import os
import aiofiles
from fastapi import UploadFile, HTTPException
from app.config import settings


async def save_audio_file(file: UploadFile, meeting_id: str) -> str:
    os.makedirs(settings.AUDIO_STORAGE_PATH, exist_ok=True)
    original_name = file.filename or "audio.wav"
    ext = os.path.splitext(original_name)[1].lower() or ".wav"

    allowed_extensions = {".wav", ".mp3", ".m4a", ".ogg", ".flac", ".mp4", ".webm"}
    if ext not in allowed_extensions:
        raise HTTPException(
            status_code=400,
            detail=f"Unsupported audio format '{ext}'. Supported: {', '.join(allowed_extensions)}",
        )

    filename = f"{meeting_id}{ext}"
    file_path = os.path.join(settings.AUDIO_STORAGE_PATH, filename)
    max_size = settings.UPLOAD_MAX_SIZE_MB * 1024 * 1024
    total_size = 0

    async with aiofiles.open(file_path, "wb") as f:
        while True:
            chunk = await file.read(1024 * 1024)
            if not chunk:
                break
            total_size += len(chunk)
            if total_size > max_size:
                await f.close()
                os.remove(file_path)
                raise HTTPException(
                    status_code=413,
                    detail=f"File too large. Maximum allowed size is {settings.UPLOAD_MAX_SIZE_MB}MB",
                )
            await f.write(chunk)

    return file_path