// Global variables
let quill;
let currentMode = 'richtext';
let currentContent = '';
let pages = [];

// Initialize Quill editor
function initQuill() {
    quill = new Quill('#quillEditor', {
        theme: 'snow',
        modules: {
            toolbar: '#quillToolbar'
        },
        placeholder: 'Start writing your letter content here...'
    });

    // Update preview on content change
    quill.on('text-change', () => {
        updatePreview();
    });
}

// Mode switching
document.getElementById('richTextMode').addEventListener('click', () => {
    switchMode('richtext');
});

document.getElementById('markdownMode').addEventListener('click', () => {
    switchMode('markdown');
});

document.getElementById('previewMode').addEventListener('click', () => {
    switchMode('preview');
});

function switchMode(mode) {
    // Update button states
    document.querySelectorAll('.toolbar-left .btn').forEach(btn => {
        btn.classList.remove('active', 'btn-primary');
    });

    // Hide all editors
    document.querySelectorAll('.editor-mode').forEach(editor => {
        editor.classList.remove('active');
    });

    currentMode = mode;

    switch(mode) {
        case 'richtext':
            document.getElementById('richTextMode').classList.add('active', 'btn-primary');
            document.getElementById('richTextEditor').classList.add('active');
            // Convert markdown to rich text if switching from markdown
            if (currentMode === 'markdown') {
                const markdownContent = document.getElementById('markdownTextarea').value;
                const html = marked.parse(markdownContent);
                quill.root.innerHTML = DOMPurify.sanitize(html);
            }
            break;
        case 'markdown':
            document.getElementById('markdownMode').classList.add('active', 'btn-primary');
            document.getElementById('markdownEditor').classList.add('active');
            // Convert rich text to markdown if switching from rich text
            if (currentMode === 'richtext') {
                const html = quill.root.innerHTML;
                document.getElementById('markdownTextarea').value = htmlToMarkdown(html);
            }
            break;
        case 'preview':
            document.getElementById('previewMode').classList.add('active', 'btn-primary');
            // Hide editor section
            document.querySelector('.editor-section').style.display = 'none';
            document.querySelector('.preview-section').style.flex = '1';
            break;
    }

    if (mode !== 'preview') {
        document.querySelector('.editor-section').style.display = 'flex';
        document.querySelector('.preview-section').style.flex = '1';
    }

    updatePreview();
}

// Markdown editor functions
function insertMarkdown(before, after) {
    const textarea = document.getElementById('markdownTextarea');
    const start = textarea.selectionStart;
    const end = textarea.selectionEnd;
    const selectedText = textarea.value.substring(start, end);
    const replacement = before + selectedText + after;
    
    textarea.value = textarea.value.substring(0, start) + replacement + textarea.value.substring(end);
    textarea.focus();
    textarea.setSelectionRange(start + before.length, start + before.length + selectedText.length);
    
    updatePreview();
}

function insertTable() {
    const table = '\n| Header 1 | Header 2 | Header 3 |\n|----------|----------|----------|\n| Cell 1   | Cell 2   | Cell 3   |\n| Cell 4   | Cell 5   | Cell 6   |\n';
    const textarea = document.getElementById('markdownTextarea');
    const start = textarea.selectionStart;
    
    textarea.value = textarea.value.substring(0, start) + table + textarea.value.substring(start);
    textarea.focus();
    textarea.setSelectionRange(start + table.length, start + table.length);
    
    updatePreview();
}

// Update preview on markdown change
document.getElementById('markdownTextarea').addEventListener('input', updatePreview);

// Convert HTML to Markdown (basic conversion)
function htmlToMarkdown(html) {
    let markdown = html;
    
    // Headers
    markdown = markdown.replace(/<h1[^>]*>(.*?)<\/h1>/gi, '# $1\n');
    markdown = markdown.replace(/<h2[^>]*>(.*?)<\/h2>/gi, '## $1\n');
    markdown = markdown.replace(/<h3[^>]*>(.*?)<\/h3>/gi, '### $1\n');
    
    // Bold and italic
    markdown = markdown.replace(/<strong[^>]*>(.*?)<\/strong>/gi, '**$1**');
    markdown = markdown.replace(/<b[^>]*>(.*?)<\/b>/gi, '**$1**');
    markdown = markdown.replace(/<em[^>]*>(.*?)<\/em>/gi, '*$1*');
    markdown = markdown.replace(/<i[^>]*>(.*?)<\/i>/gi, '*$1*');
    
