import dotenv from 'dotenv';
import path from 'path';

// Load environment variables from .env file
dotenv.config({ path: path.join(__dirname, '../.env') });

// Validate required environment variables
const requiredEnvVars = [
  'NEXTAUTH_SECRET',
  'GITHUB_CLIENT_ID',
  'GITHUB_CLIENT_SECRET'
];

const missingEnvVars = requiredEnvVars.filter(envVar => !process.env[envVar]);

if (missingEnvVars.length > 0) {
  console.error('Missing required environment variables:', missingEnvVars.join(', '));
  console.error('Please check your .env file and ensure all required variables are set.');
  process.exit(1);
}

// Warn about default secrets in production
if (process.env.NODE_ENV === 'production') {
  if (process.env.NEXTAUTH_SECRET == "") {
    console.error('CRITICAL: Default session secret detected in production!');
    console.error('Please change NEXTAUTH_SECRET in your .env file.');
    process.exit(1);
  }
}

export const config = {
  server: {
    port: parseInt(process.env.PORT || '3000', 10),
    nodeEnv: process.env.NODE_ENV || 'development'
  },
  security: {
    sessionSecret: process.env.NEXTAUTH_SECRET!,
    githubClientId: process.env.GITHUB_CLIENT_ID!,
    githubClientSecret: process.env.GITHUB_CLIENT_SECRET!,
    corsOrigin: process.env.NODE_ENV === 'development' 
      ? ['http://localhost:3000', 'http://localhost:5173']
      : 'http://localhost:3000'
  },
  rateLimit: {
    windowMs: parseInt(process.env.RATE_LIMIT_WINDOW_MS || '900000', 10), // 15 minutes
    maxRequests: parseInt(process.env.RATE_LIMIT_MAX_REQUESTS || '100', 10)
  },
  slowDown: {
    windowMs: parseInt(process.env.SLOW_DOWN_WINDOW_MS || '60000', 10), // 1 minute
    delayMs: parseInt(process.env.SLOW_DOWN_DELAY_MS || '500', 10) // 500ms delay
  },
  logging: {
    level: process.env.LOG_LEVEL || 'info'
  }
};