{% extends "base.html" %}

{% block title %}Encode Message - Stegasoo{% endblock %}

{% block content %}
<div class="row justify-content-center">
    <div class="col-lg-8">
        <div class="card">
            <div class="card-header">
                <h5 class="mb-0"><i class="bi bi-lock-fill me-2"></i>Encode Secret Message or File</h5>
            </div>
            <div class="card-body">
                <form method="POST" enctype="multipart/form-data" id="encodeForm">
                    <input type="hidden" name="client_date" id="clientDate" value="">
                    
                    <div class="row">
                        <div class="col-md-6 mb-3">
                            <label class="form-label">
                                <i class="bi bi-image me-1"></i> Reference Photo
                            </label>
                            <div class="drop-zone" id="refDropZone">
                                <input type="file" name="reference_photo" accept="image/*" required>
                                <div class="drop-zone-label">
                                    <i class="bi bi-cloud-arrow-up fs-3 d-block mb-2 text-muted"></i>
                                    <span class="text-muted">Drop image or click to browse</span>
                                </div>
                                <img class="drop-zone-preview d-none" id="refPreview">
                            </div>
                            <div class="form-text">
                                The secret photo both parties have (NOT transmitted)
                            </div>
                        </div>
                        
                        <div class="col-md-6 mb-3">
                            <label class="form-label">
                                <i class="bi bi-file-image me-1"></i> Carrier Image
                            </label>
                            <div class="drop-zone" id="carrierDropZone">
                                <input type="file" name="carrier" accept="image/*" required id="carrierInput">
                                <div class="drop-zone-label">
                                    <i class="bi bi-cloud-arrow-up fs-3 d-block mb-2 text-muted"></i>
                                    <span class="text-muted">Drop image or click to browse</span>
                                </div>
                                <img class="drop-zone-preview d-none" id="carrierPreview">
                            </div>
                            <div class="form-text">
                                The image to hide your message in (e.g., a meme)
                            </div>
                        </div>
                    </div>
                    
                    <!-- Capacity Info Panel (shown when carrier loaded) -->
                    <div class="alert alert-info small d-none" id="capacityPanel">
                        <div class="row align-items-center">
                            <div class="col">
                                <i class="bi bi-rulers me-1"></i>
                                <strong>Carrier:</strong> <span id="carrierDimensions">-</span>
                            </div>
                            <div class="col-auto">
                                <span class="badge bg-primary me-1" id="lsbCapacityBadge">LSB: -</span>
                                <span class="badge bg-secondary" id="dctCapacityBadge">DCT: -</span>
                            </div>
                        </div>
                    </div>
                    
                    <!-- Payload Type Selector -->
                    <div class="mb-3">
                        <label class="form-label">
                            <i class="bi bi-box me-1"></i> What to Encode
                        </label>
                        <div class="btn-group w-100" role="group">
                            <input type="radio" class="btn-check" name="payload_type" id="payloadText" value="text" checked>
                            <label class="btn btn-outline-primary" for="payloadText">
                                <i class="bi bi-chat-left-text me-1"></i> Text Message
                            </label>
                            
                            <input type="radio" class="btn-check" name="payload_type" id="payloadFile" value="file">
                            <label class="btn btn-outline-primary" for="payloadFile">
                                <i class="bi bi-file-earmark me-1"></i> File
                            </label>
                        </div>
                    </div>
                    
                    <!-- Text Message Input -->
                    <div class="mb-3" id="textPayloadSection">
                        <label class="form-label">
                            <i class="bi bi-chat-left-text me-1"></i> Secret Message
                        </label>
                        <textarea name="message" class="form-control" rows="4" id="messageInput"
                                  placeholder="Enter your secret message here..."></textarea>
                        <div class="d-flex justify-content-between form-text">
                            <span>
                                <span id="charCount">0</span> / 250,000 characters
                                <span id="charWarning" class="text-warning d-none ms-2">
                                    <i class="bi bi-exclamation-triangle"></i> Getting long!
                                </span>
                            </span>
                            <span id="charPercent" class="text-muted">0%</span>
                        </div>
                    </div>
                    
