// mediasoupClient is loaded via <script> tag in index.html (esbuild bundle)
const { Device } = mediasoupClient;

const serverUrlInput = document.getElementById('serverUrl');
const serverPasswordInput = document.getElementById('serverPassword');
const sourcesGrid = document.getElementById('sourcesGrid');
const audioSelect = document.getElementById('audioSelect');
const getSourcesBtn = document.getElementById('getSourcesBtn');
const startBtn = document.getElementById('startBtn');
const stopBtn = document.getElementById('stopBtn');
const localVideo = document.getElementById('localVideo');
const statusText = document.getElementById('statusText');
const statsPanel = document.getElementById('statsPanel');
const viewerCountDiv = document.getElementById('viewerCount');
const qualitySelect = document.getElementById('qualitySelect');

let socket;
let activeStream;
let selectedVideoSourceId = null;

// --- Mediasoup State ---
let device;
let sendTransport;
let videoProducer;
let audioProducer;

// Chart.js instance tracking
let bitrateChart = null;

// 1. Get Desktop Sources / Switch Video Source Mid-Stream
getSourcesBtn.addEventListener('click', async () => {
    // --- Mid-Stream Video Source Switching ---
    if (activeStream) {
        try {
            // On Wayland, the compositor limits concurrent ScreenCast sessions.
            // We MUST stop the old session BEFORE requesting a new one.
            activeStream.getVideoTracks().forEach(t => {
                t.onended = null;
                t.stop();
            });

            // Give the compositor time to tear down the old ScreenCast session
            await new Promise(r => setTimeout(r, 1000));

            const newStream = await navigator.mediaDevices.getUserMedia({
                audio: false,
                video: { mandatory: { chromeMediaSource: 'desktop' } }
            });

            const newVideoTrack = newStream.getVideoTracks()[0];
            if (!newVideoTrack) return;

            await newVideoTrack.applyConstraints({ frameRate: { ideal: 60 } });

            // Swap the track in the active stream
            if (activeStream.getVideoTracks()[0]) {
                activeStream.removeTrack(activeStream.getVideoTracks()[0]);
            }
            activeStream.addTrack(newVideoTrack);

            // Hot-swap on the mediasoup producer (no renegotiation needed!)
            if (videoProducer) {
                await videoProducer.replaceTrack({ track: newVideoTrack });
            }

            // Update local preview
            localVideo.srcObject = activeStream;
            newVideoTrack.onended = stopSharing;
        } catch (e) {
            console.error("Failed to switch video source:", e);
            stopSharing();
        }
        return;
    }

    // --- Normal Source Selection (when not broadcasting) ---
    sourcesGrid.innerHTML = '<div style="color:var(--text-secondary); width:100%;">Loading sources...</div>';
    startBtn.disabled = true;
    selectedVideoSourceId = null;
    
    try {
        const sources = await window.electronAPI.getSources();
        sourcesGrid.innerHTML = '';
        sources.forEach(source => {
            const item = document.createElement('div');
            item.className = 'source-item';
            
            const img = document.createElement('img');
            img.src = source.thumbnail;
            
            const label = document.createElement('span');
            label.innerText = source.name || `Screen ${source.id}`;
            label.title = source.name || `Screen ${source.id}`;
            
            item.appendChild(img);
            item.appendChild(label);
            
            item.addEventListener('click', () => {
                document.querySelectorAll('.source-item').forEach(i => i.classList.remove('selected'));
                item.classList.add('selected');
                selectedVideoSourceId = source.id;
                startPreview(source.id);
                startBtn.disabled = false;
            });
            
            sourcesGrid.appendChild(item);
        });

        if (sources.length === 1) {
            sourcesGrid.classList.add('single-item');
            selectedVideoSourceId = sources[0].id;
            sourcesGrid.firstChild.classList.add('selected');
            startBtn.disabled = false;
        } else {
            sourcesGrid.classList.remove('single-item');
        }

        if (!selectedVideoSourceId) {
            startBtn.disabled = true;
        }
    } catch (e) {
        console.error(e);
        sourcesGrid.innerHTML = '<div style="color:red; width:100%;">Error loading sources</div>';
    }
});

