from sqlalchemy import create_engine
from sqlalchemy.orm import Session
from sqlalchemy.pool import QueuePool

from app.core.config import Settings

settings = Settings()

class DatabaseConfig:
    DB_USER = settings.DB_USER
    DB_PASSWORD = settings.DB_PASSWORD
    DB_HOST = settings.DB_HOST
    DB_PORT = settings.DB_PORT
    DB_NAME = settings.DB_NAME

    @classmethod
    def get_connection_string(cls):
        return f"postgresql://{cls.DB_USER}:{cls.DB_PASSWORD}@{cls.DB_HOST}:{cls.DB_PORT}/{cls.DB_NAME}"

class SessionManager:
    def __init__(self, db_config):
        self.engine = create_engine(
            db_config.get_connection_string(),
            poolclass=QueuePool,
            pool_size=10,
            max_overflow=5,
            pool_timeout=30,
            pool_recycle=1800,
            pool_pre_ping=True,
            echo=False
        )

    def get_session(self):
        session = Session(self.engine)
        return session

    def close_session(self, session):
        session.close()