from __future__ import annotations

from sqlalchemy import create_engine, event
from sqlalchemy.engine import Engine

from app.core.config import settings


def _create_read_only_engine(connection_url: str) -> Engine:
    engine = create_engine(
        connection_url, pool_pre_ping=True, pool_recycle=3600, future=True
    )

    @event.listens_for(engine, "connect")
    def _on_connect(dbapi_connection, _connection_record) -> None:
        cursor = dbapi_connection.cursor()
        try:
            cursor.execute("SET TRANSACTION ISOLATION LEVEL READ COMMITTED;")
        finally:
            cursor.close()

    return engine


def create_warehouse_engines() -> dict[str, Engine]:
    return {
        "wwi": _create_read_only_engine(settings.wwi_connection_url),
        "aw": _create_read_only_engine(settings.aw_connection_url),
    }


def dispose_engines(engines: dict[str, Engine]) -> None:
    for engine in engines.values():
        engine.dispose()