from __future__ import annotations

import json
from pathlib import Path
from typing import Any

import aiohttp

from app.config import ElevenLabsConfig


ELEVENLABS_SPEECH_TO_TEXT_URL = "https://api.elevenlabs.io/v1/speech-to-text"


class TranscriptionError(RuntimeError):
    pass


async def transcribe_file(
    path: Path,
    config: ElevenLabsConfig,
    *,
    content_type: str | None = None,
) -> str:
    if not config.api_key:
        raise TranscriptionError("ElevenLabs API key is not configured")

    form = aiohttp.FormData()
    form.add_field("model_id", config.model_id)
    form.add_field("tag_audio_events", "false")
    if config.language_code:
        form.add_field("language_code", config.language_code)

    timeout = aiohttp.ClientTimeout(total=config.request_timeout_seconds)
    headers = {"xi-api-key": config.api_key}

    with path.open("rb") as media_file:
        form.add_field(
            "file",
            media_file,
            filename=path.name,
            content_type=content_type or "application/octet-stream",
        )
        try:
            async with aiohttp.ClientSession(timeout=timeout) as session:
                async with session.post(
                    ELEVENLABS_SPEECH_TO_TEXT_URL,
                    data=form,
                    headers=headers,
                ) as response:
                    body = await response.text()
                    if response.status >= 400:
                        raise TranscriptionError(
                            f"ElevenLabs returned HTTP {response.status}: {body[:500]}"
                        )
        except (aiohttp.ClientError, TimeoutError) as exc:
            raise TranscriptionError("ElevenLabs request failed") from exc

    try:
        payload: Any = json.loads(body)
    except json.JSONDecodeError as exc:
        raise TranscriptionError("ElevenLabs returned invalid JSON") from exc

    text = payload.get("text") if isinstance(payload, dict) else None
    if not isinstance(text, str) or not text.strip():
        raise TranscriptionError("ElevenLabs returned an empty transcript")
    return text.strip()