services/tts_generator.py

"""
Stage 7 — TTS Generation (MALE VOICE ONLY)
Uses Edge TTS (free, no API key). Forces male voice for ALL speakers.
"""
import logging
import asyncio
import subprocess
from pathlib import Path
from typing import List, Dict

from config import EDGE_TTS_VOICES, TTS_MAX_SPEED_FACTOR, FORCE_MALE_VOICE

logger = logging.getLogger(__name__)


def generate_dubbed_audio(
    translated_segments: List[Dict],
    speaker_profiles: Dict,
    target_language: str,
    output_dir: Path,
    progress_callback=None
) -> List[Dict]:
    """Generate TTS audio. ALWAYS uses male voice."""
    tts_dir = output_dir / "tts_segments"
    tts_dir.mkdir(exist_ok=True)

    voices = EDGE_TTS_VOICES.get(target_language)
    if not voices:
        raise ValueError(f"No voices for '{target_language}'. Supported: {list(EDGE_TTS_VOICES.keys())}")

    # FORCE MALE VOICE
    voice = voices["male"]
    logger.info(f"Using MALE voice: {voice} (forced)")

    total = len(translated_segments)
    results = []

    # Create or get event loop
    try:
        loop = asyncio.get_event_loop()
        if loop.is_closed():
            loop = asyncio.new_event_loop()
            asyncio.set_event_loop(loop)
    except RuntimeError:
        loop = asyncio.new_event_loop()
        asyncio.set_event_loop(loop)

    for idx, seg in enumerate(translated_segments):
        text = seg.get("translated_text", "").strip()
        if not text:
            seg_result = seg.copy()
            seg_result["tts_audio_path"] = None
            seg_result["tts_duration"] = 0
            results.append(seg_result)
            continue

        output_path = tts_dir / f"seg_{idx:06d}.mp3"
        try:
            loop.run_until_complete(_generate_tts_segment(text, voice, output_path))
        except Exception as e:
            logger.warning(f"TTS failed for segment {idx}: {e}")
            seg_result = seg.copy()
            seg_result["tts_audio_path"] = None
            seg_result["tts_duration"] = 0
            results.append(seg_result)
            continue

        if not output_path.exists() or output_path.stat().st_size == 0:
            seg_result = seg.copy()
            seg_result["tts_audio_path"] = None
            seg_result["tts_duration"] = 0
            results.append(seg_result)
            continue

        tts_duration = _get_audio_duration(output_path)
        original_duration = seg["end"] - seg["start"]

        # Speed-match
        if original_duration > 0 and tts_duration > 0:
            speed_ratio = tts_duration / original_duration
            if speed_ratio > 1.05:
                target_speed = min(speed_ratio, TTS_MAX_SPEED_FACTOR)
                adjusted_path = tts_dir / f"seg_{idx:06d}_adj.mp3"
                _adjust_speed(output_path, adjusted_path, target_speed)
                if adjusted_path.exists():
                    output_path = adjusted_path
                    tts_duration = _get_audio_duration(output_path)

        seg_result = seg.copy()
        seg_result["tts_audio_path"] = str(output_path)
        seg_result["tts_duration"] = round(tts_duration, 3)
        seg_result["voice_used"] = voice
        seg_result["gender_matched"] = "male"
        results.append(seg_result)

        if progress_callback and idx % 10 == 0:
            progress_callback(int((idx + 1) / total * 100))

    if progress_callback:
        progress_callback(100)

    valid = len([r for r in results if r.get("tts_audio_path")])
    logger.info(f"TTS complete: {valid}/{total} segments (MALE voice: {voice})")
    return results


async def _generate_tts_segment(text: str, voice: str, output_path: Path):
    import edge_tts
    communicate = edge_tts.Communicate(text, voice)
    await communicate.save(str(output_path))


def _get_audio_duration(audio_path: Path) -> float:
    cmd = ["ffprobe", "-v", "quiet", "-show_entries", "format=duration", "-of", "csv=p=0", str(audio_path)]
    result = subprocess.run(cmd, capture_output=True, text=True, timeout=10)
    try:
        return float(result.stdout.strip())
    except (ValueError, AttributeError):
        return 0.0


def _adjust_speed(input_path: Path, output_path: Path, speed_factor: float):
    filters = []
    remaining = speed_factor
    while remaining > 2.0:
        filters.append("atempo=2.0")
        remaining /= 2.0
    while remaining < 0.5:
        filters.append("atempo=0.5")
        remaining /= 0.5
    filters.append(f"atempo={remaining:.4f}")
    filter_chain = ",".join(filters)
    cmd = ["ffmpeg", "-y", "-i", str(input_path), "-filter:a", filter_chain, str(output_path)]
    subprocess.run(cmd, capture_output=True, text=True, timeout=30)