/**
 * Production Environment Configuration
 * This file contains production-specific settings and environment variable handling
 */

const path = require('path');

module.exports = {
  // Server Configuration
  server: {
    port: process.env.PORT || 3000,
    host: process.env.HOST || '0.0.0.0',
    environment: process.env.NODE_ENV || 'production',
    requestTimeout: parseInt(process.env.REQUEST_TIMEOUT) || 30000
  },

  // Database Configuration
  database: {
    path: process.env.DATABASE_PATH || './inventory.db',
    backupPath: process.env.DATABASE_BACKUP_PATH || './data/backups',
    backupInterval: parseInt(process.env.DATABASE_BACKUP_INTERVAL) || 3600000, // 1 hour
    queryTimeout: parseInt(process.env.QUERY_TIMEOUT) || 5000
  },

  // File Upload Configuration
  upload: {
    maxSize: parseInt(process.env.UPLOAD_MAX_SIZE) || 10 * 1024 * 1024, // 10MB
    allowedTypes: process.env.UPLOAD_ALLOWED_TYPES?.split(',') || [
      'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
      'application/vnd.ms-excel'
    ],
    tempDir: process.env.TEMP_DIR || './data/temp'
  },

  // Export Configuration
  export: {
    dir: process.env.EXPORT_DIR || './data/exports',
    retentionDays: parseInt(process.env.EXPORT_RETENTION_DAYS) || 30
  },

  // Logging Configuration
  logging: {
    level: process.env.LOG_LEVEL || 'info',
    dir: process.env.LOG_DIR || './logs',
    maxSize: process.env.LOG_MAX_SIZE || '10m',
    maxFiles: process.env.LOG_MAX_FILES || '14d'
  },

  // Security Configuration
  security: {
    corsOrigin: process.env.CORS_ORIGIN || '*',
    helmetCspEnabled: process.env.HELMET_CSP_ENABLED === 'true',
    rateLimitEnabled: process.env.RATE_LIMIT_ENABLED === 'true',
    rateLimitMax: parseInt(process.env.RATE_LIMIT_MAX) || 100
  },

  // Performance Configuration
  performance: {
    cacheTtl: parseInt(process.env.CACHE_TTL) || 300000, // 5 minutes
    maxConcurrentImports: parseInt(process.env.MAX_CONCURRENT_IMPORTS) || 3
  },

  // Backup Configuration
  backup: {
    enabled: process.env.BACKUP_ENABLED === 'true',
    schedule: process.env.BACKUP_SCHEDULE || '0 2 * * *', // Daily at 2 AM
    retentionDays: parseInt(process.env.BACKUP_RETENTION_DAYS) || 30
  },

  // Validate required environment variables
  validate() {
    const required = [];
    const missing = required.filter(key => !process.env[key]);
    
    if (missing.length > 0) {
      throw new Error(`Missing required environment variables: ${missing.join(', ')}`);
    }
  }
};