Refactoring code for modular approach

app/core/config.py

@@ -0,0 +1,26 @@
+from pydantic_settings import BaseSettings
+from typing import List
+import os
+
+
+class Settings(BaseSettings):
+    PROJECT_NAME: str = "Ecommerce Backend API with Marketplace Support"
+    DESCRIPTION: str = "Advanced product management system with JWT authentication"
+    VERSION: str = "2.2.0"
+
+    DATABASE_URL: str = os.getenv("DATABASE_URL", "postgresql://user:password@localhost/ecommerce")
+    SECRET_KEY: str = os.getenv("SECRET_KEY", "your-secret-key-change-in-production")
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
+
+    ALLOWED_HOSTS: List[str] = ["*"]  # Configure for production
+
+    # Rate limiting
+    RATE_LIMIT_REQUESTS: int = 100
+    RATE_LIMIT_WINDOW: int = 3600
+
+    class Config:
+        env_file = ".env"
+        extra = "ignore"
+
+
+settings = Settings()

app/core/database.py

@@ -0,0 +1,21 @@
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker, Session
+from .config import settings
+
+engine = create_engine(settings.DATABASE_URL)
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+Base = declarative_base()
+
+
+# Database dependency with connection pooling
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    except Exception as e:
+        db.rollback()
+        raise
+    finally:
+        db.close()

app/core/lifespan.py

@@ -0,0 +1,48 @@
+from contextlib import asynccontextmanager
+from fastapi import FastAPI
+from sqlalchemy import text
+from .logging import setup_logging
+from .database import engine
+from models.database_models import Base
+import logging
+
+logger = logging.getLogger(__name__)
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    """Application lifespan events"""
+    # Startup
+    logger = setup_logging()  # Configure logging first
+    logger.info("Starting up ecommerce API")
+
+    # Create tables
+    Base.metadata.create_all(bind=engine)
+
+    # Create indexes
+    create_indexes()
+
+    yield
+
+    # Shutdown
+    logger.info("Shutting down ecommerce API")
+
+
+def create_indexes():
+    """Create database indexes"""
+    with engine.connect() as conn:
+        try:
+            # User indexes
+            conn.execute(text("CREATE INDEX IF NOT EXISTS idx_user_email ON users(email)"))
+            conn.execute(text("CREATE INDEX IF NOT EXISTS idx_user_username ON users(username)"))
+
+            # Product indexes
+            conn.execute(text("CREATE INDEX IF NOT EXISTS idx_product_gtin ON products(gtin)"))
+            conn.execute(text("CREATE INDEX IF NOT EXISTS idx_product_marketplace ON products(marketplace)"))
+
+            # Stock indexes
+            conn.execute(text("CREATE INDEX IF NOT EXISTS idx_stock_gtin_location ON stock(gtin, location)"))
+
+            conn.commit()
+            logger.info("Database indexes created successfully")
+        except Exception as e:
+            logger.warning(f"Index creation warning: {e}")

app/core/logging.py

@@ -0,0 +1,42 @@
+# app/core/logging.py
+import logging
+import sys
+from pathlib import Path
+from app.core.config import settings
+
+
+def setup_logging():
+    """Configure application logging with file and console handlers"""
+
+    # Create logs directory if it doesn't exist
+    log_file = Path(settings.LOG_FILE)
+    log_file.parent.mkdir(parents=True, exist_ok=True)
+
+    # Configure root logger
+    logger = logging.getLogger()
+    logger.setLevel(getattr(logging, settings.LOG_LEVEL.upper()))
+
+    # Remove existing handlers
+    for handler in logger.handlers[:]:
+        logger.removeHandler(handler)
+
+    # Create formatters
+    formatter = logging.Formatter(
+        '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+    )
+
+    # Console handler
+    console_handler = logging.StreamHandler(sys.stdout)
+    console_handler.setFormatter(formatter)
+    logger.addHandler(console_handler)
+
+    # File handler
+    file_handler = logging.FileHandler(log_file)
+    file_handler.setFormatter(formatter)
+    logger.addHandler(file_handler)
+
+    # Configure specific loggers
+    logging.getLogger("uvicorn.access").setLevel(logging.WARNING)
+    logging.getLogger("sqlalchemy.engine").setLevel(logging.WARNING)
+
+    return logging.getLogger(__name__)