                    <!-- File Upload Input -->
                    <div class="mb-3 d-none" id="filePayloadSection">
                        <label class="form-label">
                            <i class="bi bi-file-earmark me-1"></i> File to Embed
                        </label>
                        <div class="drop-zone" id="payloadDropZone">
                            <input type="file" name="payload_file" id="payloadFileInput">
                            <div class="drop-zone-label" id="payloadDropLabel">
                                <i class="bi bi-cloud-arrow-up fs-3 d-block mb-2 text-muted"></i>
                                <span class="text-muted">Drop any file or click to browse</span>
                                <div class="small text-muted mt-1">Max {{ max_payload_kb }} KB</div>
                            </div>
                        </div>
                        <div class="form-text">
                            Supports any file type: PDF, ZIP, documents, etc.
                        </div>
                        <div id="fileInfo" class="d-none mt-2 p-2 bg-dark rounded">
                            <i class="bi bi-file-earmark-check text-success me-2"></i>
                            <span id="fileInfoName"></span>
                            <span class="text-muted">(<span id="fileInfoSize"></span>)</span>
                        </div>
                    </div>
                    
                    <div class="mb-3">
                        <label class="form-label" id="dayPhraseLabel">
                            <i class="bi bi-chat-quote me-1"></i> Day's Phrase
                        </label>
                        <input type="text" name="day_phrase" class="form-control" 
                               placeholder="e.g., correct horse battery" required>
                        <div class="form-text">
                            Your phrase for <strong>today</strong> (based on your local timezone)
                        </div>
                    </div>
                    
                    <hr class="my-4">
                    
                    <h6 class="text-muted mb-3">
                        SECURITY FACTORS 
                        <span class="text-warning small">(provide at least one: PIN or RSA Key)</span>
                    </h6>
                    
                    <div class="row">
                        <div class="col-md-6 mb-3">
                          <label class="form-label"><i class="bi bi-123 me-1"></i> PIN</label>
                          <div class="input-group">
                            <input type="password" name="pin" class="form-control" id="pinInput" placeholder="6-9 digits" maxlength="9">
                            <button class="btn btn-outline-secondary" type="button" id="togglePin">
                              <i class="bi bi-eye"></i>
                            </button>
                          </div>
                        <div class="form-text">Your static 6-9 digit PIN (if configured)</div>
                        </div>
                        
                        <div class="col-md-6 mb-3">
                            <label class="form-label">
                                <i class="bi bi-file-earmark-lock me-1"></i> RSA Key
                            </label>
                            <ul class="nav nav-tabs nav-tabs-sm mb-2" role="tablist">
                                <li class="nav-item" role="presentation">
                                    <button class="nav-link active py-1 px-2 small" data-bs-toggle="tab" data-bs-target="#rsaFileTab" type="button">
                                        <i class="bi bi-file-earmark me-1"></i>.pem File
                                    </button>
                                </li>
                                <li class="nav-item" role="presentation">
                                    <button class="nav-link py-1 px-2 small" data-bs-toggle="tab" data-bs-target="#rsaQrTab" type="button">
                                        <i class="bi bi-qr-code me-1"></i>QR Code
                                    </button>
                                </li>
                            </ul>
                            <div class="tab-content">
                                <div class="tab-pane fade show active" id="rsaFileTab" role="tabpanel">
                                    <input type="file" name="rsa_key" class="form-control form-control-sm" id="rsaKeyInput" accept=".pem,.key,application/x-pem-file">
                                    <div class="form-text small">Shared .pem format key file.</div>
                                </div>
                                <div class="tab-pane fade" id="rsaQrTab" role="tabpanel">
                                    <input type="file" name="rsa_key_qr" class="form-control form-control-sm" id="rsaKeyQrInput" accept="image/*">
                                    <div class="form-text small">PNG, JPG, or other image of QR code</div>
                                </div>
                            </div>
                        </div>
                    </div>
                    
                    <!-- RSA Key Password (shown when key selected) -->
                    <div class="mb-3 d-none" id="rsaPasswordGroup">
                        <label class="form-label">
                            <i class="bi bi-key me-1"></i> RSA Key Password
                        </label>
                        <input type="password" name="rsa_password" class="form-control"
                               placeholder="Password for the .pem file (if encrypted)">
                        <div class="form-text">
                            Leave blank if your key file is not password-protected (not needed for QR codes)
                        </div>
                    </div>
                    
