import process from 'process';

const apiKey = process.env.API_KEY || '';
if (apiKey.length < 32) {
  console.error(`FATAL: API_KEY must be at least 32 characters long, current length: ${apiKey.length}`);
  process.exit(1);
}

/**
 * Parses duration strings like "20s", "1m" to milliseconds.
 * @param {string|undefined} val 
 * @param {number} defaultMs 
 * @returns {number}
 */
const parseDuration = (val, defaultMs) => {
  if (!val) return defaultMs;
  const match = val.match(/^(\d+)(s|m|h|ms)$/);
  if (!match) return defaultMs;
  const num = parseInt(match[1], 10);
  const unit = match[2];
  switch (unit) {
    case 'ms': return num;
    case 's': return num * 1000;
    case 'm': return num * 60 * 1000;
    case 'h': return num * 60 * 60 * 1000;
    default: return defaultMs;
  }
};

export const config = {
  serverAddr: process.env.SERVER_ADDR || '127.0.0.1:47880',
  apiKey: apiKey,
  logLevel: process.env.LOG_LEVEL || 'info',
  maxMessageBytes: parseInt(process.env.MAX_MESSAGE_BYTES || '4096', 10),
  heartbeatInterval: parseDuration(process.env.HEARTBEAT_INTERVAL, 20000), // 20s
  heartbeatTimeout: parseDuration(process.env.HEARTBEAT_TIMEOUT, 30000),  // 30s
  sessionDuration: parseDuration(process.env.SESSION_DURATION, 60000),   // 60s
  rateLimitPerMin: parseInt(process.env.RATE_LIMIT_PER_MIN || '10', 10),
  environment: process.env.ENVIRONMENT || 'production',
  dbHost: process.env.DB_HOST || '127.0.0.1',
  dbPort: parseInt(process.env.DB_PORT || '3306', 10),
  dbDatabase: process.env.DB_DATABASE || 'callDB',
  dbUsername: process.env.DB_USERNAME || '',
  dbPassword: process.env.DB_PASSWORD || '',
  turnUrl: process.env.TURN_URL || '',
  turnUsername: process.env.TURN_USERNAME || '',
  turnCredential: process.env.TURN_CREDENTIAL || '',
};