<script>
  import { locale, SUPPORTED_LOCALES } from '$lib/translations';

  const isEnglish = $derived($locale === SUPPORTED_LOCALES.EN_US);

  /**
   * Switches the current locale to the opposite language (EN_US <-> PT_BR).
   * Prevents the default link behavior (e.g., page jump).
   */
  const onSwitchToOppositeLang = () => {
    $locale =
      $locale === SUPPORTED_LOCALES.EN_US
        ? SUPPORTED_LOCALES.PT_BR
        : SUPPORTED_LOCALES.EN_US;
  };
</script>

<center>
  <div class="switch">
    <input
      id="language-toggle"
      class="check-toggle check-toggle-round-flat"
      type="checkbox"
      onclick={onSwitchToOppositeLang}
      checked={isEnglish}
      onkeydown={(e) => {
        if (e.key === 'Enter' || e.key === ' ') {
          onSwitchToOppositeLang();
        }
      }}
    />
    <label for="language-toggle"></label>
    <span class="off">EN</span>
    <span class="on">PT</span>
  </div>
</center>

<style>
  .switch {
    position: relative;
    display: inline-block;
    margin: 0;
    font-weight: 700;
    z-index: 1;
  }

  .switch > span {
    position: absolute;
    top: 7px;
    pointer-events: none;
    font-weight: bold;
    font-size: 12px;
    text-transform: uppercase;
    text-shadow: 0 1px 0 rgba(0, 0, 0, 0.06);
    width: 50%;
    text-align: center;
  }

  input.check-toggle-round-flat:checked ~ .off {
    color: white !important;
  }

  input.check-toggle-round-flat:checked ~ .on {
    color: var(--color-primary) !important;
  }

  .switch > span.on {
    left: 0;
    padding-left: 2px;
    color: white;
  }

  .switch > span.off {
    right: 0;
    padding-right: 4px;
    color: var(--color-primary) !important;
  }

  .check-toggle {
    position: absolute;
    margin-left: -9999px;
    visibility: hidden;
  }
  .check-toggle + label {
    display: block;
    position: relative;
    cursor: pointer;
    outline: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
  }

  input.check-toggle-round-flat + label {
    padding: 2px;
    width: 97px;
    height: 35px;
    background-color: white;
    -webkit-border-radius: 60px;
    -moz-border-radius: 60px;
    -ms-border-radius: 60px;
    -o-border-radius: 60px;
    border-radius: 60px;
  }
  input.check-toggle-round-flat + label:before,
  input.check-toggle-round-flat + label:after {
    display: block;
    position: absolute;
    content: '';
  }

  input.check-toggle-round-flat + label:before {
    top: 2px;
    left: 2px;
    bottom: 2px;
    right: 2px;
    background-color: white;

    -moz-border-radius: 60px;
    -ms-border-radius: 60px;
    -o-border-radius: 60px;
    border-radius: 60px;
  }
  input.check-toggle-round-flat + label:after {
    top: 4px;
    left: 4px;
    bottom: 4px;
    width: 48px;
    background-color: var(--color-primary);
    -webkit-border-radius: 52px;
    -moz-border-radius: 52px;
    -ms-border-radius: 52px;
    -o-border-radius: 52px;
    border-radius: 52px;
    -webkit-transition: margin 0.2s;
    -moz-transition: margin 0.2s;
    -o-transition: margin 0.2s;
    transition: margin 0.2s;
  }

  input.check-toggle-round-flat:checked + label:after {
    margin-left: 42px;
  }
</style>