                    <!-- ================================================================
                         ADVANCED OPTIONS (v3.0) - Collapsible Section
                         ================================================================ -->
                    <div class="mb-4">
                        <a class="btn btn-sm btn-outline-secondary w-100" data-bs-toggle="collapse" href="#advancedOptions" role="button" aria-expanded="false">
                            <i class="bi bi-gear me-1"></i> Advanced Options
                            <i class="bi bi-chevron-down ms-1" id="advancedChevron"></i>
                        </a>
                        
                        <div class="collapse" id="advancedOptions">
                            <div class="card card-body mt-2 bg-dark border-secondary">
                                
                                <!-- Embedding Mode Selection -->
                                <div class="mb-3">
                                    <label class="form-label">
                                        <i class="bi bi-cpu me-1"></i> Embedding Mode
                                        <span class="badge bg-info ms-1">v3.0</span>
                                    </label>
                                    
                                    <div class="row g-2">
                                        <!-- LSB Mode Card -->
                                        <div class="col-md-6">
                                            <div class="form-check card p-3 h-100 border-primary border-2" id="lsbModeCard">
                                                <input class="form-check-input" type="radio" name="embed_mode" id="modeLsb" value="lsb" checked>
                                                <label class="form-check-label w-100" for="modeLsb">
                                                    <div class="d-flex align-items-center mb-2">
                                                        <i class="bi bi-grid-3x3-gap text-primary fs-4 me-2"></i>
                                                        <strong>LSB Mode</strong>
                                                        <span class="badge bg-success ms-auto">Default</span>
                                                    </div>
                                                    <ul class="small text-muted mb-0 ps-3">
                                                        <li>Full color PNG output</li>
                                                        <li>Higher capacity (~375 KB/MP)</li>
                                                        <li>Faster processing</li>
                                                    </ul>
                                                </label>
                                            </div>
                                        </div>
                                        
                                        <!-- DCT Mode Card -->
                                        <div class="col-md-6">
                                            <div class="form-check card p-3 h-100 {% if not has_dct %}opacity-50{% endif %}" id="dctModeCard">
                                                <input class="form-check-input" type="radio" name="embed_mode" id="modeDct" value="dct" {% if not has_dct %}disabled{% endif %}>
                                                <label class="form-check-label w-100" for="modeDct">
                                                    <div class="d-flex align-items-center mb-2">
                                                        <i class="bi bi-soundwave text-info fs-4 me-2"></i>
                                                        <strong>DCT Mode</strong>
                                                        {% if has_dct %}
                                                        <span class="badge bg-warning text-dark ms-auto">Experimental</span>
                                                        {% else %}
                                                        <span class="badge bg-secondary ms-auto">Unavailable</span>
                                                        {% endif %}
                                                    </div>
                                                    <ul class="small text-muted mb-0 ps-3">
                                                        <li>Color or grayscale output</li>
                                                        <li>Lower capacity (~75 KB/MP)</li>
                                                        <li>Better detection resistance</li>
                                                    </ul>
                                                    {% if not has_dct %}
                                                    <div class="alert alert-warning small mt-2 mb-0 py-1 px-2">
                                                        <i class="bi bi-exclamation-triangle me-1"></i>
                                                        Requires scipy: <code>pip install scipy</code>
                                                    </div>
                                                    {% endif %}
                                                </label>
                                            </div>
                                        </div>
                                    </div>
                                    
                                    <!-- Mode comparison hint -->
                                    <div class="form-text mt-2" id="modeHint">
                                        <i class="bi bi-lightbulb me-1"></i>
                                        <strong>LSB</strong> is best for most uses. 
                                        <strong>DCT</strong> provides better stealth but lower capacity.
                                    </div>
                                </div>
                                
                                <!-- DCT Options Panel (shown only when DCT selected) -->
                                <div class="d-none" id="dctOptionsPanel">
                                    
                                    <hr class="my-3">
                                    
                                    <div class="alert alert-warning small mb-3">
                                        <i class="bi bi-flask me-1"></i>
                                        <strong>Experimental Feature:</strong> DCT embedding is still being refined. 
                                        Color mode preserves original colors but extraction uses Y channel only.
                                    </div>
                                    
