JesusValeraDev / bip39

import { toggleTheme as domainToggleTheme, getThemeToggleLabel, getAriaPressed } from '../domain/themeLogic';

export function initTheme(): void {

  const savedTheme = localStorage.getItem('theme');

  const theme = savedTheme || getOSTheme();

  setDocumentTheme(theme);

  updateThemeButtonState(theme);

  setupThemeListener(savedTheme);

}

function getOSTheme(): 'light' | 'dark' {

  if (typeof window !== 'undefined' && window.matchMedia) {

    return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';

  }

  return 'dark';

}

function setDocumentTheme(theme: string): void {

  document.documentElement.setAttribute('data-theme', theme);

}

function setupThemeListener(savedTheme: string | null): void {

  if (!savedTheme && typeof window !== 'undefined' && window.matchMedia) {

    const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)');

    mediaQuery.addEventListener('change', e => {

      if (!localStorage.getItem('theme')) {

        const newTheme = e.matches ? 'dark' : 'light';

        setDocumentTheme(newTheme);

        updateThemeButtonState(newTheme);

      }

    });

  }

}

export function toggleTheme(): void {

  const currentTheme = document.documentElement.getAttribute('data-theme');

  const newTheme = domainToggleTheme(currentTheme);

  setDocumentTheme(newTheme);

  localStorage.setItem('theme', newTheme);

  updateThemeButtonState(newTheme);

}

export function updateThemeButtonState(theme: string): void {

  const themeButton = document.getElementById('theme-toggle');

  if (themeButton) {

    themeButton.setAttribute('aria-pressed', getAriaPressed(theme));

    themeButton.setAttribute('aria-label', getThemeToggleLabel(theme));

  }

}