intercept/templates/partials/modes/vdl2.html

<!-- VDL2 AIRCRAFT DATALINK MODE -->
<div id="vdl2Mode" class="mode-content" style="display: none;">
    <div class="section">
        <h3>VDL2 Datalink</h3>
        <div class="info-text" style="margin-bottom: 15px;">
            Decode VDL Mode 2 (VHF Digital Link) messages on ~136 MHz. VDL2 is the digital successor to ACARS, using D8PSK modulation for higher throughput aircraft datalink communications.
        </div>
    </div>

    <div class="section">
        <h3>Region &amp; Frequencies</h3>
        <div class="form-group">
            <label>Region</label>
            <select id="vdl2RegionSelect" onchange="updateVdl2MainFreqs()" style="width: 100%;">
                <option value="na">North America</option>
                <option value="eu">Europe</option>
                <option value="ap">Asia-Pacific</option>
            </select>
        </div>
        <div id="vdl2MainFreqSelector" style="display: flex; flex-wrap: wrap; gap: 4px; margin-bottom: 10px; font-size: 11px;">
            <!-- Populated by JS -->
        </div>
        <div class="form-group">
            <label>Gain (dB, 0 = auto)</label>
            <input type="number" id="vdl2GainInput" value="40" min="0" max="50" placeholder="0-50">
        </div>
    </div>

    <div class="section">
        <h3>Status</h3>
        <div id="vdl2StatusDisplay" class="info-text">
            <p>Status: <span id="vdl2StatusText" style="color: var(--accent-yellow);">Standby</span></p>
            <p>Messages: <span id="vdl2MessageCount">0</span></p>
        </div>
    </div>

    <!-- Antenna Guide -->
    <div class="section">
        <h3>Antenna Guide</h3>
        <div style="font-size: 11px; color: var(--text-dim); line-height: 1.5;">
            <p style="margin-bottom: 8px; color: var(--accent-cyan); font-weight: 600;">
                VHF Airband (~137 MHz) &mdash; stock SDR antenna may work at close range
            </p>

            <div style="background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 4px; padding: 10px; margin-bottom: 10px;">
                <strong style="color: var(--accent-cyan); font-size: 12px;">Simple Dipole</strong>
                <ul style="margin: 6px 0 0 14px; padding: 0;">
                    <li><strong style="color: var(--text-primary);">Element length:</strong> ~55 cm each (quarter-wave at 137 MHz)</li>
                    <li><strong style="color: var(--text-primary);">Material:</strong> Wire, coat hanger, or copper rod</li>
                    <li><strong style="color: var(--text-primary);">Orientation:</strong> Vertical (airband is vertically polarized)</li>
                    <li><strong style="color: var(--text-primary);">Placement:</strong> Outdoors, as high as possible with clear sky view</li>
                </ul>
            </div>

            <div style="background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 4px; padding: 10px;">
                <strong style="color: var(--accent-cyan); font-size: 12px;">Quick Reference</strong>
                <table style="width: 100%; margin-top: 6px; font-size: 10px; border-collapse: collapse;">
                    <tr style="border-bottom: 1px solid var(--border-color);">
                        <td style="padding: 3px 4px; color: var(--text-dim);">Primary (worldwide)</td>
                        <td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">136.975 MHz</td>
                    </tr>
                    <tr style="border-bottom: 1px solid var(--border-color);">
                        <td style="padding: 3px 4px; color: var(--text-dim);">Quarter-wave length</td>
                        <td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">55 cm</td>
                    </tr>
                    <tr style="border-bottom: 1px solid var(--border-color);">
                        <td style="padding: 3px 4px; color: var(--text-dim);">Modulation</td>
                        <td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">D8PSK 31.5 kbps</td>
                    </tr>
                    <tr style="border-bottom: 1px solid var(--border-color);">
                        <td style="padding: 3px 4px; color: var(--text-dim);">Bandwidth</td>
                        <td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">25 kHz</td>
                    </tr>
                    <tr>
                        <td style="padding: 3px 4px; color: var(--text-dim);">Polarization</td>
                        <td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">Vertical</td>
                    </tr>
                </table>
            </div>
        </div>
    </div>

    <button class="run-btn" id="startVdl2Btn" onclick="startVdl2Mode()">
        Start VDL2
    </button>
    <button class="stop-btn" id="stopVdl2Btn" onclick="stopVdl2Mode()" style="display: none;">
        Stop VDL2
    </button>
</div>

<script>
    let vdl2MainEventSource = null;
    let vdl2MainMsgCount = 0;

    // VDL2 frequencies in Hz (as required by dumpvdl2)
    const vdl2MainFrequencies = {
        'na': ['136975000', '136100000', '136650000', '136700000', '136800000'],
        'eu': ['136975000', '136675000', '136725000', '136775000', '136825000'],
        'ap': ['136975000', '136900000']
    };

