// Web Audio API Procedural Sound Synthesizer and Asset Helpers
window.PvZAudio = (function() {
  let ctx = null;
  let muted = false;

  let musicInterval = null;
  let musicPlaying = false;
  let musicStep = 0;

  const N = {
    D2: 73.42, E2: 82.41, F2: 87.31, G2: 98.00, A2: 110.00, Bb2: 116.54, B2: 123.47,
    C3: 130.81, D3: 146.83, Eb3: 155.56, E3: 164.81, F3: 174.61, G3: 196.00, A3: 220.00, Bb3: 233.08, B3: 246.94,
    C4: 261.63, Csharp4: 277.18, D4: 293.66, Eb4: 311.13, E4: 329.63, F4: 349.23, Fsharp4: 369.99, G4: 392.00, Gsharp4: 415.30, A4: 440.00, Bb4: 466.16, B4: 493.88,
    C5: 523.25, Csharp5: 554.37, D5: 587.33, Eb5: 622.25, E5: 659.25, F5: 698.46, Fsharp5: 739.99, G5: 783.99, A5: 880.00, Bb5: 932.33, B5: 987.77,
    C6: 1046.50
  };

  let currentThemeName = 'day';

  const THEMES = {
    day: {
      tempo: 230,
      bassType: 'triangle',
      leadType: 'sine',
      bassVol: 0.10,
      leadVol: 0.08,
      bass: [
        N.A2, null, N.E3, null, N.A2, null, N.E3, null,
        N.D3, null, N.A3, null, N.E3, null, N.G3, null
      ],
      lead: [
        N.A4, null, N.C5, N.E5, null, N.D5, N.C5, N.B4,
        N.A4, null, N.C5, N.A4, null, N.B4, N.C5, N.B4
      ]
    },
    night: {
      tempo: 280,
      bassType: 'sine',
      leadType: 'triangle',
      bassVol: 0.12,
      leadVol: 0.07,
      bass: [
        N.C3, null, N.G3, null, N.A2, null, N.E3, null,
        N.F3, null, N.C4, null, N.G3, null, N.B3, null
      ],
      lead: [
        N.C5, null, N.Eb5, N.G5, null, N.F5, null, N.D5,
        N.Eb5, null, N.C5, null, N.G4, null, N.Bb4, null
      ]
    },
    pool: {
      tempo: 210,
      bassType: 'triangle',
      leadType: 'sine',
      bassVol: 0.11,
      leadVol: 0.09,
      bass: [
        N.G2, null, N.D3, N.G3, N.C3, null, N.G3, N.C4,
        N.D3, null, N.A3, N.D4, N.G3, null, N.B3, null
      ],
      lead: [
        N.B4, N.D5, null, N.G5, N.Fsharp5, N.D5, null, N.B4,
        N.C5, N.E5, null, N.A5, N.G5, N.E5, N.D5, null
      ]
    },
    fog: {
      tempo: 310,
      bassType: 'sawtooth',
      leadType: 'triangle',
      bassVol: 0.07,
      leadVol: 0.07,
      bass: [
        N.D2, null, N.A2, null, N.D2, null, N.Bb2, null,
        N.A2, null, N.F2, null, N.G2, null, N.A2, null
      ],
      lead: [
        N.D5, null, null, N.F5, null, N.E5, null, N.Csharp5,
        N.D5, null, N.A4, null, null, N.F5, N.E5, null
      ]
    },
    roof: {
      tempo: 190,
      bassType: 'triangle',
      leadType: 'sawtooth',
      bassVol: 0.11,
      leadVol: 0.06,
      bass: [
        N.F3, N.F3, N.C4, N.F3, N.Bb3, N.Bb3, N.F4, N.Bb3,
        N.C3, N.C3, N.G3, N.C4, N.F3, null, N.C4, null
      ],
      lead: [
        N.F4, N.A4, N.C5, null, N.D5, N.F5, null, N.C5,
        N.Bb4, N.D5, N.F5, null, N.A5, N.G5, N.F5, null
      ]
    },
    boss: {
      tempo: 165,
      bassType: 'sawtooth',
      leadType: 'square',
      bassVol: 0.09,
      leadVol: 0.06,
      bass: [
        N.E2, N.E2, N.G2, N.E2, N.Bb2, N.A2, N.G2, N.E2,
        N.E2, N.E2, N.B2, N.Bb2, N.A2, N.G2, N.E2, N.D3
      ],
      lead: [
        N.E5, N.E5, N.G5, null, N.Bb5, N.A5, N.G5, N.E5,
        null, N.B5, N.Bb5, N.A5, null, N.G5, N.F5, N.E5
      ]
    }
  };

  function initCtx() {
    if (!ctx) {
      const AudioContext = window.AudioContext || window.webkitAudioContext;
      if (AudioContext) {
        ctx = new AudioContext();
      }
    }
    if (ctx && ctx.state === 'suspended') {
      ctx.resume();
    }
  }

