# core/database/connection_manager.py
from typing import Optional

from sqlalchemy import create_engine
from sqlalchemy.engine import Engine

from actions.config.config import Config


class Firebird:
    _engine: Optional[Engine] = None

    @classmethod
    def get_engine(cls) -> Engine:

        # Obtem as configurações de banco de dados
        database = Config.get('database/firebird.json')

        # Se nao existir engine, cria uma nova
        if cls._engine is None:

            # Caminho da conexão com o banco de dados
            dsn = (
                f"firebird://{database.user}:"
                f"{database.password}@"
                f"{database.host}:"
                f"{database.port}/"
                f"{database.name}"
            )

            # Criação da Engine
            cls._engine = create_engine(
                dsn,
                connect_args={
                    "charset": database.charset,
                },
                pool_pre_ping=database.pool.pre_ping,
                pool_size=database.pool.size,
                max_overflow=database.pool.max_overflow
            )

        # Retorna a criação da engine
        return cls._engine

    @classmethod
    def dispose(cls):

        # Verifica se existe engine
        if cls._engine:
            
            # Se existir encerra a conexão
            cls._engine.dispose()

            # Anula a engine
            cls._engine = None