"""Klient pro Deepgram pre-recorded přepis (REST, přes httpx).

Nepoužíváme těžké SDK — voláme REST endpoint přímo, aby nebyl závislý na verzích.
"""
import httpx

from ..config import DEEPGRAM_BASE_URL, UPSTREAM_TIMEOUT_SECONDS
from ..errors import UpstreamError, raise_for_upstream
from ..logging_config import get_logger

log = get_logger("audio-transcription.deepgram")


async def transcribe(
    *,
    api_key: str,
    audio: bytes,
    content_type: str,
    model: str,
    language: str,
    diarize: bool,
    smart_format: bool,
) -> str:
    """Přepíše audio Deepgramem a vrátí prostý transkript (channels[0].alternatives[0].transcript)."""
    params = {
        "model": model,
        "language": language,
        "diarize": "true" if diarize else "false",
        "smart_format": "true" if smart_format else "false",
    }
    headers = {
        "Authorization": f"Token {api_key}",
        "Content-Type": content_type or "application/octet-stream",
    }
    url = f"{DEEPGRAM_BASE_URL}/listen"

    try:
        async with httpx.AsyncClient(timeout=UPSTREAM_TIMEOUT_SECONDS) as client:
            resp = await client.post(url, params=params, headers=headers, content=audio)
    except httpx.HTTPError as exc:
        log.error("Deepgram request failed: %s", exc)
        raise UpstreamError(f"Deepgram request se nezdařil: {exc}") from exc

    if resp.status_code >= 400:
        # Deepgram vrací chybu v JSON; nikdy nelogujeme klíč (ten je jen v hlavičce).
        log.warning("Deepgram returned %s: %s", resp.status_code, resp.text[:500])
        raise_for_upstream("Deepgram", resp.status_code, resp.text)

    data = resp.json()
    try:
        channels = data["results"]["channels"]
        alternative = channels[0]["alternatives"][0]
        return alternative.get("transcript", "") or ""
    except (KeyError, IndexError, TypeError) as exc:
        log.error("Unexpected Deepgram response shape: %s", exc)
        raise UpstreamError("Neočekávaná struktura odpovědi z Deepgramu.") from exc