document.addEventListener('DOMContentLoaded', function() {
    const markdownInput = document.getElementById('markdown-input');
    const htmlOutput = document.getElementById('html-output');
    const selectAllBtn = document.getElementById('select-all');
    const copyBtn = document.getElementById('copy');

    function updateOutput() {
        const markdown = markdownInput.value;
        
        if (!markdown.trim()) {
            htmlOutput.innerHTML = '';
            return;
        }
        
        // Convert markdown to HTML client-side
        const html = marked(markdown);
        htmlOutput.innerHTML = html;
        
        // Apply alternating column colors to tables
        const tables = htmlOutput.querySelectorAll('table');
        tables.forEach(table => {
            const rows = table.querySelectorAll('tr');
            rows.forEach(row => {
                const cells = row.querySelectorAll('td');
                cells.forEach((cell, index) => {
                    if (index % 2 === 0) {
                        cell.style.backgroundColor = 'rgba(0, 0, 0, 0.25)';
                    }
                });
            });
        });
    }

    markdownInput.addEventListener('input', updateOutput);

    selectAllBtn.addEventListener('click', function() {
        if (!htmlOutput.innerHTML.trim()) {
            alert('No content to select');
            return;
        }
        
        const range = document.createRange();
        range.selectNodeContents(htmlOutput);
        const selection = window.getSelection();
        selection.removeAllRanges();
        selection.addRange(range);
    });

    copyBtn.addEventListener('click', function() {
        if (!htmlOutput.innerHTML.trim()) {
            alert('No content to copy');
            return;
        }
        
        // Use modern clipboard API if available
        if (navigator.clipboard && window.isSecureContext) {
            // Copy both HTML and plain text formats
            const htmlContent = htmlOutput.innerHTML;
            const textContent = htmlOutput.textContent || htmlOutput.innerText;
            
            const clipboardItem = new ClipboardItem({
                'text/html': new Blob([htmlContent], { type: 'text/html' }),
                'text/plain': new Blob([textContent], { type: 'text/plain' })
            });
            
            navigator.clipboard.write([clipboardItem]).then(() => {
                showNotification('Rich text copied to clipboard!');
            }).catch(err => {
                console.error('Failed to copy rich text:', err);
                // Fallback to plain text if rich text copying fails
                navigator.clipboard.writeText(textContent).then(() => {
                    showNotification('Text copied to clipboard!');
                }).catch(() => {
                    fallbackCopy();
                });
            });
        } else {
            fallbackCopy();
        }
    });
    
    function fallbackCopy() {
        const range = document.createRange();
        range.selectNodeContents(htmlOutput);
        const selection = window.getSelection();
        selection.removeAllRanges();
        selection.addRange(range);
        
        try {
            document.execCommand('copy');
            showNotification('Rich text copied to clipboard!');
        } catch (err) {
            console.error('Fallback copy failed:', err);
            showNotification('Failed to copy to clipboard', 'error');
        }
        
        selection.removeAllRanges();
    }
    
    function showNotification(message, type = 'success') {
        // Create notification element
        const notification = document.createElement('div');
        notification.textContent = message;
        notification.style.cssText = `
            position: fixed;
            top: 20px;
            right: 20px;
            background: ${type === 'error' ? '#f44336' : '#4caf50'};
            color: white;
            padding: 12px 20px;
            border-radius: 4px;
            font-family: 'Montserrat', Arial, sans-serif;
            z-index: 1000;
            animation: slideIn 0.3s ease;
        `;
        
        // Add CSS animation
        const style = document.createElement('style');
        style.textContent = `
            @keyframes slideIn {
                from { transform: translateX(100%); opacity: 0; }
                to { transform: translateX(0); opacity: 1; }
            }
        `;
        document.head.appendChild(style);
        
        document.body.appendChild(notification);
        
        // Remove notification after 3 seconds
        setTimeout(() => {
            notification.remove();
            style.remove();
        }, 3000);
    }
    
    // Handle authentication errors gracefully
    window.addEventListener('unhandledrejection', function(event) {
        if (event.reason && event.reason.message && event.reason.message.includes('authentication')) {
            showNotification('Authentication error. Please refresh and login again.', 'error');
        }
    });
});