    // Links
    markdown = markdown.replace(/<a[^>]+href="([^"]*)"[^>]*>(.*?)<\/a>/gi, '[$2]($1)');
    
    // Images
    markdown = markdown.replace(/<img[^>]+src="([^"]*)"[^>]*alt="([^"]*)"[^>]*>/gi, '![$2]($1)');
    
    // Lists
    markdown = markdown.replace(/<ul[^>]*>(.*?)<\/ul>/gis, (match, content) => {
        return content.replace(/<li[^>]*>(.*?)<\/li>/gi, '- $1\n');
    });
    
    markdown = markdown.replace(/<ol[^>]*>(.*?)<\/ol>/gis, (match, content) => {
        let index = 1;
        return content.replace(/<li[^>]*>(.*?)<\/li>/gi, () => {
            return `${index++}. $1\n`;
        });
    });
    
    // Paragraphs
    markdown = markdown.replace(/<p[^>]*>(.*?)<\/p>/gi, '$1\n\n');
    
    // Line breaks
    markdown = markdown.replace(/<br[^>]*>/gi, '\n');
    
    // Remove remaining HTML tags
    markdown = markdown.replace(/<[^>]*>/g, '');
    
    // Clean up extra whitespace
    markdown = markdown.replace(/\n\n+/g, '\n\n').trim();
    
    return markdown;
}

// Update preview function
function updatePreview() {
    let content = '';
    
    if (currentMode === 'richtext') {
        content = quill.root.innerHTML;
    } else if (currentMode === 'markdown') {
        const markdownContent = document.getElementById('markdownTextarea').value;
        content = marked.parse(markdownContent);
    }
    
    currentContent = DOMPurify.sanitize(content);
    paginateContent();
}

// Paginate content
function paginateContent() {
    const container = document.getElementById('previewContainer');
    container.innerHTML = '';
    
    // Create a temporary element to measure content
    const tempDiv = document.createElement('div');
    tempDiv.style.cssText = 'position: absolute; visibility: hidden; width: 130mm; font-size: 16px; line-height: 1.6;';
    tempDiv.innerHTML = currentContent;
    document.body.appendChild(tempDiv);
    
    // Split content into pages
    const maxHeight = 200; // mm - approximate content area height
    const elements = Array.from(tempDiv.children);
    pages = [];
    let currentPage = [];
    let currentHeight = 0;
    
    elements.forEach(element => {
        const elementHeight = element.offsetHeight / 3.78; // Convert px to mm (approximate)
        
        if (currentHeight + elementHeight > maxHeight && currentPage.length > 0) {
            pages.push(currentPage);
            currentPage = [];
            currentHeight = 0;
        }
        
        currentPage.push(element.outerHTML);
        currentHeight += elementHeight;
    });
    
    if (currentPage.length > 0) {
        pages.push(currentPage);
    }
    
    // If no pages created, create one with all content
    if (pages.length === 0) {
        pages.push([currentContent]);
    }
    
    document.body.removeChild(tempDiv);
    
    // Create preview pages
    pages.forEach((pageContent, index) => {
        const pageDiv = createPreviewPage(pageContent.join(''), index + 1);
        container.appendChild(pageDiv);
    });
    
    // Update page info
    document.getElementById('currentPage').textContent = '1';
    document.getElementById('totalPages').textContent = pages.length;
}

// Create preview page
function createPreviewPage(content, pageNumber) {
    const pageDiv = document.createElement('div');
    pageDiv.className = 'preview-page';
    pageDiv.innerHTML = `
        <!-- Background Logo -->
        <img src="logo.png" alt="OmegaTech Solution Logo" class="preview-watermark">
        
        <!-- Header Section -->
        <div class="preview-header-section">
            <img src="logo.png" alt="OmegaTech Solution" class="preview-logo">
            <div class="preview-company-info">
                <h1 class="preview-company-name">OMEGATECH SOLUTION</h1>
            </div>
        </div>
        
        <!-- Content Area -->
        <div class="preview-content-area">
            ${content}
        </div>
        
