text (un)quacker

/*
text to quacks encoder/decoder
version 1
by KKosty4ka

use the encodeText and decodeText functions
(or the encodeBytes and decodeBytes if you are crazy enough to encode byte arrays with this)
*/

function encodePunctuation(b5, b6, b7)
{
    var output = "";

    if (b5 && b6) output = "?";
    else if (b5 && !b6) output = "!";
    else if (!b5 && b6) output = "?!";

    if (b7) output = output.padEnd(output.length === 2 ? 4 : 3, ".");
    return output;
}

function encodeWord(b0, b1, b2, b3, b4)
{
    var output = "";

    output += b0 ? "Q" : "q";
    output += b1 ? "U" : "u";
    output += b2 ? "A" : "a";
    output += b3 ? "C" : "c";
    output += b4 ? "K" : "k";

    return output;
}

function encodeByte(byte)
{
    return encodeWord(
        byte & 0b00000001,
        byte & 0b00000010,
        byte & 0b00000100,
        byte & 0b00001000,
        byte & 0b00010000
    ) + encodePunctuation(
        byte & 0b00100000,
        byte & 0b01000000,
        byte & 0b10000000
    );
}

function encodeBytes(bytes)
{
    return [...bytes].map(encodeByte).join(" ");
}

function encodeText(text)
{
    return encodeBytes(new TextEncoder().encode(text));
}


function decodePunctuation(text)
{
    var b5 = 0;
    var b6 = 0;
    var b7 = +text.endsWith(".");

    if (text.startsWith("?!")) b6 = 1;
    else if (text.startsWith("!")) b5 = 1;
    else if (text.startsWith("?")) b5 = b6 = 1;

    return [b5, b6, b7];
}

function decodeWord(text)
{
    var output = [];

    for (var i = 0; i < 5; i++)
    {
        output.push(+(text[i] === text[i].toUpperCase()));
    }

    return output;
}

function decodeByte(text)
{
    var bits = decodeWord(text).concat(decodePunctuation(text.substring(5)));
    var output = 0;

    for (var i = 0; i < 8; i++)
    {
        output += bits[i] * (1 << i);
    }

    return output;
}

function decodeBytes(text)
{
    return new Uint8Array(text.split(" ").map(decodeByte));
}

function decodeText(text)
{
    return new TextDecoder().decode(decodeBytes(text));
}