script.js

let pc, dc, localStream;
let gestureDB = [];
let lastSpoken = "";
let micEnabled = true;
let camEnabled = true;
let isSender = false; 

let predictionBuffer = [];
const BUFFER_SIZE = 15; 
const CONFIDENCE_THRESHOLD = 0.75; 

const sigArea = document.getElementById("sigData");
const myLabel = document.getElementById("myLabel");
const partnerLabel = document.getElementById("partnerLabel");
const localVideo = document.getElementById("localVideo");
fetch("dataset.csv")
  .then(r => r.text())
  .then(data => {
    const rows = data.trim().split("\n");
    rows.shift(); 
    gestureDB = rows.map(r => {
      const parts = r.split(",");
      if (parts.length < 63) return null;
      return { label: parts[0], landmarks: parts.slice(1).map(Number) };
    }).filter(x => x !== null);
    console.log("Database Ready. Samples:", gestureDB.length);
  });

function calculateDistance(a, b) {
  let sum = 0;
  for (let i = 0; i < a.length; i++) sum += (a[i] - b[i]) ** 2;
  return Math.sqrt(sum);
}

function classify(input) {
  if (!gestureDB.length) return "...";
  let bestDist = Infinity;
  let bestLabel = "Unknown";
  for (const sample of gestureDB) {
    const d = calculateDistance(input, sample.landmarks);
    if (d < bestDist) { bestDist = d; bestLabel = sample.label; }
  }
  return bestLabel;
}


function getSmoothedLabel(newLabel) {
  predictionBuffer.push(newLabel);
  if (predictionBuffer.length > BUFFER_SIZE) predictionBuffer.shift();
  if (predictionBuffer.length < BUFFER_SIZE) return null;

  const counts = {};
  predictionBuffer.forEach(l => counts[l] = (counts[l] || 0) + 1);

  let maxCount = 0;
  let winner = "";
  for (const label in counts) {
    if (counts[label] > maxCount) {
      maxCount = counts[label];
      winner = label;
    }
  }
  return (maxCount / BUFFER_SIZE >= CONFIDENCE_THRESHOLD) ? winner : null;
}
function speak(text) {
  if (isSender) return; 
  if (!text || text === lastSpoken || text === "Unknown" || text === "...") return;
  
  const utterance = new SpeechSynthesisUtterance(text);
  utterance.rate = 1.0;
  window.speechSynthesis.speak(utterance);
  lastSpoken = text;
}
function toggleMic() {
  if (!localStream) return;
  micEnabled = !micEnabled;
  localStream.getAudioTracks().forEach(track => track.enabled = micEnabled);
  
  const btn = document.getElementById("micBtn");
  btn.innerText = micEnabled ? "🎤" : "🔇";
  btn.classList.toggle("off", !micEnabled);
}

function toggleCam() {
  if (!localStream) return;
  camEnabled = !camEnabled;
  localStream.getVideoTracks().forEach(track => track.enabled = camEnabled);
  localVideo.style.opacity = camEnabled ? "1" : "0";
  document.getElementById("localCard").style.background = camEnabled ? "#000" : "#3c4043";

  
  const btn = document.getElementById("camBtn");
  btn.innerText = camEnabled ? "📹" : "🚫";
  btn.classList.toggle("off", !camEnabled);
}


const hands = new Hands({ locateFile: file => `assets/${file}` });
hands.setOptions({ maxNumHands: 1, modelComplexity: 0, minDetectionConfidence: 0.7 });

hands.onResults(results => {
  
  if (!isSender || !camEnabled) return;

  if (results.multiHandLandmarks?.length) {
    const wrist = results.multiHandLandmarks[0][0];
    const flattened = results.multiHandLandmarks[0].flatMap(p => [
      p.x - wrist.x, p.y - wrist.y, p.z - wrist.z
    ]);
    
    const raw = classify(flattened);
    const smoothed = getSmoothedLabel(raw);

    if (smoothed && smoothed !== "Unknown") {
      myLabel.innerText = smoothed;
      if (dc?.readyState === "open" && smoothed !== lastSpoken) {
        dc.send(smoothed);
        lastSpoken = smoothed; 
      }
    }
  } else {
    myLabel.innerText = "...";
    predictionBuffer = [];
  }
});

const config = { iceServers: [{ urls: "stun:stun.l.google.com:19302" }] };

async function initialize() {
  try {
    localStream = await navigator.mediaDevices.getUserMedia({ video: true, audio: true });
    localVideo.srcObject = localStream;

    const camera = new Camera(localVideo, {
      onFrame: async () => {
        if (camEnabled && isSender) await hands.send({ image: localVideo });
      },
      width: 640, height: 360
    });
    camera.start();
  } catch (err) {
    alert("Camera Blocked! Use chrome://flags for non-localhost connections.");
  }
}

function setupDataChannel() {
  dc.onopen = () => console.log("Connection Established");
  dc.onmessage = e => {
    partnerLabel.innerText = e.data;
    speak(e.data); 
  };
}

async function createPeer() {
  pc = new RTCPeerConnection(config);
  pc.ontrack = e => { document.getElementById("remoteVideo").srcObject = e.streams[0]; };
  localStream.getTracks().forEach(t => pc.addTrack(t, localStream));
  pc.onicecandidate = e => {
    sigArea.value = JSON.stringify(pc.localDescription);
  };
}

async function createOffer() {
  isSender = true; 
  await createPeer();
  dc = pc.createDataChannel("gestures");
  setupDataChannel();
  
  const offer = await pc.createOffer();
  await pc.setLocalDescription(offer);
  sigArea.value = JSON.stringify(pc.localDescription);
}

async function createAnswer() {
  isSender = false;
  await createPeer();
  pc.ondatachannel = e => { dc = e.channel; setupDataChannel(); };
  
  await pc.setRemoteDescription(JSON.parse(sigArea.value));
  const answer = await pc.createAnswer();
  await pc.setLocalDescription(answer);
  sigArea.value = JSON.stringify(pc.localDescription);
}

async function setAnswer() {
  await pc.setRemoteDescription(JSON.parse(sigArea.value));
  closeSignal();
}

function openSignal() { document.getElementById("signalModal").style.display = "block"; }
function closeSignal() { document.getElementById("signalModal").style.display = "none"; }

initialize();