/**
 * The footer's links, tested where a mistake is invisible to every other check.
 *
 * ---------------------------------------------------------------------------------------
 * WHY THIS FILE EXISTS
 * ---------------------------------------------------------------------------------------
 * The footer shipped with all three "Documentation" links pointing at `/docs/`. Three
 * labels — Getting started, Administration, Building a module — and one destination. It
 * reached production and stayed there through eleven checks and two test suites, because
 * none of them could see it:
 *
 *   - `checkLinks.mjs` resolves every internal link against the build. `/docs/` resolves.
 *     Three links to a page that exists are three valid links.
 *   - `checkSidebar.mjs` compares the docs tree to the planned tree. The footer is not the
 *     sidebar and was never in scope.
 *   - `checkA11y.mjs` checks structure. Three correctly-marked-up links are correct markup.
 *
 * The bug is not a broken link. It is a link that goes somewhere other than where its label
 * says, which is the one property nothing was asserting. So that is what this file asserts,
 * and the reason `src/data/footer.mjs` exists at all — a column list inside an `.astro`
 * component cannot be imported by a test.
 */

import { test } from 'node:test';
import assert from 'node:assert/strict';

import { footerColumns, docsEntryPoints } from '../src/data/footer.mjs';

/** A stand-in for the rendered brand; only the two Project links read it. */
const brand = {
  giteaOrg: 'https://gitea.example.com/Org',
  discordInvite: 'https://discord.gg/example',
};

const columns = footerColumns(brand);
const documentation = columns.find((c) => c.heading === 'Documentation');

test('every link in a column has its own destination', () => {
  for (const column of columns) {
    const hrefs = column.links.map((l) => l.href);
    assert.equal(
      new Set(hrefs).size,
      hrefs.length,
      `the ${column.heading} column has two links pointing at the same page: ${hrefs.join(', ')}`,
    );
  }
});

test('no two columns offer the same destination twice', () => {
  const all = columns.flatMap((c) => c.links.map((l) => l.href));
  assert.equal(new Set(all).size, all.length, `a footer destination is repeated: ${all.join(', ')}`);
});

test('each documentation link lands inside the section its label names', () => {
  // The exact failure that shipped: `/docs/` under all three labels satisfies "starts with
  // /docs/" but names no section, so the prefixes below are section prefixes, not `/docs/`.
  const expected = [
    ['Getting started', '/docs/getting-started/'],
    ['Administration', '/docs/administration/'],
    ['Building a module', '/docs/modules/'],
  ];

  for (const [label, prefix] of expected) {
    const link = documentation.links.find((l) => l.label === label);
    assert.ok(link, `the Documentation column no longer has a "${label}" link`);
    assert.ok(
      link.href.startsWith(prefix),
      `"${label}" points at ${link.href}, which is not inside ${prefix}`,
    );
  }
});

test('no documentation link is the docs home, which the header already carries', () => {
  for (const link of documentation.links) {
    assert.notEqual(
      link.href,
      '/docs/',
      `"${link.label}" points at the docs home; the header's Docs link is that page`,
    );
  }
});

test('every documentation entry point is a directory URL', () => {
  // Astro builds these as directories with an index.html; a missing trailing slash costs a
  // redirect on every click and reads as a broken path in the status bar.
  for (const [section, href] of Object.entries(docsEntryPoints)) {
    assert.ok(href.endsWith('/'), `the ${section} entry point (${href}) needs a trailing slash`);
    assert.ok(href.startsWith('/docs/'), `the ${section} entry point (${href}) is not under /docs/`);
  }
});

test('the brand supplies the two Project links rather than the code', () => {
  const project = columns.find((c) => c.heading === 'Project');
  const hrefs = project.links.map((l) => l.href);
  assert.ok(hrefs.includes(brand.giteaOrg), 'the Source link no longer reads brand.giteaOrg');
  assert.ok(hrefs.includes(brand.discordInvite), 'the Discord link no longer reads brand.discordInvite');
});