    // Display-friendly MHz labels
    const vdl2FreqLabels = {
        '136975000': '136.975',
        '136100000': '136.100',
        '136650000': '136.650',
        '136700000': '136.700',
        '136800000': '136.800',
        '136675000': '136.675',
        '136725000': '136.725',
        '136775000': '136.775',
        '136825000': '136.825',
        '136900000': '136.900'
    };

    function updateVdl2MainFreqs() {
        const region = document.getElementById('vdl2RegionSelect').value;
        const freqs = vdl2MainFrequencies[region] || vdl2MainFrequencies['na'];
        const container = document.getElementById('vdl2MainFreqSelector');

        const previouslyChecked = new Set();
        container.querySelectorAll('input:checked').forEach(cb => previouslyChecked.add(cb.value));

        container.innerHTML = freqs.map(freq => {
            const checked = previouslyChecked.size === 0 || previouslyChecked.has(freq) ? 'checked' : '';
            const label = vdl2FreqLabels[freq] || freq;
            return `
                <label style="display: flex; align-items: center; gap: 3px; padding: 2px 6px; background: var(--bg-secondary); border-radius: 3px; cursor: pointer;">
                    <input type="checkbox" class="vdl2-main-freq-cb" value="${freq}" ${checked} style="margin: 0; cursor: pointer;">
                    <span>${label}</span>
                </label>
            `;
        }).join('');
    }

    function getVdl2MainSelectedFreqs() {
        const checkboxes = document.querySelectorAll('.vdl2-main-freq-cb:checked');
        const selected = Array.from(checkboxes).map(cb => cb.value);
        if (selected.length === 0) {
            const region = document.getElementById('vdl2RegionSelect').value;
            return vdl2MainFrequencies[region] || vdl2MainFrequencies['na'];
        }
        return selected;
    }

    function startVdl2Mode() {
        const gain = document.getElementById('vdl2GainInput').value || '40';
        const device = document.getElementById('deviceSelect')?.value || '0';
        const frequencies = getVdl2MainSelectedFreqs();

        fetch('/vdl2/start', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ device, gain, frequencies })
        })
        .then(r => r.json())
        .then(data => {
            if (data.status === 'started') {
                document.getElementById('startVdl2Btn').style.display = 'none';
                document.getElementById('stopVdl2Btn').style.display = 'block';
                document.getElementById('vdl2StatusText').textContent = 'Listening';
                document.getElementById('vdl2StatusText').style.color = 'var(--accent-green)';
                vdl2MainMsgCount = 0;
                startVdl2MainSSE();
            } else {
                alert(data.message || 'Failed to start VDL2');
            }
        })
        .catch(err => alert('Error: ' + err.message));
    }

    function stopVdl2Mode() {
        fetch('/vdl2/stop', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ source: 'vdl2_mode' })
        })
        .then(async (r) => {
            const text = await r.text();
            const data = text ? JSON.parse(text) : {};
            if (!r.ok || (data.status !== 'stopped' && data.status !== 'success')) {
                throw new Error(data.message || `HTTP ${r.status}`);
            }
            return data;
        })
        .then(() => {
            document.getElementById('startVdl2Btn').style.display = 'block';
            document.getElementById('stopVdl2Btn').style.display = 'none';
            document.getElementById('vdl2StatusText').textContent = 'Standby';
            document.getElementById('vdl2StatusText').style.color = 'var(--accent-yellow)';
            if (vdl2MainEventSource) {
                vdl2MainEventSource.close();
                vdl2MainEventSource = null;
            }
        })
        .catch(err => alert('Failed to stop VDL2: ' + err.message));
    }

    function startVdl2MainSSE() {
        if (vdl2MainEventSource) vdl2MainEventSource.close();

        vdl2MainEventSource = new EventSource('/vdl2/stream');
        vdl2MainEventSource.onmessage = function(e) {
            try {
                const data = JSON.parse(e.data);
                if (data.type === 'vdl2') {
                    vdl2MainMsgCount++;
                    document.getElementById('vdl2MessageCount').textContent = vdl2MainMsgCount;
                }
            } catch (err) {}
        };

        vdl2MainEventSource.onerror = function() {
            setTimeout(() => {
                if (document.getElementById('stopVdl2Btn').style.display === 'block') {
                    startVdl2MainSSE();
                }
            }, 2000);
        };
    }

    // Check initial status
    fetch('/vdl2/status')
    .then(r => r.json())
    .then(data => {
        if (data.running) {
            document.getElementById('startVdl2Btn').style.display = 'none';
            document.getElementById('stopVdl2Btn').style.display = 'block';
            document.getElementById('vdl2StatusText').textContent = 'Listening';
            document.getElementById('vdl2StatusText').style.color = 'var(--accent-green)';
            document.getElementById('vdl2MessageCount').textContent = data.message_count || 0;
            vdl2MainMsgCount = data.message_count || 0;
            startVdl2MainSSE();
        }
    })
    .catch(() => {});

    // Initialize frequency checkboxes
    document.addEventListener('DOMContentLoaded', () => updateVdl2MainFreqs());
</script>