# app/audio/generate.py
from __future__ import annotations

import platform
import shutil
import subprocess
from pathlib import Path

from loguru import logger


def generate_rep_audio_files(
    *,
    max_count: int,
    rate: int,
    output_dir: Path,
    overwrite: bool = False,
) -> None:
    """
    确保 0~max_count 的运动次数语音 wav 文件存在。

    默认生成到：

        resources/audio/reps/0.aiff  # macOS
        resources/audio/reps/0.wav   # Windows / Linux
        ...
        resources/audio/reps/200.aiff 或 200.wav

    服务启动时调用一次即可。
    """
    output_dir.mkdir(parents=True, exist_ok=True)
    system = platform.system().lower()
    suffix = ".aiff" if system == "darwin" else ".wav"

    missing_counts = [
        count
        for count in range(0, max_count + 1)
        if overwrite or not _audio_path(output_dir, count, suffix=suffix).exists()
    ]

    if not missing_counts:
        logger.info("Rep audio files already prepared: {}", output_dir)
        return

    logger.info(
        "Preparing rep audio files, system={}, count={}, output_dir={}",
        system,
        len(missing_counts),
        output_dir,
    )

    if system == "darwin":
        _generate_with_macos_say(
            counts=missing_counts,
            output_dir=output_dir,
            rate=rate,
        )
    else:
        _generate_with_pyttsx3(
            counts=missing_counts,
            output_dir=output_dir,
            rate=rate,
        )

    logger.info("Rep audio files prepared: {}", output_dir)


def _generate_with_macos_say(
    *,
    counts: list[int],
    output_dir: Path,
    rate: int,
) -> None:
    """macOS 使用 say 命令生成 wav。"""
    if platform.system().lower() != "darwin":
        raise RuntimeError("say command is only available on macOS")

    if shutil.which("say") is None:
        raise RuntimeError("macOS say command not found")

    for count in counts:
        audio_file = _audio_path(output_dir, count, suffix=".aiff")

        try:
            subprocess.run(
                [
                    "say",
                    "-r",
                    str(rate),
                    "--file-format=AIFF",
                    "-o",
                    str(audio_file),
                    str(count),
                ],
                stdout=subprocess.DEVNULL,
                stderr=subprocess.PIPE,
                text=True,
                check=True,
            )
        except subprocess.CalledProcessError as exc:
            message = exc.stderr.strip() or f"exit status {exc.returncode}"
            raise RuntimeError(f"Failed to generate {audio_file}: {message}") from exc


def _generate_with_pyttsx3(
    *,
    counts: list[int],
    output_dir: Path,
    rate: int,
) -> None:
    """Windows / Linux 使用 pyttsx3 生成 wav。"""
    try:
        import pyttsx3
    except Exception as exc:
        raise RuntimeError(f"pyttsx3 unavailable: {exc}") from exc

    engine = pyttsx3.init()
    engine.setProperty("rate", rate)
    engine.setProperty("volume", 1.0)

    for count in counts:
        audio_file = _audio_path(output_dir, count, suffix=".wav")
        engine.save_to_file(str(count), str(audio_file))

    engine.runAndWait()


def _audio_path(output_dir: Path, count: int, *, suffix: str) -> Path:
    return output_dir / f"{count}{suffix}"