#!/usr/bin/env node
/**
 * Assert that the browser viewer actually built.
 *
 * `codegraph ui` serves dist/viewer/ as static files. If that tree is missing
 * or half-written, the CLI still starts and the browser gets a 404 — a failure
 * that would otherwise surface after the release is published. So the build
 * fails here instead: index.html must exist, be non-trivial, and every local
 * asset it references must be on disk next to it.
 *
 * It also re-asserts that the compiled engine is still there. The viewer build
 * empties its own output directory, and `dist/ui/` — the obvious name — is
 * where tsc puts the TERMINAL ui, so a mis-pointed outDir silently deletes
 * modules the CLI requires at startup.
 *
 * Usage: node scripts/check-ui-build.mjs [--root <dir>]
 *   --root  directory holding dist/ (default: the repo root). The release
 *           bundler points this at its staging dir to verify the copy.
 */
import { existsSync, readFileSync, statSync } from 'node:fs';
import { dirname, join, resolve, sep } from 'node:path';
import { fileURLToPath } from 'node:url';

const argv = process.argv.slice(2);
const rootFlag = argv.indexOf('--root');
const staged = rootFlag >= 0 && Boolean(argv[rootFlag + 1]);
const root = staged
  ? resolve(argv[rootFlag + 1])
  : resolve(dirname(fileURLToPath(import.meta.url)), '..');

const viewerDir = join(root, 'dist', 'viewer');
const indexHtml = join(viewerDir, 'index.html');

function fail(message, hint) {
  console.error(`[check-ui-build] ${message}`);
  if (hint) console.error(`[check-ui-build] ${hint}`);
  process.exit(1);
}

if (!existsSync(indexHtml)) {
  fail(
    `missing ${indexHtml}`,
    staged
      ? 'this bundle predates the UI or was assembled from a stale archive — rebuild it with scripts/build-bundle.sh'
      : 'the UI workspace did not build — run `npm run build:ui` (or `npm ci` if ui/ has no node_modules)'
  );
}

const html = readFileSync(indexHtml, 'utf8');
if (html.length < 200 || !/<div id="app">/.test(html)) {
  fail(`${indexHtml} does not look like the built viewer (${html.length} bytes)`);
}

// Every local src=/href= in the document must resolve inside dist/ui. This is
// what catches a partial write: index.html naming a hashed bundle that the
// build never emitted.
const referenced = [...html.matchAll(/\s(?:src|href)="([^"]+)"/g)].map((m) => m[1]);
const local = referenced.filter(
  (url) => !/^(?:[a-z][a-z0-9+.-]*:|\/\/)/i.test(url) && !url.startsWith('#')
);

const missing = [];
let assets = 0;
for (const url of local) {
  const rel = url.replace(/^\.\//, '').replace(/[?#].*$/, '');
  if (!rel) continue;
  const onDisk = join(viewerDir, ...rel.split('/'));
  if (!existsSync(onDisk) || !statSync(onDisk).isFile()) missing.push(rel);
  else assets += 1;
}

if (missing.length > 0) {
  fail(
    `index.html references ${missing.length} file(s) that are not in dist/viewer: ${missing.join(', ')}`,
    'the UI build was interrupted or dist/viewer was copied incompletely'
  );
}

if (assets === 0) {
  fail('index.html references no bundled assets — the UI build produced no JS/CSS');
}

// The viewer build must never have eaten the tsc output next door.
for (const compiled of [join('bin', 'codegraph.js'), 'index.js', join('ui', 'shimmer-progress.js')]) {
  if (!existsSync(join(root, 'dist', compiled))) {
    fail(
      `dist/${compiled.split(sep).join('/')} is missing — the compiled engine is incomplete`,
      "if this appeared with a UI change, check ui/vite.config.ts: build.outDir must stay dist/viewer, and emptyOutDir must never point at a directory tsc writes (dist/ui is the TERMINAL ui)"
    );
  }
}

console.log(`[check-ui-build] dist/viewer ok (index.html + ${assets} referenced asset(s)); dist/ engine intact`);