gateway/modules/configuration.py

"""
Utility module for configuration management.

This module provides a global APP_CONFIG object for accessing configuration from both 
config.ini files and environment variables stored in .env files, using a flat structure.
"""

import os
import logging
from typing import Any, Dict, Optional
from pathlib import Path

# Set up logging
logger = logging.getLogger(__name__)

class Configuration:
    """
    Configuration class with attribute-style access to flattened configuration.
    """
    def __init__(self):
        """Initialize the configuration object"""
        self._data = {}
        self._config_file_path = None
        self._env_file_path = None
        self._config_mtime = 0
        self._env_mtime = 0
        self.refresh()
    
    def refresh(self):
        """Reload configuration from files"""
        self._load_config()
        self._load_env()
        logger.info("Configuration refreshed")
    
    def _load_config(self):
        """Load configuration from config.ini file in flattened format"""
        # Find config.ini file (look in current directory and parent directory)
        config_path = Path('config.ini')
        if not config_path.exists():
            # Try in parent directory
            config_path = Path('../config.ini')
            if not config_path.exists():
                logger.warning(f"Configuration file not found at {config_path.absolute()}")
                return
        
        self._config_file_path = config_path
        current_mtime = os.path.getmtime(config_path)
        
        # Skip if file hasn't changed
        if current_mtime <= self._config_mtime:
            return
            
        self._config_mtime = current_mtime

        try:
            with open(config_path, 'r') as f:
                for line in f:
                    line = line.strip()
                    # Skip empty lines and comments
                    if not line or line.startswith('#'):
                        continue
                        
                    # Parse key-value pairs
                    if '=' in line:
                        key, value = line.split('=', 1)
                        key = key.strip()
                        value = value.strip()
                        
                        # Add directly to data dictionary
                        self._data[key] = value
                
                    
        except Exception as e:
            logger.error(f"Error loading configuration: {e}")
    
    def _load_env(self):
        """Load environment variables from .env file"""
        # Find .env file (look in current directory and parent directory)
        env_path = Path('.env')
        if not env_path.exists():
            # Try in parent directory
            env_path = Path('../.env')
            if not env_path.exists():
                logger.warning(f"Environment file not found at {env_path.absolute()}")
                return
        
        self._env_file_path = env_path
        current_mtime = os.path.getmtime(env_path)
        
        # Skip if file hasn't changed
        if current_mtime <= self._env_mtime:
            return
            
        self._env_mtime = current_mtime
        
        try:
            with open(env_path, 'r') as f:
                for line in f:
                    line = line.strip()
                    # Skip empty lines and comments
                    if not line or line.startswith('#'):
                        continue
                        
                    # Parse key-value pairs
                    if '=' in line:
                        key, value = line.split('=', 1)
                        key = key.strip()
                        value = value.strip()
                        
                        # Add directly to data dictionary
                        self._data[key] = value
            
            logger.info(f"Loaded environment variables from {env_path.absolute()}")
            
            # Also load system environment variables (don't override existing)
            for key, value in os.environ.items():
                if key not in self._data:
                    self._data[key] = value
                    
        except Exception as e:
            logger.error(f"Error loading environment variables: {e}")
    
    def check_for_updates(self):
        """Check if configuration files have changed and reload if necessary"""
        if self._config_file_path and os.path.exists(self._config_file_path):
            current_mtime = os.path.getmtime(self._config_file_path)
            if current_mtime > self._config_mtime:
                logger.info("Config file has changed, reloading...")
                self._load_config()
                
        if self._env_file_path and os.path.exists(self._env_file_path):
            current_mtime = os.path.getmtime(self._env_file_path)
            if current_mtime > self._env_mtime:
                logger.info("Environment file has changed, reloading...")
                self._load_env()
    
    def get(self, key: str, default: Any = None) -> Any:
        """Get configuration value with optional default"""
        self.check_for_updates()  # Check for file changes
        
        if key in self._data:
            value = self._data[key]
            # Handle secrets (keys ending with _SECRET)
            if key.endswith("_SECRET"):
                return handle_secret(value)
            return value
        return default
    
    def __getattr__(self, name: str) -> Any:
        """Enable attribute-style access to configuration"""
        self.check_for_updates()  # Check for file changes
        
        value = self.get(name)
        if value is None:
            raise AttributeError(f"Configuration key '{name}' not found")
        return value
    
    def __dir__(self) -> list:
        """Support auto-completion of attributes"""
        self.check_for_updates()  # Check for file changes
        return list(self._data.keys()) + super().__dir__()
    
    def set(self, key: str, value: Any) -> None:
        """Set a configuration value (for testing/overrides)"""
        self._data[key] = value

def handle_secret(value: str) -> str:
    """
    Handle secret values. Currently just returns the plain text value,
    but can be enhanced to provide actual decryption in the future.
    
    Args:
        value: The secret value to handle
        
    Returns:
        str: Processed secret value
    """
    # For now, just return the value as-is
    # In the future, this could be enhanced to decrypt values
    return value

# Create the global APP_CONFIG instance
APP_CONFIG = Configuration()