<header>
  <svg width="20" height="20" viewBox="0 0 240 260" class="svg-check site-logo">
    <polyline class="cls-1" points="16 149 72 225 225 16" pathLength="1" />
  </svg>
  <h1>TODOs</h1>
</header>

<form id="todo-form" class="todo-form">
  <label>
    <span class="screen-reader-text">New TODO</span>
    <input type="text" name="todo">
  </label>
  <button id="button-add-todo" class="button-add-todo">
    <svg viewBox="-20 -20 240 240" class="svg-plus">
      <g>
        <line x1="100" x2="100" y2="200" />
        <line y1="100" x2="200" y2="100" />
      </g>
    </svg>
  </button>
</form>

<ol id="todo-list" class="todo-list"></ol>

* {
  box-sizing: border-box;
}
html {
  --gray800: oklch(10% 0% 0);
  --gray600: oklch(40% 0% 0);
  --gray100: oklch(92% 0% 0);
  --brand: oklch(85% 0.3 145);

  font-family: system-ui, sans-serif;
  background: var(--gray100);
}
body {
  margin: 0;
}

header {
  background: var(--gray800);
  color: white;
  padding: 1rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  h1 {
    margin: 0;
    font-variation-settings: "wght" 900, "wdth" 700;
  }
  .svg-check {
    width: 2lh;
    height: 2lh;
    stroke: var(--brand);
  }
}
.svg-check,
.svg-plus {
  fill: none;
  stroke-width: 30;
  stroke-linecap: round;
  stroke-linejoin: round;
  display: block;
  pointer-events: none;
}

.todo-form {
  background: var(--gray600);
  justify-content: center;
  padding: 1rem;
  display: flex;
  gap: 0.5rem;
  align-items: stretch;
  label {
    flex: 1 0;
    max-width: 40ch;
  }
  input {
    background: var(--gray100);
    width: 100%;
    border: 0;
    padding: 0.5rem;
    box-shadow: inset 1px 1px 2px oklch(0% 0% 0 / 0.6);
    border-radius: 5px;
    font: inherit;
    font-size: 2rem;
    &:focus {
      background: white;
    }
  }
  .svg-plus {
    stroke: black;
    width: 66%;
  }
}

.button-add-todo {
  border: 0;
  border-radius: 5px;
  font: inherit;
  font-size: 2rem;
  font-weight: 900;
  background: var(--brand);
  aspect-ratio: 1;
  height: 3.35rem;
  display: inline-grid;
  place-items: center;
  line-height: 0;

  &.shake {
    rotate: 0deg;
    transform-origin: bottom right;
    animation: shake 0.4s cubic-bezier(0.36, 0.07, 0.19, 0.97) both;
  }
  &.added {
    transform-origin: center center;
    animation: added 0.4s cubic-bezier(0.36, 0.07, 0.19, 0.97) both;
  }
}
@keyframes shake {
  50% {
    rotate: -12deg;
  }
}
@keyframes added {
  50% {
    rotate: 1turn;
    translate: 0 50px;
  }
}

.todo-list {
  padding: 1rem;
  list-style: none;
  li {
    background: white;
    box-shadow: 1px 1px 2px oklch(0% 0% 0 / 0.2);
    padding: 0.5rem;
    margin-block-end: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    .button-complete {
      order: -1;
    }
    .svg-check {
      stroke: black;
      position: absolute;
      width: 2rem;
      height: 2rem;
      top: -0.5rem;
      left: 0.1rem;
      opacity: 0;
    }
    &.complete {
      .svg-check {
        opacity: 1;
        stroke-dasharray: 1;
        stroke-dashoffset: 1;
        /* https://css-tricks.com/a-trick-that-makes-drawing-svg-lines-way-easier/ */
        animation: do-check 1s infinite alternate;
      }
    }
  }
}

@keyframes do-check {
  from {
    stroke-dashoffset: 1;
  }
  to {
    stroke-dashoffset: 0;
  }
}

.button-complete {
  border: 0;
  background: var(--gray100);
  box-shadow: inset 1px 1px 2px oklch(0% 0% 0 / 0.2);
  padding: 0.25rem;
  width: 1.5rem;
  height: 1.5rem;
  position: relative;
}

.screen-reader-text {
  text-indent: -9999em;
  width: 0;
  height: 0;
  display: block;
}

const form = document.querySelector("#todo-form");
const list = document.querySelector("#todo-list");
const buttonAddTodo = document.querySelector("#button-add-todo");

// Get Data
let TODOs = [];
if (localStorage["data"] !== null && localStorage["data"] !== undefined) {
  TODOs = JSON.parse(localStorage["data"]);
}

function buildUI() {
  let HTML = ``;
  TODOs.forEach((todo) => {
    HTML += `<li id="${todo.id}" style="view-transition-name: list-item-${todo.id};">
      ${todo.title}
      <button aria-label="Complete" class="button-complete">
        <svg width="20" height="20" viewBox="0 0 241.44 259.83" class="svg-check">
          <polyline points="16.17 148.63 72.17 225.63 225.17 11.63" pathLength="1" />
        </svg>
      </button>
    </li>`;
  });
  list.innerHTML = HTML;
}

form.addEventListener("submit", (event) => {
  event.preventDefault();
  // Don't allow empty todo
  if (!form[0].value) {
    buttonAddTodo.classList.add("shake");
    return;
  }
  addTodo(event);
  form.reset();
});

buttonAddTodo.addEventListener("animationend", () => {
  buttonAddTodo.classList.remove("shake", "added");
});

function addTodo() {
  TODOs.push({
    title: form[0].value,
    complete: false,
    id: self.crypto.randomUUID()
  });
  localStorage["data"] = JSON.stringify(TODOs);
  buttonAddTodo.classList.add("added");
  buildUI();
}

document.documentElement.addEventListener("click", (event) => {
  if (event.target.classList.contains("button-complete")) {
    removeTodo(event);
  }
});

function removeTodo(event) {
  const listItem = event.target.parentElement;
  // Trigger complete animation
  listItem.classList.toggle("complete");
  setTimeout(() => {
    TODOs = TODOs.filter((todo) => todo.id !== event.target.parentElement.id);
    localStorage["data"] = JSON.stringify(TODOs);
    if (!document.startViewTransition) {
      buildUI();
    } else {
      document.startViewTransition(() => {
        buildUI();
      });
    }
  }, 1000);
}

buildUI();