let rec;
let gumStream;
let captureTimeout;

function streaming() {
    const audioContext = new(window.AudioContext || window.webkitAudioContext)({
        sampleRate: 16000,
    });
    let arr = [];

    navigator.mediaDevices.getUserMedia({
            audio: true
        })
        .then((stream) => {
            const audioSource = audioContext.createMediaStreamSource(stream);
            gumStream = stream;

            let stop = false;
            let input = audioContext.createMediaStreamSource(stream); // Added 'let' to declare 'input'

            // Create the Recorder object and configure to record mono sound (1 channel)
            // Recording 2 channels will double the file size
            rec = new Recorder(input, {
                numChannels: 1
            });

            // Start the recording process
            rec.record();

            // Start capturing audio asynchronously
            captureAndSendAudio();

        })
        .catch((error) => {
            console.error('Error accessing microphone:', error);
        });
}



function floatTo16BitPCM(output, offset, input) {
    for (var i = 0; i < input.length; i++, offset += 2) {
        var s = Math.max(-1, Math.min(1, input[i]));
        output.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true);
    }
}

function captureAndSendAudio() {
    rec.getBuffer((buffers) => {
        const float32Array = buffers[0];
        rec.clear();
        const flatArray = Array.prototype.slice.call(float32Array);

        if (flatArray.length > 0) {
            var buffer = new ArrayBuffer(float32Array.length * 2);
            var view = new DataView(buffer);
            floatTo16BitPCM(view, 0, float32Array);
            var byteArray = [];

            for (var i = 0; i < view.byteLength; i++) {
                byteArray.push(view.getUint8(i));
            }
            sendMicChunkToDart(byteArray);
        }
    });

    captureTimeout = setTimeout("captureAndSendAudio()", 200);
}

function sendMicChunkToDart(array) {
  window.parent.postMessage({
    type: 'micChunk',
    array: array
  }, '*');
}

function stopRecording() {
    clearTimeout(captureTimeout);
    try{
        rec.clear();
        rec.stop();
        gumStream.getAudioTracks()[0].stop();
    }catch(e){}
    window.parent.postMessage({
        type: 'micStop'
      }, '*');
}


function checkMicPermission(){

    // Check if the browser supports the microphone API.
    if (navigator.mediaDevices === undefined) {
      throw new Error('Browser does not support microphone API');
    }

    // Check if the user has granted permission to use the microphone.
    navigator.mediaDevices.getUserMedia({audio: true}).then((stream) => {
      // The user has granted permission.
    }).catch((error) => {
      // The user has denied permission.
    });

    var retVal = true;
    // Request permission to use the microphone.
    navigator.mediaDevices.getUserMedia({audio: true}).then((stream) => {
      // The user has granted permission.
      retVal = true;
    }).catch((error) => {
      if (error.name === 'PermissionDeniedError') {
        // The user has denied permission.
      }
      retVal = false;
    });

    return retVal;
}