from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from pathlib import Path
import os

# Get project root directory and create a storage directory
PROJECT_ROOT = Path(
    os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
)
DB_DIR = PROJECT_ROOT / "storage" / "db"
DB_DIR.mkdir(parents=True, exist_ok=True)

# SQLite database URL
SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_DIR}/db.sqlite"

# Create the SQLAlchemy engine
engine = create_engine(
    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
)

# Create a SessionLocal class
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

# Create a Base class for declarative models
Base = declarative_base()


# Create tables (important for first run)
def create_tables():
    Base.metadata.create_all(bind=engine)


# Dependency to get a database session
def get_db():
    db = SessionLocal()
    try:
        # Test the connection
        db.execute("SELECT 1")
        yield db
    except Exception as e:
        # Log the error (in a real-world application)
        print(f"Database connection error: {e}")
        # Provide a user-friendly error
        from fastapi import HTTPException, status

        raise HTTPException(
            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
            detail="Database connection error. Please try again later.",
        )
    finally:
        db.close()