// Global state
let currentMode = 'edit';
let selectedElement = null;
let isDragging = false;
let dragOffset = { x: 0, y: 0 };

// Initialize the application
document.addEventListener('DOMContentLoaded', function() {
    initializeEventListeners();
    setupCanvas();
});

function initializeEventListeners() {
    // Mode buttons
    document.getElementById('previewMode').addEventListener('click', () => switchMode('preview'));
    document.getElementById('editMode').addEventListener('click', () => switchMode('edit'));
    
    // Load code button
    document.getElementById('loadCode').addEventListener('click', loadPPT);
    
    // Export button
    document.getElementById('exportBtn').addEventListener('click', exportPPT);
    
    // Canvas events
    document.getElementById('canvasContainer').addEventListener('click', handleCanvasClick);
    document.addEventListener('keydown', handleKeyDown);
    document.addEventListener('contextmenu', handleContextMenu);
}

function setupCanvas() {
    // Set up initial canvas state
    const canvas = document.getElementById('canvasContainer');
    canvas.addEventListener('mousedown', startDrag);
    canvas.addEventListener('mousemove', handleDrag);
    canvas.addEventListener('mouseup', stopDrag);
}

function switchMode(mode) {
    currentMode = mode;
    const previewBtn = document.getElementById('previewMode');
    const editBtn = document.getElementById('editMode');
    
    if (mode === 'preview') {
        previewBtn.classList.remove('bg-gray-200', 'text-gray-700');
        previewBtn.classList.add('bg-primary', 'text-white');
        editBtn.classList.remove('bg-primary', 'text-white');
        editBtn.classList.add('bg-gray-200', 'text-gray-700');
        disableEditing();
    } else {
        editBtn.classList.remove('bg-gray-200', 'text-gray-700');
        editBtn.classList.add('bg-primary', 'text-white');
        previewBtn.classList.remove('bg-primary', 'text-white');
        previewBtn.classList.add('bg-gray-200', 'text-gray-700');
        enableEditing();
    }
}

function loadPPT() {
    const codeInput = document.getElementById('codeInput').value;
    const canvasContainer = document.getElementById('canvasContainer');
    
    if (!codeInput.trim()) {
        alert('Please enter PPT HTML code');
        return;
    }
    
    try {
        // Clear previous content
        canvasContainer.innerHTML = '';
        
        // Create iframe to safely render the HTML
        const iframe = document.createElement('iframe');
        iframe.style.width = '100%';
        iframe.style.height = '500px';
        iframe.style.border = 'none';
        iframe.style.borderRadius = '8px';
        
        iframe.onload = function() {
            // Once iframe is loaded, extract the content and make it editable
            const iframeDoc = iframe.contentDocument || iframe.contentWindow.document;
            iframeDoc.open();
            iframeDoc.write(codeInput);
            iframeDoc.close();
            
            // Replace iframe with editable content
            setTimeout(() => {
                const slideContent = iframeDoc.body.firstElementChild.cloneNode(true);
                canvasContainer.innerHTML = '';
                canvasContainer.appendChild(slideContent);
                
                // Make elements editable
                makeElementsEditable(slideContent);
                
                // Scale the slide to fit container
                scaleSlideToFit(slideContent);
            }, 100);
        };
        
        canvasContainer.appendChild(iframe);
    } catch (error) {
        console.error('Error loading PPT:', error);
        alert('Error loading PPT. Please check your HTML code.');
    }
}

function makeElementsEditable(container) {
    // Add editable class to all elements
    const allElements = container.querySelectorAll('*');
    allElements.forEach(element => {
        element.classList.add('editable-element');
        
        // Make text elements directly editable
        if (element.tagName === 'P' || element.tagName === 'H1' || element.tagName === 'H2' || 
            element.tagName === 'H3' || element.tagName === 'LI' || element.tagName === 'SPAN') {
            element.setAttribute('contenteditable', 'true');
        }
        
        // Add event listeners for interaction
        element.addEventListener('mousedown', handleElementMouseDown);
        element.addEventListener('dblclick', handleElementDoubleClick);
    });
}

function scaleSlideToFit(slide) {
    const container = document.getElementById('canvasContainer');
    const containerWidth = container.clientWidth;
    const slideWidth = 1280; // Standard 16:9 slide width
    
    if (slideWidth > containerWidth) {
        const scale = (containerWidth - 40) / slideWidth;
        slide.style.transform = `scale(${scale})`;
        slide.style.transformOrigin = 'center top';
    }
}

function handleElementMouseDown(e) {
    if (currentMode !== 'edit') return;
    
    e.stopPropagation();
    selectElement(e.target);
    
    if (e.target.tagName === 'IMG' || e.target.classList.contains('image-content')) {
        isDragging = true;
        const rect = e.target.getBoundingClientRect();
        dragOffset.x = e.clientX - rect.left;
        dragOffset.y = e.clientY - rect.top;
    }
}

function handleElementDoubleClick(e) {
    if (currentMode !== 'edit') return;
    
    e.stopPropagation();
    const element = e.target;
    
    if (element.tagName === 'P' || element.tagName === 'H1' || element.tagName === 'H2' || 
        element.tagName === 'H3' || element.tagName === 'LI') {
        element.focus();
        selectElement(element);
    }
}

