#!/usr/bin/env node
/**
 * checkSidebar.mjs — PLAN.md §12, added in phase 8.
 *
 * `src/config/sidebar.mjs` holds two trees: `docsSidebar`, which Starlight renders, and
 * `plannedSidebar`, the tree §10 planned. While pages were still being written the second
 * was a checklist. Now that every page exists it is a second copy of the first, maintained
 * by hand — and a hand-maintained copy with nothing reading it is exactly the shape of
 * thing §1 is about.
 *
 * It had already drifted, silently: phase 7 added the `Content` page under D37 and this
 * list was never updated. Nothing failed, because nothing read it. That is the whole
 * argument for this check.
 *
 * So the two must agree on groups, labels AND order. Order is checked because the order of
 * "Getting started" IS the installation path — §10 calls it the priority of the whole
 * project — and a reordering that nobody noticed would be a worse defect than a missing
 * page.
 *
 *   node scripts/checkSidebar.mjs
 *
 * No token and no network: both trees are in this repository.
 */

import { docsSidebar, plannedSidebar } from '../src/config/sidebar.mjs';

const failures = [];
const fail = (what, detail) => failures.push({ what, detail });

const live = new Map(docsSidebar.map((g) => [g.label, g.items.map((i) => i.label)]));
const planned = new Map(Object.entries(plannedSidebar));

// ── Groups ──────────────────────────────────────────────────────────────────
for (const label of live.keys()) {
  if (!planned.has(label)) fail(`group ${label}`, 'is in the live sidebar and not in plannedSidebar');
}
for (const label of planned.keys()) {
  if (!live.has(label)) fail(`group ${label}`, 'is in plannedSidebar and not in the live sidebar');
}

// ── Pages, in order ─────────────────────────────────────────────────────────
for (const [label, liveItems] of live) {
  const plannedItems = planned.get(label);
  if (!plannedItems) continue;

  for (const page of liveItems) {
    if (!plannedItems.includes(page)) fail(`${label} → ${page}`, 'is live but not in plannedSidebar');
  }
  for (const page of plannedItems) {
    if (!liveItems.includes(page)) fail(`${label} → ${page}`, 'is planned but has no live sidebar entry');
  }

  // Only meaningful once membership matches; otherwise it just repeats the above.
  if (liveItems.length === plannedItems.length && liveItems.every((p) => plannedItems.includes(p))) {
    if (liveItems.join(' | ') !== plannedItems.join(' | ')) {
      fail(
        `${label} order`,
        `live "${liveItems.join(' → ')}" vs planned "${plannedItems.join(' → ')}"`,
      );
    }
  }
}

// ── Report ──────────────────────────────────────────────────────────────────
if (failures.length === 0) {
  const pages = [...live.values()].reduce((n, items) => n + items.length, 0);
  console.log(`checkSidebar: ${live.size} groups and ${pages} pages agree with plannedSidebar.`);
} else {
  console.error(`\ncheckSidebar: ${failures.length} disagreement(s) between the two trees:\n`);
  for (const f of failures) console.error(`  ✗ ${f.what}\n      ${f.detail}`);
  console.error(`
Both trees are in src/config/sidebar.mjs. Decide which one is right — if a page was
deliberately added, renamed or reordered, plannedSidebar records that decision and
should move with it.
`);
  process.exit(1);
}