/* eslint @typescript-eslint/no-var-requires: "off" */

"use strict";

import { ipcMain } from "electron";
import { backgroundMitt } from '@/modules/emitter';

const portAudio = require('naudiodon');

// Audio in and out stream objects.
let ai: typeof portAudio.AudioIO | boolean = false;
let ao: typeof portAudio.AudioIO | boolean = false;

// Whether activly recording.
let record = false;

const audioContainer = {
    input: '',
}

const audioOptions = {
    channelCount: 1,
    sampleFormat: 16,
    sampleRate: 16000,
    deviceId: -1,
    closeOnError: false,
}

// Toggles record to true to begin capturing chunks.
const onRecordingStart = (_event: any, _payload: any) => {
    console.log("AUDIO: Beginning audio capture.")
    record = true;
}

// Returns recorded audio to frontend and sets record to false.
const onRecordingEnd = async (_event: any, payload: any) => {
    console.log("AUDIO:Sending audio to browser.")

    return new Promise((resolve, reject) => {

        try {
            resolve(audioContainer.input);
            record = false; 
        } catch (e) {
            reject()
        }

    });
};


// Main audio function run by run.ts module.
export function initAudioIO(): void {
    console.log("AUDIO:Starting io streams.")

    if (!ai) {

        // Initialize and start input stream.
        ai = new portAudio.AudioIO({ inOptions: audioOptions });
        ai.setEncoding("hex");
        ai.start();

        // On each data chunk...
        ai.on('data', (chunk: string) => {

            // If recording, we capture the data.
            if (record) {
                console.log('AUDIO:Recording...')
                audioContainer.input += chunk;
            }

            // Else, we don't capture and also clear audioContainer.
            else {
                if (audioContainer.input.length) {
                    audioContainer.input = "";
                }
            }

        });
    }

    if (!ao) {

        // Initialize and start input stream.
        ao = new portAudio.AudioIO({ outOptions: audioOptions });
        ao.start();

    }

    // Listen to record.
    console.log("AUDIO:Adding recording listeners.")

    ipcMain.removeAllListeners("start-recording");
    ipcMain.on("start-recording", onRecordingStart);

    ipcMain.removeHandler("stop-recording");
    ipcMain.handle("stop-recording", onRecordingEnd);
}


// ---Audio playback--------------------------------------------

// Split Buffer into an array of len-sized Buffers.
function bufSplit(buf: Buffer, len: number): Array<Buffer> {
    const chunks = [];
    let i = 0;
    let L = len;

    while(i < buf.byteLength) {
      chunks.push(buf.slice(i, L));
      i = L;
      L += len;
    }

    return chunks;
}

// Audio playback.
export function play(input: string): void {

    // Format the audio.
    const audio = bufSplit(
        Buffer.from(input as string, 'hex'), 
        8192
    );

    // Called on end of write.
    const callback = () => {

        // We stop audio playback anim.
        backgroundMitt.emit('ipc-renderer', {
            endpoint: 'stop-playback-anim'
        });

    }

    write();

    // Iterate through audio array and write buffers to portAudio writable.
    function write() {
        let chunk: Buffer;
        let ok = true;
        let i = 0;

        do {
            chunk = audio[i];
            if (i === audio.length - 1) {
                // write last chunk.
                ao.write(chunk, null, callback);
            } else {
                // check for backpreassure.
                ok = ao.write(chunk, null);
            }
            i++;
        } while (i < audio.length && ok);

        if (i < audio.length) {
            // Had to stop early!
            // Write some more once it drains.
            ao.once('drain', write);
        }
    }
}

// -------------------------------------------------------------

// Get's called on window close.
export function stopStream() {
    console.log("AUDIO:Stopping audio stream.")
    if (ai) {
        ai.quit()
    }
    if (ao) {
        ao.quit()
    }
    console.log("AUDIO:Audio closed.")
}