from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from sqlalchemy.pool import QueuePool
import os
from dotenv import load_dotenv
from pathlib import Path

ROOT_DIR = Path(__file__).parent
load_dotenv(ROOT_DIR / '.env')

DATABASE_URL = os.environ.get('DATABASE_URL', 'postgresql://user:password@localhost:5432/membership_db')

# Configure engine with connection pooling and connection health checks
engine = create_engine(
    DATABASE_URL,
    poolclass=QueuePool,
    pool_size=5,              # Keep 5 connections open
    max_overflow=10,          # Allow up to 10 extra connections during peak
    pool_pre_ping=True,       # CRITICAL: Test connections before using them
    pool_recycle=3600,        # Recycle connections every hour (prevents stale connections)
    echo=False,               # Set to True for SQL debugging
    connect_args={
        'connect_timeout': 10,  # Timeout connection attempts after 10 seconds
        'options': '-c statement_timeout=30000'  # 30 second query timeout
    }
)

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

Base = declarative_base()

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