// Initialize extension
document.addEventListener('DOMContentLoaded', async () => {
  await updateStats();
  setupEventListeners();
});

// Update tab and window count statistics
async function updateStats() {
  try {
    const tabs = await chrome.tabs.query({});
    const windows = await chrome.windows.getAll();
    
    document.getElementById('tab-count').textContent = tabs.length;
    document.getElementById('window-count').textContent = windows.length;
  } catch (error) {
    console.error('Error updating stats:', error);
  }
}

// Setup event listeners
function setupEventListeners() {
  const exportBtn = document.getElementById('export-btn');
  exportBtn.addEventListener('click', handleExport);
  
  // Keyboard accessibility for options
  const checkboxes = document.querySelectorAll('input[type="checkbox"]');
  checkboxes.forEach(checkbox => {
    checkbox.addEventListener('keydown', (e) => {
      if (e.key === 'Enter' || e.key === ' ') {
        e.preventDefault();
        checkbox.checked = !checkbox.checked;
      }
    });
  });
}

// Main export handler
async function handleExport() {
  const exportBtn = document.getElementById('export-btn');
  const statusEl = document.getElementById('export-status');
  
  // Get user options
  const includeDescriptions = document.getElementById('include-descriptions').checked;
  const groupByWindow = document.getElementById('group-by-window').checked;
  const includeTimestamp = document.getElementById('include-timestamp').checked;
  
  // Disable button and show loading state
  exportBtn.disabled = true;
  const originalContent = exportBtn.innerHTML;
  exportBtn.innerHTML = '<span class="btn-icon loading" aria-hidden="true">⏳</span>Exporting...';
  
  statusEl.textContent = 'Collecting tab information...';
  statusEl.className = 'status-message loading';
  
  try {
    // Get all tabs
    const tabs = await chrome.tabs.query({});
    
    // Fetch descriptions if needed
    if (includeDescriptions) {
      statusEl.textContent = `Fetching descriptions (0/${tabs.length})...`;
      await fetchDescriptions(tabs, statusEl);
    }
    
    // Generate markdown content
    const markdown = await generateMarkdown(tabs, {
      includeDescriptions,
      groupByWindow,
      includeTimestamp
    });
    
    // Trigger download
    downloadMarkdown(markdown);
    
    // Show success message
    statusEl.textContent = '✓ Successfully exported ' + tabs.length + ' tabs!';
    statusEl.className = 'status-message success';
    
  } catch (error) {
    console.error('Export error:', error);
    statusEl.textContent = '✗ Error: ' + error.message;
    statusEl.className = 'status-message error';
  } finally {
    // Re-enable button
    exportBtn.disabled = false;
    exportBtn.innerHTML = originalContent;
  }
}

// Fetch descriptions from tabs
async function fetchDescriptions(tabs, statusEl) {
  for (let i = 0; i < tabs.length; i++) {
    const tab = tabs[i];
    statusEl.textContent = `Fetching descriptions (${i + 1}/${tabs.length})...`;
    
    try {
      // Try to execute script to get description
      const results = await chrome.scripting.executeScript({
        target: { tabId: tab.id },
        func: extractDescription
      });
      
      if (results && results[0] && results[0].result) {
        tab.description = results[0].result;
      }
    } catch (error) {
      // Tab might not support script injection (e.g., chrome:// pages)
      tab.description = null;
    }
  }
}

// Function to extract description (runs in tab context)
function extractDescription() {
  const metaDesc = document.querySelector('meta[name="description"]');
  const ogDesc = document.querySelector('meta[property="og:description"]');
  return (metaDesc && metaDesc.content) || 
         (ogDesc && ogDesc.content) || 
         null;
}

// Generate markdown content
async function generateMarkdown(tabs, options) {
  let markdown = '# Browser Tabs Export\n\n';
  
  if (options.includeTimestamp) {
    const now = new Date();
    const timestamp = now.toLocaleString('en-US', {
      dateStyle: 'full',
      timeStyle: 'short'
    });
    markdown += `**Exported:** ${timestamp}\n\n`;
  }
  
  markdown += `**Total Tabs:** ${tabs.length}\n\n`;
  markdown += '---\n\n';
  
  if (options.groupByWindow) {
    // Group tabs by window
    const windows = await chrome.windows.getAll();
    const tabsByWindow = {};
    
    tabs.forEach(tab => {
      if (!tabsByWindow[tab.windowId]) {
        tabsByWindow[tab.windowId] = [];
      }
      tabsByWindow[tab.windowId].push(tab);
    });
    
    let windowIndex = 1;
    for (const windowId in tabsByWindow) {
      markdown += `## Window ${windowIndex}\n\n`;
      markdown += formatTabs(tabsByWindow[windowId], options.includeDescriptions);
      markdown += '---\n\n';
      windowIndex++;
    }
  } else {
    // List all tabs together
    markdown += formatTabs(tabs, options.includeDescriptions);
  }
  
  return markdown;
}

// Format tabs as markdown
function formatTabs(tabs, includeDescriptions) {
  let content = '';
  
  tabs.forEach((tab, index) => {
    // List item with title and URL
    content += `- **${escapeMarkdown(tab.title)}**\n`;
    content += `  - URL: ${tab.url}\n`;
    
    // Description if available
    if (includeDescriptions && tab.description) {
      content += `  - Description: ${escapeMarkdown(tab.description)}\n`;
    }
    
    content += '\n';
  });
  
  return content;
}

// Escape markdown special characters
function escapeMarkdown(text) {
  if (!text) return '';
  return text.replace(/[\\`*_{}[\]()#+\-.!]/g, '\\$&');
}

// Download markdown file
function downloadMarkdown(content) {
  const blob = new Blob([content], { type: 'text/markdown;charset=utf-8' });
  const url = URL.createObjectURL(blob);
  
  const timestamp = new Date().toISOString().slice(0, 19).replace(/:/g, '-');
  const filename = `tabs-export-${timestamp}.md`;
  
  chrome.downloads.download({
    url: url,
    filename: filename,
    saveAs: true
  }, (downloadId) => {
    // Cleanup object URL after download starts
    setTimeout(() => URL.revokeObjectURL(url), 100);
  });
}