/**
 * app.js — Main frontend orchestration using Gradio JS Client.
 */
import { Client } from "https://cdn.jsdelivr.net/npm/@gradio/client/dist/index.min.js";
import { startWaveform, stopWaveform } from './waveform.js';
import { renderTriageCard } from './triage-card.js';

let gradioClient = null;

// --- DOM Elements ---
const statusPill = document.getElementById('status-pill');
const statusText = statusPill.querySelector('.status-text');

// Mic Card
const micBtn = document.getElementById('mic-button');
const micStatus = document.getElementById('mic-status');
const waveformCanvas = document.getElementById('waveform-canvas');
const transcriptContainer = document.getElementById('transcript-container');
const transcriptText = document.getElementById('transcript-text');
const editTranscriptBtn = document.getElementById('edit-transcript-btn');

// Camera Card
const openCameraBtn = document.getElementById('open-camera-btn');
const uploadPhotoBtn = document.getElementById('upload-photo-btn');
const captureBtn = document.getElementById('capture-btn');
const fileInput = document.getElementById('photo-file-input');
const cameraPreview = document.getElementById('camera-preview');
const photoPreview = document.getElementById('photo-preview');
const cameraPlaceholder = document.getElementById('camera-placeholder');
const photoDescriptionBox = document.getElementById('photo-description');

// Triage & Output
const triageBtn = document.getElementById('triage-btn');
const outputSection = document.getElementById('output-section');
const triageCardContainer = document.getElementById('triage-card');
const resetBtn = document.getElementById('reset-btn');

// --- Global State ---
let isRecording = false;
let mediaRecorder = null;
let audioChunks = [];
let waveformCleanup = null;
let currentCameraStream = null;

let state = {
    symptomsText: "",
    visualDescription: "",
    hindiAudioB64: "",
    englishAudioB64: ""
};

// --- Initialization ---
async function initClient() {
    try {
        gradioClient = await Client.connect(window.location.origin);
        statusPill.setAttribute('data-state', 'ready');
        statusText.textContent = "Ready";
        
        // Ping health endpoint via fetch (just to verify)
        fetch('/health').catch(e => console.error("Health check failed", e));
    } catch (err) {
        console.error("Gradio Client connection failed:", err);
        statusPill.setAttribute('data-state', 'error');
        statusText.textContent = "Offline";
    }
}

document.addEventListener('DOMContentLoaded', initClient);

// --- Audio Recording Flow ---
micBtn.addEventListener('click', async () => {
    if (!gradioClient) {
        alert("System is still connecting. Please wait.");
        return;
    }

    if (!isRecording) {
        try {
            const stream = await navigator.mediaDevices.getUserMedia({ audio: true });
            mediaRecorder = new MediaRecorder(stream);
            audioChunks = [];

            mediaRecorder.ondataavailable = event => {
                if (event.data.size > 0) audioChunks.push(event.data);
            };

            mediaRecorder.onstop = async () => {
                const audioBlob = new Blob(audioChunks, { type: 'audio/webm' });
                stream.getTracks().forEach(track => track.stop());
                if (waveformCleanup) waveformCleanup();
                stopWaveform(waveformCanvas);
                
                await processAudio(audioBlob);
            };

            mediaRecorder.start();
            isRecording = true;
            micBtn.classList.add('recording');
            micStatus.textContent = "Recording... Tap to stop";
            
            // Start waveform visualization
            waveformCleanup = startWaveform(waveformCanvas, stream);
            
        } catch (err) {
            console.error("Microphone access denied:", err);
            alert("Microphone access is required to record symptoms.");
        }
    } else {
        mediaRecorder.stop();
        isRecording = false;
        micBtn.classList.remove('recording');
        micStatus.textContent = "Processing...";
    }
});

async function processAudio(blob) {
    try {
        // Convert blob to base64
        const reader = new FileReader();
        reader.readAsDataURL(blob);
        reader.onloadend = async () => {
            let base64data = reader.result;
            // Remove data URL prefix (e.g., "data:audio/webm;base64,")
            base64data = base64data.split(',')[1];

            micStatus.innerHTML = '<span class="spinner"></span> Transcribing...';
            
            const result = await gradioClient.predict("/transcribe", { audio_b64: base64data });
            
            if (result.data[0] && result.data[0].text) {
                state.symptomsText = result.data[0].text;
                transcriptText.textContent = state.symptomsText;
                transcriptContainer.classList.add('visible');
                micStatus.textContent = "Audio transcribed.";
                checkReadyForTriage();
            } else if (result.data[0] && result.data[0].error) {
                throw new Error(result.data[0].error);
            } else {
                throw new Error("No transcription returned");
            }
        };
    } catch (err) {
        console.error("Transcription failed:", err);
        micStatus.textContent = "Error transcribing audio.";
    }
}

// Editable transcript
editTranscriptBtn.addEventListener('click', () => {
    transcriptText.contentEditable = "true";
    transcriptText.focus();
});
transcriptText.addEventListener('blur', () => {
    transcriptText.contentEditable = "false";
    state.symptomsText = transcriptText.textContent.trim();
});

