// Initialize Lucide icons
lucide.createIcons();

// Global variables
let uploadedImageData = null;
let uploadedMetadata = null;
let currentThreshold = 0.5;
let showGradCAM = false;

// DOM elements
const fileInput = document.getElementById('fileInput');
const metadataInput = document.getElementById('metadataInput');
const uploadArea = document.getElementById('uploadArea');
const uploadContent = document.getElementById('uploadContent');
const uploadedContent = document.getElementById('uploadedContent');
const uploadedImage = document.getElementById('uploadedImage');
const metadataStatus = document.getElementById('metadataStatus');
const analyzeBtn = document.getElementById('analyzeBtn');
const analyzingBtn = document.getElementById('analyzingBtn');
const thresholdSlider = document.getElementById('threshold');
const thresholdValue = document.getElementById('thresholdValue');
const resultsSection = document.getElementById('resultsSection');
const readyState = document.getElementById('readyState');
const toggleGradCAM = document.getElementById('toggleGradCAM');
const gradcamContent = document.getElementById('gradcamContent');
const predictionResult = document.getElementById('predictionResult');
const confidenceScore = document.getElementById('confidenceScore');
const confidenceBar = document.getElementById('confidenceBar');
const processingTime = document.getElementById('processingTime');
const gradcamOriginal = document.getElementById('gradcamOriginal');
const gradcamHeatmap = document.getElementById('gradcamHeatmap');
const metadataSection = document.getElementById('metadataSection');
const metadataContent = document.getElementById('metadataContent');

// Threshold slider handler
thresholdSlider.addEventListener('input', function() {
    currentThreshold = parseFloat(this.value);
    thresholdValue.textContent = Math.round(currentThreshold * 100) + '%';
    thresholdSlider.setAttribute('aria-valuenow', currentThreshold);
    document.getElementById('thresholdDisplay').textContent = `Threshold: ${Math.round(currentThreshold * 100)}%`;
});

// File upload handlers
fileInput.addEventListener('change', handleFileUpload);
metadataInput.addEventListener('change', handleMetadataUpload);

// Drag and drop handlers
uploadArea.addEventListener('dragenter', handleDrag);
uploadArea.addEventListener('dragover', handleDrag);
uploadArea.addEventListener('dragleave', handleDragLeave);
uploadArea.addEventListener('drop', handleDrop);

// Analyze button handler
analyzeBtn.addEventListener('click', analyzeDocument);

// Grad-CAM toggle
toggleGradCAM.addEventListener('click', function() {
    showGradCAM = !showGradCAM;
    if (showGradCAM) {
        gradcamContent.classList.remove('hidden');
        this.querySelector('span').textContent = 'Hide Analysis';
    } else {
        gradcamContent.classList.add('hidden');
        this.querySelector('span').textContent = 'Show Analysis';
    }
});

function handleDrag(e) {
    e.preventDefault();
    e.stopPropagation();
    uploadArea.classList.add('drag-over');
}

function handleDragLeave(e) {
    e.preventDefault();
    e.stopPropagation();
    uploadArea.classList.remove('drag-over');
}

function handleDrop(e) {
    e.preventDefault();
    e.stopPropagation();
    uploadArea.classList.remove('drag-over');
    
    const files = e.dataTransfer.files;
    for (let file of files) {
        if (file.type.startsWith('image/')) {
            processFile(file, 'image');
        } else if (file.name.endsWith('.xlsx')) {
            processFile(file, 'metadata');
        }
    }
}

function handleFileUpload(e) {
    const file = e.target.files[0];
    if (file) {
        processFile(file, 'image');
    }
}

function handleMetadataUpload(e) {
    const file = e.target.files[0];
    if (file) {
        processFile(file, 'metadata');
    }
}

function processFile(file, type) {
    if (type === 'image') {
        // Validate image
        if (!file.type.startsWith('image/')) {
            alert('Please select an image file (JPG, JPEG, PNG)');
            return;
        }
        if (file.size > 10 * 1024 * 1024) {
            alert('Image file size must be less than 10MB');
            return;
        }
        