                                    <!-- DCT Color Mode (NEW in v3.0.1) -->
                                    <div class="mb-3">
                                        <label class="form-label">
                                            <i class="bi bi-palette me-1"></i> DCT Color Mode
                                            <span class="badge bg-success ms-1">v3.0.1</span>
                                        </label>
                                        
                                        <div class="row g-2">
                                            <div class="col-6">
                                                <div class="form-check card p-2 text-center border-success border-2" id="dctColorCard">
                                                    <input class="form-check-input mx-auto" type="radio" name="dct_color_mode" id="dctColorColor" value="color" checked>
                                                    <label class="form-check-label w-100" for="dctColorColor">
                                                        <i class="bi bi-palette-fill text-success fs-5 d-block"></i>
                                                        <strong>Color</strong>
                                                        <div class="small text-muted">Preserve colors</div>
                                                    </label>
                                                </div>
                                            </div>
                                            <div class="col-6">
                                                <div class="form-check card p-2 text-center" id="dctGrayscaleCard">
                                                    <input class="form-check-input mx-auto" type="radio" name="dct_color_mode" id="dctColorGrayscale" value="grayscale">
                                                    <label class="form-check-label w-100" for="dctColorGrayscale">
                                                        <i class="bi bi-circle-half text-secondary fs-5 d-block"></i>
                                                        <strong>Grayscale</strong>
                                                        <div class="small text-muted">Traditional DCT</div>
                                                    </label>
                                                </div>
                                            </div>
                                        </div>
                                        
                                        <div class="form-text mt-2">
                                            <i class="bi bi-info-circle me-1"></i>
                                            <strong>Color</strong> preserves original image colors (recommended).
                                            <strong>Grayscale</strong> converts to B&W (traditional DCT steganography).
                                        </div>
                                    </div>
                                    
                                    <!-- DCT Output Format -->
                                    <div class="mb-3">
                                        <label class="form-label">
                                            <i class="bi bi-file-image me-1"></i> DCT Output Format
                                        </label>
                                        
                                        <div class="row g-2">
                                            <div class="col-6">
                                                <div class="form-check card p-2 text-center border-primary border-2" id="dctPngCard">
                                                    <input class="form-check-input mx-auto" type="radio" name="dct_output_format" id="dctFormatPng" value="png" checked>
                                                    <label class="form-check-label w-100" for="dctFormatPng">
                                                        <i class="bi bi-file-earmark-image text-primary fs-5 d-block"></i>
                                                        <strong>PNG</strong>
                                                        <div class="small text-muted">Lossless, larger</div>
                                                    </label>
                                                </div>
                                            </div>
                                            <div class="col-6">
                                                <div class="form-check card p-2 text-center" id="dctJpegCard">
                                                    <input class="form-check-input mx-auto" type="radio" name="dct_output_format" id="dctFormatJpeg" value="jpeg">
                                                    <label class="form-check-label w-100" for="dctFormatJpeg">
                                                        <i class="bi bi-file-earmark-richtext text-warning fs-5 d-block"></i>
                                                        <strong>JPEG</strong>
                                                        <div class="small text-muted">Smaller, natural</div>
                                                    </label>
                                                </div>
                                            </div>
                                        </div>
                                        
                                        <div class="form-text mt-2">
                                            <i class="bi bi-info-circle me-1"></i>
                                            <strong>PNG</strong> is 100% reliable. <strong>JPEG</strong> produces smaller, more natural-looking files but uses lossy compression (Q=95).
                                        </div>
                                    </div>
                                    
                                </div>
                                
                                <!-- Capacity Comparison (populated by JS) -->
                                <div class="d-none" id="modeCapacityComparison">
                                    <hr class="my-3">
                                    <div class="alert alert-secondary small mb-0">
                                        <div class="row text-center">
                                            <div class="col-6 border-end">
                                                <div class="text-muted">LSB Capacity</div>
                                                <div class="fs-5 text-primary" id="lsbCapacityDetail">-</div>
                                            </div>
                                            <div class="col-6">
                                                <div class="text-muted">DCT Capacity</div>
                                                <div class="fs-5 text-info" id="dctCapacityDetail">-</div>
                                            </div>
                                        </div>
                                        <div class="text-center mt-2 small text-muted" id="capacityRatio">
                                            DCT is ~20% of LSB capacity
                                        </div>
                                    </div>
                                </div>
                                
