"""
asyncpg connection pool with JSONB codec registration.
Call init_pool() once at startup and close_pool() at shutdown.
"""

import json
import logging
import asyncpg

logger = logging.getLogger(__name__)

_pool: asyncpg.Pool | None = None


async def _init_conn(conn: asyncpg.Connection):
    """Register JSONB/JSON codecs so Python dicts/lists are passed transparently."""
    await conn.set_type_codec('jsonb', encoder=json.dumps, decoder=json.loads, schema='pg_catalog')
    await conn.set_type_codec('json', encoder=json.dumps, decoder=json.loads, schema='pg_catalog')


async def init_pool(dsn: str):
    global _pool
    _pool = await asyncpg.create_pool(
        dsn,
        min_size=2,
        max_size=10,
        command_timeout=30,
        init=_init_conn,
    )
    logger.info("PostgreSQL pool initialized")


async def close_pool():
    global _pool
    if _pool:
        await _pool.close()
        _pool = None
        logger.info("PostgreSQL pool closed")


def get_pool() -> asyncpg.Pool:
    if _pool is None:
        raise RuntimeError("Database pool not initialized — call init_pool() first")
    return _pool