pySonnerie/backend/app/audio_player.py

from __future__ import annotations

import logging
import subprocess
import threading
from pathlib import Path
from typing import Optional


logger = logging.getLogger("pysonnerie.audio")


class AudioPlayer:
    def __init__(self, music_dir: Path):
        self.music_dir = music_dir
        self._lock = threading.RLock()
        self._proc: Optional[subprocess.Popen] = None
        self._decoder_proc: Optional[subprocess.Popen] = None

    def _resolve_music_path(self, music_file: str) -> Path:
        candidate = (self.music_dir / music_file).resolve()
        if self.music_dir.resolve() not in candidate.parents:
            raise ValueError("music_file path traversal is forbidden")
        if not candidate.exists() or not candidate.is_file():
            raise FileNotFoundError(f"Music file not found: {music_file}")
        return candidate

    def _read_duration_seconds(self, music_path: Path) -> Optional[float]:
        try:
            result = subprocess.run(
                ["soxi", "-D", str(music_path)],
                capture_output=True,
                check=True,
                text=True,
            )
            return float(result.stdout.strip())
        except (subprocess.CalledProcessError, FileNotFoundError, ValueError):
            logger.warning("Unable to read duration with soxi for %s", music_path)

        # Fallback for setups where sox lacks some codecs (e.g. mp3).
        try:
            result = subprocess.run(
                [
                    "ffprobe",
                    "-v",
                    "error",
                    "-show_entries",
                    "format=duration",
                    "-of",
                    "default=noprint_wrappers=1:nokey=1",
                    str(music_path),
                ],
                capture_output=True,
                check=True,
                text=True,
            )
            return float(result.stdout.strip())
        except (subprocess.CalledProcessError, FileNotFoundError, ValueError):
            logger.warning("Unable to read duration with ffprobe for %s", music_path)
            return None

    def play(
        self,
        music_file: str,
        start_seconds: float = 0.0,
        end_seconds: Optional[float] = None,
        volume: int = 80,
        fade_in_seconds: float = 0.0,
        fade_out_seconds: float = 0.0,
        normalize_audio: bool = False,
    ) -> None:
        with self._lock:
            music_path = self._resolve_music_path(music_file)
            self.stop()

            if start_seconds < 0:
                raise ValueError("start_seconds must be greater than or equal to 0")

            duration: Optional[float] = None
            if end_seconds is not None:
                duration = float(end_seconds) - float(start_seconds)
                if duration <= 0:
                    raise ValueError("end_seconds must be greater than start_seconds")

            volume_factor = max(0.0, min(1.0, float(volume) / 100.0))
            cmd = [
                "play",
                "-q",
                "-v",
                str(volume_factor),
                str(music_path),
            ]

            effects: list[str] = []
            if normalize_audio:
                effects += ["gain", "-n"]

            effects += ["trim", str(float(start_seconds))]
            if duration is not None:
                effects.append(str(duration))

            fade_in = max(0.0, float(fade_in_seconds))
            fade_out = max(0.0, float(fade_out_seconds))
            if fade_in > 0 or fade_out > 0:
                play_duration = duration
                if play_duration is None:
                    total_duration = self._read_duration_seconds(music_path)
                    if total_duration is not None:
                        play_duration = total_duration - float(start_seconds)

                if play_duration is not None:
                    if play_duration <= 0:
                        raise ValueError("Playback window is empty")

                    fade_in = min(fade_in, play_duration)
                    fade_out = min(fade_out, play_duration)

                    if fade_out > 0:
                        effects += ["fade", "t", str(fade_in), str(play_duration), str(fade_out)]
                    else:
                        effects += ["fade", "t", str(fade_in)]
                else:
                    if fade_out > 0:
                        logger.warning(
                            "fade_out_seconds ignored for %s because duration is unknown",
                            music_path,
                        )
                    effects += ["fade", "t", str(fade_in)]

            # If sox lacks mp3 handlers, decode with ffmpeg and stream wav to sox.
            if music_path.suffix.lower() == ".mp3":
                decoder_cmd = ["ffmpeg", "-v", "error", "-i", str(music_path), "-f", "wav", "-"]
                self._decoder_proc = subprocess.Popen(
                    decoder_cmd,
                    stdout=subprocess.PIPE,
                    stderr=subprocess.DEVNULL,
                )
                cmd += ["-t", "wav", "-"] + effects
                self._proc = subprocess.Popen(
                    cmd,
                    stdin=self._decoder_proc.stdout,
                    stdout=subprocess.DEVNULL,
                    stderr=subprocess.DEVNULL,
                )
                if self._decoder_proc.stdout is not None:
                    self._decoder_proc.stdout.close()
            else:
                cmd += [str(music_path)] + effects
                self._proc = subprocess.Popen(cmd, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)

    def stop(self) -> None:
        with self._lock:
            if self._decoder_proc and self._decoder_proc.poll() is None:
                self._decoder_proc.terminate()
                try:
                    self._decoder_proc.wait(timeout=2)
                except subprocess.TimeoutExpired:
                    self._decoder_proc.kill()
            self._decoder_proc = None

            if self._proc and self._proc.poll() is None:
                self._proc.terminate()
                try:
                    self._proc.wait(timeout=2)
                except subprocess.TimeoutExpired:
                    self._proc.kill()
            self._proc = None