        <!-- Footer -->
        <div class="preview-footer">
            <div class="preview-footer-content">
                <div class="footer-left">
                    <div class="footer-item">
                        <svg class="footer-icon" viewBox="0 0 24 24">
                            <path d="M20 4H4c-1.1 0-1.99.9-1.99 2L2 18c0 1.1.9 2 2 2h16c1.1 0 2-.9 2-2V6c0-1.1-.9-2-2-2zm0 4l-8 5-8-5V6l8 5 8-5v2z"/>
                        </svg>
                        hello@omegatechsolution.org
                    </div>
                    <div class="footer-item">
                        <svg class="footer-icon" viewBox="0 0 24 24">
                            <path d="M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm-1 17.93c-3.94-.49-7-3.85-7-7.93 0-.62.08-1.21.21-1.79L9 15v1c0 1.1.9 2 2 2v1.93zm6.9-2.54c-.26-.81-1-1.39-1.9-1.39h-1v-3c0-.55-.45-1-1-1H8v-2h2c.55 0 1-.45 1-1V7h2c1.1 0 2-.9 2-2v-.41c2.93 1.19 5 4.06 5 7.41 0 2.08-.8 3.97-2.1 5.39z"/>
                        </svg>
                        https://omegatechsolution.org
                    </div>
                </div>
                <div class="footer-right">
                    <div class="footer-item">
                        <svg class="footer-icon" viewBox="0 0 24 24">
                            <path d="M6.62 10.79c1.44 2.83 3.76 5.14 6.59 6.59l2.2-2.2c.27-.27.67-.36 1.02-.24 1.12.37 2.33.57 3.57.57.55 0 1 .45 1 1V20c0 .55-.45 1-1 1-9.39 0-17-7.61-17-17 0-.55.45-1 1-1h3.5c.55 0 1 .45 1 1 0 1.25.2 2.45.57 3.57.11.35.03.74-.25 1.02l-2.2 2.2z"/>
                        </svg>
                        +960 9198026
                    </div>
                </div>
            </div>
        </div>
    `;
    
    return pageDiv;
}

// PDF Quality Settings
const pdfQualitySettings = {
    low: { scale: 0.8, quality: 0.7, compression: 'FAST' },
    medium: { scale: 1.2, quality: 0.85, compression: 'FAST' },
    high: { scale: 1.5, quality: 0.95, compression: 'SLOW' }
};

// Dropdown menu functionality
document.getElementById('exportPdfBtn').addEventListener('click', (e) => {
    e.stopPropagation();
    const menu = document.getElementById('pdfQualityMenu');
    menu.classList.toggle('show');
});

// Close dropdown when clicking outside
document.addEventListener('click', () => {
    document.getElementById('pdfQualityMenu').classList.remove('show');
});

// Handle PDF export with quality selection
document.querySelectorAll('.dropdown-item').forEach(item => {
    item.addEventListener('click', async (e) => {
        const quality = e.target.getAttribute('data-quality');
        document.getElementById('pdfQualityMenu').classList.remove('show');
        await exportPDF(quality);
    });
});

// Export to PDF function
async function exportPDF(quality = 'medium') {
    const { jsPDF } = window.jspdf;
    const settings = pdfQualitySettings[quality];
    
    // Show export modal
    const modal = createExportModal(`Generating ${quality} quality PDF...`);
    document.body.appendChild(modal);
    
    try {
        const pdf = new jsPDF('p', 'mm', 'a4', true); // Enable compression
        const pageWidth = pdf.internal.pageSize.getWidth();
        const pageHeight = pdf.internal.pageSize.getHeight();
        
        for (let i = 0; i < pages.length; i++) {
            // Update progress
            updateExportProgress(modal, (i / pages.length) * 100);
            
            // Create a temporary page for rendering
            const tempPage = createPreviewPage(pages[i].join(''), i + 1);
            tempPage.style.cssText = 'position: absolute; left: -9999px; width: 210mm; height: 297mm; background: white;';
            document.body.appendChild(tempPage);
            
            // Wait for images to load
            await waitForImages(tempPage);
            
            // Render to canvas with quality-based settings
            const canvas = await html2canvas(tempPage, {
                scale: settings.scale,
                useCORS: true,
                backgroundColor: '#ffffff',
                logging: false,
                imageTimeout: 15000,
                removeContainer: true,
                allowTaint: false,
                foreignObjectRendering: false
            });
            
            // Convert to JPEG with quality-based compression
            const imgData = canvas.toDataURL('image/jpeg', settings.quality);
            if (i > 0) {
                pdf.addPage();
            }
            
