#!/usr/bin/env node

/**
 * Phase 3 Patch Application Script
 * Applies final modifications to server/index.mjs
 */

import fs from 'fs';
import path from 'path';
import { fileURLToPath } from 'url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const indexFile = path.join(__dirname, 'server', 'index.mjs');
const backupFile = `${indexFile}.backup.${Date.now()}`;

console.log('\n🚀 Phase 3 Patch Application');
console.log('================================\n');

try {
  // Step 1: Create backup
  console.log('📦 Creating backup...');
  fs.copyFileSync(indexFile, backupFile);
  console.log(`✅ Backup created: ${backupFile}\n`);

  // Step 2: Read the file
  console.log('📖 Reading index.mjs...');
  let content = fs.readFileSync(indexFile, 'utf-8');
  console.log('✅ File read successfully\n');

  // Step 3: Add performance endpoint setup
  console.log('🔧 Adding performance endpoint setup...');
  const performanceEndpointSetup = `// Phase 3: Setup performance monitoring endpoint
setupPerformanceEndpoint(app, performanceMonitor, metadataCache, meilisearchCircuitBreaker);

`;

  // Insert before "// Créer le répertoire de la voûte"
  content = content.replace(
    '// Créer le répertoire de la voûte s\'il n\'existe pas',
    performanceEndpointSetup + '// Créer le répertoire de la voûte s\'il n\'existe pas'
  );
  console.log('✅ Performance endpoint setup added\n');

  // Step 4: Update app.listen() for deferred indexing
  console.log('🔧 Updating app.listen() for deferred indexing...');

  const oldListen = `app.listen(PORT, '0.0.0.0', () => {
  console.log(\`ObsiViewer server running on http://0.0.0.0:\${PORT}\`);
  console.log(\`Vault directory: \${vaultDir}\`);
});`;

  const newListen = `// Phase 3: Deferred Meilisearch indexing (non-blocking)
let indexingState = { inProgress: false, completed: false };
const scheduleIndexing = async () => {
  if (indexingState.inProgress) return;
  indexingState.inProgress = true;
  
  setImmediate(async () => {
    try {
      console.time('[Meilisearch] Background indexing');
      await fullReindex(vaultDir);
      console.timeEnd('[Meilisearch] Background indexing');
      indexingState.completed = true;
      console.log('[Meilisearch] ✅ Background indexing completed');
    } catch (error) {
      console.error('[Meilisearch] ❌ Background indexing failed:', error.message);
      indexingState.completed = false;
      // Retry after 5 minutes
      setTimeout(() => {
        indexingState.inProgress = false;
        scheduleIndexing();
      }, 5 * 60 * 1000);
    }
  });
};

const server = app.listen(PORT, '0.0.0.0', () => {
  console.log(\`🚀 ObsiViewer server running on http://0.0.0.0:\${PORT}\`);
  console.log(\`📁 Vault directory: \${vaultDir}\`);
  console.log(\`📊 Performance monitoring: http://0.0.0.0:\${PORT}/__perf\`);
  
  // Schedule background indexing (non-blocking)
  scheduleIndexing();
  console.log('✅ Server ready - Meilisearch indexing in background');
});

// Graceful shutdown
process.on('SIGINT', () => {
  console.log('\\n🛑 Shutting down server...');
  server.close(() => {
    console.log('✅ Server shutdown complete');
    process.exit(0);
  });
});`;

  content = content.replace(oldListen, newListen);
  console.log('✅ app.listen() updated with deferred indexing\n');

  // Step 5: Write the modified content
  console.log('💾 Writing modified index.mjs...');
  fs.writeFileSync(indexFile, content, 'utf-8');
  console.log('✅ File written successfully\n');

  // Step 6: Verify changes
  console.log('🔍 Verifying changes...');
  const verifyContent = fs.readFileSync(indexFile, 'utf-8');

  const checks = [
    { name: 'Performance endpoint setup', pattern: 'setupPerformanceEndpoint' },
    { name: 'Deferred indexing', pattern: 'scheduleIndexing' },
    { name: 'Graceful shutdown', pattern: "process.on('SIGINT'" },
    { name: 'Performance monitoring URL', pattern: '__perf' }
  ];

  let allPassed = true;
  for (const check of checks) {
    if (verifyContent.includes(check.pattern)) {
      console.log(`  ✅ ${check.name}`);
    } else {
      console.log(`  ❌ ${check.name}`);
      allPassed = false;
    }
  }

  console.log('');
  if (allPassed) {
    console.log('✅ All verification checks passed!\n');
  } else {
    console.log('⚠️  Some verification checks failed\n');
  }

  console.log('================================');
  console.log('✅ Phase 3 patch applied successfully!\n');
  console.log('Next steps:');
  console.log('1. Test the server: npm run start');
  console.log('2. Check performance: curl http://localhost:3000/__perf');
  console.log('3. Monitor cache hits in the logs');
  console.log('4. Verify Meilisearch indexing in background\n');

} catch (error) {
  console.error('❌ Error applying patch:', error.message);
  console.error('\nRolling back...');
  if (fs.existsSync(backupFile)) {
    fs.copyFileSync(backupFile, indexFile);
    console.log('✅ Rollback complete');
  }
  process.exit(1);
}