// ==============================================================================
//  DriveSafe HUD Dashboard JavaScript
//  Establishes real-time EventSource connection, draws Chart.js EKG, and manages HUD state.
// ==============================================================================

let earChart;
const maxChartPoints = 40;
let chartData = Array(maxChartPoints).fill(0.3);
let chartLabels = Array(maxChartPoints).fill("");
let renderedChatLogsCount = 0;

// --- Initialize Chart.js on DOM Load ---
document.addEventListener("DOMContentLoaded", () => {
    const ctx = document.getElementById('earChart').getContext('2d');
    
    // Create futuristic neon line chart
    earChart = new Chart(ctx, {
        type: 'line',
        data: {
            labels: chartLabels,
            datasets: [{
                label: 'Eye Aspect Ratio (EAR)',
                data: chartData,
                borderColor: '#00bfff',
                borderWidth: 2,
                pointRadius: 0,
                fill: true,
                backgroundColor: 'rgba(0, 191, 255, 0.05)',
                tension: 0.4
            }]
        },
        options: {
            responsive: true,
            maintainAspectRatio: false,
            plugins: {
                legend: { display: false }
            },
            scales: {
                x: { display: false },
                y: {
                    min: 0.0,
                    max: 0.45,
                    grid: { color: 'rgba(255, 255, 255, 0.03)' },
                    ticks: {
                        color: '#64748b',
                        font: { family: 'Share Tech Mono', size: 10 }
                    }
                }
            },
            animation: { duration: 0 } // Disable default anims for absolute high-speed rendering
        }
    });

    // Initialize Telemetry EventSource listener
    initTelemetry();
});

// --- Server-Sent Events (SSE) Telemetry Listener ---
function initTelemetry() {
    const sse = new EventSource('/telemetry');
    
    sse.onmessage = (event) => {
        const data = JSON.parse(event.data);
        
        // 1. Update Core Readouts
        updateMetrics(data);
        
        // 2. Shift EAR Graph Data
        updateChart(data.ear);
        
        // 3. Update Conversation Chat Logs
        updateChat(data.chat_history);
        
        // 4. Update HUD panel glowing states
        updateStateOverlays(data.state, data.alert_message);
    };
    
    sse.onerror = (err) => {
        console.error("SSE connection dropped:", err);
    };
}

// --- Update Circular Gauge & Numeric Metrics ---
function updateMetrics(data) {
    // Current numeric readout
    document.getElementById("ear-val").innerText = data.ear.toFixed(2);
    
    // Circular radial progress math
    const gauge = document.getElementById("ear-gauge");
    const radius = gauge.r.baseVal.value;
    const circumference = 2 * Math.PI * radius;
    
    // EAR bounds are normally between 0.10 (fully closed) and 0.35 (wide open)
    // Normalize EAR to 0% - 100% range
    let percentage = (data.ear - 0.10) / (0.35 - 0.10);
    percentage = Math.max(0, Math.min(1, percentage)); // Clamp between 0 and 1
    
    const offset = circumference - (percentage * circumference);
    gauge.style.strokeDashoffset = offset;
    
    // Change gauge color relative to EAR thresholds
    const warnThreshold = 0.23;
    const closedThreshold = 0.20;
    
    if (data.ear <= closedThreshold) {
        gauge.style.stroke = "var(--danger-color)";
    } else if (data.ear <= warnThreshold) {
        gauge.style.stroke = "var(--warn-color)";
    } else {
        gauge.style.stroke = "var(--safe-color)";
    }
    
    // Update Drowsiness Count
    const countElement = document.getElementById("drowsiness-count");
    countElement.innerText = data.drowsiness_count;
    if (data.drowsiness_count > 0) {
        countElement.style.color = "var(--danger-color)";
        countElement.style.textShadow = "0 0 10px rgba(255, 40, 80, 0.4)";
    } else {
        countElement.style.color = "var(--safe-color)";
        countElement.style.textShadow = "none";
    }
    
    // Update Engine FPS
    document.getElementById("engine-fps").innerText = `${data.fps} FPS`;
    
    // Update Tracking active button toggle
    const trackingBtn = document.getElementById("toggle-tracking-btn");
    const label = trackingBtn.querySelector("span");
    if (data.detection_active) {
        trackingBtn.classList.add("active");
        label.innerText = "ACTIVE TRACKING";
    } else {
        trackingBtn.classList.remove("active");
        label.innerText = "TRACKING PAUSED";
    }
}

// --- EKG EAR Waveform Chart Shifter ---
function updateChart(newEar) {
    chartData.push(newEar);
    chartData.shift();
    
    // Swap graph colors based on EAR values
    if (newEar < 0.20) {
        earChart.data.datasets[0].borderColor = "#ff2850";
        earChart.data.datasets[0].backgroundColor = "rgba(255, 40, 80, 0.05)";
    } else if (newEar < 0.23) {
        earChart.data.datasets[0].borderColor = "#ffaa00";
        earChart.data.datasets[0].backgroundColor = "rgba(255, 170, 0, 0.05)";
    } else {
        earChart.data.datasets[0].borderColor = "#00ff80";
        earChart.data.datasets[0].backgroundColor = "rgba(0, 255, 128, 0.05)";
    }
    
    earChart.update();
}

// --- Dynamic Conversational Chat Logs renderer ---
function updateChat(history) {
    if (history.length === renderedChatLogsCount) return;
    
    const chatBox = document.getElementById("chat-box");
    