            // Add image with compression
            pdf.addImage(imgData, 'JPEG', 0, 0, pageWidth, pageHeight, undefined, settings.compression);
            
            // Clean up
            document.body.removeChild(tempPage);
            
            // Clear canvas to free memory
            canvas.width = 0;
            canvas.height = 0;
        }
        
        // Update progress to 100%
        updateExportProgress(modal, 100);
        
        // Save PDF with compression
        const pdfOutput = pdf.output('blob');
        const url = URL.createObjectURL(pdfOutput);
        const a = document.createElement('a');
        a.href = url;
        a.download = `letter-omegatech-${quality}.pdf`;
        a.click();
        URL.revokeObjectURL(url);
        
        // Close modal after a short delay
        setTimeout(() => {
            document.body.removeChild(modal);
        }, 500);
        
    } catch (error) {
        console.error('Error generating PDF:', error);
        alert('Error generating PDF. Please try again.');
        document.body.removeChild(modal);
    }
}

// Export to HTML
document.getElementById('exportHtml').addEventListener('click', () => {
    // Create HTML document
    let htmlContent = `<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>OmegaTech Solution - Letter</title>
    <style>
        ${getExportStyles()}
    </style>
</head>
<body>
    <div class="letterhead-container">`;
    
    // Add each page
    pages.forEach((pageContent, index) => {
        htmlContent += `
        <div class="page">
            <!-- Background Logo -->
            <img src="logo.png" alt="OmegaTech Solution Logo" class="company-logo-bg">
            
            <!-- Header Section -->
            <div class="header">
                <img src="logo.png" alt="OmegaTech Solution" class="header-logo">
                <div class="company-info">
                    <h1 class="company-name">OMEGATECH SOLUTION</h1>
                </div>
            </div>
            
            <!-- Content Area -->
            <div class="content-area">
                ${pageContent.join('')}
            </div>
            
            <!-- Footer -->
            <div class="footer">
                <div class="footer-content">
                    <div class="footer-left">
                        <div class="footer-item">
                            <svg class="footer-icon" viewBox="0 0 24 24">
                                <path d="M20 4H4c-1.1 0-1.99.9-1.99 2L2 18c0 1.1.9 2 2 2h16c1.1 0 2-.9 2-2V6c0-1.1-.9-2-2-2zm0 4l-8 5-8-5V6l8 5 8-5v2z"/>
                            </svg>
                            hello@omegatechsolution.org
                        </div>
                        <div class="footer-item">
                            <svg class="footer-icon" viewBox="0 0 24 24">
                                <path d="M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm-1 17.93c-3.94-.49-7-3.85-7-7.93 0-.62.08-1.21.21-1.79L9 15v1c0 1.1.9 2 2 2v1.93zm6.9-2.54c-.26-.81-1-1.39-1.9-1.39h-1v-3c0-.55-.45-1-1-1H8v-2h2c.55 0 1-.45 1-1V7h2c1.1 0 2-.9 2-2v-.41c2.93 1.19 5 4.06 5 7.41 0 2.08-.8 3.97-2.1 5.39z"/>
                            </svg>
                            https://omegatechsolution.org
                        </div>
                    </div>
                    <div class="footer-right">
                        <div class="footer-item">
                            <svg class="footer-icon" viewBox="0 0 24 24">
                                <path d="M6.62 10.79c1.44 2.83 3.76 5.14 6.59 6.59l2.2-2.2c.27-.27.67-.36 1.02-.24 1.12.37 2.33.57 3.57.57.55 0 1 .45 1 1V20c0 .55-.45 1-1 1-9.39 0-17-7.61-17-17 0-.55.45-1 1-1h3.5c.55 0 1 .45 1 1 0 1.25.2 2.45.57 3.57.11.35.03.74-.25 1.02l-2.2 2.2z"/>
                            </svg>
                            +960 9198026
                        </div>
                    </div>
                </div>
            </div>
        </div>`;
    });
    
    htmlContent += `
    </div>
</body>
</html>`;
    
    // Download HTML file
    const blob = new Blob([htmlContent], { type: 'text/html' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = 'letter-omegatech.html';
    a.click();
    URL.revokeObjectURL(url);
});