  function playTone(freq, type, duration, startVol = 0.2, endVol = 0.001) {
    if (muted) return;
    initCtx();
    if (!ctx) return;
    try {
      const osc = ctx.createOscillator();
      const gain = ctx.createGain();
      osc.type = type;
      osc.frequency.setValueAtTime(freq, ctx.currentTime);
      gain.gain.setValueAtTime(startVol, ctx.currentTime);
      gain.gain.exponentialRampToValueAtTime(endVol, ctx.currentTime + duration);
      osc.connect(gain);
      gain.connect(ctx.destination);
      osc.start();
      osc.stop(ctx.currentTime + duration);
    } catch (e) {}
  }

  return {
    init: initCtx,
    toggleMute: function() {
      muted = !muted;
      return muted;
    },
    isMuted: function() {
      return muted;
    },
    playShoot: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      try {
        const osc = ctx.createOscillator();
        const gain = ctx.createGain();
        osc.type = 'triangle';
        osc.frequency.setValueAtTime(600, ctx.currentTime);
        osc.frequency.exponentialRampToValueAtTime(120, ctx.currentTime + 0.12);
        gain.gain.setValueAtTime(0.25, ctx.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.12);
        osc.connect(gain);
        gain.connect(ctx.destination);
        osc.start();
        osc.stop(ctx.currentTime + 0.12);
      } catch (e) {}
    },
    playHit: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      try {
        const osc = ctx.createOscillator();
        const gain = ctx.createGain();
        osc.type = 'square';
        osc.frequency.setValueAtTime(180, ctx.currentTime);
        osc.frequency.exponentialRampToValueAtTime(60, ctx.currentTime + 0.08);
        gain.gain.setValueAtTime(0.2, ctx.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.08);
        osc.connect(gain);
        gain.connect(ctx.destination);
        osc.start();
        osc.stop(ctx.currentTime + 0.08);
      } catch (e) {}
    },
    playSun: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      try {
        const notes = [523.25, 659.25, 783.99, 1046.50]; // C5, E5, G5, C6
        notes.forEach((freq, idx) => {
          const osc = ctx.createOscillator();
          const gain = ctx.createGain();
          osc.type = 'sine';
          osc.frequency.setValueAtTime(freq, ctx.currentTime + idx * 0.05);
          gain.gain.setValueAtTime(0.18, ctx.currentTime + idx * 0.05);
          gain.gain.exponentialRampToValueAtTime(0.001, ctx.currentTime + idx * 0.05 + 0.2);
          osc.connect(gain);
          gain.connect(ctx.destination);
          osc.start(ctx.currentTime + idx * 0.05);
          osc.stop(ctx.currentTime + idx * 0.05 + 0.2);
        });
      } catch (e) {}
    },
    playPlant: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      try {
        const osc = ctx.createOscillator();
        const gain = ctx.createGain();
        osc.type = 'sine';
        osc.frequency.setValueAtTime(220, ctx.currentTime);
        osc.frequency.exponentialRampToValueAtTime(440, ctx.currentTime + 0.1);
        gain.gain.setValueAtTime(0.3, ctx.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.15);
        osc.connect(gain);
        gain.connect(ctx.destination);
        osc.start();
        osc.stop(ctx.currentTime + 0.15);
      } catch (e) {}
    },
    playChomp: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      try {
        const osc = ctx.createOscillator();
        const gain = ctx.createGain();
        osc.type = 'sawtooth';
        osc.frequency.setValueAtTime(140, ctx.currentTime);
        osc.frequency.exponentialRampToValueAtTime(80, ctx.currentTime + 0.1);
        gain.gain.setValueAtTime(0.15, ctx.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.1);
        osc.connect(gain);
        gain.connect(ctx.destination);
        osc.start();
        osc.stop(ctx.currentTime + 0.1);
      } catch (e) {}
    },
    playExplosion: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      try {
        // Noise buffer for explosion
        const bufferSize = ctx.sampleRate * 0.5;
        const buffer = ctx.createBuffer(1, bufferSize, ctx.sampleRate);
        const data = buffer.getChannelData(0);
        for (let i = 0; i < bufferSize; i++) {
          data[i] = Math.random() * 2 - 1;
        }
        const noise = ctx.createBufferSource();
        noise.buffer = buffer;
        const filter = ctx.createBiquadFilter();
        filter.type = 'lowpass';
        filter.frequency.setValueAtTime(800, ctx.currentTime);
        filter.frequency.exponentialRampToValueAtTime(50, ctx.currentTime + 0.5);
        const gain = ctx.createGain();
        gain.gain.setValueAtTime(0.5, ctx.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.5);
        noise.connect(filter);
        filter.connect(gain);
        gain.connect(ctx.destination);
        noise.start();
      } catch (e) {}
    },
    playMower: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      try {
        const osc = ctx.createOscillator();
        const gain = ctx.createGain();
        osc.type = 'sawtooth';
        osc.frequency.setValueAtTime(90, ctx.currentTime);
        osc.frequency.linearRampToValueAtTime(240, ctx.currentTime + 1.2);
        gain.gain.setValueAtTime(0.3, ctx.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 1.2);
        osc.connect(gain);
        gain.connect(ctx.destination);
        osc.start();
        osc.stop(ctx.currentTime + 1.2);
      } catch (e) {}
    },
    playCoin: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      const osc = ctx.createOscillator();
      const gain = ctx.createGain();
      osc.type = 'sine';
      osc.frequency.setValueAtTime(987.77, ctx.currentTime); // B5
      osc.frequency.setValueAtTime(1318.51, ctx.currentTime + 0.06); // E6
      gain.gain.setValueAtTime(0.2, ctx.currentTime);
      gain.gain.exponentialRampToValueAtTime(0.001, ctx.currentTime + 0.3);
      osc.connect(gain);
      gain.connect(ctx.destination);
      osc.start();
      osc.stop(ctx.currentTime + 0.3);
    },
    playSizzle: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      try {
        const bufferSize = ctx.sampleRate * 0.8;
        const buffer = ctx.createBuffer(1, bufferSize, ctx.sampleRate);
        const data = buffer.getChannelData(0);
        for (let i = 0; i < bufferSize; i++) {
          data[i] = Math.random() * 2 - 1;
        }
        const noise = ctx.createBufferSource();
        noise.buffer = buffer;
        const filter = ctx.createBiquadFilter();
        filter.type = 'bandpass';
        filter.frequency.setValueAtTime(1400, ctx.currentTime);
        filter.frequency.exponentialRampToValueAtTime(300, ctx.currentTime + 0.8);
        const gain = ctx.createGain();
        gain.gain.setValueAtTime(0.4, ctx.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.8);
        noise.connect(filter);
        filter.connect(gain);
        gain.connect(ctx.destination);
        noise.start();
      } catch (e) {}
    },
    playMine: function() {
      this.playExplosion();
      playTone(550, 'sine', 0.15, 0.3, 0.01);
    },
    playVault: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      const osc = ctx.createOscillator();
      const gain = ctx.createGain();
      osc.type = 'triangle';
      osc.frequency.setValueAtTime(180, ctx.currentTime);
      osc.frequency.exponentialRampToValueAtTime(620, ctx.currentTime + 0.3);
      gain.gain.setValueAtTime(0.25, ctx.currentTime);
      gain.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.3);
      osc.connect(gain);
      gain.connect(ctx.destination);
      osc.start();
      osc.stop(ctx.currentTime + 0.3);
    },
    playGulp: function() {
      playTone(180, 'sine', 0.18, 0.35, 0.01);
      setTimeout(() => playTone(120, 'sine', 0.22, 0.3, 0.01), 90);
    },
    playStrike: function() {
      playTone(240, 'square', 0.1, 0.3, 0.01);
      playTone(120, 'sawtooth', 0.2, 0.35, 0.01);
    },
    playHugeWave: function() {
      playTone(180, 'sawtooth', 0.6, 0.35, 0.01);
    },
    playWin: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      const fanfare = [392, 523, 659, 784, 1046];
      fanfare.forEach((f, i) => {
        setTimeout(() => playTone(f, 'triangle', 0.35, 0.3, 0.01), i * 160);
      });
    },
    playLose: function() {
      if (muted) return;
      initCtx();
      if (!ctx) return;
      const doom = [400, 360, 320, 280, 220];
      doom.forEach((f, i) => {
        setTimeout(() => playTone(f, 'sawtooth', 0.4, 0.3, 0.01), i * 200);
      });
    },
    // Background Music (Multi-Biome Procedural Chiptune Synthesizer)
    startMusic: function(themeName = 'day') {
      const targetTheme = THEMES[themeName] ? themeName : 'day';