                            </div>
                        </div>
                    </div>
                    
                    <button type="submit" class="btn btn-primary btn-lg w-100" id="encodeBtn">
                        <i class="bi bi-lock me-2"></i>Encode
                    </button>
                </form>
               
                <hr class="my-4">
                
                <div class="row text-center text-muted small">
                    <div class="col-4">
                        <i class="bi bi-shield-check fs-4 d-block mb-1 text-success"></i>
                        AES-256-GCM Encryption
                    </div>
                    <div class="col-4">
                        <i class="bi bi-shuffle fs-4 d-block mb-1 text-info"></i>
                        Random Pixel Embedding
                    </div>
                    <div class="col-4">
                        <i class="bi bi-eye-slash fs-4 d-block mb-1 text-warning"></i>
                        Undetectable by Analysis
                    </div>
                </div>
                
                <div class="alert alert-secondary mt-4 small">
                    <i class="bi bi-info-circle me-1"></i>
                    <strong>Limits:</strong> 
                    Carrier image max ~24 megapixels (6000x4000). 
                    Files max 30MB upload. 
                    Payload max {{ max_payload_kb }} KB.
                </div>
            </div>
        </div>
    </div>
</div>
{% endblock %}

{% block scripts %}
<script>
// Detect client's local date and day
const now = new Date();
const dayNames = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
const localDay = dayNames[now.getDay()];
const localDate = now.getFullYear() + '-' + 
    String(now.getMonth() + 1).padStart(2, '0') + '-' + 
    String(now.getDate()).padStart(2, '0');

// Update day label to client's local day
const dayLabel = document.getElementById('dayPhraseLabel');
if (dayLabel) {
    dayLabel.innerHTML = `<i class="bi bi-chat-quote me-1"></i>Secure with <span class="day-of-week-highlight">${localDay}</span>'s Phrase`;
}

// Set hidden field with client's local date for server
const dateInput = document.getElementById('clientDate');
if (dateInput) {
    dateInput.value = localDate;
}

// Payload type switching
const payloadTextRadio = document.getElementById('payloadText');
const payloadFileRadio = document.getElementById('payloadFile');
const textSection = document.getElementById('textPayloadSection');
const fileSection = document.getElementById('filePayloadSection');
const messageInput = document.getElementById('messageInput');
const payloadFileInput = document.getElementById('payloadFileInput');

function updatePayloadSection() {
    const isText = payloadTextRadio.checked;
    textSection.classList.toggle('d-none', !isText);
    fileSection.classList.toggle('d-none', isText);
    
    // Update required attribute
    if (isText) {
        messageInput.required = true;
        payloadFileInput.required = false;
    } else {
        messageInput.required = false;
        payloadFileInput.required = true;
    }
}

payloadTextRadio.addEventListener('change', updatePayloadSection);
payloadFileRadio.addEventListener('change', updatePayloadSection);

// File payload info display
const fileInfo = document.getElementById('fileInfo');
const fileInfoName = document.getElementById('fileInfoName');
const fileInfoSize = document.getElementById('fileInfoSize');
const payloadDropLabel = document.getElementById('payloadDropLabel');

payloadFileInput.addEventListener('change', function() {
    if (this.files && this.files[0]) {
        const file = this.files[0];
        fileInfoName.textContent = file.name;
        fileInfoSize.textContent = formatFileSize(file.size);
        fileInfo.classList.remove('d-none');
        payloadDropLabel.innerHTML = `<i class="bi bi-check-circle text-success fs-3 d-block mb-2"></i><span>${file.name}</span>`;
    } else {
        fileInfo.classList.add('d-none');
        payloadDropLabel.innerHTML = `<i class="bi bi-cloud-arrow-up fs-3 d-block mb-2 text-muted"></i><span class="text-muted">Drop any file or click to browse</span><div class="small text-muted mt-1">Max {{ max_payload_kb }} KB</div>`;
    }
});

function formatFileSize(bytes) {
    if (bytes < 1024) return bytes + ' B';
    if (bytes < 1024 * 1024) return (bytes / 1024).toFixed(1) + ' KB';
    return (bytes / (1024 * 1024)).toFixed(1) + ' MB';
}

