"""FluentGerman.ai — Voice service (API provider + browser fallback)."""

import io
import logging

import openai

from app.config import get_settings


async def transcribe(audio_bytes: bytes, filename: str = "audio.webm") -> str:
    """Transcribe audio to text using OpenAI Whisper API."""
    settings = get_settings()
    # Use dedicated OpenAI key if available, otherwise fallback to LLM key
    api_key = settings.openai_api_key or settings.llm_api_key

    key_type = "OPENAI_API_KEY" if settings.openai_api_key else "LLM_API_KEY"
    masked = f"{api_key[:4]}...{api_key[-4:]}" if api_key and len(api_key) > 8 else "EMPTY"
    logging.getLogger("fluentgerman.voice").info(f"Transcribing with {key_type}: {masked}")

    client = openai.AsyncOpenAI(api_key=api_key)

    audio_file = io.BytesIO(audio_bytes)
    audio_file.name = filename

    transcript = await client.audio.transcriptions.create(
        model=settings.stt_model,
        file=audio_file,
        prompt="FluentGerman.ai — German language tutor. Deutsch, Grammatik, Übung, Aussprache.",
    )
    return transcript.text


async def synthesize(text: str) -> bytes:
    """Synthesize text to speech using OpenAI TTS API."""
    settings = get_settings()
    # Use dedicated OpenAI key if available, otherwise fallback to LLM key
    api_key = settings.openai_api_key or settings.llm_api_key

    key_type = "OPENAI_API_KEY" if settings.openai_api_key else "LLM_API_KEY"
    masked = f"{api_key[:4]}...{api_key[-4:]}" if api_key and len(api_key) > 8 else "EMPTY"
    logging.getLogger("fluentgerman.voice").info(f"Synthesizing with {key_type}: {masked}")

    client = openai.AsyncOpenAI(api_key=api_key)

    response = await client.audio.speech.create(
        model=settings.tts_model,
        voice=settings.tts_voice,
        input=text,
        response_format="mp3",
    )

    return response.content