: 0.13 }), 120);
  },

  // 打字/录音音效（~800ms）
  typing() {
    for (let i = 0; i < 6; i++) {
      setTimeout(() => {
        Snd.synth({ freq: 600 + Math.random() * 200, dur: 30, type: 'sine', vol: 0.1 });
      }, i * 120);
    }
  },

  // 发送音效
  send() {
    Snd.synth({ freq: 400, freq2: 900, dur: 120, type: 'sine', vol: 0.18 });
  },

  // 结局音效
  ending() {
    Snd.synth({ freq: 523, dur: 400, vol: 0.25 });
    setTimeout(() => Snd.synth({ freq: 659, dur: 400, vol: 0.2 }), 450);
    setTimeout(() => Snd.synth({ freq: 784, dur: 600, vol: 0.15 }), 900);
  },
};