"""Sequences multiple agent utterances into one debate audio drama."""
import uuid
from pathlib import Path
from pydub import AudioSegment
from ..config import AUDIO_CACHE
from .voxcpm_engine import synthesize


def build_debate(agent_outputs: list) -> str | None:
    """Returns a server-relative path under /audio/... for the frontend."""
    if not agent_outputs:
        return None
    track = AudioSegment.silent(duration=300)
    for ao in agent_outputs:
        text  = ao.get("tts_speech_text", "")
        voice = ao.get("tts_voice_design", {}) or {}
        wav_path = synthesize(text, voice)
        try:
            seg = AudioSegment.from_wav(wav_path)
            track += seg + AudioSegment.silent(duration=400)
        except Exception:
            continue
    out_path = AUDIO_CACHE / f"debate_{uuid.uuid4().hex}.wav"
    track.export(out_path, format="wav")
    # Return /audio/<filename> for the static mount
    return f"/audio/{out_path.name}"