#!/usr/bin/env python3
"""Generate the audio fixtures `webapi_smoke.py` expects.

Synthesised rather than downloaded so the smoke test has no network dependency
and no external tools — `soundfile` and `numpy` come in with `librosa`, so this
runs in the container image as-is (no ffmpeg needed).

  sine440.wav    12 s, 440 Hz, stereo, -12 dBFS  — a known-tone reference
  pinknoise.wav   8 s, pink noise, stereo        — broadband, exercises the STFT
  tagged.mp3     a tagged file                   — only if ffmpeg is available

Usage:  python3 scripts/make_fixtures.py [output_dir]     (default /tmp/ujm-test)
"""

from __future__ import annotations

import shutil
import subprocess
import sys
from pathlib import Path

import numpy as np
import soundfile as sf

SR = 44100


def sine(path: Path, seconds: float = 12.0, hz: float = 440.0,
         dbfs: float = -12.0) -> None:
  """A tone at a known level. Peak is exactly 10**(dbfs/20) before encoding."""
  t = np.arange(int(seconds * SR)) / SR
  mono = (10 ** (dbfs / 20)) * np.sin(2 * np.pi * hz * t)
  sf.write(path, np.stack([mono, mono], axis=1), SR, subtype="PCM_16")


def pink(path: Path, seconds: float = 8.0, peak: float = 0.25) -> None:
  """Pink noise via 1/sqrt(f) shaping, normalised to a known peak."""
  rng = np.random.default_rng(7)
  n = int(seconds * SR)
  spectrum = np.fft.rfft(rng.standard_normal(n))
  freqs = np.fft.rfftfreq(n, 1 / SR)
  freqs[0] = freqs[1]                       # avoid dividing by zero at DC
  shaped = np.fft.irfft(spectrum / np.sqrt(freqs), n)
  mono = peak * shaped / np.max(np.abs(shaped))
  sf.write(path, np.stack([mono, mono], axis=1), SR, subtype="PCM_16")


def tagged_mp3(path: Path) -> bool:
  """An MP3 with ID3 tags, so the tag-reading path is exercised.

  Genuinely optional: MP3 encoding is the one thing numpy cannot do, so this
  needs ffmpeg and is skipped when it is absent. The suite's tag assertions
  adapt — see `webapi_smoke.py`.
  """
  if shutil.which("ffmpeg") is None:
    return False
  subprocess.run(
    ["ffmpeg", "-y", "-loglevel", "error",
     "-f", "lavfi", "-i", "sine=frequency=330:duration=6:sample_rate=44100",
     "-metadata", "artist=Test Artist", "-metadata", "title=Test Title",
     "-codec:a", "libmp3lame", "-q:a", "2", str(path)],
    check=True,
  )
  return True


def main() -> int:
  out = Path(sys.argv[1] if len(sys.argv) > 1 else "/tmp/ujm-test")
  out.mkdir(parents=True, exist_ok=True)

  sine(out / "sine440.wav")
  pink(out / "pinknoise.wav")
  mp3 = tagged_mp3(out / "テスト.mp3")

  for f in sorted(out.iterdir()):
    print(f"  {f.name}  {f.stat().st_size / 1024:.0f} KiB")
  if not mp3:
    print("\nnote: no ffmpeg, so no tagged MP3 fixture was written "
          "(tag assertions will be skipped)")
  return 0


if __name__ == "__main__":
  raise SystemExit(main())