// --- Preview Stream Logic ---
let previewStream = null;

async function startPreview(videoSourceId) {
    if (previewStream) {
        previewStream.getTracks().forEach(t => t.stop());
        previewStream = null;
    }
    
    if (!videoSourceId) {
        localVideo.style.display = 'none';
        const placeholder = document.getElementById('videoPlaceholder');
        if (placeholder) placeholder.style.display = 'block';
        return;
    }

    try {
        previewStream = await navigator.mediaDevices.getUserMedia({
            audio: false, 
            video: {
                mandatory: {
                    chromeMediaSource: 'desktop',
                    chromeMediaSourceId: videoSourceId,
                }
            }
        });

        const videoTrack = previewStream.getVideoTracks()[0];
        await videoTrack.applyConstraints({ frameRate: { ideal: 60 } });

        localVideo.srcObject = previewStream;
        localVideo.style.display = 'block';
        const placeholder = document.getElementById('videoPlaceholder');
        if (placeholder) placeholder.style.display = 'none';
    } catch (e) {
        console.error("Failed to start preview stream:", e);
    }
}

// --- Audio Capture Helper ---
async function getAudioStream(targetAppName, videoSourceId) {
    if (!targetAppName || targetAppName === 'none') return null;

    if (targetAppName === 'all_desktop') {
        const linked = await window.electronAPI.linkMonitorAudio();
        if (linked) {
            const devices = await navigator.mediaDevices.enumerateDevices();
            const virtMic = devices.find(d => d.kind === 'audioinput' && d.label.toLowerCase().includes('simplescreenshare'));
            
            if (virtMic) {
                return await navigator.mediaDevices.getUserMedia({
                    audio: { 
                        deviceId: { exact: virtMic.deviceId },
                        echoCancellation: { exact: false },
                        autoGainControl: { exact: false },
                        noiseSuppression: { exact: false },
                        channelCount: 2,
                        sampleRate: 48000
                    },
                    video: false
                });
            } else {
                console.warn("Virtual mic device not found for monitor capture");
            }
        } else {
            console.warn("Failed to link system monitor audio.");
        }
        return null;
    }

    // Application specific (Pipewire)
    const linked = await window.electronAPI.linkAppAudio(targetAppName);
    if (linked) {
        const devices = await navigator.mediaDevices.enumerateDevices();
        const virtMic = devices.find(d => d.kind === 'audioinput' && d.label.toLowerCase().includes('simplescreenshare'));
        
        if (virtMic) {
            return await navigator.mediaDevices.getUserMedia({
                audio: { 
                    deviceId: { exact: virtMic.deviceId },
                    echoCancellation: { exact: false },
                    autoGainControl: { exact: false },
                    noiseSuppression: { exact: false },
                    channelCount: 2,
                    sampleRate: 48000
                },
                video: false
            });
        } else {
             console.warn("Virtual mic device not found in navigator enumeration");
        }
    } else {
        console.warn("Failed to link application audio.");
    }
    return null;
}

// 2. Start Broadcast
startBtn.addEventListener('click', async () => {
    const url = serverUrlInput.value;
    const password = serverPasswordInput.value;
    const videoSourceId = selectedVideoSourceId;
    const targetAppName = audioSelect.value;

    if (!url || !password) {
        alert("Please fill out URL and Password.");
        return;
    }

    window.electronAPI.saveConfig({ serverUrl: url, serverPassword: password });

    try {
        let stream;
        if (previewStream) {
            stream = previewStream;
            previewStream = null;
        } else {
            const videoMandatory = { chromeMediaSource: 'desktop' };
            if (selectedVideoSourceId) {
                videoMandatory.chromeMediaSourceId = selectedVideoSourceId;
            }
            stream = await navigator.mediaDevices.getUserMedia({
                audio: false,
                video: { mandatory: videoMandatory }
            });
        }

        const videoTrack = stream.getVideoTracks()[0];
        const [, targetFps] = (qualitySelect.value || '8000000|60').split('|');
        if (videoTrack) await videoTrack.applyConstraints({ frameRate: { ideal: parseInt(targetFps) } });

        if (targetAppName && targetAppName !== 'none') {
            const audioStream = await getAudioStream(targetAppName, videoSourceId);
            if (audioStream) {
                stream.addTrack(audioStream.getAudioTracks()[0]);
            }
        }

        activeStream = stream;
        localVideo.srcObject = stream;
        localVideo.style.display = 'block';
        
        await connectAndBroadcast(url, password);
        
        startBtn.style.display = 'none';
        stopBtn.style.display = 'inline-block';
        statsPanel.style.display = 'block';
        if (viewerCountDiv) viewerCountDiv.style.display = 'block';
        statusText.innerText = `Broadcasting to ${url}`;

        stream.getVideoTracks()[0].onended = stopSharing;

