/**
 * Linux BenchTools - Theme Manager
 * Handles dynamic theme loading and switching
 */

(function() {
  'use strict';

  const THEME_STORAGE_KEY = 'benchtools_theme';
  const DEFAULT_THEME = 'monokai-dark';

  const THEMES = {
    'monokai-dark': {
      name: 'Monokai Dark',
      file: 'css/themes/monokai-dark.css'
    },
    'monokai-light': {
      name: 'Monokai Light',
      file: 'css/themes/monokai-light.css'
    },
    'gruvbox-dark': {
      name: 'Gruvbox Dark',
      file: 'css/themes/gruvbox-dark.css'
    },
    'gruvbox-light': {
      name: 'Gruvbox Light',
      file: 'css/themes/gruvbox-light.css'
    },
    'mix-monokai-gruvbox': {
      name: 'Mix Monokai-Gruvbox',
      file: 'css/themes/mix-monokai-gruvbox.css'
    }
  };

  /**
   * Get the current theme from localStorage
   * @returns {string} Theme identifier
   */
  function getCurrentTheme() {
    return localStorage.getItem(THEME_STORAGE_KEY) || DEFAULT_THEME;
  }

  /**
   * Set the current theme in localStorage
   * @param {string} theme - Theme identifier
   */
  function setCurrentTheme(theme) {
    if (!THEMES[theme]) {
      console.warn(`Theme "${theme}" not found, using default`);
      theme = DEFAULT_THEME;
    }
    localStorage.setItem(THEME_STORAGE_KEY, theme);
  }

  /**
   * Load a theme CSS file
   * @param {string} theme - Theme identifier
   */
  function loadTheme(theme) {
    if (!THEMES[theme]) {
      console.warn(`Theme "${theme}" not found, using default`);
      theme = DEFAULT_THEME;
    }

    // Remove existing theme link if present
    const existingThemeLink = document.getElementById('theme-stylesheet');
    if (existingThemeLink) {
      existingThemeLink.remove();
    }

    // Create new theme link
    const themeLink = document.createElement('link');
    themeLink.id = 'theme-stylesheet';
    themeLink.rel = 'stylesheet';
    themeLink.href = THEMES[theme].file;

    // Insert after the last stylesheet or in the head
    const lastStylesheet = Array.from(document.head.querySelectorAll('link[rel="stylesheet"]')).pop();
    if (lastStylesheet) {
      lastStylesheet.after(themeLink);
    } else {
      document.head.appendChild(themeLink);
    }

    // Update body data attribute for theme-specific styling
    document.body.setAttribute('data-theme', theme);
  }

  /**
   * Apply theme and save preference
   * @param {string} theme - Theme identifier
   */
  function applyTheme(theme) {
    setCurrentTheme(theme);
    loadTheme(theme);

    // Dispatch custom event for theme change
    const event = new CustomEvent('themeChanged', {
      detail: { theme, themeName: THEMES[theme].name }
    });
    window.dispatchEvent(event);
  }

  /**
   * Initialize theme on page load
   */
  function initTheme() {
    const currentTheme = getCurrentTheme();
    loadTheme(currentTheme);
  }

  // Initialize theme immediately
  initTheme();

  // Export API to window
  window.ThemeManager = {
    getCurrentTheme,
    setCurrentTheme,
    loadTheme,
    applyTheme,
    themes: THEMES,
    defaultTheme: DEFAULT_THEME
  };

})();