"""XTTS v2 wrapper for voice cloning from non-voice audio samples."""

import os
import random
import tempfile
from pathlib import Path

try:
    from TTS.api import TTS
except ImportError:
    TTS = None  # Tests patch this; real runtime requires the TTS package

from server.config import config


class VoiceGenerator:
    """Generates speech cloned from arbitrary audio samples via XTTS v2."""

    def __init__(
        self,
        device: str | None = None,
        model_name: str | None = None,
        samples_dir: str | None = None,
    ):
        self.device = device or config.device
        self.model_name = model_name or config.models.xtts_model
        self.samples_dir = Path(samples_dir or config.samples_dir)
        if TTS is None:
            raise RuntimeError(
                "TTS package is not installed; cannot instantiate VoiceGenerator"
            )
        self._tts = TTS(model_name=self.model_name)
        self._tts.to(self.device)

    def generate(self, text: str, speaker_wav: str | None = None) -> bytes:
        """Generate speech as WAV bytes. Uses a random clone source if none specified."""
        if speaker_wav is None:
            speaker_wav = self.random_clone_source()
        if speaker_wav is None:
            raise ValueError("No speaker WAV provided and no samples available")

        # XTTS writes to file, so use a temp file
        tmp = tempfile.NamedTemporaryFile(suffix=".wav", delete=False)
        tmp.close()
        try:
            self._tts.tts_to_file(
                text=text,
                speaker_wav=speaker_wav,
                language=config.models.xtts_language,
                file_path=tmp.name,
            )
            with open(tmp.name, "rb") as f:
                return f.read()
        finally:
            try:
                os.unlink(tmp.name)
            except OSError:
                pass

    def list_clone_sources(self) -> list[str]:
        """List all WAV files in the samples directory."""
        if not self.samples_dir.is_dir():
            return []
        return [
            str(p) for p in sorted(self.samples_dir.glob("*.wav"))
        ]

    def random_clone_source(self) -> str | None:
        """Pick a random clone source WAV file."""
        sources = self.list_clone_sources()
        if not sources:
            return None
        return random.choice(sources)