"""web/simon SFX 合成（numpy，44.1kHz 立体声 wav，后续 ffmpeg 转 ogg/m4a）。

6 种手势特征音 + 4 个反馈音：
  tone_up         上行琶音 C5-E5-G5-C6（明亮弹拨）
  tone_down       下行低音 A2-F2-D2-A1（浑厚）
  tone_left       E4 弹拨，声像极左
  tone_right      G4 弹拨，声像极右
  tone_tap        短促底鼓
  tone_doubletap  两声连响（木琴质感）
  correct         上行双音和弦（答对）
  wrong           失谐锯齿低鸣（答错）
  newrecord       快速号角琶音（新纪录）
  gameover        下行三音（游戏结束）
"""
import os
import numpy as np
import soundfile as sf

SR = 44100
OUT = os.path.join(os.path.dirname(__file__), "..", "audio", "sfx", "wav_tmp")
os.makedirs(OUT, exist_ok=True)


def env_adsr(n, a=0.005, d=0.05, s=0.3, r=0.08):
    """a/d/r 为秒，s 为 sustain 电平（0~1）。"""
    na, nd, nr = int(a * SR), int(d * SR), int(r * SR)
    ns = max(0, n - na - nd - nr)
    e = np.concatenate([
        np.linspace(0, 1, na, endpoint=False),
        np.linspace(1, s, nd, endpoint=False),
        np.full(ns, s),
        np.linspace(s, 0, nr),
    ])
    return e[:n] if len(e) >= n else np.pad(e, (0, n - len(e)))


def pluck(freq, dur, brightness=4, decay=6.0):
    """类弹拨/木琴：基频 + 递减泛音，指数衰减。"""
    n = int(dur * SR)
    t = np.arange(n) / SR
    sig = np.zeros(n)
    for h in range(1, brightness + 1):
        sig += (1.0 / h) * np.sin(2 * np.pi * freq * h * t)
    sig *= np.exp(-decay * t)
    return sig


def kick(dur=0.18):
    """底鼓：正弦扫频 150→45Hz + 起始咔哒噪声。"""
    n = int(dur * SR)
    t = np.arange(n) / SR
    f = 45 + (150 - 45) * np.exp(-30 * t)
    phase = 2 * np.pi * np.cumsum(f) / SR
    sig = np.sin(phase) * np.exp(-18 * t)
    click = np.random.default_rng(7).standard_normal(n) * np.exp(-400 * t) * 0.3
    return sig + click


def saw(freq, dur, detune=1.01):
    n = int(dur * SR)
    t = np.arange(n) / SR
    def s(f):
        # 加法合成锯齿（前 12 次泛音）
        out = np.zeros(n)
        for h in range(1, 13):
            out += (1.0 / h) * np.sin(2 * np.pi * f * h * t)
        return out
    sig = (s(freq) + s(freq * detune)) * 0.5
    return sig * env_adsr(n, a=0.01, d=0.1, s=0.6, r=0.15)


def stereo(mid, pan=0.0):
    """pan: -1 极左 ~ +1 极右。"""
    mid = mid / (np.max(np.abs(mid)) + 1e-9) * 0.85
    l = mid * np.sqrt((1 - pan) / 2) * np.sqrt(2)
    r = mid * np.sqrt((1 + pan) / 2) * np.sqrt(2)
    return np.stack([l, r], axis=1)


def seq(notes, gap=0.0, **kw):
    """音符序列拼接：notes = [(freq, dur), ...]，gap 为音符间隔秒。"""
    parts = []
    gapbuf = np.zeros(int(gap * SR))
    for f, d in notes:
        parts.append(pluck(f, d, **kw))
        parts.append(gapbuf)
    return np.concatenate(parts[:-1]) if parts else np.zeros(1)


def save(name, sig):
    sig = sig / (np.max(np.abs(sig)) + 1e-9) * 0.85
    if sig.ndim == 1:
        sig = np.stack([sig, sig], axis=1)
    path = os.path.join(OUT, name + ".wav")
    sf.write(path, sig, SR)
    print(path, f"{len(sig)/SR:.2f}s")


# ---- 6 手势音 ----
save("tone_up", stereo(seq([(523.25, .14), (659.25, .14), (783.99, .14), (1046.50, .30)], decay=8)))
save("tone_down", stereo(seq([(110.0, .18), (87.31, .18), (73.42, .18), (55.0, .40)], brightness=3, decay=5)))
save("tone_left", stereo(pluck(329.63, 0.4, decay=7), pan=-0.93))
save("tone_right", stereo(pluck(392.0, 0.4, decay=7), pan=0.93))
save("tone_tap", stereo(kick()))
dbl = np.concatenate([pluck(880, 0.10, decay=14), np.zeros(int(0.09 * SR)), pluck(1174.66, 0.16, decay=12)])
save("tone_doubletap", stereo(dbl))

# ---- 反馈音 ----
save("correct", stereo(seq([(783.99, .14), (1318.51, .30)], decay=9)))
save("wrong", stereo(saw(110, 0.6)))
save("newrecord", stereo(seq([(523.25, .10), (659.25, .10), (783.99, .10), (1046.50, .10), (1318.51, .35)], decay=8)))
save("gameover", stereo(seq([(392.0, .22), (311.13, .22), (246.94, .5)], brightness=3, decay=5)))