      if (musicPlaying && currentThemeName === targetTheme && musicInterval) {
        return;
      }

      currentThemeName = targetTheme;
      musicPlaying = true;
      initCtx();

      if (musicInterval) {
        clearInterval(musicInterval);
        musicInterval = null;
      }

      musicStep = 0;
      const theme = THEMES[currentThemeName];

      musicInterval = setInterval(() => {
        if (!musicPlaying || muted) return;
        const b = theme.bass[musicStep % theme.bass.length];
        const l = theme.lead[musicStep % theme.lead.length];
        if (b) {
          playTone(b, theme.bassType, (theme.tempo / 1000) * 1.05, theme.bassVol, 0.001);
        }
        if (l) {
          playTone(l, theme.leadType, (theme.tempo / 1000) * 0.95, theme.leadVol, 0.001);
        }
        musicStep++;
      }, theme.tempo);
    },
    setTheme: function(themeName) {
      if (musicPlaying) {
        this.startMusic(themeName);
      } else {
        currentThemeName = THEMES[themeName] ? themeName : 'day';
      }
    },
    getTheme: function() {
      return currentThemeName;
    },
    stopMusic: function() {
      musicPlaying = false;
      if (musicInterval) {
        clearInterval(musicInterval);
        musicInterval = null;
      }
    },
    toggleMusic: function() {
      if (musicPlaying) {
        this.stopMusic();
        return false;
      } else {
        this.startMusic(currentThemeName);
        return true;
      }
    },
    isMusicPlaying: function() {
      return musicPlaying;
    }
  };
})();