#!/usr/bin/env ts-node
/**
 * Environment Variables Validation Script
 * 
 * Validates that all required environment variables are set
 * before deployment to production.
 * 
 * Usage:
 *   ts-node scripts/validate-env.ts
 *   or
 *   npm run validate:env
 */

// Load environment variables from .env file
const dotenv = require('dotenv');
const path = require('path');
const fs = require('fs');

// Try to load .env file
const envPath = path.resolve(process.cwd(), '.env');
if (fs.existsSync(envPath)) {
  dotenv.config({ path: envPath });
  console.log(`✅ Loaded environment variables from ${envPath}\n`);
} else {
  console.warn(`⚠️  Warning: .env file not found at ${envPath}`);
  console.warn('   Trying to load from process.env only...\n');
  // Still try to load from current directory
  dotenv.config();
}

const requiredVars = [
  // Core
  'DATABASE_URL',
  'NEXTAUTH_URL',
  'NEXTAUTH_SECRET',
  
  // Keycloak
  'KEYCLOAK_BASE_URL',
  'KEYCLOAK_REALM',
  'KEYCLOAK_CLIENT_ID',
  'KEYCLOAK_CLIENT_SECRET',
  'KEYCLOAK_ISSUER',
  'NEXT_PUBLIC_KEYCLOAK_ISSUER',
];

const optionalButRecommended = [
  // Redis
  'REDIS_HOST',
  'REDIS_PORT',
  'REDIS_PASSWORD',
  
  // External Services
  'N8N_API_KEY',
  'N8N_WEBHOOK_URL',
  'LEANTIME_API_URL',
  'LEANTIME_TOKEN',
  'ROCKET_CHAT_TOKEN',
  'ROCKET_CHAT_USER_ID',
];

interface ValidationResult {
  valid: boolean;
  missing: string[];
  warnings: string[];
  errors: string[];
}

function validateEnvironment(): ValidationResult {
  const result: ValidationResult = {
    valid: true,
    missing: [],
    warnings: [],
    errors: [],
  };

  // Check required variables
  for (const varName of requiredVars) {
    const value = process.env[varName];
    if (!value || value.trim() === '') {
      result.missing.push(varName);
      result.valid = false;
    }
  }

  // Check optional but recommended
  for (const varName of optionalButRecommended) {
    const value = process.env[varName];
    if (!value || value.trim() === '') {
      result.warnings.push(varName);
    }
  }

  // Validate DATABASE_URL format
  const dbUrl = process.env.DATABASE_URL;
  if (dbUrl) {
    if (!dbUrl.startsWith('postgresql://') && !dbUrl.startsWith('postgres://')) {
      result.errors.push('DATABASE_URL must start with postgresql:// or postgres://');
      result.valid = false;
    }

    // Check for connection pool parameters
    if (!dbUrl.includes('connection_limit')) {
      result.warnings.push(
        'DATABASE_URL should include connection_limit parameter (e.g., ?connection_limit=10&pool_timeout=20)'
      );
    }
  }

  // Validate NEXTAUTH_SECRET strength
  const nextAuthSecret = process.env.NEXTAUTH_SECRET;
  if (nextAuthSecret && nextAuthSecret.length < 32) {
    result.warnings.push('NEXTAUTH_SECRET should be at least 32 characters long');
  }

  // Validate URLs
  const urlVars = ['NEXTAUTH_URL', 'KEYCLOAK_BASE_URL', 'NEXT_PUBLIC_KEYCLOAK_ISSUER'];
  for (const varName of urlVars) {
    const value = process.env[varName];
    if (value) {
      try {
        new URL(value);
      } catch {
        result.errors.push(`${varName} is not a valid URL: ${value}`);
        result.valid = false;
      }
    }
  }

  return result;
}

function main() {
  console.log('🔍 Validating environment variables...\n');

  const result = validateEnvironment();

  if (result.missing.length > 0) {
    console.error('❌ Missing required environment variables:');
    result.missing.forEach((varName) => {
      console.error(`   - ${varName}`);
    });
    console.error('');
  }

  if (result.errors.length > 0) {
    console.error('❌ Validation errors:');
    result.errors.forEach((error) => {
      console.error(`   - ${error}`);
    });
    console.error('');
  }

  if (result.warnings.length > 0) {
    console.warn('⚠️  Warnings:');
    result.warnings.forEach((warning) => {
      console.warn(`   - ${warning}`);
    });
    console.warn('');
  }

  if (result.valid) {
    console.log('✅ All required environment variables are set!\n');
    if (result.warnings.length > 0) {
      console.log('⚠️  Some optional variables are missing, but deployment can proceed.\n');
    }
    process.exit(0);
  } else {
    console.error('❌ Environment validation failed!\n');
    console.error('Please set all required variables before deploying.\n');
    process.exit(1);
  }
}

if (require.main === module) {
  main();
}

export { validateEnvironment };