function startDrag(e) {
    if (currentMode !== 'edit' || !selectedElement) return;
    
    isDragging = true;
    const rect = selectedElement.getBoundingClientRect();
    dragOffset.x = e.clientX - rect.left;
    dragOffset.y = e.clientY - rect.top;
}

function handleDrag(e) {
    if (!isDragging || !selectedElement) return;
    
    e.preventDefault();
    
    const container = document.getElementById('canvasContainer');
    const containerRect = container.getBoundingClientRect();
    
    const newX = e.clientX - containerRect.left - dragOffset.x;
    const newY = e.clientY - containerRect.top - dragOffset.y;
    
    selectedElement.style.position = 'absolute';
    selectedElement.style.left = `${newX}px`;
    selectedElement.style.top = `${newY}px`;
    selectedElement.style.zIndex = '1000';
}

function stopDrag() {
    isDragging = false;
}

function selectElement(element) {
    // Deselect previous element
    if (selectedElement) {
        selectedElement.classList.remove('selected');
    }
    
    // Select new element
    selectedElement = element;
    selectedElement.classList.add('selected');
}

function handleCanvasClick(e) {
    if (e.target === document.getElementById('canvasContainer')) {
        if (selectedElement) {
            selectedElement.classList.remove('selected');
            selectedElement = null;
        }
    }
}

function handleKeyDown(e) {
    if (currentMode !== 'edit' || !selectedElement) return;
    
    // Delete selected element
    if (e.key === 'Delete' || e.key === 'Backspace') {
        e.preventDefault();
        selectedElement.remove();
        selectedElement = null;
    }
}

function handleContextMenu(e) {
    if (currentMode !== 'edit') return;
    
    e.preventDefault();
    
    const element = e.target;
    if (element.classList.contains('editable-element')) {
        selectElement(element);
        showContextMenu(e.clientX, e.clientY, element);
    }
}

function showContextMenu(x, y, element) {
    // Remove existing context menu
    const existingMenu = document.querySelector('.context-menu');
    if (existingMenu) {
        existingMenu.remove();
    }
    
    const contextMenu = document.createElement('div');
    contextMenu.className = 'context-menu';
    contextMenu.style.left = `${x}px`;
    contextMenu.style.top = `${y}px`;
    
    const menuItems = [
        { icon: 'edit-3', text: 'Edit Text', action: () => editText(element) },
        { icon: 'trash-2', text: 'Delete', action: () => deleteElement(element) },
        { icon: 'copy', text: 'Duplicate', action: () => duplicateElement(element) },
        { icon: 'layers', text: 'Bring to Front', action: () => bringToFront(element) },
        { icon: 'move', text: 'Move to Back', action: () => moveToBack(element) }
    ];
    
    menuItems.forEach(item => {
        const menuItem = document.createElement('div');
        menuItem.className = 'context-menu-item';
        menuItem.innerHTML = `
            <i data-feather="${item.icon}"></i>
            <span>${item.text}</span>
        `;
        menuItem.addEventListener('click', item.action);
        contextMenu.appendChild(menuItem);
    });
    
    document.body.appendChild(contextMenu);
    feather.replace();
    
    // Close context menu when clicking elsewhere
    setTimeout(() => {
        document.addEventListener('click', function closeMenu() {
            contextMenu.remove();
            document.removeEventListener('click', closeMenu);
        });
    }, 10);
}

function editText(element) {
    element.focus();
    const range = document.createRange();
    range.selectNodeContents(element);
    const selection = window.getSelection();
    selection.removeAllRanges();
    selection.addRange(range);
}

function deleteElement(element) {
    element.remove();
    selectedElement = null;
}

function duplicateElement(element) {
    const clone = element.cloneNode(true);
    element.parentNode.insertBefore(clone, element.nextSibling);
    makeElementsEditable(clone);
    selectElement(clone);
}

function bringToFront(element) {
    element.style.zIndex = '1000';
}

function moveToBack(element) {
    element.style.zIndex = '0';
}

function enableEditing() {
    const editableElements = document.querySelectorAll('.editable-element');
    editableElements.forEach(element => {
        element.style.cursor = 'move';
        if (element.tagName === 'P' || element.tagName === 'H1' || element.tagName === 'H2' || 
        element.tagName === 'H3' || element.tagName === 'LI' || element.tagName === 'SPAN') {
            element.setAttribute('contenteditable', 'true');
        }
    });
}

function disableEditing() {
    const editableElements = document.querySelectorAll('.editable-element');
    editableElements.forEach(element => {
        element.style.cursor = 'default';
        element.removeAttribute('contenteditable');
    });
}

function exportPPT() {
    const slideContent = document.querySelector('#canvasContainer > *');
    if (!slideContent) {
        alert('No PPT content to export');
        return;
    }
    
    const htmlContent = `
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
${document.querySelector('style').outerHTML}
</head>
<body>
    ${slideContent.outerHTML}
</body>
</html>`;
    
    // Create download link
    const blob = new Blob([htmlContent], { type: 'text/html' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = 'presentation.html';
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
    
    alert('PPT exported successfully!');
}