        // Display uploaded image
        const reader = new FileReader();
        reader.onload = function(e) {
            uploadedImageData = e.target.result;
            uploadedImage.src = uploadedImageData;
            
            // Update UI
            uploadContent.classList.add('hidden');
            uploadedContent.classList.remove('hidden');
            uploadArea.classList.add('uploaded');
            analyzeBtn.classList.remove('hidden');
            
            // Hide results
            resultsSection.classList.add('hidden');
            readyState.classList.remove('hidden');
        };
        reader.readAsDataURL(file);
        fileInput.file = file; // Store file for analysis
    } else if (type === 'metadata') {
        // Validate metadata
        if (!file.name.endsWith('.xlsx')) {
            alert('Please select an XLSX file for metadata');
            return;
        }
        if (file.size > 10 * 1024 * 1024) {
            alert('Metadata file size must be less than 10MB');
            return;
        }
        
        // Store metadata file
        uploadedMetadata = file;
        metadataStatus.classList.remove('hidden');
        metadataStatus.textContent = `Metadata file uploaded: ${file.name}`;
    }
}

function analyzeDocument() {
    if (!uploadedImageData || !fileInput.file) {
        alert('Please upload an image first');
        return;
    }

    // Show analyzing state
    analyzeBtn.classList.add('hidden');
    analyzingBtn.classList.remove('hidden');

    // Prepare form data
    const formData = new FormData();
    formData.append('file', fileInput.file);
    formData.append('threshold', currentThreshold);
    if (uploadedMetadata) {
        formData.append('metadata', uploadedMetadata);
    }

    // Send to Flask backend
    fetch('/analyze', {
        method: 'POST',
        body: formData
    })
    .then(response => response.json())
    .then(data => {
        if (data.error) {
            alert(data.error);
            throw new Error(data.error);
        }

        // Update results
        confidenceScore.textContent = data.confidence + '%';
        processingTime.textContent = data.processing_time + 'ms';
        confidenceBar.style.width = data.confidence + '%';
        confidenceBar.className = `h-3 rounded-full transition-all duration-500 ${data.is_authentic ? 'bg-green-500' : 'bg-red-500'}`;

        // Update prediction
        predictionResult.className = `p-4 sm:p-6 rounded-xl border-2 ${data.is_authentic ? 'bg-green-50 border-green-200' : 'bg-red-50 border-red-200'}`;
        predictionResult.innerHTML = `
            <div class="flex items-center space-x-3">
                <i data-lucide="${data.is_authentic ? 'check-circle' : 'alert-triangle'}" class="h-6 sm:h-8 w-6 sm:w-8 ${data.is_authentic ? 'text-green-600' : 'text-red-600'}"></i>
                <div>
                    <h4 class="text-base sm:text-lg font-semibold ${data.is_authentic ? 'text-green-800' : 'text-red-800'}">
                        Document is ${data.is_authentic ? 'Authentic' : 'Possibly Fake'}
                    </h4>
                    <p class="text-xs sm:text-sm ${data.is_authentic ? 'text-green-600' : 'text-red-600'}">
                        ${data.is_authentic ? 'High similarity to verified land title documents in our database.' : 'Low similarity suggests potential forgery or document type mismatch.'}
                    </p>
                </div>
            </div>
        `;

        // Update Grad-CAM
        gradcamOriginal.src = data.original_image;
        gradcamHeatmap.src = data.heatmap_image;

        // Update metadata
        if (data.metadata) {
            metadataSection.classList.remove('hidden');
            metadataContent.textContent = data.metadata;
        } else {
            metadataSection.classList.add('hidden');
        }

        // Show results
        readyState.classList.add('hidden');
        resultsSection.classList.remove('hidden');

        // Reset buttons
        analyzingBtn.classList.add('hidden');
        analyzeBtn.classList.remove('hidden');

        // Re-initialize icons
        lucide.createIcons();
    })
    .catch(error => {
        console.error('Error:', error);
        alert('Error analyzing document');
        analyzingBtn.classList.add('hidden');
        analyzeBtn.classList.remove('hidden');
    });
}