app.js

var entrada = document.querySelector('#entrada');
var botonEncriptar = document.querySelector('#encriptar');
var botonDesencriptar = document.querySelector('#desencriptar');
var barra = document.querySelector('.barra-lateral');
var clipboard = document.querySelector('.copiar');
var copyText = document.querySelector('.copy-text');
var salida
var conta = 0;
entrada.focus();

function toggleDarkLight() {
    var element = document.body;
    var element1 = document.querySelector('.foot');
    element.classList.toggle("dark-mode");
    conta++;
    if(conta === 2){
        conta = 0;
    } else{
        conta = 1;
    }
    conta === 1 ? element1.classList.add("dark-mode") : element1.classList.remove("dark-mode");   
}

function laSalida() {
    const elem = document.querySelector('#salida');
    const hijo = document.createTextNode('');

    elem.innerHTML = ''
    elem.appendChild(hijo);
    salida = hijo;
}

laSalida();

function codificador(item){
    switch(item) {
        case 'a': return 'ai'
        case 'e': return 'enter'
        case 'i': return 'imes'
        case 'o': return 'ober'
        case 'u': return 'ufat'
        default: return item
    }
}

function iteraCode(txt){
    txt = entrada.value.toLowerCase();
    var t = '';
    for(var i = 0; i < txt.length; i++) {
        t += codificador(txt[i]);
    }
    return t;
}

function iteraDeCode(txt){
    txt = entrada.value.toLowerCase();
    return txt.replace(/ai|enter|imes|ober|ufat/gi, function(matched){
        switch(matched) {
            case 'ai': return 'a'
            case 'enter': return 'e'
            case 'imes': return 'i'
            case 'ober': return 'o'
            case 'ufat': return 'u'
            case ' ': return ''
            default: return matched
        }
    });
}

botonEncriptar.addEventListener('click', function() {
    var txt = entrada.value;
    if(txt.length === 0) {
        salida.nodeValue = ''
        ocultarRes();
    } else {
        salida.nodeValue = iteraCode(txt).toLowerCase();
        mostrarRes();
    }
});

function mostrarRes(){
    barra.classList.add('con-salida');
}

function ocultarRes(){
    barra.classList.remove('con-salida');
}

botonDesencriptar.addEventListener('click', function() {
    var valor = entrada.value;
    if(valor.length === 0) {
        salida.nodeValue= ''
        ocultarRes();
    } else {
        salida.nodeValue = iteraDeCode(valor);
        mostrarRes();
    }
    
}); 

entrada.addEventListener('input', function() {
    var valor = entrada.value;
    if(valor.length === 0) {
        salida.nodeValue= ''
        ocultarRes();
    }

});

var clip = navigator.clipboard;

clipboard.addEventListener('click', function(){
    var input = salida.nodeValue;
    if(clip){
        clip.writeText(input);
        copyText.classList.add('active');
        setTimeout(function(){
            copyText.classList.remove('active');
        }, 2000);
    }
})