main.js

const resultElement = document.querySelector("#result");
const lengthElement = document.querySelector("#length");
const capitalElement = document.querySelector("#capital");
const smallElement  = document.querySelector('#small'); 
const numberElement = document.querySelector('#number');
const specialElement = document.querySelector('#symbol');
const form = document.querySelector('#pg-form');
const clipBoard = document.querySelector('.clipboard');

const fieldsArray = [
    {
        field: capitalElement,
        getChar: getCapitalLetter
    },
    {
        field: smallElement,
        getChar: getSmallLetter
    },
    {
        field: numberElement,
        getChar: getNumber
    },
    {
        field: specialElement,
        getChar: getSpecialChar
    },
];


function getRandomChar(min, max) {
    const limit = max - min +1; //4 -> 2 . ascii code 
    return String.fromCharCode(Math.floor(Math.random() * limit) + min);
}

function getCapitalLetter(){
    return getRandomChar(65, 90);
}

function getSmallLetter(){
    return getRandomChar(97, 122);
}

function getNumber(){
    return getRandomChar(48, 57);
}

function getSpecialChar(){
    return getRandomChar(33, 47);
}

function getSpecialChar(){
    const specialChar = "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~'";
    return specialChar[Math.floor(Math.random() * specialChar.length)];
}

form.addEventListener('submit', (e) => {
    e.preventDefault();
    const length = lengthElement.value;
    let generatedPassword = '';
    const checkedFields  = fieldsArray.filter(({field})=> field.checked);

    for(i=0; i<length; i++){
        const index = Math.floor(Math.random() * checkedFields.length);
        const letter = checkedFields[index].getChar();
        generatedPassword += letter;
    }

    resultElement.value = generatedPassword;
});

clipBoard.addEventListener('click', async(e) => {

    const text = resultElement.value;
    if(text){
        await navigator.clipboard.writeText(text);
        alert('Copied to your clipboard');
    }
    else{
        alert('No password to copy');
    }
    
});