/**
 * SSTV General Mode
 * Terrestrial Slow-Scan Television decoder interface
 */

const SSTVGeneral = (function() {
    // State
    let isRunning = false;
    let eventSource = null;
    let images = [];
    let currentMode = null;
    let progress = 0;

    /**
     * Initialize the SSTV General mode
     */
    function init() {
        checkStatus();
        loadImages();
    }

    /**
     * Select a preset frequency from the dropdown
     */
    function selectPreset(value) {
        if (!value) return;

        const parts = value.split('|');
        const freq = parseFloat(parts[0]);
        const mod = parts[1];

        const freqInput = document.getElementById('sstvGeneralFrequency');
        const modSelect = document.getElementById('sstvGeneralModulation');

        if (freqInput) freqInput.value = freq;
        if (modSelect) modSelect.value = mod;

        // Update strip display
        const stripFreq = document.getElementById('sstvGeneralStripFreq');
        const stripMod = document.getElementById('sstvGeneralStripMod');
        if (stripFreq) stripFreq.textContent = freq.toFixed(3);
        if (stripMod) stripMod.textContent = mod.toUpperCase();
    }

    /**
     * Check current decoder status
     */
    async function checkStatus() {
        try {
            const response = await fetch('/sstv-general/status');
            const data = await response.json();

            if (!data.available) {
                updateStatusUI('unavailable', 'Decoder not installed');
                showStatusMessage('SSTV decoder not available. Install slowrx: apt install slowrx', 'warning');
                return;
            }

            if (data.running) {
                isRunning = true;
                updateStatusUI('listening', 'Listening...');
                startStream();
            } else {
                updateStatusUI('idle', 'Idle');
            }

            updateImageCount(data.image_count || 0);
        } catch (err) {
            console.error('Failed to check SSTV General status:', err);
        }
    }

    /**
     * Start SSTV decoder
     */
    async function start() {
        const freqInput = document.getElementById('sstvGeneralFrequency');
        const modSelect = document.getElementById('sstvGeneralModulation');
        const deviceSelect = document.getElementById('deviceSelect');

        const frequency = parseFloat(freqInput?.value || '14.230');
        const modulation = modSelect?.value || 'usb';
        const device = parseInt(deviceSelect?.value || '0', 10);

        updateStatusUI('connecting', 'Starting...');

        try {
            const response = await fetch('/sstv-general/start', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ frequency, modulation, device })
            });

            const data = await response.json();

            if (data.status === 'started' || data.status === 'already_running') {
                isRunning = true;
                updateStatusUI('listening', `${frequency} MHz ${modulation.toUpperCase()}`);
                startStream();
                showNotification('SSTV', `Listening on ${frequency} MHz ${modulation.toUpperCase()}`);

                // Update strip
                const stripFreq = document.getElementById('sstvGeneralStripFreq');
                const stripMod = document.getElementById('sstvGeneralStripMod');
                if (stripFreq) stripFreq.textContent = frequency.toFixed(3);
                if (stripMod) stripMod.textContent = modulation.toUpperCase();
            } else {
                updateStatusUI('idle', 'Start failed');
                showStatusMessage(data.message || 'Failed to start decoder', 'error');
            }
        } catch (err) {
            console.error('Failed to start SSTV General:', err);
            updateStatusUI('idle', 'Error');
            showStatusMessage('Connection error: ' + err.message, 'error');
        }
    }

    /**
     * Stop SSTV decoder
     */
    async function stop() {
        try {
            await fetch('/sstv-general/stop', { method: 'POST' });
            isRunning = false;
            stopStream();
            updateStatusUI('idle', 'Stopped');
            showNotification('SSTV', 'Decoder stopped');
        } catch (err) {
            console.error('Failed to stop SSTV General:', err);
        }
    }

    /**
     * Update status UI elements
     */
    function updateStatusUI(status, text) {
        const dot = document.getElementById('sstvGeneralStripDot');
        const statusText = document.getElementById('sstvGeneralStripStatus');
        const startBtn = document.getElementById('sstvGeneralStartBtn');
        const stopBtn = document.getElementById('sstvGeneralStopBtn');

        if (dot) {
            dot.className = 'sstv-general-strip-dot';
            if (status === 'listening' || status === 'detecting') {
                dot.classList.add('listening');
            } else if (status === 'decoding') {
                dot.classList.add('decoding');
            } else {
                dot.classList.add('idle');
            }
        }

        if (statusText) {
            statusText.textContent = text || status;
        }

        if (startBtn && stopBtn) {
            if (status === 'listening' || status === 'decoding') {
                startBtn.style.display = 'none';
                stopBtn.style.display = 'inline-block';
            } else {
                startBtn.style.display = 'inline-block';
                stopBtn.style.display = 'none';
            }
        }

        // Update live content area
        const liveContent = document.getElementById('sstvGeneralLiveContent');
        if (liveContent) {
            if (status === 'idle' || status === 'unavailable') {
                liveContent.innerHTML = renderIdleState();
            }
        }
    }

    /**
     * Render idle state HTML
     */
    function renderIdleState() {
        return `
            <div class="sstv-general-idle-state">
                <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5">
                    <rect x="3" y="3" width="18" height="18" rx="2"/>
                    <circle cx="12" cy="12" r="3"/>
                    <path d="M3 9h2M19 9h2M3 15h2M19 15h2"/>
                </svg>
                <h4>SSTV Decoder</h4>
                <p>Select a frequency and click Start to listen for SSTV transmissions</p>
            </div>
        `;
    }