// Helper functions
function createExportModal(message) {
    const modal = document.createElement('div');
    modal.className = 'export-modal';
    modal.innerHTML = `
        <div class="export-modal-content">
            <h3>${message}</h3>
            <div class="export-progress">
                <div class="export-progress-bar" style="width: 0%"></div>
            </div>
        </div>
    `;
    return modal;
}

function updateExportProgress(modal, percent) {
    const progressBar = modal.querySelector('.export-progress-bar');
    progressBar.style.width = percent + '%';
}

function waitForImages(element) {
    const images = element.querySelectorAll('img');
    const promises = Array.from(images).map(img => {
        return new Promise((resolve) => {
            if (img.complete) {
                resolve();
            } else {
                img.onload = resolve;
                img.onerror = resolve;
            }
        });
    });
    return Promise.all(promises);
}

function getExportStyles() {
    return `
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            margin: 0;
            padding: 0;
            background: #f8f9fa;
            color: #333;
            line-height: 1.6;
        }
        
        .letterhead-container {
            width: 210mm;
            margin: 0 auto;
            padding: 0;
            box-sizing: border-box;
            background: white;
            box-shadow: 0 0 20px rgba(0,0,0,0.1);
            position: relative;
        }
        
        .page {
            width: 210mm;
            height: 297mm;
            padding: 40px;
            box-sizing: border-box;
            page-break-after: always;
            position: relative;
            background: white;
            display: flex;
            flex-direction: column;
        }
        
        .page:last-child {
            page-break-after: auto;
        }
        
        .company-logo-bg {
            max-width: 600px;
            opacity: 0.08;
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            z-index: 1;
            pointer-events: none;
        }
        
        .header {
            display: flex;
            align-items: center;
            margin-bottom: 40px;
            position: relative;
            z-index: 10;
            flex-shrink: 0;
        }
        
        .header-logo {
            width: 60px;
            height: 60px;
            margin-right: 20px;
            flex-shrink: 0;
        }
        
        .company-info {
            display: flex;
            flex-direction: column;
        }
        
        .company-name {
            font-size: 24px;
            font-weight: bold;
            color: #2c3e50;
            margin: 0;
            letter-spacing: 0.5px;
        }
        
        .content-area {
            flex: 1;
            position: relative;
            z-index: 10;
            overflow: hidden;
        }
        
        .content-area h1 {
            font-size: 28px;
            margin: 20px 0 15px 0;
            color: #2c3e50;
        }
        
        .content-area h2 {
            font-size: 22px;
            margin: 18px 0 12px 0;
            color: #34495e;
        }
        
        .content-area h3 {
            font-size: 18px;
            margin: 15px 0 10px 0;
            color: #34495e;
        }
        
        .content-area p {
            margin: 10px 0;
            line-height: 1.6;
        }
        
        .content-area ul, .content-area ol {
            margin: 10px 0;
            padding-left: 25px;
        }
        
        .content-area img {
            max-width: 100%;
            height: auto;
            margin: 10px 0;
        }
        
        .content-area table {
            width: 100%;
            border-collapse: collapse;
            margin: 15px 0;
        }
        
        .content-area th, .content-area td {
            border: 1px solid #ddd;
            padding: 8px;
            text-align: left;
        }
        
        .content-area th {
            background-color: #f8f8f8;
            font-weight: bold;
        }
        
        .footer {
            margin-top: auto;
            padding-top: 25px;
            border-top: 1px solid #ecf0f1;
            position: relative;
            z-index: 10;
            flex-shrink: 0;
        }
        
        .footer-content {
            display: flex;
            justify-content: space-between;
            align-items: flex-start;
            max-width: 100%;
        }
        
        .footer-left, .footer-right {
            display: flex;
            flex-direction: column;
            gap: 8px;
        }
        
        .footer-item {
            display: flex;
            align-items: center;
            font-size: 12px;
            color: #666;
        }
        
        .footer-icon {
            width: 14px;
            height: 14px;
            margin-right: 8px;
            fill: #666;
            flex-shrink: 0;
        }
        
        @media print {
            body {
                background: white;
            }
            
            .letterhead-container {
                width: 100%;
                margin: 0;
                box-shadow: none;
            }
            
            .page {
                page-break-after: always;
                margin: 0;
                padding: 20mm;
            }
            
            .page:last-child {
                page-break-after: avoid;
            }
            
            .company-logo-bg {
                max-width: 500px;
                opacity: 0.05;
            }
        }
    `;
}

// Initialize on page load
document.addEventListener('DOMContentLoaded', () => {
    initQuill();
    updatePreview();
});