/**
 * Theme Screenshot Capture Script
 * WorkRoot IT Solutions — Dark/Light Mode Visual Reference
 *
 * Generates full-page screenshots of all major pages in both themes
 * across desktop, tablet, and mobile viewports.
 *
 * Usage:
 *   1. Start dev server:  npm run dev
 *   2. Run this script:   node scripts/capture-theme-screenshots.js
 *
 * Output: .agents/frontend-specialist/screenshots/{light,dark}/{page}-{viewport}.png
 *
 * Prerequisites:
 *   npm install playwright
 *   npx playwright install chromium
 */

const { chromium } = require('playwright');
const path = require('path');
const fs = require('fs');

// ─── Configuration ────────────────────────────────────────────────────────────

const BASE_URL = process.env.BASE_URL || 'http://localhost:4321';

const PAGES = [
  { name: 'home',      path: '/'          },
  { name: 'about',     path: '/about'     },
  { name: 'services',  path: '/services'  },
  { name: 'portfolio', path: '/portfolio' },
  { name: 'contact',   path: '/contact'   },
];

const VIEWPORTS = [
  { name: 'desktop', width: 1440, height: 900  },
  { name: 'tablet',  width: 768,  height: 1024 },
  { name: 'mobile',  width: 390,  height: 844  },
];

const THEMES = ['light', 'dark'];

/** Milliseconds to wait after theme switch for transitions to settle */
const THEME_SETTLE_MS = 300;

/** Milliseconds to wait after page load for animations to complete */
const PAGE_SETTLE_MS = 500;

/** Output directory (relative to project root) */
const OUTPUT_DIR = path.join(
  __dirname,
  '..',
  '.agents',
  'frontend-specialist',
  'screenshots'
);

// ─── Helpers ──────────────────────────────────────────────────────────────────

function ensureDir(dirPath) {
  if (!fs.existsSync(dirPath)) {
    fs.mkdirSync(dirPath, { recursive: true });
  }
}

function screenshotPath(theme, pageName, viewportName) {
  return path.join(OUTPUT_DIR, theme, `${pageName}-${viewportName}.png`);
}

async function waitForPageReady(page) {
  // Wait for network idle + animations to complete
  await page.waitForLoadState('networkidle');
  await page.waitForTimeout(PAGE_SETTLE_MS);
}

async function setTheme(page, theme) {
  await page.evaluate((t) => {
    if (t === 'dark') {
      document.documentElement.classList.add('dark');
    } else {
      document.documentElement.classList.remove('dark');
    }
    try {
      localStorage.setItem('theme', t);
    } catch (_) {
      // localStorage may be unavailable in some contexts
    }
  }, theme);
  // Wait for CSS transitions to settle
  await page.waitForTimeout(THEME_SETTLE_MS);
}

async function captureScreenshot(page, filePath, fullPage = true) {
  await page.screenshot({
    path: filePath,
    fullPage,
    animations: 'disabled', // Freeze CSS/JS animations for clean captures
  });
  const sizeKB = Math.round(fs.statSync(filePath).size / 1024);
  console.log(`  ✓ Saved: ${path.relative(process.cwd(), filePath)} (${sizeKB}KB)`);
}

// ─── Main ─────────────────────────────────────────────────────────────────────

async function main() {
  console.log('');
  console.log('═══════════════════════════════════════════════════════════');
  console.log('  WorkRoot Theme Screenshot Capture');
  console.log(`  Base URL: ${BASE_URL}`);
  console.log(`  Output:   ${OUTPUT_DIR}`);
  console.log('═══════════════════════════════════════════════════════════');
  console.log('');

  // Create output directories
  for (const theme of THEMES) {
    ensureDir(path.join(OUTPUT_DIR, theme));
  }

  const browser = await chromium.launch({
    headless: true,
  });

  let totalScreenshots = 0;
  let errors = [];

  try {
    for (const viewport of VIEWPORTS) {
      console.log(`\n── Viewport: ${viewport.name} (${viewport.width}×${viewport.height}) ──`);

      const context = await browser.newContext({
        viewport: { width: viewport.width, height: viewport.height },
        deviceScaleFactor: 2, // Retina quality for crisp screenshots
        colorScheme: 'light',  // Start light; we override via JS
      });

      const page = await context.newPage();

