import os
import logging
from typing import Optional

from bson import ObjectId
from motor.motor_asyncio import AsyncIOMotorClient

logger = logging.getLogger(__name__)

_client: Optional[AsyncIOMotorClient] = None
_db = None


async def connect():
    global _client, _db
    uri = os.getenv("MONGODB_URI")
    if not uri:
        logger.warning("MONGODB_URI not set — MongoDB writes disabled")
        return
    db_name = os.getenv("MONGODB_DB_NAME", "myapp")
    _client = AsyncIOMotorClient(uri)
    _db = _client[db_name]
    logger.info("Connected to MongoDB database '%s'", db_name)


async def disconnect():
    global _client
    if _client:
        _client.close()


async def update_deepfake_result(post_id: str, image_index: int, is_deepfake: bool) -> None:
    """Write the boolean deepfake result back into the post's image_deepfake_results array."""
    if _db is None:
        logger.debug("MongoDB not connected; skipping write for post %s[%d]", post_id, image_index)
        return
    try:
        field = f"image_deepfake_results.{image_index}"
        result = await _db.posts.update_one(
            {"_id": ObjectId(post_id)},
            {"$set": {field: is_deepfake}},
        )
        if result.matched_count == 0:
            logger.warning("Post %s not found; deepfake result not saved", post_id)
    except Exception:
        logger.exception("Failed to update deepfake result for post %s[%d]", post_id, image_index)