Enhance configuration management with comprehensive environment setup

- Added detailed .env.example with extensive configuration options
- Created centralized configuration module with type-safe environment variable loading
- Implemented configuration validation and default value handling
- Added support for different environment modes (development, production, test)
- Introduced interfaces for robust type definitions across the project
- Implemented middleware for request validation, security, and input sanitization

src/config/index.ts

@@ -0,0 +1,87 @@
+import { config } from 'dotenv';
+import { resolve } from 'path';
+
+// Load environment variables based on NODE_ENV
+const envFile = process.env.NODE_ENV === 'production'
+    ? '.env'
+    : process.env.NODE_ENV === 'test'
+        ? '.env.test'
+        : '.env.development';
+
+console.log(`Loading environment from ${envFile}`);
+config({ path: resolve(process.cwd(), envFile) });
+
+// Home Assistant Configuration
+export const HASS_CONFIG = {
+    HOST: process.env.HASS_HOST || 'http://homeassistant.local:8123',
+    TOKEN: process.env.HASS_TOKEN,
+    SOCKET_URL: process.env.HASS_SOCKET_URL || 'ws://homeassistant.local:8123/api/websocket'
+};
+
+// Server Configuration
+export const SERVER_CONFIG = {
+    PORT: parseInt(process.env.PORT || '3000', 10),
+    NODE_ENV: process.env.NODE_ENV || 'development',
+    DEBUG: process.env.DEBUG === 'true',
+    LOG_LEVEL: process.env.LOG_LEVEL || 'info'
+};
+
+// AI Configuration
+export const AI_CONFIG = {
+    PROCESSOR_TYPE: process.env.PROCESSOR_TYPE || 'claude',
+    OPENAI_API_KEY: process.env.OPENAI_API_KEY
+};
+
+// Rate Limiting Configuration
+export const RATE_LIMIT_CONFIG = {
+    REGULAR: parseInt(process.env.RATE_LIMIT_REGULAR || '100', 10),
+    WEBSOCKET: parseInt(process.env.RATE_LIMIT_WEBSOCKET || '1000', 10)
+};
+
+// Security Configuration
+export const SECURITY_CONFIG = {
+    JWT_SECRET: process.env.JWT_SECRET || 'default_secret_key_change_in_production',
+    CORS_ORIGINS: (process.env.CORS_ORIGINS || 'http://localhost:3000,http://localhost:8123')
+        .split(',')
+        .map(origin => origin.trim())
+};
+
+// Test Configuration
+export const TEST_CONFIG = {
+    HASS_HOST: process.env.TEST_HASS_HOST || 'http://localhost:8123',
+    HASS_TOKEN: process.env.TEST_HASS_TOKEN || 'test_token',
+    HASS_SOCKET_URL: process.env.TEST_HASS_SOCKET_URL || 'ws://localhost:8123/api/websocket',
+    PORT: parseInt(process.env.TEST_PORT || '3001', 10)
+};
+
+// Mock Configuration (for testing)
+export const MOCK_CONFIG = {
+    SERVICES: process.env.MOCK_SERVICES === 'true',
+    RESPONSES_DIR: process.env.MOCK_RESPONSES_DIR || '__tests__/mock-responses'
+};
+
+// Validate required configuration
+function validateConfig() {
+    const missingVars: string[] = [];
+
+    if (!HASS_CONFIG.TOKEN) missingVars.push('HASS_TOKEN');
+    if (!SECURITY_CONFIG.JWT_SECRET) missingVars.push('JWT_SECRET');
+
+    if (missingVars.length > 0) {
+        throw new Error(`Missing required environment variables: ${missingVars.join(', ')}`);
+    }
+}
+
+// Export configuration validation
+export const validateConfiguration = validateConfig;
+
+// Export all configurations as a single object
+export const AppConfig = {
+    HASS: HASS_CONFIG,
+    SERVER: SERVER_CONFIG,
+    AI: AI_CONFIG,
+    RATE_LIMIT: RATE_LIMIT_CONFIG,
+    SECURITY: SECURITY_CONFIG,
+    TEST: TEST_CONFIG,
+    MOCK: MOCK_CONFIG
+};