const lighthouse = require('lighthouse');
const puppeteer = require('puppeteer');
const { URL } = require('url');
const fs = require('fs');
const path = require('path');

// Configuration for Lighthouse
const LIGHTHOUSE_CONFIG = {
  extends: 'lighthouse:default',
  settings: {
    onlyCategories: ['performance', 'accessibility', 'best-practices', 'seo'],
    formFactor: 'desktop',
    throttlingMethod: 'simulate',
  },
};

// Set threshold values for each category
const THRESHOLDS = {
  performance: 90,
  accessibility: 90,
  'best-practices': 90,
  seo: 90,
};

async function runLighthouse(url) {
  // Launch a headless browser
  const browser = await puppeteer.launch({ headless: true });
  
  // Create a new Lighthouse runner
  const { lhr } = await lighthouse(url, {
    port: (new URL(browser.wsEndpoint())).port,
    output: 'json',
    logLevel: 'info',
  }, LIGHTHOUSE_CONFIG);
  
  await browser.close();
  
  // Create directory for reports if it doesn't exist
  const reportsDir = path.join(__dirname, 'reports');
  if (!fs.existsSync(reportsDir)) {
    fs.mkdirSync(reportsDir);
  }
  
  // Save the report
  const reportPath = path.join(reportsDir, `lighthouse-report-${Date.now()}.json`);
  fs.writeFileSync(reportPath, JSON.stringify(lhr, null, 2));
  
  console.log('\nLighthouse Results:');
  console.log('--------------------');
  
  // Process and display results
  let allPassed = true;
  Object.keys(THRESHOLDS).forEach(category => {
    const score = Math.round(lhr.categories[category].score * 100);
    const threshold = THRESHOLDS[category];
    const passed = score >= threshold;
    
    if (!passed) {
      allPassed = false;
    }
    
    console.log(`${category}: ${score}/100 - ${passed ? 'PASS' : 'FAIL'} (Threshold: ${threshold})`);
  });
  
  // Display audits that failed
  console.log('\nFailed Audits:');
  console.log('--------------');
  let hasFailedAudits = false;
  
  Object.values(lhr.audits).forEach(audit => {
    if (audit.score !== null && audit.score < 0.9) {
      hasFailedAudits = true;
      console.log(`- ${audit.title}: ${Math.round(audit.score * 100)}/100`);
      console.log(`  ${audit.description}`);
    }
  });
  
  if (!hasFailedAudits) {
    console.log('No significant audit failures!');
  }
  
  console.log(`\nDetailed report saved to: ${reportPath}`);
  
  return allPassed;
}

// URL to test - this should be your local server address
const url = process.argv[2] || 'http://localhost:8080';

runLighthouse(url)
  .then(passed => {
    console.log(`\nOverall: ${passed ? 'PASSED' : 'FAILED'}`);
    process.exit(passed ? 0 : 1);
  })
  .catch(error => {
    console.error('Error running Lighthouse:', error);
    process.exit(1);
  });