// --- Camera & Photo Flow ---
openCameraBtn.addEventListener('click', async () => {
    try {
        currentCameraStream = await navigator.mediaDevices.getUserMedia({ 
            video: { facingMode: 'environment' } 
        });
        cameraPreview.srcObject = currentCameraStream;
        cameraPreview.classList.add('visible');
        cameraPlaceholder.style.display = 'none';
        photoPreview.classList.remove('visible');
        captureBtn.style.display = 'block';
        openCameraBtn.style.display = 'none';
        uploadPhotoBtn.style.display = 'none';
    } catch (err) {
        console.error("Camera access denied:", err);
        alert("Camera access is required. Try uploading a photo instead.");
    }
});

captureBtn.addEventListener('click', () => {
    if (!currentCameraStream) return;
    
    const canvas = document.createElement('canvas');
    canvas.width = cameraPreview.videoWidth;
    canvas.height = cameraPreview.videoHeight;
    canvas.getContext('2d').drawImage(cameraPreview, 0, 0);
    
    // Convert canvas to blob (jpeg)
    canvas.toBlob(blob => {
        const file = new File([blob], "capture.jpg", { type: "image/jpeg" });
        displayPhotoAndProcess(file);
    }, 'image/jpeg', 0.8);

    // Stop camera
    currentCameraStream.getTracks().forEach(track => track.stop());
    currentCameraStream = null;
    cameraPreview.classList.remove('visible');
    captureBtn.style.display = 'none';
    openCameraBtn.style.display = 'block';
    uploadPhotoBtn.style.display = 'block';
});

uploadPhotoBtn.addEventListener('click', () => {
    fileInput.click();
});

fileInput.addEventListener('change', (e) => {
    const file = e.target.files[0];
    if (file) displayPhotoAndProcess(file);
});

// Drag and drop onto placeholder
cameraPlaceholder.addEventListener('dragover', (e) => {
    e.preventDefault();
    cameraPlaceholder.style.borderColor = 'var(--green-primary)';
});
cameraPlaceholder.addEventListener('dragleave', (e) => {
    e.preventDefault();
    cameraPlaceholder.style.borderColor = 'var(--border-color)';
});
cameraPlaceholder.addEventListener('drop', (e) => {
    e.preventDefault();
    cameraPlaceholder.style.borderColor = 'var(--border-color)';
    const file = e.dataTransfer.files[0];
    if (file && file.type.startsWith('image/')) {
        displayPhotoAndProcess(file);
    }
});
cameraPlaceholder.addEventListener('click', () => fileInput.click());

function displayPhotoAndProcess(file) {
    const imgUrl = URL.createObjectURL(file);
    photoPreview.src = imgUrl;
    photoPreview.classList.add('visible');
    cameraPlaceholder.style.display = 'none';
    
    // Convert to base64 and send
    const reader = new FileReader();
    reader.readAsDataURL(file);
    reader.onloadend = async () => {
        let base64data = reader.result.split(',')[1];
        
        photoDescriptionBox.innerHTML = '<span class="spinner"></span> Analyzing image...';
        photoDescriptionBox.classList.add('visible');

        try {
            const result = await gradioClient.predict("/describe_image", { image_b64: base64data });
            if (result.data[0] && result.data[0].description) {
                state.visualDescription = result.data[0].description;
                photoDescriptionBox.innerHTML = `<strong>Vision findings:</strong> ${state.visualDescription}`;
                checkReadyForTriage();
            } else {
                throw new Error(result.data[0]?.error || "No description returned");
            }
        } catch (err) {
            console.error("Vision failed:", err);
            photoDescriptionBox.textContent = "Error analyzing image.";
        }
    };
}


// --- Triage Flow ---
function checkReadyForTriage() {
    if (state.symptomsText || state.visualDescription) {
        triageBtn.disabled = false;
    }
}

triageBtn.addEventListener('click', async () => {
    if (!gradioClient) return;

    triageBtn.disabled = true;
    const originalBtnHtml = triageBtn.innerHTML;
    triageBtn.innerHTML = '<span class="spinner" style="border-top-color: white;"></span> Evaluating...';

    // Show output section immediately to display loading state
    outputSection.classList.add('visible');
    triageCardContainer.innerHTML = `
        <div class="skeleton-bar"></div>
        <div class="skeleton-bar"></div>
        <div class="skeleton-bar"></div>
    `;

    try {
        const result = await gradioClient.predict("/run_triage", {
            symptoms_text: state.symptomsText,
            visual_description: state.visualDescription
        });
        
        const report = result.data[0];
        if (report.error) throw new Error(report.error);

        // Render Card
        renderTriageCard(triageCardContainer, report);

        // Build summary texts for TTS
        const hindiText = buildHindiSummary(report);
        const englishText = buildEnglishSummary(report);

        // Request audio asynchronously (don't block the UI)
        requestTTS(hindiText, "hindi");
        requestTTS(englishText, "english");

    } catch (err) {
        console.error("Triage failed:", err);
        triageCardContainer.innerHTML = `<p style="color: #D32F2F;">❌ Error generating triage report: ${err.message}</p>`;
    } finally {
        triageBtn.innerHTML = originalBtnHtml;
        triageBtn.disabled = false;
    }
});

