ebook-extension/ebook_backend_admin_panel/admin-backend/utils/logger.py

"""
Professional logging utility for the Ebook Coupon Management System
Provides structured logging with proper formatting and log levels.
"""
import logging
import logging.handlers
import os
import sys
from datetime import datetime
from typing import Optional, Any, Dict
import json

class SafeJSONEncoder(json.JSONEncoder):
    """Custom JSON encoder that handles non-serializable objects safely"""
    
    def default(self, obj):
        """Handle non-serializable objects by converting them to strings"""
        if hasattr(obj, '__dict__'):
            return str(obj)
        elif hasattr(obj, '__str__'):
            return str(obj)
        else:
            return f"<{type(obj).__name__} object>"

class StructuredFormatter(logging.Formatter):
    """Custom formatter for structured logging"""
    
    def format(self, record: logging.LogRecord) -> str:
        """Format log record with structured data"""
        log_entry = {
            "timestamp": datetime.utcnow().isoformat(),
            "level": record.levelname,
            "logger": record.name,
            "message": record.getMessage(),
            "module": record.module,
            "function": record.funcName,
            "line": record.lineno
        }
        
        # Add extra fields if present
        if hasattr(record, 'request_id'):
            log_entry['request_id'] = record.request_id
        if hasattr(record, 'method'):
            log_entry['method'] = record.method
        if hasattr(record, 'path'):
            log_entry['path'] = record.path
        if hasattr(record, 'status_code'):
            log_entry['status_code'] = record.status_code
        if hasattr(record, 'process_time'):
            log_entry['process_time'] = record.process_time
        if hasattr(record, 'client_ip'):
            log_entry['client_ip'] = record.client_ip
        if hasattr(record, 'user_agent'):
            log_entry['user_agent'] = record.user_agent
        if hasattr(record, 'error'):
            log_entry['error'] = record.error
        if hasattr(record, 'exception_type'):
            log_entry['exception_type'] = record.exception_type
        if hasattr(record, 'exception_message'):
            log_entry['exception_message'] = record.exception_message
        if hasattr(record, 'errors'):
            # Handle errors list safely
            try:
                if isinstance(record.errors, list):
                    log_entry['errors'] = [str(error) if not isinstance(error, (dict, str, int, float, bool)) else error for error in record.errors]
                else:
                    log_entry['errors'] = str(record.errors)
            except Exception:
                log_entry['errors'] = str(record.errors)
        if hasattr(record, 'app_name'):
            log_entry['app_name'] = record.app_name
        if hasattr(record, 'version'):
            log_entry['version'] = record.version
        if hasattr(record, 'environment'):
            log_entry['environment'] = record.environment
        if hasattr(record, 'debug'):
            log_entry['debug'] = record.debug
        
        # Add exception info if present
        if record.exc_info:
            log_entry['exception'] = self.formatException(record.exc_info)
        
        return json.dumps(log_entry, ensure_ascii=False, cls=SafeJSONEncoder)

def setup_logger(name: str, level: Optional[str] = None) -> logging.Logger:
    """
    Setup a logger with proper configuration
    
    Args:
        name: Logger name
        level: Log level (DEBUG, INFO, WARNING, ERROR, CRITICAL)
        
    Returns:
        Configured logger instance
    """
    # Get log level from environment or use default
    log_level = level or os.getenv("LOG_LEVEL", "INFO").upper()
    
    # Create logger
    logger = logging.getLogger(name)
    logger.setLevel(getattr(logging, log_level))
    
    # Avoid duplicate handlers
    if logger.handlers:
        return logger
    
    # Create formatters
    structured_formatter = StructuredFormatter()
    console_formatter = logging.Formatter(
        '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
    )
    
    # Console handler
    console_handler = logging.StreamHandler(sys.stdout)
    console_handler.setLevel(logging.DEBUG)
    console_handler.setFormatter(console_formatter)
    logger.addHandler(console_handler)
    
    # File handler for structured logs
    log_dir = "logs"
    os.makedirs(log_dir, exist_ok=True)
    
    file_handler = logging.handlers.RotatingFileHandler(
        os.path.join(log_dir, "app.log"),
        maxBytes=10*1024*1024,  # 10MB
        backupCount=5
    )
    file_handler.setLevel(logging.INFO)
    file_handler.setFormatter(structured_formatter)
    logger.addHandler(file_handler)
    
    # Error file handler
    error_handler = logging.handlers.RotatingFileHandler(
        os.path.join(log_dir, "error.log"),
        maxBytes=10*1024*1024,  # 10MB
        backupCount=5
    )
    error_handler.setLevel(logging.ERROR)
    error_handler.setFormatter(structured_formatter)
    logger.addHandler(error_handler)
    
    return logger

def get_logger(name: str) -> logging.Logger:
    """
    Get a logger instance
    
    Args:
        name: Logger name
        
    Returns:
        Logger instance
    """
    return logging.getLogger(name)

# Create default logger
default_logger = setup_logger("ebook_coupon_system")