from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
from sqlalchemy.orm import sessionmaker, declarative_base
import os
from dotenv import load_dotenv

load_dotenv()

# Support both DATABASE_URL (Supabase/production) and individual env vars (local dev)
DATABASE_URL = os.getenv("DATABASE_URL")

if DATABASE_URL:
    # Use DATABASE_URL if provided (Supabase/Vercel)
    # Convert postgres:// to postgresql+asyncpg:// if needed
    if DATABASE_URL.startswith("postgres://"):
        DATABASE_URL = DATABASE_URL.replace("postgres://", "postgresql+asyncpg://", 1)
    elif DATABASE_URL.startswith("postgresql://"):
        DATABASE_URL = DATABASE_URL.replace("postgresql://", "postgresql+asyncpg://", 1)
    
    # --- ADD THIS FIX ---
    # Strip sslmode if present (asyncpg doesn't support it in the connection string)
    if "sslmode=" in DATABASE_URL:
        DATABASE_URL = DATABASE_URL.split("?")[0]
    # --------------------
else:
    # Fall back to individual environment variables (local development)
    DB_USER = os.getenv("DB_USER", "postgres")
    DB_PASSWORD = os.getenv("DB_PASSWORD", "password")
    DB_HOST = os.getenv("DB_HOST", "localhost")
    DB_PORT = os.getenv("DB_PORT", "5432")
    DB_NAME = os.getenv("DB_NAME", "lawbot_db")
    DATABASE_URL = f"postgresql+asyncpg://{DB_USER}:{DB_PASSWORD}@{DB_HOST}:{DB_PORT}/{DB_NAME}"


engine = create_async_engine(
    DATABASE_URL, 
    echo=True,
    pool_pre_ping=True,  # Check connection alive before using
    pool_recycle=300     # Refresh connection every 5 minutes
)

AsyncSessionLocal = sessionmaker(
    bind=engine,
    class_=AsyncSession,
    expire_on_commit=False,
)

Base = declarative_base()

async def get_db():
    async with AsyncSessionLocal() as session:
        yield session