from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
import os
from dotenv import load_dotenv

load_dotenv()

# Get DATABASE_URL from environment, fallback to SQLite for local/HuggingFace deployment
DATABASE_URL = os.getenv("DATABASE_URL")

if DATABASE_URL:
    # Fix Heroku-style postgres:// URLs
    if DATABASE_URL.startswith("postgres://"):
        DATABASE_URL = DATABASE_URL.replace("postgres://", "postgresql://", 1)
else:
    # Fallback to SQLite for HuggingFace Spaces / local development without database
    DATABASE_URL = "sqlite:///./data/road_damage.db"
    print(f"[DB] No DATABASE_URL set, using SQLite: {DATABASE_URL}")

# Create engine
engine = create_engine(
    DATABASE_URL,
    connect_args={"check_same_thread": False} if DATABASE_URL.startswith("sqlite") else {}
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()

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