script.js

// Arrays for special characters, numbers, letters
var upperCasedCharacters = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z",];
var lowerCasedCharacters = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"];
var numericCharacters = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];
var specialCharacters = ['@', '%', '+', '\\', '/', "'", '!', '#', '$', '^', '?', ':', ',', ')', '(', '}', '{', ']', '[', '~', '-', '_', '.'];
var selections = []

// Function to prompt user for password options

function getPasswordOptions() {
  var length = parseInt(
    prompt("How many characters would you like your password to contain?")
  )
   if (isNaN(length) === true) {
    alert("Password length must be provided as a number");
    return;
   } 
   if (length < 8) {
    alert("Password length must be at least 8 characters");
    return;
  }
    if (length > 128) {
      alert("Password length must be less than 129 characters");
      return;
    }
  var hasSpecialCharacters = confirm("Click OK to confirm including special characters");
  var hasNumericCharacters = confirm("Click OK to confirm including numeric characters.");
  var hasLowerCasedCharacters = confirm("Click OK to confirm including lowercase characters.");
  var hasUpperCasedCharacters = confirm("Click OK to confirm including uppercase characters.");

  if (
    hasSpecialCharacters === false &&
    hasNumericCharacters === false &&
    hasLowerCasedCharacters === false &&
    hasUpperCasedCharacters === false
  ) {
    alert("Must select at least one character type");
    return;
  }

  var passwordOptions = {
    length: length, 
    hasSpecialCharacters: hasSpecialCharacters,
    hasNumericCharacters: hasNumericCharacters,
    hasLowerCasedCharacters: hasLowerCasedCharacters,
    hasUpperCasedCharacters: hasUpperCasedCharacters
  };

  return passwordOptions;
}

function getRandom(arr) {
  var randIndex = Math.floor(Math.random() * arr.length);
  var randElement = arr[randIndex];

  return randElement;
}

function generatePassword() {
  var options = getPasswordOptions();
  var result = [];
  var possibleCharacters = [];
  var guaranteedCharacters = [];

  if (options.hasSpecialCharacters) {
    possibleCharacters = possibleCharacters.concat(specialCharacters);
    guaranteedCharacters.push(getRandom(specialCharacters));
  }
  if (options.hasNumericCharacters) {
    possibleCharacters = possibleCharacters.concat(numericCharacters);
    guaranteedCharacters.push(getRandom(numericCharacters));
  }
  if (options.hasLowerCasedCharacters) {
    possibleCharacters = possibleCharacters.concat(lowerCasedCharacters);
    guaranteedCharacters.push(getRandom(lowerCasedCharacters));
  }
  if (options.hasUpperCasedCharacters) {
    possibleCharacters = possibleCharacters.concat(upperCasedCharacters);
    guaranteedCharacters.push(getRandom(upperCasedCharacters));
  }
  for (var i = 0; i < options.length; i++) {
    var possibleCharacter = getRandom(possibleCharacters);
    result.push(possibleCharacter);
  }
  for (var i = 0; i < guaranteedCharacters.length;i++) {
    result[i] = guaranteedCharacters[i];
  }
  return result.join('');
}

var generateBtn = document.querySelector('#generate');

function writePassword() {
  var password = generatePassword();
  var passwordText = document.querySelector('#password');

  passwordText.value = password;
}

generateBtn.addEventListener('click', writePassword);