import { BreadcrumbListSchema } from './types';

interface BreadcrumbItem {
  name: string;
  url?: string;  // Optional for last item (current page)
}

/**
 * Generate BreadcrumbList schema (JSON-LD)
 * Pure function - takes breadcrumb items, returns schema object
 * 
 * @param items - Array of breadcrumb items with name and optional URL
 * @returns BreadcrumbListSchema object
 * @example
 * const breadcrumbs = [
 *   { name: 'Home', url: 'https://example.com' },
 *   { name: 'Products', url: 'https://example.com/products' },
 *   { name: 'Product Name' }  // Current page (no URL)
 * ];
 * const schema = generateBreadcrumbSchema(breadcrumbs);
 */
export function generateBreadcrumbSchema(
  items: BreadcrumbItem[]
): BreadcrumbListSchema {
  return {
    '@context': 'https://schema.org',
    '@type': 'BreadcrumbList',
    itemListElement: items.map((item, index) => ({
      '@type': 'ListItem',
      position: index + 1,
      name: item.name,
      ...(item.url && { item: item.url }),  // Only include item if URL exists
    })),
  };
}

/**
 * Generate standard breadcrumbs for product pages
 * 
 * @param baseUrl - Site base URL
 * @param locale - Locale code
 * @param productName - Product name
 * @param productSlug - Product slug
 * @returns BreadcrumbListSchema object
 */
export function generateProductBreadcrumbs(
  baseUrl: string,
  locale: string,
  productName: string,
  productSlug: string
): BreadcrumbListSchema {
  const localePrefix = locale === 'sr' ? '' : `/${locale}`;
  
  const items: BreadcrumbItem[] = [
    { name: 'Home', url: `${baseUrl}${localePrefix || '/'}` },
    { name: 'Products', url: `${baseUrl}${localePrefix}/products` },
    { name: productName },  // Current page
  ];

  return generateBreadcrumbSchema(items);
}

/**
 * Generate breadcrumbs for static pages
 * 
 * @param baseUrl - Site base URL
 * @param locale - Locale code
 * @param pageName - Current page name
 * @returns BreadcrumbListSchema object
 */
export function generatePageBreadcrumbs(
  baseUrl: string,
  locale: string,
  pageName: string
): BreadcrumbListSchema {
  const localePrefix = locale === 'sr' ? '' : `/${locale}`;
  
  const items: BreadcrumbItem[] = [
    { name: 'Home', url: `${baseUrl}${localePrefix || '/'}` },
    { name: pageName },  // Current page
  ];

  return generateBreadcrumbSchema(items);
}