    } catch (e) {
        console.error("Stream capture error:", e);
        alert("Failed to capture screen. See console for details.");
    }
});

// --- Mediasoup SFU Connection ---
async function connectAndBroadcast(url, password) {
    return new Promise((resolve, reject) => {
        // io() is available globally from socket.io-client script tag in index.html
        socket = io(url);

        socket.on('connect', async () => {
            try {
                // 1. Authenticate as broadcaster
                socket.emit('broadcaster', password);

                // 2. Get router RTP capabilities
                const rtpCapabilities = await new Promise((res, rej) => {
                    socket.emit('getRouterRtpCapabilities', (data) => {
                        if (data.error) rej(new Error(data.error));
                        else res(data);
                    });
                });

                // 3. Create mediasoup Device and load capabilities
                device = new Device();
                await device.load({ routerRtpCapabilities: rtpCapabilities });

                // 4. Create send transport
                const transportParams = await new Promise((res, rej) => {
                    socket.emit('createWebRtcTransport', { direction: 'send' }, (data) => {
                        if (data.error) rej(new Error(data.error));
                        else res(data);
                    });
                });

                sendTransport = device.createSendTransport(transportParams);

                // Transport 'connect' event: DTLS handshake
                sendTransport.on('connect', async ({ dtlsParameters }, callback, errback) => {
                    try {
                        await new Promise((res, rej) => {
                            socket.emit('connectTransport', {
                                transportId: sendTransport.id,
                                dtlsParameters
                            }, (result) => {
                                if (result && result.error) rej(new Error(result.error));
                                else res();
                            });
                        });
                        callback();
                    } catch (e) {
                        errback(e);
                    }
                });

                // Transport 'produce' event: server creates the Producer
                sendTransport.on('produce', async ({ kind, rtpParameters }, callback, errback) => {
                    try {
                        const result = await new Promise((res, rej) => {
                            socket.emit('produce', {
                                transportId: sendTransport.id,
                                kind,
                                rtpParameters
                            }, (data) => {
                                if (data.error) rej(new Error(data.error));
                                else res(data);
                            });
                        });
                        callback({ id: result.id });
                    } catch (e) {
                        errback(e);
                    }
                });

                // 5. Produce video
                const videoTrack = activeStream.getVideoTracks()[0];
                if (videoTrack) {
                    const [targetBitrate] = (qualitySelect.value || '8000000|60').split('|');
                    videoProducer = await sendTransport.produce({
                        track: videoTrack,
                        encodings: [{
                            maxBitrate: parseInt(targetBitrate),
                        }],
                        codecOptions: {
                            videoGoogleStartBitrate: 1000
                        }
                    });

                    videoProducer.on('transportclose', () => {
                        videoProducer = null;
                    });
                }

                // 6. Produce audio (if present)
                const audioTrack = activeStream.getAudioTracks()[0];
                if (audioTrack) {
                    audioProducer = await sendTransport.produce({
                        track: audioTrack,
                        codecOptions: {
                            opusStereo: true,
                            opusDtx: true,
                            opusMaxPlaybackRate: 48000,
                            opusMaxAverageBitrate: 510000
                        }
                    });

                    audioProducer.on('transportclose', () => {
                        audioProducer = null;
                    });
                }

                // 7. Track viewer count
                socket.on('viewerCount', (count) => {
                    if (viewerCountDiv) viewerCountDiv.innerText = `Viewers: ${count}`;
                });

                // Get initial viewer count
                socket.emit('getViewerCount', (count) => {
                    if (viewerCountDiv) viewerCountDiv.innerText = `Viewers: ${count}`;
                });

                resolve();
            } catch (e) {
                console.error('Mediasoup setup error:', e);
                reject(e);
            }
        });

        socket.on('authError', (msg) => {
            alert(msg);
            stopSharing();
            reject(new Error(msg));
        });

        socket.on('connect_error', (err) => {
            console.error('Socket connection error:', err);
        });
    });
}

function stopSharing() {
    // Close producers
    if (videoProducer) {
        videoProducer.close();
        videoProducer = null;
    }
    if (audioProducer) {
        audioProducer.close();
        audioProducer = null;
    }
    
