"""Connessione asyncpg al database ml. Pool singleton."""
from __future__ import annotations

import asyncpg
from typing import Optional

from core.config import settings

_pool: Optional[asyncpg.Pool] = None


async def init_pool() -> asyncpg.Pool:
    global _pool
    if _pool is None:
        _pool = await asyncpg.create_pool(
            host=settings.pg_host,
            port=settings.pg_port,
            user=settings.pg_user,
            password=settings.pg_password,
            database=settings.pg_db,
            min_size=1,
            max_size=10,
            command_timeout=30,
        )
    return _pool


async def close_pool() -> None:
    global _pool
    if _pool is not None:
        await _pool.close()
        _pool = None


def pool() -> asyncpg.Pool:
    if _pool is None:
        raise RuntimeError("DB pool not initialized — call init_pool() at startup")
    return _pool


async def fetch(sql: str, *args):
    async with pool().acquire() as c:
        return await c.fetch(sql, *args)


async def fetchrow(sql: str, *args):
    async with pool().acquire() as c:
        return await c.fetchrow(sql, *args)


async def execute(sql: str, *args):
    async with pool().acquire() as c:
        return await c.execute(sql, *args)