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

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

// Configuration
const siteUrl = 'http://localhost:1313'; // Your local Hugo server
const pages = [
  '/',
  '/about/',
  '/how-it-works/',
  '/posts/blog1/'
  // Add more pages to test
];
const outputFile = 'css-analysis.json';

// CSS files to analyze
const cssFiles = [
  '/css/vendor/material.indigo-pink.min.css',
  '/css/vendor/fontawesome.min.css',
  '/css/vendor/video-js.min.css',
  '/css/app.min.css',
  '/css/custom.css'
];

async function analyzePage(page, url) {
  await page.goto(url, { waitUntil: 'networkidle2' });
  
  // Get all used CSS selectors
  const usedSelectors = await page.evaluate((cssFiles) => {
    const used = {};
    cssFiles.forEach(file => { used[file] = []; });
    
    // Function to get all CSS rules
    const getAllCssRules = (stylesheet) => {
      if (!stylesheet.href || !cssFiles.some(file => stylesheet.href.includes(file))) {
        return [];
      }
      
      const file = cssFiles.find(file => stylesheet.href.includes(file));
      const rules = [];
      
      try {
        // Extract rules from stylesheet
        for (let i = 0; i < stylesheet.cssRules.length; i++) {
          const rule = stylesheet.cssRules[i];
          
          if (rule.selectorText) {
            rules.push({
              selector: rule.selectorText,
              file: file
            });
          } else if (rule.cssRules) { // Handle media queries
            for (let j = 0; j < rule.cssRules.length; j++) {
              const nestedRule = rule.cssRules[j];
              if (nestedRule.selectorText) {
                rules.push({
                  selector: nestedRule.selectorText,
                  file: file
                });
              }
            }
          }
        }
      } catch (e) {
        console.error('Error accessing stylesheet:', e);
      }
      
      return rules;
    };
    
    // Get all stylesheets and their rules
    const allRules = [];
    Array.from(document.styleSheets).forEach(stylesheet => {
      allRules.push(...getAllCssRules(stylesheet));
    });
    
    // Test each selector
    allRules.forEach(({selector, file}) => {
      try {
        if (document.querySelector(selector) !== null) {
          used[file].push(selector);
        }
      } catch (e) {
        // Invalid selector, skip
      }
    });
    
    return used;
  }, cssFiles);
  
  return usedSelectors;
}

async function run() {
  const browser = await puppeteer.launch();
  const page = await browser.newPage();
  
  console.log('Starting CSS analysis across pages...');
  let results = {};
  
  // Initialize results object
  cssFiles.forEach(file => {
    results[file] = {
      usedSelectors: new Set(),
      allSelectors: new Set()
    };
  });
  
  // Analyze each page
  for (const url of pages) {
    console.log(`Analyzing ${siteUrl}${url}...`);
    const pageResults = await analyzePage(page, `${siteUrl}${url}`);
    
    // Merge results
    for (const file in pageResults) {
      pageResults[file].forEach(selector => {
        results[file].usedSelectors.add(selector);
      });
    }
  }
  
  // Get all selectors
  for (const file of cssFiles) {
    console.log(`Getting all selectors from ${file}...`);
    await page.goto(`${siteUrl}${file}`, { waitUntil: 'networkidle2' });
    
    const allSelectors = await page.evaluate(() => {
      const text = document.querySelector('body')?.innerText || '';
      
      // Very simplistic parsing - won't work for all cases
      // For production, use a proper CSS parser
      const selectors = [];
      const rules = text.split('}');
      
      rules.forEach(rule => {
        const selectorPart = rule.split('{')[0];
        if (selectorPart) {
          selectorPart.split(',').forEach(s => {
            s = s.trim();
            if (s.length > 0) {
              selectors.push(s);
            }
          });
        }
      });
      
      return selectors;
    });
    
    allSelectors.forEach(selector => {
      results[file].allSelectors.add(selector);
    });
  }
  
  // Convert Sets to Arrays for JSON serialization
  const finalResults = {};
  for (const file in results) {
    finalResults[file] = {
      used: Array.from(results[file].usedSelectors),
      all: Array.from(results[file].allSelectors),
      usage: {
        total: results[file].allSelectors.size,
        used: results[file].usedSelectors.size,
        unused: results[file].allSelectors.size - results[file].usedSelectors.size,
        percentage: (results[file].usedSelectors.size / results[file].allSelectors.size * 100).toFixed(2)
      }
    };
  }
  
  // Generate summary
  const summary = {
    totalSelectorsUsed: Object.values(finalResults).reduce((sum, file) => sum + file.used.length, 0),
    totalSelectors: Object.values(finalResults).reduce((sum, file) => sum + file.all.length, 0),
    files: {}
  };
  
  for (const file in finalResults) {
    summary.files[file] = finalResults[file].usage;
  }
  
  finalResults.summary = summary;
  
  // Save results
  fs.writeFileSync(outputFile, JSON.stringify(finalResults, null, 2));
  
  console.log(`Analysis complete! Results saved to ${outputFile}`);
  console.log('Summary:');
  console.log(`Total selectors: ${summary.totalSelectors}`);
  console.log(`Total used: ${summary.totalSelectorsUsed} (${(summary.totalSelectorsUsed / summary.totalSelectors * 100).toFixed(2)}%)`);
  
  for (const file in summary.files) {
    console.log(`${file}: ${summary.files[file].used}/${summary.files[file].total} (${summary.files[file].percentage}%)`);
  }
  
  await browser.close();
}

run().catch(console.error);