from __future__ import annotations

import argparse
import os
from pathlib import Path
import sys
import tempfile


ROOT = Path(__file__).resolve().parents[1]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

from services.ai_voice_runtime_service.audiosocket import pcm16le_to_wav_bytes, resample_pcm16le
from services.ai_voice_runtime_service.providers.tts import build_tts_provider


def _parse_args() -> argparse.Namespace:
    default_provider = os.getenv("AI_VOICE_TTS_PROVIDER", "yandex").strip() or "yandex"
    parser = argparse.ArgumentParser(
        description="Generate TTS once, cache it on the server, and materialize a WAV prompt file.",
    )
    parser.add_argument("--text", required=True, help="Text to synthesize.")
    parser.add_argument("--output", required=True, help="Target WAV path.")
    parser.add_argument("--language", default=None, help="Optional language hint.")
    parser.add_argument(
        "--provider",
        default=default_provider,
        help="TTS provider name. Defaults to AI_VOICE_TTS_PROVIDER or yandex.",
    )
    parser.add_argument("--sample-rate", type=int, default=8000, help="Target WAV sample rate. Defaults to 8000.")
    return parser.parse_args()


def _write_atomic(target: Path, payload: bytes) -> None:
    target.parent.mkdir(parents=True, exist_ok=True)
    temp_path: str | None = None
    try:
        with tempfile.NamedTemporaryFile(dir=target.parent, delete=False, suffix=".tmp") as handle:
            handle.write(payload)
            temp_path = handle.name
        Path(temp_path).replace(target)
        target.chmod(0o644)
    finally:
        if temp_path:
            try:
                Path(temp_path).unlink(missing_ok=True)
            except OSError:
                pass


def main() -> int:
    args = _parse_args()
    provider = build_tts_provider(args.provider)
    synthesis = provider.synthesize(args.text, language=args.language)
    pcm_bytes = resample_pcm16le(
        synthesis.audio_bytes,
        input_rate_hz=synthesis.sample_rate_hz,
        output_rate_hz=max(args.sample_rate, 1),
    )
    wav_bytes = pcm16le_to_wav_bytes(
        pcm_bytes,
        sample_rate_hz=max(args.sample_rate, 1),
    )
    output_path = Path(args.output).expanduser()
    _write_atomic(output_path, wav_bytes)
    print(output_path)
    return 0


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