// --- TTS & Audio Player ---
function buildHindiSummary(report) {
    let actions = (report.immediate_actions || []).join("। ");
    let referText = report.refer_to_doctor ? "डॉक्टर से संपर्क करने की सलाह दी जाती है।" : "डॉक्टर से तुरंत परामर्श की आवश्यकता नहीं है।";
    let reasonText = report.refer_reason ? \` रेफरल का कारण: \${report.refer_reason}।\` : "";
    return \`स्वास्थ्य मूल्यांकन रिपोर्ट। संभावित स्थिति: \${report.likely_condition}। गंभीरता स्तर: पांच में से \${report.severity}। आवश्यक कदम: \${actions}। \${referText}\${reasonText}\`;
}

function buildEnglishSummary(report) {
    let actions = (report.immediate_actions || []).join(". ");
    let referText = report.refer_to_doctor ? "Referral recommended." : "Consultation not immediately required.";
    let reasonText = report.refer_reason ? \` Reason: \${report.refer_reason}.\` : "";
    return \`Triage complete. Likely condition: \${report.likely_condition}. Severity: \${report.severity} out of 5. Actions: \${actions}. Doctor referral status: \${referText}\${reasonText}\`;
}

async function requestTTS(text, language) {
    try {
        const result = await gradioClient.predict("/synthesize_audio", { text, language });
        const data = result.data[0];
        
        if (data.audio_b64) {
            const dataUrl = \`data:\${data.mime_type};base64,\${data.audio_b64}\`;
            setupCustomAudioPlayer(\`audio-\${language}\`, dataUrl);
        }
    } catch (err) {
        console.error(\`\${language} TTS failed:\`, err);
    }
}

function setupCustomAudioPlayer(containerId, dataUrl) {
    const container = document.getElementById(containerId);
    if (!container) return;
    
    const audioEl = container.querySelector('audio');
    const playBtn = container.querySelector('.play-btn');
    const playIcon = playBtn.querySelector('.play-icon');
    const pauseIcon = playBtn.querySelector('.pause-icon');
    const progressFill = container.querySelector('.progress-fill');
    const progressBar = container.querySelector('.progress-bar');
    const timeDisplay = container.querySelector('.time-display');

    audioEl.src = dataUrl;

    // Play/Pause
    playBtn.onclick = () => {
        if (audioEl.paused) {
            audioEl.play();
            playIcon.style.display = 'none';
            pauseIcon.style.display = 'block';
        } else {
            audioEl.pause();
            playIcon.style.display = 'block';
            pauseIcon.style.display = 'none';
        }
    };

    // Update Progress
    audioEl.ontimeupdate = () => {
        const percent = (audioEl.currentTime / audioEl.duration) * 100;
        if (!isNaN(percent)) {
            progressFill.style.width = \`\${percent}%\`;
        }
        
        // Format time display (e.g. 0:05)
        const current = Math.floor(audioEl.currentTime);
        const mins = Math.floor(current / 60);
        const secs = current % 60;
        timeDisplay.textContent = \`\${mins}:\${secs.toString().padStart(2, '0')}\`;
    };

    // End event
    audioEl.onended = () => {
        playIcon.style.display = 'block';
        pauseIcon.style.display = 'none';
        progressFill.style.width = '0%';
        timeDisplay.textContent = '0:00';
    };

    // Click to seek
    progressBar.onclick = (e) => {
        const rect = progressBar.getBoundingClientRect();
        const pos = (e.clientX - rect.left) / rect.width;
        if (!isNaN(audioEl.duration)) {
            audioEl.currentTime = pos * audioEl.duration;
        }
    };
}

// --- Reset Flow ---
resetBtn.addEventListener('click', () => {
    state = { symptomsText: "", visualDescription: "", hindiAudioB64: "", englishAudioB64: "" };
    
    // Reset Mic UI
    transcriptContainer.classList.remove('visible');
    transcriptText.textContent = "";
    micStatus.textContent = "Tap to record";
    stopWaveform(waveformCanvas);

    // Reset Camera UI
    photoPreview.src = "";
    photoPreview.classList.remove('visible');
    cameraPreview.classList.remove('visible');
    cameraPlaceholder.style.display = 'flex';
    openCameraBtn.style.display = 'block';
    uploadPhotoBtn.style.display = 'block';
    captureBtn.style.display = 'none';
    photoDescriptionBox.classList.remove('visible');
    photoDescriptionBox.textContent = "";
    fileInput.value = "";

    // Reset Output
    triageBtn.disabled = true;
    outputSection.classList.remove('visible');
    triageCardContainer.innerHTML = "";
    
    // Stop any playing audio
    document.querySelectorAll('audio').forEach(a => {
        a.pause();
        a.src = "";
    });
    
    window.scrollTo({ top: 0, behavior: 'smooth' });
});

// Draw initial flat waveform line
document.addEventListener('DOMContentLoaded', () => {
    stopWaveform(waveformCanvas);
});