"""Synthesises the Player's two cue sounds into assets/sounds/ (standard library only).

- stretching_cue.wav: a soft singing bowl, slow attack, long gentle decay.
- workout_cue.wav: a short, muted wooden "tok".

Both are kept quiet (peak about -12 dBFS) so they sit under the user's music.
"""

import math
import random
import struct
import wave
from pathlib import Path

RATE = 22050


def write(path: Path, samples: list[float]) -> None:
    peak = max(abs(s) for s in samples) or 1.0
    scale = 0.25 / peak  # about -12 dBFS
    with wave.open(str(path), "wb") as out:
        out.setnchannels(1)
        out.setsampwidth(2)
        out.setframerate(RATE)
        out.writeframes(b"".join(struct.pack("<h", int(s * scale * 32767)) for s in samples))


def singing_bowl(seconds: float = 2.6) -> list[float]:
    # Inharmonic partials of a bowl, each fading at its own pace, with a slight beat.
    partials = [(392.0, 1.0, 1.4), (393.2, 0.6, 1.5), (1062.0, 0.35, 0.8), (2010.0, 0.12, 0.45)]
    samples = []
    for n in range(int(seconds * RATE)):
        t = n / RATE
        attack = min(1.0, t / 0.04)
        value = sum(a * math.exp(-t / decay) * math.sin(2 * math.pi * f * t) for f, a, decay in partials)
        samples.append(attack * value)
    return samples


def wood_tok(seconds: float = 0.12) -> list[float]:
    rng = random.Random(7)
    samples = []
    for n in range(int(seconds * RATE)):
        t = n / RATE
        body = math.exp(-t / 0.018) * (math.sin(2 * math.pi * 820 * t) + 0.4 * math.sin(2 * math.pi * 1640 * t))
        click = math.exp(-t / 0.002) * (rng.random() * 2 - 1) * 0.3
        samples.append(body + click)
    return samples


def main() -> None:
    out = Path(__file__).resolve().parents[2] / "assets" / "sounds"
    out.mkdir(parents=True, exist_ok=True)
    write(out / "stretching_cue.wav", singing_bowl())
    write(out / "workout_cue.wav", wood_tok())
    for f in sorted(out.glob("*.wav")):
        print(f"{f.name}: {f.stat().st_size / 1000:.0f} kB")


if __name__ == "__main__":
    main()