static/js/ws.js

const messageHistory = document.getElementById('chatHistory')
let stream;
let ws
let silenceDetectorNode;
let silenceCount = 0
let recording = false;
let mediaRecorder;
let continuousRecorder
let audioContext;
let source;
let currentAudioChunks = [];
let allAudioChunks = [];
const uuid = generateUUID()
const startRecordingButton = document.getElementById('startRecording')
const loadingModal = document.getElementById('loadingModal');
function makeLoading() {
    loadingModal.style.visibility = 'visible';
}

function stopLoading() {
    loadingModal.style.visibility = 'hidden';
}

function showMessage(message_text) {
    const message = document.getElementById('message');
    message.innerText = message_text
    message.style.display = 'block';

    setTimeout(function () {
        message.style.display = 'none';
    }, 2000);
}

function createMessage(type, message) {
    const newMessage = document.createElement('div')
    newMessage.className = 'message rounded-4 bg-white mb-4 mx-4 py-2 px-3 border'
    newMessage.innerHTML = `
    <h5>${type}</h5>
    ${message}
    `
    messageHistory.appendChild(newMessage)
}
function playResponse(data) {
    const response = JSON.parse(data)
    createMessage('User', response['user_query'])
    stopLoading()
    console.log(response)
    const audioSrc = `data:audio/mp3;base64,${response['voice_response']}`;
    const audio = new Audio(audioSrc)
    audio.play()
    audio.onended = () => {
        recording = true
        createMessage('Liza', response['ai_response'])
        showMessage('You can speak!')
        startMediaRecorder()
    }
}

startRecordingButton.addEventListener('click', async () => {
    if (!recording) {
        if (mediaRecorder && mediaRecorder.state !== 'inactive') {
            mediaRecorder.stop();
        }
        stream = await navigator.mediaDevices.getUserMedia({audio: true, video: false});
        mediaRecorder = new MediaRecorder(stream);
        ws = new WebSocket(`ws://localhost:8000/ws/${uuid}`);
        ws.onclose = (event) => {
            if (mediaRecorder && mediaRecorder.state !== 'inactive') {
                mediaRecorder.stop();
            }
        }
        ws.onerror = (error) => {
            alert('Something was wrong. Try again later.')
            console.log(error)
            window.location.reload()
        };
        ws.onmessage = (event) => {
            const response = event.data
            playResponse(response)
        }

        startRecordingButton.innerHTML = 'Stop call';
        try {
            audioContext = new AudioContext();
            await audioContext.audioWorklet.addModule('../../../static/js/audio-processor.js');
            silenceDetectorNode = new AudioWorkletNode(audioContext, 'silence-detector-processor');
            silenceDetectorNode.port.onmessage = (event) => {
                if (event.data.type === 'silence') {
                    if (currentAudioChunks.length > 0) {
                        if (silenceCount === 0) {
                            silenceCount += 1;
                            stopRecorder();
                        }
                    }
                } else if (event.data.type === 'sound') {
                    silenceCount = 0;
                }
            };
            source = audioContext.createMediaStreamSource(stream);
            mediaRecorder.start(1000);
            mediaRecorder.ondataavailable = event => {
                currentAudioChunks.push(event.data);
            };
            source.connect(silenceDetectorNode).connect(audioContext.destination);
            continuousRecorder = new MediaRecorder(stream);
            continuousRecorder.start();
            continuousRecorder.ondataavailable = event => {
                allAudioChunks.push(event.data);
            };
            recording = true;
        } catch (error) {
            console.error('Access to microphone denied:', error);
        }
    } else {
        await stopRecording();
    }
});

async function stopRecording() {
    // startRecordingButton.innerHTML = 'Start recording';
    // recording = false;
    // mediaRecorder.stop();
    // continuousRecorder.stop();
    // silenceDetectorNode.disconnect();
    // source.disconnect();
    // audioContext.close();
    // currentAudioChunks = [];
    window.location.reload()
}

function sendAudioToServer(audioBlob) {
    return new Promise((resolve, reject) => {
        console.log("Sending audio to server...", audioBlob);
        const reader = new FileReader();
        reader.readAsDataURL(audioBlob);
        reader.onloadend = () => {
            let base64String = reader.result;
            base64String = base64String.split(',')[1];
            const dataWS = {'audio': base64String};
            ws.send(JSON.stringify(dataWS));
            makeLoading()
            resolve();
        };
        reader.onerror = reject;
    });
}


async function stopRecorder() {
    if (mediaRecorder && mediaRecorder.state !== 'inactive') {
        mediaRecorder.stop();
    }
    await sendAudioToServer(new Blob(currentAudioChunks, {type: 'audio/wav'}));
    currentAudioChunks = [];
}

async function startMediaRecorder() {
    mediaRecorder = new MediaRecorder(stream);
    mediaRecorder.start(1000);
    mediaRecorder.ondataavailable = event => {
        currentAudioChunks.push(event.data);
    }
}

function generateUUID() {
    const arr = new Uint8Array(16)
    window.crypto.getRandomValues(arr)

    arr[6] = (arr[6] & 0x0f) | 0x40
    arr[8] = (arr[8] & 0x3f) | 0x80

    return ([...arr].map((b, i) =>
        (i === 4 || i === 6 || i === 8 || i === 10 ? "-" : "") + b.toString(16).padStart(2, "0")
    ).join(""))
}