    // Close transport
    if (sendTransport) {
        sendTransport.close();
        sendTransport = null;
    }

    device = null;

    if (activeStream) {
        activeStream.getTracks().forEach(t => t.stop());
        activeStream = null;
    }
    if (socket) {
        socket.disconnect();
        socket = null;
    }

    localVideo.style.display = 'none';
    const placeholder = document.getElementById('videoPlaceholder');
    if (placeholder) placeholder.style.display = 'block';
    
    statsPanel.style.display = 'none';
    startBtn.style.display = 'inline-block';
    stopBtn.style.display = 'none';
    statusText.innerText = 'Not Broadcasting';
    if (viewerCountDiv) {
        viewerCountDiv.style.display = 'none';
        viewerCountDiv.innerText = 'Viewers: 0';
    }
    
    if (bitrateChart) {
        bitrateChart.destroy();
        bitrateChart = null;
    }
}

stopBtn.addEventListener('click', stopSharing);

// --- Dynamic Audio Switching ---
audioSelect.addEventListener('change', async () => {
    if (!activeStream || !sendTransport) return;
    
    const targetAppName = audioSelect.value;
    try {
        const newAudioStream = await getAudioStream(targetAppName, selectedVideoSourceId);
        const newAudioTrack = newAudioStream ? newAudioStream.getAudioTracks()[0] : null;
        
        // Remove old track from local active stream
        const oldAudioTracks = activeStream.getAudioTracks();
        if (oldAudioTracks.length > 0) {
            oldAudioTracks.forEach(t => {
                t.stop();
                activeStream.removeTrack(t);
            });
        }
        
        if (newAudioTrack) {
            activeStream.addTrack(newAudioTrack);
        }

        // Hot-swap on the mediasoup audio producer
        if (audioProducer && newAudioTrack) {
            await audioProducer.replaceTrack({ track: newAudioTrack });
        } else if (audioProducer && !newAudioTrack) {
            // Mute by pausing the producer
            await audioProducer.pause();
        } else if (!audioProducer && newAudioTrack) {
            // Need to create a new producer for audio
            audioProducer = await sendTransport.produce({
                track: newAudioTrack,
                codecOptions: {
                    opusStereo: true,
                    opusDtx: true,
                    opusMaxPlaybackRate: 48000,
                    opusMaxAverageBitrate: 510000
                }
            });
            audioProducer.on('transportclose', () => {
                audioProducer = null;
            });
        }
        
    } catch (e) {
        console.error("Failed to switch audio dynamically:", e);
    }
});

// --- Dynamic Quality Switching ---
qualitySelect.addEventListener('change', async () => {
    if (!activeStream || !videoProducer) return;
    
    const [targetBitrate, targetFps] = qualitySelect.value.split('|');
    
    // Update frame rate on the video track
    const videoTrack = activeStream.getVideoTracks()[0];
    if (videoTrack) {
        await videoTrack.applyConstraints({ frameRate: { ideal: parseInt(targetFps) } }).catch(e => console.error(e));
    }
    
    // Update max bitrate on the producer's encoding
    if (videoProducer) {
        try {
            const params = videoProducer.rtpSender.getParameters();
            if (params.encodings && params.encodings.length > 0) {
                params.encodings[0].maxBitrate = parseInt(targetBitrate);
                await videoProducer.rtpSender.setParameters(params);
            }
        } catch (e) {
            console.error("Failed to update bitrate:", e);
        }
    }
});

// --- Stats Monitoring Loop ---
let lastBytesSent = 0;
let lastTimestamp = 0;

setInterval(async () => {
    if (!activeStream || !videoProducer) return;
    
