// Upload and Prediction JavaScript

// Image preview functionality
function setupImagePreview(inputId, previewId, placeholderId) {
    const input = document.getElementById(inputId);
    const preview = document.getElementById(previewId);
    const placeholder = input.parentElement.querySelector('.upload-placeholder');
    
    if (input) {
        input.addEventListener('change', function(e) {
            const file = e.target.files[0];
            if (file) {
                const reader = new FileReader();
                reader.onload = function(e) {
                    preview.src = e.target.result;
                    preview.style.display = 'block';
                    if (placeholder) placeholder.style.display = 'none';
                };
                reader.readAsDataURL(file);
            }
        });
    }
}

// Setup previews based on mode
if (mode === 'multimodal') {
    setupImagePreview('fundusImage', 'fundusPreview');
    setupImagePreview('octImage', 'octPreview');
} else if (mode === 'fundus') {
    setupImagePreview('fundusImage', 'fundusPreview');
} else if (mode === 'oct') {
    setupImagePreview('octImage', 'octPreview');
}

// Form submission
const form = document.getElementById('uploadForm');
const analyzeBtn = document.getElementById('analyzeBtn');
const btnText = document.getElementById('btnText');
const btnLoader = document.getElementById('btnLoader');
const errorMessage = document.getElementById('errorMessage');
const resultsSection = document.getElementById('resultsSection');

form.addEventListener('submit', async function(e) {
    e.preventDefault();
    
    // Show loading state
    btnText.style.display = 'none';
    btnLoader.style.display = 'inline-block';
    analyzeBtn.disabled = true;
    errorMessage.style.display = 'none';
    resultsSection.style.display = 'none';
    
    try {
        const formData = new FormData(form);
        const endpoint = `/predict/${mode}`;
        
        const response = await fetch(endpoint, {
            method: 'POST',
            body: formData
        });
        
        if (!response.ok) {
            throw new Error('Prediction failed');
        }
        
        const result = await response.json();
        
        // Display results
        displayResults(result);
        
    } catch (error) {
        console.error('Error:', error);
        errorMessage.textContent = 'An error occurred during analysis. Please try again.';
        errorMessage.style.display = 'block';
    } finally {
        // Reset button state
        btnText.style.display = 'inline';
        btnLoader.style.display = 'none';
        analyzeBtn.disabled = false;
    }
});

function displayResults(result) {
    let html = '';
    
    if (mode === 'fundus') {
        html = generateFundusResults(result);
    } else if (mode === 'oct') {
        html = generateOCTResults(result);
    } else if (mode === 'multimodal') {
        html = generateMultimodalResults(result);
    }
    
    resultsSection.innerHTML = html;
    resultsSection.style.display = 'block';
    
    // Scroll to results
    resultsSection.scrollIntoView({ behavior: 'smooth', block: 'start' });
}

function generateFundusResults(result) {
    const isGlaucoma = result.prediction === 'GON+';
    const headerClass = isGlaucoma ? 'warning' : 'success';
    
    return `
        <div class="result-header ${headerClass}">
            <div class="result-prediction">${result.prediction}</div>
            <div class="result-confidence">Confidence: ${(result.confidence * 100).toFixed(1)}%</div>
        </div>
        
        <div class="result-grid">
            <div class="result-card">
                <h4>Original Image</h4>
                <img src="data:image/jpeg;base64,${result.original_image}" class="result-image" alt="Original">
            </div>
            
            <div class="result-card">
                <h4>Grad-CAM Visualization</h4>
                ${result.gradcam_image ? 
                    `<img src="data:image/png;base64,${result.gradcam_image}" class="result-image" alt="Grad-CAM">` :
                    '<p>Visualization not available</p>'
                }
            </div>
        </div>
        
        <div class="clinical-features">
            <div class="feature-item">
                <div class="feature-label">vCDR (Cup-to-Disc Ratio)</div>
                <div class="feature-value">${result.vcdr.toFixed(2)}</div>
            </div>
            <div class="feature-item">
                <div class="feature-label">Prediction Confidence</div>
                <div class="feature-value">${(result.confidence * 100).toFixed(1)}%</div>
            </div>
        </div>
        
