from __future__ import annotations

import logging
from typing import Optional

import asyncpg

from app.config import settings

logger = logging.getLogger(__name__)

_pool: Optional[asyncpg.Pool] = None


async def init_pool() -> None:
    """Create the global asyncpg connection pool."""
    global _pool
    logger.info(
        "Connecting to database %s@%s:%s/%s ...",
        settings.db_user,
        settings.db_host,
        settings.db_port,
        settings.db_name,
    )
    try:
        _pool = await asyncpg.create_pool(
            host=settings.db_host,
            port=settings.db_port,
            user=settings.db_user,
            password=settings.db_password,
            database=settings.db_name,
            server_settings={"search_path": "crawl"},
        )
        logger.info("Database connection pool created successfully.")
    except Exception as exc:
        logger.error("Failed to connect to database: %s", exc)
        raise


async def close_pool() -> None:
    """Close the global asyncpg connection pool."""
    global _pool
    if _pool is not None:
        await _pool.close()
        _pool = None
        logger.info("Database connection pool closed.")


def get_pool() -> asyncpg.Pool:
    """Return the global connection pool. Must be called after init_pool()."""
    if _pool is None:
        raise RuntimeError("Database pool is not initialised. Call init_pool() first.")
    return _pool