app.js

//Selectors
const todoInput = document.querySelector(".todo-input");
const todoButton = document.querySelector(".todo-button");
const todoList = document.querySelector(".todo-list");
const filterOption = document.querySelector(".filter-todo");

//Event Listeners
document.addEventListener("DOMContentLoaded", getTodos);
todoButton.addEventListener("click", addTodo);
todoList.addEventListener("click", deleteCheck);
filterOption.addEventListener("click", filterTodo);

//Functions
function addTodo(event) {
  //prevent button from reseting the page
  event.preventDefault();
  //if statement to avoid adding empty tasks
  if (todoInput.value.length != 0) {
    //Todo div
    const todoDiv = document.createElement("div");
    todoDiv.classList.add("todo");

    //Create Li
    const newTodo = document.createElement("li");
    newTodo.innerText = todoInput.value;
    newTodo.classList.add("todo-item");
    //place the li inside the div
    todoDiv.appendChild(newTodo);

    // Add todo to local storage
    saveLocalTodos(todoInput.value);

    //Check mark button
    const completedButton = document.createElement("button");
    completedButton.innerHTML = "<i class='fas fa-check'></i>";
    completedButton.classList.add("complete-btn");
    //place the button inside the div
    todoDiv.appendChild(completedButton);

    //trash button
    const trashButton = document.createElement("button");
    trashButton.innerHTML = "<i class='fas fa-trash'></i>";
    trashButton.classList.add("trash-btn");
    //place the button inside the div
    todoDiv.appendChild(trashButton);

    //append the entire div to the list
    todoList.appendChild(todoDiv);

    //reset and delete todo input after submiting
    todoInput.value = "";
  } else {
    alert("Please define your task before adding it to your list.");
  }
}

function deleteCheck(event) {
  const item = event.target;
  if (item.classList[0] === "trash-btn") {
    const deleteItem = item.parentElement;
    deleteItem.classList.add("fall");
    removeLocalTodos(deleteItem);
    deleteItem.addEventListener("transitionend", function () {
      deleteItem.remove();
    });
  }
  if (item.classList[0] === "complete-btn") {
    const completedItem = item.parentElement;
    completedItem.classList.toggle("completed");
  }
}

function filterTodo(event) {
  const todos = todoList.childNodes;
  todos.forEach(function (todo) {
    switch (event.target.value) {
      case "all":
        todo.style.display = "flex";
        break;
      case "done":
        if (todo.classList.contains("completed")) {
          todo.style.display = "flex";
        } else {
          todo.style.display = "none";
        }
        break;
      case "uncompleted":
        if (!todo.classList.contains("completed")) {
          todo.style.display = "flex";
        } else {
          todo.style.display = "none";
        }
        break;
    }
  });
}

function saveLocalTodos(todo) {
  //check if there is any data
  let todos;
  if (localStorage.getItem("todos") === null) {
    todos = [];
  } else {
    todos = JSON.parse(localStorage.getItem("todos"));
  }

  todos.push(todo);
  localStorage.setItem("todos", JSON.stringify(todos));
}

function getTodos() {
  let todos;
  if (localStorage.getItem("todos") === null) {
    todos = [];
  } else {
    todos = JSON.parse(localStorage.getItem("todos"));
  }
  todos.forEach(function (todo) {
    //Todo div
    const todoDiv = document.createElement("div");
    todoDiv.classList.add("todo");

    //Create Li
    const newTodo = document.createElement("li");
    newTodo.innerText = todo;
    newTodo.classList.add("todo-item");
    //place the li inside the div
    todoDiv.appendChild(newTodo);

    //Check mark button
    const completedButton = document.createElement("button");
    completedButton.innerHTML = "<i class='fas fa-check'></i>";
    completedButton.classList.add("complete-btn");
    //place the button inside the div
    todoDiv.appendChild(completedButton);

    //trash button
    const trashButton = document.createElement("button");
    trashButton.innerHTML = "<i class='fas fa-trash'></i>";
    trashButton.classList.add("trash-btn");
    //place the button inside the div
    todoDiv.appendChild(trashButton);

    //append the entire div to the list
    todoList.appendChild(todoDiv);
  });
}

function removeLocalTodos(todo) {
  //check if there is any data
  let todos;
  if (localStorage.getItem("todos") === null) {
    todos = [];
  } else {
    todos = JSON.parse(localStorage.getItem("todos"));
  }
  // const todoIndex =
  const todoIndex = todo.children[0].innerText;
  todos.splice(todos.indexOf(todoIndex), 1);
  localStorage.setItem("todos", JSON.stringify(todos));
}