        <div class="interpretation">
            <strong>Clinical Interpretation:</strong><br>
            ${result.interpretation}
        </div>
    `;
}

function generateOCTResults(result) {
    const isNormal = result.prediction === 'NO';
    const headerClass = isNormal ? 'success' : 'warning';
    
    let top3HTML = result.top3.map((item, index) => 
        `<div class="feature-item">
            <div class="feature-label">${index + 1}. ${item.class}</div>
            <div class="feature-value">${(item.probability * 100).toFixed(1)}%</div>
        </div>`
    ).join('');
    
    return `
        <div class="result-header ${headerClass}">
            <div class="result-prediction">${result.prediction}</div>
            <div class="result-confidence">Confidence: ${(result.confidence * 100).toFixed(1)}%</div>
        </div>
        
        <div class="result-grid">
            <div class="result-card">
                <h4>Original Image</h4>
                <img src="data:image/jpeg;base64,${result.original_image}" class="result-image" alt="Original">
            </div>
            
            <div class="result-card">
                <h4>Grad-CAM Visualization</h4>
                ${result.gradcam_image ? 
                    `<img src="data:image/png;base64,${result.gradcam_image}" class="result-image" alt="Grad-CAM">` :
                    '<p>Visualization not available</p>'
                }
            </div>
        </div>
        
        <div class="result-card">
            <h4>Top 3 Predictions</h4>
            <div class="clinical-features">
                ${top3HTML}
            </div>
        </div>
        
        <div class="interpretation">
            <strong>Clinical Interpretation:</strong><br>
            ${result.interpretation}
        </div>
    `;
}

function generateMultimodalResults(result) {
    const isGlaucoma = result.prediction === 'GLAUCOMA';
    const headerClass = isGlaucoma ? 'warning' : 'success';
    
    return `
        <div class="result-header ${headerClass}">
            <div class="result-prediction">${result.prediction}</div>
            <div class="result-confidence">Confidence: ${(result.confidence * 100).toFixed(1)}%</div>
        </div>
        
        <div class="result-grid">
            <div class="result-card">
                <h4>Fundus Image</h4>
                <img src="data:image/jpeg;base64,${result.fundus_image}" class="result-image" alt="Fundus">
                <h5 style="margin-top: 1rem;">Fundus Grad-CAM</h5>
                ${result.fundus_gradcam ? 
                    `<img src="data:image/png;base64,${result.fundus_gradcam}" class="result-image" alt="Fundus Grad-CAM">` :
                    '<p>Visualization not available</p>'
                }
            </div>
            
            <div class="result-card">
                <h4>OCT Image</h4>
                <img src="data:image/jpeg;base64,${result.oct_image}" class="result-image" alt="OCT">
                <h5 style="margin-top: 1rem;">OCT Grad-CAM</h5>
                ${result.oct_gradcam ? 
                    `<img src="data:image/png;base64,${result.oct_gradcam}" class="result-image" alt="OCT Grad-CAM">` :
                    '<p>Visualization not available</p>'
                }
            </div>
        </div>
        
        <div class="clinical-features">
            <div class="feature-item">
                <div class="feature-label">vCDR (Cup-to-Disc Ratio)</div>
                <div class="feature-value">${result.vcdr.toFixed(2)}</div>
            </div>
            <div class="feature-item">
                <div class="feature-label">RNFL Thickness</div>
                <div class="feature-value">${result.rnfl.toFixed(1)} μm</div>
            </div>
            <div class="feature-item">
                <div class="feature-label">Prediction Confidence</div>
                <div class="feature-value">${(result.confidence * 100).toFixed(1)}%</div>
            </div>
            <div class="feature-item">
                <div class="feature-label">Analysis Type</div>
                <div class="feature-value">Multimodal</div>
            </div>
        </div>
        
        <div class="interpretation">
            <strong>Clinical Interpretation:</strong><br>
            ${result.interpretation}
        </div>
    `;
}