x-ui/web/html/xui/component/themeSwitch.html

{{define "component/themeSwitchTemplate"}}
<template>
  <a-tooltip :title="themeSwitcher.isDarkTheme ? 'Dark Mode' : 'Light Mode'">
    <a-icon type="bulb"
      :theme="themeSwitcher.isDarkTheme ? 'filled' : 'outlined'"
      style="font-size: 1rem; margin-right: .5rem;"
      @click="themeSwitcher.toggleTheme()" />
  </a-tooltip>
</template>
{{end}}

{{define "component/themeSwitcher"}}
<script>
  function createThemeSwitcher() {
    const isDarkTheme = localStorage.getItem('dark-mode') === 'true';
    const theme = isDarkTheme ? 'dark' : 'light';
    return {
      isDarkTheme,
      get currentTheme() {
        return this.isDarkTheme ? 'dark' : 'light';
      },
      toggleTheme() {
        this.isDarkTheme = !this.isDarkTheme;
        localStorage.setItem('dark-mode', this.isDarkTheme);
        document.getElementById('message').className = themeSwitcher.currentTheme;
      },
    };
  }

  const themeSwitcher = createThemeSwitcher();

  Vue.component('theme-switch', {
    props: [],
    template: `{{template "component/themeSwitchTemplate"}}`,
    data: () => ({ themeSwitcher }),
    mounted() {
      this.$message.config({getContainer: () => document.getElementById('message')});
      document.getElementById('message').className = themeSwitcher.currentTheme;
    }
  });
</script>
{{end}}