export interface UserSettings {
  // Quality preferences
  defaultQualityPreset: 'high-quality' | 'balanced' | 'small-file' | 'web-optimized';

  // Behavior preferences
  autoStartConversion: boolean;
  showConversionHistory: boolean;
  clearHistoryOnReset: boolean;

  // Default formats (optional)
  defaultVideoFormat?: string;
  defaultAudioFormat?: string;
  defaultImageFormat?: string;
}

const SETTINGS_KEY = 'convert-ui-settings';

const DEFAULT_SETTINGS: UserSettings = {
  defaultQualityPreset: 'balanced',
  autoStartConversion: false,
  showConversionHistory: true,
  clearHistoryOnReset: false,
};

/**
 * Get user settings from localStorage
 */
export function getSettings(): UserSettings {
  if (typeof window === 'undefined') return DEFAULT_SETTINGS;

  try {
    const stored = localStorage.getItem(SETTINGS_KEY);
    if (!stored) return DEFAULT_SETTINGS;

    const settings = JSON.parse(stored);
    return { ...DEFAULT_SETTINGS, ...settings };
  } catch (error) {
    console.error('Failed to load settings:', error);
    return DEFAULT_SETTINGS;
  }
}

/**
 * Save user settings to localStorage
 */
export function saveSettings(settings: Partial<UserSettings>): void {
  if (typeof window === 'undefined') return;

  try {
    const current = getSettings();
    const updated = { ...current, ...settings };
    localStorage.setItem(SETTINGS_KEY, JSON.stringify(updated));

    // Dispatch custom event for settings updates
    window.dispatchEvent(new CustomEvent('settingsUpdated', { detail: updated }));
  } catch (error) {
    console.error('Failed to save settings:', error);
  }
}

/**
 * Reset settings to defaults
 */
export function resetSettings(): void {
  if (typeof window === 'undefined') return;

  try {
    localStorage.setItem(SETTINGS_KEY, JSON.stringify(DEFAULT_SETTINGS));
    window.dispatchEvent(new CustomEvent('settingsUpdated', { detail: DEFAULT_SETTINGS }));
  } catch (error) {
    console.error('Failed to reset settings:', error);
  }
}
