import { describe, it, expect } from 'vitest';
import fs from 'fs';
import path from 'path';
import matter from 'gray-matter';
import { getAllProducts } from '../lib/products';

const productsDir = path.join(process.cwd(), 'content', 'products');
const productFiles = fs.readdirSync(productsDir).filter((f) => f.endsWith('.mdx'));

interface CatalogEntry {
  slug: string;
  parseable: boolean;
  error?: string;
  declaresImages: boolean;
}

// Single parse pass at module load, mirroring the production loader's first
// touch of each file (gray-matter caches per input string, so re-parsing the
// same file inside individual tests would not re-throw parse errors).
const catalog: CatalogEntry[] = productFiles.map((file) => {
  const raw = fs.readFileSync(path.join(productsDir, file), 'utf-8');
  try {
    const { data } = matter(raw);
    return {
      slug: file.replace('.mdx', ''),
      parseable: true,
      declaresImages: Array.isArray(data.images) && data.images.length > 0,
    };
  } catch (error) {
    return {
      slug: file.replace('.mdx', ''),
      parseable: false,
      error: `${file}: ${(error as Error).message.split('\n')[0]}`,
      // An unparseable file cannot declare anything and must never silently
      // shrink the expected catalog — require it to be listed.
      declaresImages: true,
    };
  }
});

const ALUMINIUM_LOW_VOLTAGE_SLUGS = ['nayy', 'naycwy', 'nay2y', 'na2xy', 'na2x2y'];

describe('Product catalog content contract', () => {
  it('every product file has parseable frontmatter', () => {
    expect(catalog.filter((entry) => !entry.parseable).map((e) => e.error)).toEqual([]);
  });

  it('exposes every product that declares images in the catalog listing', async () => {
    const expected = catalog
      .filter((entry) => entry.declaresImages)
      .map((e) => e.slug)
      .sort();
    const actual = (await getAllProducts('de')).map((p) => p.slug).sort();
    expect(actual).toEqual(expected);
  });

  it('lists all aluminium low-voltage cable types (NAYY, NAYCWY, NAY2Y, NA2XY, NA2X2Y)', async () => {
    const slugs = (await getAllProducts('de')).map((p) => p.slug);
    for (const slug of ALUMINIUM_LOW_VOLTAGE_SLUGS) {
      expect(slugs).toContain(slug);
    }
  });

  it('categorizes the aluminium low-voltage types as Niederspannungskabel', async () => {
    const products = await getAllProducts('de');
    for (const slug of ALUMINIUM_LOW_VOLTAGE_SLUGS) {
      const product = products.find((p) => p.slug === slug);
      expect(product?.frontmatter.categories[0]).toBe('Niederspannungskabel');
    }
  });
});