// Show RSA password field when key is selected (only for .pem files, not QR)
const rsaKeyInput = document.getElementById('rsaKeyInput');
const rsaKeyQrInput = document.getElementById('rsaKeyQrInput');
const rsaPasswordGroup = document.getElementById('rsaPasswordGroup');

if (rsaKeyInput) {
    rsaKeyInput.addEventListener('change', function() {
        // Show password field only for .pem files
        rsaPasswordGroup.classList.toggle('d-none', !this.files.length);
        // Clear QR input if file is selected
        if (rsaKeyQrInput && this.files.length) {
            rsaKeyQrInput.value = '';
        }
    });
}

if (rsaKeyQrInput) {
    rsaKeyQrInput.addEventListener('change', function() {
        // Hide password field for QR codes (they're unencrypted)
        rsaPasswordGroup.classList.add('d-none');
        // Clear file input if QR is selected
        if (rsaKeyInput && this.files.length) {
            rsaKeyInput.value = '';
        }
    });
}

// Form submit loading state
document.getElementById('encodeForm').addEventListener('submit', function(e) {
    const btn = document.getElementById('encodeBtn');
    const selectedMode = document.querySelector('input[name="embed_mode"]:checked').value;
    let modeLabel = selectedMode.toUpperCase();
    
    if (selectedMode === 'dct') {
        const colorMode = document.querySelector('input[name="dct_color_mode"]:checked')?.value || 'color';
        const outputFormat = document.querySelector('input[name="dct_output_format"]:checked')?.value || 'png';
        modeLabel += ` (${colorMode}, ${outputFormat.toUpperCase()})`;
    }
    
    btn.innerHTML = `<span class="spinner-border spinner-border-sm me-2"></span>Encoding (${modeLabel})...`;
    btn.disabled = true;
});

// Character counter for text
const charCount = document.getElementById('charCount');
const charWarning = document.getElementById('charWarning');
const charPercent = document.getElementById('charPercent');
const maxChars = 250000;

messageInput.addEventListener('input', function() {
    const len = this.value.length;
    charCount.textContent = len.toLocaleString();
    
    const pct = Math.round((len / maxChars) * 100);
    charPercent.textContent = pct + '%';
    
    charWarning.classList.toggle('d-none', len < maxChars * 0.8);
    charCount.classList.toggle('text-danger', len > maxChars * 0.95);
});

// ============================================================================
// v3.0 - Capacity Comparison API
// ============================================================================

const carrierInput = document.getElementById('carrierInput');
const capacityPanel = document.getElementById('capacityPanel');
const carrierDimensions = document.getElementById('carrierDimensions');
const lsbCapacityBadge = document.getElementById('lsbCapacityBadge');
const dctCapacityBadge = document.getElementById('dctCapacityBadge');
const lsbCapacityDetail = document.getElementById('lsbCapacityDetail');
const dctCapacityDetail = document.getElementById('dctCapacityDetail');
const modeCapacityComparison = document.getElementById('modeCapacityComparison');
const capacityRatio = document.getElementById('capacityRatio');

let currentCapacity = null;

async function fetchCapacityComparison(file) {
    const formData = new FormData();
    formData.append('carrier', file);
    
    try {
        const response = await fetch('/api/compare-capacity', {
            method: 'POST',
            body: formData
        });
        
        if (response.ok) {
            const data = await response.json();
            if (data.success) {
                currentCapacity = data;
                updateCapacityDisplay(data);
            }
        }
    } catch (err) {
        console.error('Capacity comparison failed:', err);
    }
}

function updateCapacityDisplay(data) {
    // Update top panel
    carrierDimensions.textContent = `${data.width} x ${data.height}`;
    lsbCapacityBadge.textContent = `LSB: ${data.lsb.capacity_kb} KB`;
    
    if (data.dct.available) {
        dctCapacityBadge.textContent = `DCT: ${data.dct.capacity_kb} KB`;
        dctCapacityBadge.classList.remove('bg-secondary');
        dctCapacityBadge.classList.add('bg-info');
    } else {
        dctCapacityBadge.textContent = `DCT: N/A`;
        dctCapacityBadge.classList.remove('bg-info');
        dctCapacityBadge.classList.add('bg-secondary');
    }
    
    capacityPanel.classList.remove('d-none');
    
