python-hello-world-enhanced/hello_world.py

#!/usr/bin/env python3
"""
Enhanced Hello World Script
Version: 1.0.1
Author: The Optimizer - Performance & Security Engineer
Date: 2026-03-16
Description: Enhanced hello world script with comprehensive logging,
error handling, and CLI support.
Optimized for security and performance.
"""

import argparse
import logging
import sys
from logging.handlers import RotatingFileHandler
import traceback

# Global configuration
LOG_FILE = "hello_world.log"
LOG_MAX_BYTES = 5 * 1024 * 1024  # 5MB
LOG_BACKUP_COUNT = 3
DEFAULT_NAME = "World"


def setup_logging():
    """Configure comprehensive logging system"""
    try:
        logger = logging.getLogger()
        logger.setLevel(logging.DEBUG)

        file_handler = RotatingFileHandler(
            LOG_FILE,
            maxBytes=LOG_MAX_BYTES,
            backupCount=LOG_BACKUP_COUNT,
            encoding="utf-8",
        )
        file_handler.setLevel(logging.DEBUG)

        console_handler = logging.StreamHandler(sys.stdout)
        console_handler.setLevel(logging.INFO)

        formatter = logging.Formatter(
            "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
        )

        file_handler.setFormatter(formatter)
        console_handler.setFormatter(formatter)

        logger.addHandler(file_handler)
        logger.addHandler(console_handler)

        logging.info("Logging system initialized successfully")
        return logger

    except Exception as e:
        logging.error(f"Failed to initialize logging system: {e}")
        logging.debug(traceback.format_exc())
        sys.exit(1)


def parse_arguments():
    """Parse command-line arguments with comprehensive validation"""
    try:
        parser = argparse.ArgumentParser(
            description="Enhanced Hello World Script with comprehensive features",
            formatter_class=argparse.RawDescriptionHelpFormatter,
        )

        parser.add_argument(
            "-n",
            "--name",
            type=str,
            default=DEFAULT_NAME,
            help="Name to greet (default: World)",
        )

        parser.add_argument(
            "-l",
            "--log-level",
            type=str.upper,
            choices=["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"],
            default="INFO",
            help="Set logging level (default: INFO)",
        )

        parser.add_argument(
            "-v",
            "--version",
            action="version",
            version="Enhanced Hello World Script 1.0.1",
        )

        args = parser.parse_args()

        if args.log_level:
            logging.getLogger().setLevel(getattr(logging, args.log_level))

        logging.info(f"Command-line arguments parsed successfully: {args}")
        return args

    except Exception as e:
        logging.error(f"Failed to parse command-line arguments: {e}")
        logging.debug(traceback.format_exc())
        sys.exit(1)


def greet(name):
    """Generate greeting message with validation"""
    try:
        if not name or not isinstance(name, str):
            raise ValueError("Name must be a non-empty string")

        if len(name) > 100:
            raise ValueError("Name cannot exceed 100 characters")

        message = f"Hello, {name}!"
        logging.info(f"Generated greeting message: {message}")
        return message

    except ValueError as e:
        logging.error(f"Validation error in greet function: {e}")
        raise
    except Exception as e:
        logging.error(f"Unexpected error in greet function: {e}")
        logging.debug(traceback.format_exc())
        raise


def main():
    """Main application entry point with comprehensive error handling"""
    try:
        logging.info("Application started")

        logger = setup_logging()

        args = parse_arguments()

        try:
            message = greet(args.name)
            print(message)
            logging.info("Greeting displayed successfully")

        except ValueError as e:
            logging.error(f"Invalid input: {e}")
            print(f"Error: {e}", file=sys.stderr)
            sys.exit(1)

        except Exception as e:
            logging.critical(f"Unexpected error during greeting: {e}")
            logging.debug(traceback.format_exc())
            print(
                "An unexpected error occurred. Check logs for details.",
                file=sys.stderr,
            )
            sys.exit(1)

        logging.info("Application completed successfully")

    except SystemExit as e:
        logging.warning(f"Application exiting with code: {e.code}")
        raise

    except KeyboardInterrupt:
        logging.warning("Application interrupted by user")
        print("\nOperation cancelled by user.", file=sys.stderr)
        sys.exit(1)

    except Exception as e:
        logging.critical(f"Fatal error in main application: {e}")
        logging.debug(traceback.format_exc())
        print(
            "A fatal error occurred. Check logs for details.",
            file=sys.stderr,
        )
        sys.exit(1)


if __name__ == "__main__":
    main()