"""Original short, softly enveloped cues; reproducible, no external audio license."""
import math, struct, wave
from pathlib import Path
root = Path(__file__).resolve().parent.parent / 'public/assets/audio'
root.mkdir(parents=True, exist_ok=True)
for kind, notes in [('success', [(660, 0, .14), (880, .075, .16)]), ('error', [(330, 0, .17)])]:
    rate, duration = 22050, .26
    frames = []
    for i in range(int(rate * duration)):
        t = i / rate
        value = 0
        for freq, start, length in notes:
            x = t - start
            if 0 <= x < length:
                envelope = min(1, x / .012) * (1 - x / length) ** 2
                value += .32 * envelope * math.sin(2 * math.pi * freq * x)
        frames.append(struct.pack('<h', round(value * 32767)))
    with wave.open(str(root / f'learning-{kind}.wav'), 'wb') as output:
        output.setparams((1, 2, rate, 0, 'NONE', 'not compressed'))
        output.writeframes(b''.join(frames))