import os
from sqlalchemy import create_engine
from sqlalchemy.orm import declarative_base, sessionmaker

# Database configuration
DB_HOST = os.getenv("DB_HOST")
DB_PORT = os.getenv("DB_PORT", "5432")
DB_NAME = os.getenv("DB_NAME", "plum_db")
DB_USER = os.getenv("DB_USER")
DB_PASSWORD = os.getenv("DB_PASSWORD")

if DB_HOST and DB_USER and DB_PASSWORD:
    # Use PostgreSQL
    DATABASE_URL = f"postgresql://{DB_USER}:{DB_PASSWORD}@{DB_HOST}:{DB_PORT}/{DB_NAME}"
else:
    # Use SQLite fallback for local development
    db_dir = os.path.dirname(os.path.abspath(__file__))
    os.makedirs(db_dir, exist_ok=True)
    sqlite_db_path = os.path.join(db_dir, "plum.db")
    DATABASE_URL = f"sqlite:///{sqlite_db_path}"

# Create engine
# SQLite needs check_same_thread=False
connect_args = {"check_same_thread": False} if DATABASE_URL.startswith("sqlite") else {}
engine = create_engine(DATABASE_URL, connect_args=connect_args)

SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()