"""Database connection and session management

Supports MySQL database with connection pooling.
All tables use 'tr_' prefix to avoid conflicts in shared database.
"""
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from app.core.config import get_settings

settings = get_settings()

# Create engine with MySQL connection pooling
engine = create_engine(
    settings.DATABASE_URL,
    pool_size=5,
    max_overflow=10,
    pool_pre_ping=True,  # Verify connection before using
    pool_recycle=3600,  # Recycle connections after 1 hour
    echo=settings.DEBUG,
)

# Create session factory
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

# Base class for models
Base = declarative_base()


def get_db():
    """FastAPI dependency to get database session"""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()