"""
MongoDB connection management using Motor async driver.
"""

import logging
from motor.motor_asyncio import AsyncIOMotorClient, AsyncIOMotorDatabase
from app.core.config import get_settings

logger = logging.getLogger(__name__)

_client: AsyncIOMotorClient | None = None
_db: AsyncIOMotorDatabase | None = None


async def connect_db() -> None:
    """Establish MongoDB connection and create indexes."""
    global _client, _db
    settings = get_settings()
    _client = AsyncIOMotorClient(settings.MONGODB_URL)
    _db = _client[settings.DB_NAME]

    # Create indexes - inspections
    await _db.inspections.create_index("inspection_id", unique=True)
    await _db.inspections.create_index([("url", 1), ("created_at", -1)])
    await _db.inspections.create_index([("created_at", -1)])

    # Create indexes - site_inspections
    await _db.site_inspections.create_index("site_inspection_id", unique=True)
    await _db.site_inspections.create_index([("domain", 1), ("created_at", -1)])
    await _db.site_inspections.create_index([("created_at", -1)])

    # Verify connection
    await _client.admin.command("ping")
    logger.info("MongoDB connected successfully: %s", settings.DB_NAME)


async def close_db() -> None:
    """Close MongoDB connection."""
    global _client, _db
    if _client is not None:
        _client.close()
        _client = None
        _db = None
        logger.info("MongoDB connection closed")


def get_db() -> AsyncIOMotorDatabase:
    """
    Get database instance.
    Uses 'if db is None' pattern for pymongo>=4.9 compatibility.
    """
    if _db is None:
        raise RuntimeError("Database is not connected. Call connect_db() first.")
    return _db