    // Render only new logs added since last pass
    for (let i = renderedChatLogsCount; i < history.length; i++) {
        const log = history[i];
        
        // System logs represent state announcements
        if (log.speaker === "System") {
            const systemDiv = document.createElement("div");
            systemDiv.className = "chat-bubble system-bubble";
            systemDiv.innerText = log.message;
            chatBox.appendChild(systemDiv);
        } else {
            // User query
            if (log.query) {
                const userDiv = document.createElement("div");
                userDiv.className = "chat-bubble driver-bubble";
                userDiv.innerHTML = `<span class="bubble-label">Driver</span>${escapeHTML(log.query)}`;
                chatBox.appendChild(userDiv);
            }
            
            // AI response
            if (log.message) {
                const aiDiv = document.createElement("div");
                aiDiv.className = "chat-bubble slm-bubble";
                aiDiv.innerHTML = `<span class="bubble-label">DriveSafe SLM</span>${escapeHTML(log.message)}`;
                chatBox.appendChild(aiDiv);
            }
        }
    }
    
    renderedChatLogsCount = history.length;
    
    // Auto-scroll chat box down with a short delay for fluid rendering
    setTimeout(() => {
        chatBox.scrollTop = chatBox.scrollHeight;
    }, 50);
}

// --- Toggle HUD Glowing Cockpit States ---
function updateStateOverlays(state, alertMsg) {
    const mainPanel = document.getElementById("main-panel");
    const badge = document.getElementById("hud-state-badge");
    const slmIndicator = document.getElementById("slm-indicator");
    
    // Clean current state classes
    mainPanel.className = "glass-panel video-panel";
    
    if (state === "NORMAL") {
        mainPanel.classList.add("state-normal");
        badge.innerText = alertMsg ? alertMsg : "NORMAL";
        badge.style.borderColor = "var(--safe-color)";
        badge.style.color = "var(--safe-color)";
        badge.style.boxShadow = "0 0 10px rgba(0, 255, 128, 0.2)";
        slmIndicator.innerText = "SLM STANDBY";
        slmIndicator.style.color = "var(--safe-color)";
    } 
    else if (state === "CLOSED_3S") {
        mainPanel.classList.add("state-warn");
        badge.innerText = alertMsg ? alertMsg : "EYES CLOSED (3-5s)";
        badge.style.borderColor = "var(--warn-color)";
        badge.style.color = "var(--warn-color)";
        badge.style.boxShadow = "0 0 15px rgba(255, 170, 0, 0.3)";
    } 
    else if (state === "CLOSED_5S" || state === "WAITING_REST_RESPONSE" || state === "WAITING_SONG_RESPONSE") {
        mainPanel.classList.add("state-danger");
        badge.innerText = alertMsg ? alertMsg : "CRITICAL WARNING";
        badge.style.borderColor = "var(--danger-color)";
        badge.style.color = "var(--danger-color)";
        badge.style.boxShadow = "0 0 25px rgba(255, 40, 80, 0.5)";
        
        if (state.startsWith("WAITING")) {
            slmIndicator.innerText = "SLM ACTIVE DIALOGUE";
            slmIndicator.style.color = "var(--accent-color)";
        }
    }
    else if (state === "PLAYING_MUSIC") {
        mainPanel.classList.add("state-normal");
        badge.innerText = "BEATS PLAYING";
        badge.style.borderColor = "var(--accent-color)";
        badge.style.color = "var(--accent-color)";
        badge.style.boxShadow = "0 0 10px rgba(0, 191, 255, 0.2)";
    }
}

// --- Control Desk AJAX REST Bridge ---

function toggleTracking() {
    fetch('/api/toggle_detection', { method: 'POST' })
        .then(response => response.json())
        .then(data => {
            console.log("Tracking toggled, active state:", data.detection_active);
        })
        .catch(err => console.error("Error toggling tracking:", err));
}

function triggerReset() {
    fetch('/api/reset', { method: 'POST' })
        .then(response => response.json())
        .then(data => {
            console.log("System reset:", data.message);
        })
        .catch(err => console.error("Error triggering reset:", err));
}

function triggerMusic() {
    fetch('/api/trigger_music', { method: 'POST' })
        .then(response => response.json())
        .then(data => {
            console.log("Music play request sent:", data.message);
        })
        .catch(err => console.error("Error playing energetic beats:", err));
}

// --- Helper Functions ---
function escapeHTML(str) {
    return str.replace(/[&<>'"]/g, 
        tag => ({
            '&': '&amp;',
            '<': '&lt;',
            '>': '&gt;',
            "'": '&#39;',
            '"': '&quot;'
        }[tag] || tag)
    );
}