import os
from contextlib import contextmanager
from typing import Generator

from sqlalchemy import create_engine
from sqlalchemy.orm import Session, sessionmaker

from schema import Base

# Database configuration
DATABASE_URL = os.getenv("DATABASE_URL", "sqlite:///investors.db")

# Create engine
engine = create_engine(DATABASE_URL, echo=False)

# Create session factory
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


def init_database():
    """Initialize the database by creating all tables"""
    Base.metadata.create_all(bind=engine)
    print("Database initialized successfully!")


@contextmanager
def get_session() -> Generator[Session, None, None]:
    """Get a database session with automatic cleanup"""
    session = SessionLocal()
    try:
        yield session
        session.commit()
    except Exception as e:
        session.rollback()
        raise e
    finally:
        session.close()


def get_session_sync() -> Session:
    """Get a database session for synchronous operations"""
    return SessionLocal()