    // Update advanced options panel
    lsbCapacityDetail.textContent = `${data.lsb.capacity_kb} KB`;
    dctCapacityDetail.textContent = data.dct.available ? `${data.dct.capacity_kb} KB` : 'N/A';
    capacityRatio.textContent = data.dct.available 
        ? `DCT is ${data.dct.ratio}% of LSB capacity` 
        : 'DCT mode not available';
    modeCapacityComparison.classList.remove('d-none');
}

// Listen for carrier file selection
if (carrierInput) {
    carrierInput.addEventListener('change', function() {
        if (this.files && this.files[0]) {
            fetchCapacityComparison(this.files[0]);
        } else {
            capacityPanel.classList.add('d-none');
            modeCapacityComparison.classList.add('d-none');
            currentCapacity = null;
        }
    });
}

// ============================================================================
// Mode card highlighting & DCT options visibility
// ============================================================================

const lsbModeCard = document.getElementById('lsbModeCard');
const dctModeCard = document.getElementById('dctModeCard');
const modeLsb = document.getElementById('modeLsb');
const modeDct = document.getElementById('modeDct');
const dctOptionsPanel = document.getElementById('dctOptionsPanel');

// DCT format cards
const dctPngCard = document.getElementById('dctPngCard');
const dctJpegCard = document.getElementById('dctJpegCard');
const dctFormatPng = document.getElementById('dctFormatPng');
const dctFormatJpeg = document.getElementById('dctFormatJpeg');

// DCT color mode cards
const dctColorCard = document.getElementById('dctColorCard');
const dctGrayscaleCard = document.getElementById('dctGrayscaleCard');
const dctColorColor = document.getElementById('dctColorColor');
const dctColorGrayscale = document.getElementById('dctColorGrayscale');

function updateModeCardHighlight() {
    // Mode cards
    lsbModeCard.classList.toggle('border-primary', modeLsb.checked);
    lsbModeCard.classList.toggle('border-2', modeLsb.checked);
    dctModeCard.classList.toggle('border-info', modeDct.checked);
    dctModeCard.classList.toggle('border-2', modeDct.checked);
    
    // Show/hide DCT options panel
    if (dctOptionsPanel) {
        dctOptionsPanel.classList.toggle('d-none', !modeDct.checked);
    }
}

function updateDctFormatCardHighlight() {
    if (dctPngCard && dctJpegCard) {
        dctPngCard.classList.toggle('border-primary', dctFormatPng.checked);
        dctPngCard.classList.toggle('border-2', dctFormatPng.checked);
        dctJpegCard.classList.toggle('border-warning', dctFormatJpeg.checked);
        dctJpegCard.classList.toggle('border-2', dctFormatJpeg.checked);
    }
}

function updateDctColorCardHighlight() {
    if (dctColorCard && dctGrayscaleCard) {
        dctColorCard.classList.toggle('border-success', dctColorColor.checked);
        dctColorCard.classList.toggle('border-2', dctColorColor.checked);
        dctGrayscaleCard.classList.toggle('border-secondary', dctColorGrayscale.checked);
        dctGrayscaleCard.classList.toggle('border-2', dctColorGrayscale.checked);
    }
}

modeLsb.addEventListener('change', updateModeCardHighlight);
modeDct.addEventListener('change', updateModeCardHighlight);
dctFormatPng?.addEventListener('change', updateDctFormatCardHighlight);
dctFormatJpeg?.addEventListener('change', updateDctFormatCardHighlight);
dctColorColor?.addEventListener('change', updateDctColorCardHighlight);
dctColorGrayscale?.addEventListener('change', updateDctColorCardHighlight);

updateModeCardHighlight(); // Initial state
updateDctFormatCardHighlight(); // Initial state
updateDctColorCardHighlight(); // Initial state

// Advanced options chevron rotation
document.getElementById('advancedOptions').addEventListener('show.bs.collapse', function() {
    document.getElementById('advancedChevron').classList.add('bi-chevron-up');
    document.getElementById('advancedChevron').classList.remove('bi-chevron-down');
});
document.getElementById('advancedOptions').addEventListener('hide.bs.collapse', function() {
    document.getElementById('advancedChevron').classList.remove('bi-chevron-up');
    document.getElementById('advancedChevron').classList.add('bi-chevron-down');
});

