const axios = require('axios');

const BASE_URL = 'http://localhost:3000/api';

// Test configuration
const ITERATIONS = 10;

// Colors for terminal output
const colors = {
  reset: '\x1b[0m',
  green: '\x1b[32m',
  yellow: '\x1b[33m',
  blue: '\x1b[34m',
  cyan: '\x1b[36m',
  magenta: '\x1b[35m'
};

const log = (message, color = 'reset') => {
  console.log(`${colors[color]}${message}${colors.reset}`);
};

/**
 * Measure endpoint performance
 */
const measureEndpoint = async (name, url, options = {}) => {
  const times = [];
  
  for (let i = 0; i < ITERATIONS; i++) {
    const startTime = Date.now();
    try {
      await axios.get(url, options);
      const endTime = Date.now();
      times.push(endTime - startTime);
    } catch (error) {
      // Some endpoints may return errors (401, etc.) but we still measure time
      const endTime = Date.now();
      times.push(endTime - startTime);
    }
  }
  
  const avg = times.reduce((a, b) => a + b, 0) / times.length;
  const min = Math.min(...times);
  const max = Math.max(...times);
  
  return { name, avg, min, max, times };
};

/**
 * Run performance benchmarks
 */
async function runBenchmarks() {
  log('\n═══════════════════════════════════════════════════════', 'cyan');
  log('       Performance Benchmark Test Suite', 'cyan');
  log('═══════════════════════════════════════════════════════', 'cyan');
  log(`\n📊 Running ${ITERATIONS} iterations per endpoint...\n`, 'blue');
  
  const results = [];
  
  try {
    // Test 1: Categories list (should be cached after first request)
    log('Testing: GET /categories', 'yellow');
    const categoriesResult = await measureEndpoint(
      'Categories List',
      `${BASE_URL}/categories`
    );
    results.push(categoriesResult);
    log(`  Average: ${categoriesResult.avg.toFixed(2)}ms`, 'green');
    
    // Test 2: Health check (simple query)
    log('\nTesting: GET /health', 'yellow');
    const healthResult = await measureEndpoint(
      'Health Check',
      'http://localhost:3000/health'
    );
    results.push(healthResult);
    log(`  Average: ${healthResult.avg.toFixed(2)}ms`, 'green');
    
    // Test 3: API docs JSON (file serving)
    log('\nTesting: GET /api-docs.json', 'yellow');
    const docsResult = await measureEndpoint(
      'API Documentation',
      'http://localhost:3000/api-docs.json'
    );
    results.push(docsResult);
    log(`  Average: ${docsResult.avg.toFixed(2)}ms`, 'green');
    
    // Test 4: Guest session creation (database write)
    log('\nTesting: POST /guest/start-session', 'yellow');
    const guestTimes = [];
    for (let i = 0; i < ITERATIONS; i++) {
      const startTime = Date.now();
      try {
        await axios.post(`${BASE_URL}/guest/start-session`);
        const endTime = Date.now();
        guestTimes.push(endTime - startTime);
      } catch (error) {
        // Rate limited, still measure
        const endTime = Date.now();
        guestTimes.push(endTime - startTime);
      }
      // Small delay to avoid rate limiting
      await new Promise(resolve => setTimeout(resolve, 100));
    }
    const guestAvg = guestTimes.reduce((a, b) => a + b, 0) / guestTimes.length;
    results.push({
      name: 'Guest Session Creation',
      avg: guestAvg,
      min: Math.min(...guestTimes),
      max: Math.max(...guestTimes),
      times: guestTimes
    });
    log(`  Average: ${guestAvg.toFixed(2)}ms`, 'green');
    
    // Summary
    log('\n═══════════════════════════════════════════════════════', 'cyan');
    log('                Performance Summary', 'cyan');
    log('═══════════════════════════════════════════════════════', 'cyan');
    
    results.sort((a, b) => a.avg - b.avg);
    
    results.forEach((result, index) => {
      const emoji = index === 0 ? '🏆' : index === 1 ? '🥈' : index === 2 ? '🥉' : '📊';
      log(`\n${emoji} ${result.name}:`, 'blue');
      log(`   Average: ${result.avg.toFixed(2)}ms`, 'green');
      log(`   Min:     ${result.min}ms`, 'cyan');
      log(`   Max:     ${result.max}ms`, 'cyan');
      
      // Performance rating
      if (result.avg < 50) {
        log('   Rating:  ⚡ Excellent', 'green');
      } else if (result.avg < 100) {
        log('   Rating:  ✓ Good', 'green');
      } else if (result.avg < 200) {
        log('   Rating:  ⚠ Fair', 'yellow');
      } else {
        log('   Rating:  ⚠️ Needs Optimization', 'yellow');
      }
    });
    
    // Cache effectiveness test
    log('\n═══════════════════════════════════════════════════════', 'cyan');
    log('           Cache Effectiveness Test', 'cyan');
    log('═══════════════════════════════════════════════════════', 'cyan');
    
    log('\n🔄 Testing cache hit vs miss for categories...', 'blue');
    
    // Clear cache by making a write operation (if applicable)
    // First request (cache miss)
    const cacheMissStart = Date.now();
    await axios.get(`${BASE_URL}/categories`);
    const cacheMissTime = Date.now() - cacheMissStart;
    
    // Second request (cache hit)
    const cacheHitStart = Date.now();
    await axios.get(`${BASE_URL}/categories`);
    const cacheHitTime = Date.now() - cacheHitStart;
    
    log(`\n  First Request (cache miss):  ${cacheMissTime}ms`, 'yellow');
    log(`  Second Request (cache hit):  ${cacheHitTime}ms`, 'green');
    
    if (cacheHitTime < cacheMissTime) {
      const improvement = ((1 - cacheHitTime / cacheMissTime) * 100).toFixed(1);
      log(`  Cache Improvement: ${improvement}% faster 🚀`, 'green');
    }
    
    // Overall statistics
    log('\n═══════════════════════════════════════════════════════', 'cyan');
    log('              Overall Statistics', 'cyan');
    log('═══════════════════════════════════════════════════════', 'cyan');
    
    const overallAvg = results.reduce((sum, r) => sum + r.avg, 0) / results.length;
    const fastest = results[0];
    const slowest = results[results.length - 1];
    
    log(`\n  Total Endpoints Tested: ${results.length}`, 'blue');
    log(`  Total Requests Made: ${results.length * ITERATIONS}`, 'blue');
    log(`  Overall Average: ${overallAvg.toFixed(2)}ms`, 'magenta');
    log(`  Fastest Endpoint: ${fastest.name} (${fastest.avg.toFixed(2)}ms)`, 'green');
    log(`  Slowest Endpoint: ${slowest.name} (${slowest.avg.toFixed(2)}ms)`, 'yellow');
    
    if (overallAvg < 100) {
      log('\n  🎉 Overall Performance: EXCELLENT', 'green');
    } else if (overallAvg < 200) {
      log('\n  ✓ Overall Performance: GOOD', 'green');
    } else {
      log('\n  ⚠️  Overall Performance: NEEDS IMPROVEMENT', 'yellow');
    }
    
    log('\n═══════════════════════════════════════════════════════', 'cyan');
    log('  Benchmark complete! Performance data collected.', 'cyan');
    log('═══════════════════════════════════════════════════════\n', 'cyan');
    
  } catch (error) {
    log(`\n❌ Benchmark error: ${error.message}`, 'yellow');
    console.error(error);
  }
}

// Run benchmarks
console.log('\nStarting performance benchmarks in 2 seconds...');
console.log('Make sure the server is running on http://localhost:3000\n');

setTimeout(runBenchmarks, 2000);