    // Initialize chart if not present
    if (!bitrateChart) {
        const ctx = document.getElementById('bitrateChart').getContext('2d');
        bitrateChart = new Chart(ctx, {
            type: 'line',
            data: {
                labels: Array(20).fill(''),
                datasets: [{
                    label: 'Bitrate (kbps)',
                    data: Array(20).fill(0),
                    borderColor: '#aaaaaa',
                    backgroundColor: 'rgba(170, 170, 170, 0.1)',
                    borderWidth: 2,
                    fill: true,
                    tension: 0.4,
                    pointRadius: 0
                }]
            },
            options: {
                responsive: true,
                maintainAspectRatio: false,
                animation: false,
                plugins: {
                    legend: { display: false }
                },
                scales: {
                    x: { display: false },
                    y: { 
                        display: true, 
                        position: 'right',
                        ticks: { color: '#94a3b8', font: { size: 10 } },
                        grid: { color: 'rgba(255,255,255,0.05)' }
                    }
                }
            }
        });
    }

    try {
        const stats = await videoProducer.getStats();
        let videoCodec = 'Unknown';
        let audioCodec = 'Unknown';
        
        stats.forEach(report => {
            if (report.type === 'codec') {
                if (report.mimeType.toLowerCase().includes('video')) videoCodec = report.mimeType.split('/')[1] || report.mimeType;
                if (report.mimeType.toLowerCase().includes('audio')) audioCodec = report.mimeType.split('/')[1] || report.mimeType;
            }
        });

        stats.forEach(report => {
            if (report.type === 'outbound-rtp' && report.kind === 'video') {
                const fps = report.framesPerSecond || 0;
                const bytesSent = report.bytesSent || 0;
                const timestamp = report.timestamp;
                const res = `${report.frameWidth || 0}x${report.frameHeight || 0}`;
                
                let bitrate = 0;
                if (lastTimestamp && lastBytesSent) {
                    const timeDiff = timestamp - lastTimestamp;
                    const bytesDiff = bytesSent - lastBytesSent;
                    bitrate = Math.round((bytesDiff * 8) / timeDiff); 
                }
                lastBytesSent = bytesSent;
                lastTimestamp = timestamp;

                document.getElementById('statsFps').innerText = fps;
                document.getElementById('statsRes').innerText = res;
                document.getElementById('statsBitrate').innerText = bitrate + ' kbps';
                document.getElementById('statsVideoCodec').innerText = videoCodec;
                
                if (bitrateChart) {
                    bitrateChart.data.datasets[0].data.shift();
                    bitrateChart.data.datasets[0].data.push(bitrate);
                    bitrateChart.update();
                }
            }
        });

        // Get audio codec from audio producer stats
        if (audioProducer) {
            const audioStats = await audioProducer.getStats();
            audioStats.forEach(report => {
                if (report.type === 'codec' && report.mimeType.toLowerCase().includes('audio')) {
                    document.getElementById('statsAudioCodec').innerText = report.mimeType.split('/')[1] || report.mimeType;
                }
            });
        }
    } catch (e) { console.error("Stats error", e); }
}, 1000);

// --- Reusable Audio Dropdown Population ---
function populateAudioSelect(audioApps) {
    const currentValue = audioSelect.value;
    audioSelect.innerHTML = '<option value="none">No Audio (Video Only)</option>';
    
    const allDesktopOption = document.createElement('option');
    allDesktopOption.value = 'all_desktop';
    allDesktopOption.text = 'All Desktop Audio (System Default)';
    audioSelect.appendChild(allDesktopOption);
    
    audioApps.forEach(app => {
        const option = document.createElement('option');
        option.value = app.name;
        option.text = `${app.name} (${app.mediaName})`;
        audioSelect.appendChild(option);
    });

    const options = Array.from(audioSelect.options);
    if (options.some(o => o.value === currentValue)) {
        audioSelect.value = currentValue;
    }
}

// Listen for live audio source updates from PipeWire monitor
window.electronAPI.onAudioAppsUpdated((apps) => {
    populateAudioSelect(apps);
});

// Initial load: config + audio apps only (no portal prompt on startup)
window.electronAPI.getConfig().then(cfg => {
    if (cfg.serverUrl) serverUrlInput.value = cfg.serverUrl;
    if (cfg.serverPassword) serverPasswordInput.value = cfg.serverPassword;
});

// Fetch audio applications on startup
(async () => {
    try {
        const audioApps = await window.electronAPI.getAudioApps();
        populateAudioSelect(audioApps);
    } catch (e) {
        console.error('Failed to load audio apps:', e);
        audioSelect.innerHTML = '<option value="none">No Audio (Video Only)</option>';
    }

    sourcesGrid.innerHTML = '<div style="color:var(--text-secondary); width:100%; text-align:center; padding:1rem;"></div>';
    startBtn.disabled = false;
})();