from typing import Optional
from sqlalchemy import create_engine
from sqlalchemy.engine import Engine
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(".env")

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

            # DSN para o SQLAlchemy usando firebird-driver
            dsn = (
                f"firebird+firebird://{env_database.ORIUS_API_FDB_USER}:"
                f"{env_database.ORIUS_API_FDB_PASSWORD}@"
                f"{env_database.ORIUS_API_FDB_HOST}:"
                f"{env_database.ORIUS_API_FDB_PORT}/"
                f"{env_database.ORIUS_API_FDB_NAME}"
            )

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

        return cls._engine

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