    /**
     * Start SSE stream
     */
    function startStream() {
        if (eventSource) {
            eventSource.close();
        }

        eventSource = new EventSource('/sstv-general/stream');

        eventSource.onmessage = (e) => {
            try {
                const data = JSON.parse(e.data);
                if (data.type === 'sstv_progress') {
                    handleProgress(data);
                }
            } catch (err) {
                console.error('Failed to parse SSE message:', err);
            }
        };

        eventSource.onerror = () => {
            console.warn('SSTV General SSE error, will reconnect...');
            setTimeout(() => {
                if (isRunning) startStream();
            }, 3000);
        };
    }

    /**
     * Stop SSE stream
     */
    function stopStream() {
        if (eventSource) {
            eventSource.close();
            eventSource = null;
        }
    }

    /**
     * Handle progress update
     */
    function handleProgress(data) {
        currentMode = data.mode || currentMode;
        progress = data.progress || 0;

        if (data.status === 'decoding') {
            updateStatusUI('decoding', `Decoding ${currentMode || 'image'}...`);
            renderDecodeProgress(data);
        } else if (data.status === 'complete' && data.image) {
            images.unshift(data.image);
            updateImageCount(images.length);
            renderGallery();
            showNotification('SSTV', 'New image decoded!');
            updateStatusUI('listening', 'Listening...');
        } else if (data.status === 'detecting') {
            updateStatusUI('listening', data.message || 'Listening...');
        }
    }

    /**
     * Render decode progress in live area
     */
    function renderDecodeProgress(data) {
        const liveContent = document.getElementById('sstvGeneralLiveContent');
        if (!liveContent) return;

        liveContent.innerHTML = `
            <div class="sstv-general-canvas-container">
                <canvas id="sstvGeneralCanvas" width="320" height="256"></canvas>
            </div>
            <div class="sstv-general-decode-info">
                <div class="sstv-general-mode-label">${data.mode || 'Detecting mode...'}</div>
                <div class="sstv-general-progress-bar">
                    <div class="progress" style="width: ${data.progress || 0}%"></div>
                </div>
                <div class="sstv-general-status-message">${data.message || 'Decoding...'}</div>
            </div>
        `;
    }

    /**
     * Load decoded images
     */
    async function loadImages() {
        try {
            const response = await fetch('/sstv-general/images');
            const data = await response.json();

            if (data.status === 'ok') {
                images = data.images || [];
                updateImageCount(images.length);
                renderGallery();
            }
        } catch (err) {
            console.error('Failed to load SSTV General images:', err);
        }
    }

    /**
     * Update image count display
     */
    function updateImageCount(count) {
        const countEl = document.getElementById('sstvGeneralImageCount');
        const stripCount = document.getElementById('sstvGeneralStripImageCount');

        if (countEl) countEl.textContent = count;
        if (stripCount) stripCount.textContent = count;
    }

    /**
     * Render image gallery
     */
    function renderGallery() {
        const gallery = document.getElementById('sstvGeneralGallery');
        if (!gallery) return;

        if (images.length === 0) {
            gallery.innerHTML = `
                <div class="sstv-general-gallery-empty">
                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
                        <rect x="3" y="3" width="18" height="18" rx="2"/>
                        <circle cx="8.5" cy="8.5" r="1.5"/>
                        <polyline points="21 15 16 10 5 21"/>
                    </svg>
                    <p>No images decoded yet</p>
                </div>
            `;
            return;
        }

        gallery.innerHTML = images.map(img => `
            <div class="sstv-general-image-card" onclick="SSTVGeneral.showImage('${escapeHtml(img.url)}')">
                <img src="${escapeHtml(img.url)}" alt="SSTV Image" class="sstv-general-image-preview" loading="lazy">
                <div class="sstv-general-image-info">
                    <div class="sstv-general-image-mode">${escapeHtml(img.mode || 'Unknown')}</div>
                    <div class="sstv-general-image-timestamp">${formatTimestamp(img.timestamp)}</div>
                </div>
            </div>
        `).join('');
    }

    /**
     * Show full-size image in modal
     */
    function showImage(url) {
        let modal = document.getElementById('sstvGeneralImageModal');
        if (!modal) {
            modal = document.createElement('div');
            modal.id = 'sstvGeneralImageModal';
            modal.className = 'sstv-general-image-modal';
            modal.innerHTML = `
                <button class="sstv-general-modal-close" onclick="SSTVGeneral.closeImage()">&times;</button>
                <img src="" alt="SSTV Image">
            `;
            modal.addEventListener('click', (e) => {
                if (e.target === modal) closeImage();
            });
            document.body.appendChild(modal);
        }

        modal.querySelector('img').src = url;
        modal.classList.add('show');
    }

    /**
     * Close image modal
     */
    function closeImage() {
        const modal = document.getElementById('sstvGeneralImageModal');
        if (modal) modal.classList.remove('show');
    }

    /**
     * Format timestamp for display
     */
    function formatTimestamp(isoString) {
        if (!isoString) return '--';
        try {
            const date = new Date(isoString);
            return date.toLocaleString();
        } catch {
            return isoString;
        }
    }

    /**
     * Escape HTML for safe display
     */
    function escapeHtml(text) {
        if (!text) return '';
        const div = document.createElement('div');
        div.textContent = text;
        return div.innerHTML;
    }

    /**
     * Show status message
     */
    function showStatusMessage(message, type) {
        if (typeof showNotification === 'function') {
            showNotification('SSTV', message);
        } else {
            console.log(`[SSTV General ${type}] ${message}`);
        }
    }

    // Public API
    return {
        init,
        start,
        stop,
        loadImages,
        showImage,
        closeImage,
        selectPreset
    };
})();