from typing import Optional
from sqlalchemy import create_engine
from sqlalchemy.engine import Engine

from actions.config.config import Config
from actions.env.env_config_loader import EnvConfigLoader


class Firebird:
    _engine: Optional[Engine] = None

    @classmethod
    def get_engine(cls) -> Engine:

        # Instancia o loader com o prefixo correto
        env_database = EnvConfigLoader(prefix="ORIUS_API_FDB")

        # Cria a engine apenas uma vez
        if cls._engine is None:

            # DSN para o SQLAlchemy usando firebird-driver
            dsn = (
                f"firebird+firebird://{env_database.user}:"
                f"{env_database.password}@"
                f"{env_database.host}:"
                f"{env_database.port}/"
                f"{env_database.name}"
            )

            # Criação da engine SQLAlchemy
            cls._engine = create_engine(
                dsn,
                connect_args={"charset": env_database.charset},
                pool_pre_ping=bool(env_database.pool_pre_ping),
                pool_size=env_database.pool_size,
                max_overflow=env_database.pool_max_overflow,
            )

        return cls._engine

    @classmethod
    def dispose(cls):
        if cls._engine:
            cls._engine.dispose()
            cls._engine = None