      // Disable animations globally for cleaner screenshots
      await page.addInitScript(() => {
        const style = document.createElement('style');
        style.textContent = `
          *, *::before, *::after {
            animation-duration: 0.01ms !important;
            animation-iteration-count: 1 !important;
            transition-duration: 0.01ms !important;
          }
        `;
        document.head.appendChild(style);
      });

      for (const pageConfig of PAGES) {
        const url = `${BASE_URL}${pageConfig.path}`;
        console.log(`\n  Page: ${pageConfig.name} (${url})`);

        for (const theme of THEMES) {
          try {
            // Navigate to page
            await page.goto(url, { waitUntil: 'domcontentloaded' });
            await waitForPageReady(page);

            // Set theme
            await setTheme(page, theme);

            // Capture screenshot
            const filePath = screenshotPath(theme, pageConfig.name, viewport.name);
            await captureScreenshot(page, filePath);
            totalScreenshots++;

          } catch (err) {
            const label = `${theme}/${pageConfig.name}-${viewport.name}`;
            errors.push({ label, error: err.message });
            console.error(`  ✗ Failed ${label}: ${err.message}`);
          }
        }
      }

      await context.close();
    }

  } finally {
    await browser.close();
  }

  // Summary
  console.log('');
  console.log('═══════════════════════════════════════════════════════════');
  console.log(`  Done! Captured ${totalScreenshots} screenshots`);
  if (errors.length > 0) {
    console.log(`  ⚠  ${errors.length} error(s):`);
    for (const { label, error } of errors) {
      console.log(`     • ${label}: ${error}`);
    }
  }
  console.log('═══════════════════════════════════════════════════════════');
  console.log('');

  // Generate index file listing all screenshots
  generateIndex(totalScreenshots, errors);
}

// ─── Index Generator ──────────────────────────────────────────────────────────

function generateIndex(total, errors) {
  const lines = [
    '# Theme Screenshots Index',
    '',
    `Generated: ${new Date().toISOString()}`,
    `Total: ${total} screenshots`,
    errors.length > 0 ? `Errors: ${errors.length}` : 'All captures successful ✓',
    '',
    '## File Listing',
    '',
  ];

  for (const theme of THEMES) {
    lines.push(`### ${theme.charAt(0).toUpperCase() + theme.slice(1)} Theme`);
    lines.push('');
    lines.push('| Page | Desktop | Tablet | Mobile |');
    lines.push('|------|---------|--------|--------|');

    for (const pageConfig of PAGES) {
      const cells = VIEWPORTS.map((vp) => {
        const file = `${pageConfig.name}-${vp.name}.png`;
        const fullPath = path.join(OUTPUT_DIR, theme, file);
        const exists = fs.existsSync(fullPath);
        if (!exists) return '❌ missing';
        const sizeKB = Math.round(fs.statSync(fullPath).size / 1024);
        return `[${file}](./${theme}/${file}) (${sizeKB}KB)`;
      });

      lines.push(`| ${pageConfig.name} | ${cells.join(' | ')} |`);
    }
    lines.push('');
  }

  if (errors.length > 0) {
    lines.push('## Errors');
    lines.push('');
    for (const { label, error } of errors) {
      lines.push(`- **${label}**: ${error}`);
    }
    lines.push('');
  }

  lines.push('---');
  lines.push('*Generated by `scripts/capture-theme-screenshots.js`*');

  const indexPath = path.join(OUTPUT_DIR, 'INDEX.md');
  fs.writeFileSync(indexPath, lines.join('\n'));
  console.log(`  Index written: ${path.relative(process.cwd(), indexPath)}`);
}

// ─── Entry Point ──────────────────────────────────────────────────────────────

main().catch((err) => {
  console.error('Fatal error:', err);
  process.exit(1);
});