// ============================================================================
// Drag & drop with preview for images
// ============================================================================

document.querySelectorAll('.drop-zone').forEach(zone => {
    const input = zone.querySelector('input[type="file"]');
    const label = zone.querySelector('.drop-zone-label');
    const preview = zone.querySelector('.drop-zone-preview');
    const isPayloadZone = zone.id === 'payloadDropZone';
    const isCarrierZone = zone.id === 'carrierDropZone';
    
    ['dragenter', 'dragover'].forEach(evt => {
        zone.addEventListener(evt, e => {
            e.preventDefault();
            zone.classList.add('drag-over');
        });
    });
    
    ['dragleave', 'drop'].forEach(evt => {
        zone.addEventListener(evt, e => {
            e.preventDefault();
            zone.classList.remove('drag-over');
        });
    });
    
    zone.addEventListener('drop', e => {
        if (e.dataTransfer.files.length) {
            input.files = e.dataTransfer.files;
            input.dispatchEvent(new Event('change'));
            
            if (!isPayloadZone) {
                showPreview(e.dataTransfer.files[0]);
            }
            
            // Trigger capacity check for carrier
            if (isCarrierZone && e.dataTransfer.files[0]) {
                fetchCapacityComparison(e.dataTransfer.files[0]);
            }
        }
    });
    
    if (!isPayloadZone) {
        input.addEventListener('change', function() {
            if (this.files && this.files[0]) {
                showPreview(this.files[0]);
            }
        });
    }
    
    function showPreview(file) {
        if (!file.type.startsWith('image/')) return;
        
        const reader = new FileReader();
        reader.onload = e => {
            if (preview) {
                preview.src = e.target.result;
                preview.classList.remove('d-none');
            }
            label.innerHTML = '<i class="bi bi-check-circle text-success me-1"></i>' + file.name;
        };
        reader.readAsDataURL(file);
    }
});

// PIN Toggle Logic
document.getElementById('togglePin').addEventListener('click', function() {
    const input = document.getElementById('pinInput');
    const icon = this.querySelector('i');
    if (input.type === 'password') {
        input.type = 'text';
        icon.classList.replace('bi-eye', 'bi-eye-slash');
    } else {
        input.type = 'password';
        icon.classList.replace('bi-eye-slash', 'bi-eye');
    }
});

// Prevent Same File Selection
function checkDuplicateFiles() {
    const refInput = document.querySelector('input[name="reference_photo"]');
    const carInput = document.querySelector('input[name="carrier"]');
    
    if (refInput.files[0] && carInput.files[0]) {
        if (refInput.files[0].name === carInput.files[0].name && 
            refInput.files[0].size === carInput.files[0].size) {
            alert("Security Warning: You cannot use the same image for both Reference and Carrier!");
            carInput.value = '';
            document.getElementById('carrierPreview').classList.add('d-none');
            document.querySelector('#carrierDropZone .drop-zone-label').innerHTML = 
                '<i class="bi bi-cloud-arrow-up fs-3 d-block mb-2 text-muted"></i>' +
                '<span class="text-muted">Drop image or click to browse</span>';
            capacityPanel.classList.add('d-none');
        }
    }
}
document.querySelector('input[name="reference_photo"]').addEventListener('change', checkDuplicateFiles);
document.querySelector('input[name="carrier"]').addEventListener('change', checkDuplicateFiles);

// Paste from Clipboard
document.addEventListener('paste', function(e) {
    const items = e.clipboardData.items;
    for (let i = 0; i < items.length; i++) {
        if (items[i].type.indexOf("image") !== -1) {
            const blob = items[i].getAsFile();
            
            const carrierInput = document.querySelector('input[name="carrier"]');
            const refInput = document.querySelector('input[name="reference_photo"]');
            
            const targetInput = (!carrierInput.files.length) ? carrierInput : refInput;
            
            const container = new DataTransfer();
            container.items.add(blob);
            targetInput.files = container.files;
            
            targetInput.dispatchEvent(new Event('change'));
            
            // Trigger capacity check if pasted to carrier
            if (targetInput === carrierInput) {
                fetchCapacityComparison(blob);
            }
            break;
        }
    }
});
</script>
{% endblock %}