// Copyright (c) Meta Platforms, Inc. and affiliates.

/**
 * @file utils.ts
 * @output Utility functions for Selector
 * @position Utilities; used by Selector.tsx
 */

import type { SelectorOptionType, SelectorOptionData, SelectorDivider, SelectorSection } from "./types.js";

/**
 * Type guard: check if option is a selectable option (string or OptionData)
 */
export function isOptionData(option: SelectorOptionType): option is SelectorOptionData | string {
  if (typeof option === 'string') {
    return true;
  }
  return !('type' in option);
}

/**
 * Type guard: check if option is a divider
 */
export function isDivider(option: SelectorOptionType): option is SelectorDivider {
  return typeof option === 'object' && 'type' in option && option.type === 'divider';
}

/**
 * Type guard: check if option is a section
 */
export function isSection(option: SelectorOptionType): option is SelectorSection {
  return typeof option === 'object' && 'type' in option && option.type === 'section';
}

/**
 * Normalize string or option to consistent shape
 */
export function normalizeOption(option: string | SelectorOptionData): SelectorOptionData {
  if (typeof option === 'string') {
    return {
      value: option,
      label: option
    };
  }
  return {
    ...option,
    label: option.label ?? option.value
  };
}

/**
 * Get all selectable options (flattening sections)
 */
export function getSelectableOptions(options: SelectorOptionType[]): SelectorOptionData[] {
  const result: SelectorOptionData[] = [];
  for (const option of options) {
    if (isOptionData(option)) {
      result.push(normalizeOption(option));
    } else if (isSection(option)) {
      for (const opt of option.options) {
        result.push(normalizeOption(opt));
      }
    }
    // Skip dividers
  }
  return result;
}