/**
 * Packages `blume build` output for the assets-only Cloudflare Worker.
 *
 * Two things have to be reconciled:
 *
 * 1. `deployment.base: '/docs'` makes Blume emit URLs like `/docs/foo`, but it
 *    does NOT nest the output — pages land in `dist/foo/index.html`. The worker
 *    is asked for `/docs/foo` (the website proxies the full path through), so
 *    the build is moved under `build/docs/` to line up with the served paths.
 *
 * 2. Astro's own `redirects` are unusable under a base: it prefixes a
 *    redirect's source but not its target, emitting `url=/guides` rather than
 *    `/docs/guides`. So the redirects are written here as a Cloudflare
 *    `_redirects` file, which must sit at the root of the assets directory.
 */
import { readdirSync } from 'node:fs';
import { cp, mkdir, rm, writeFile } from 'node:fs/promises';
import { dirname, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';

const root = resolve(dirname(fileURLToPath(import.meta.url)), '..');
const dist = resolve(root, 'dist');
const out = resolve(root, 'build');
const content = resolve(root, 'content/docs');

const slugs = (dir) =>
  readdirSync(resolve(content, dir), { withFileTypes: true })
    .filter((e) => e.isFile() && e.name.endsWith('.mdx') && e.name !== 'index.mdx')
    .map((e) => e.name.replace(/\.mdx$/, ''));

// Guides moved from `/docs/<slug>` to `/docs/guides/<slug>` (Blume scopes a tab's
// sidebar by route prefix). The old URLs are public, so forward them.
const rootSlugs = new Set(slugs('.'));
const GUIDE_REDIRECTS = slugs('guides')
  // A slug that is also a root page would shadow it — `_redirects` beats assets.
  .filter((slug) => !rootSlugs.has(slug))
  .map((slug) => `/docs/${slug} /docs/guides/${slug} 301`)
  .join('\n');

const REDIRECTS = `# Generated by scripts/package-assets.mjs — do not edit.
/docs/ /docs 301
/docs/home /docs 301
/docs/how-to-guides/* /docs/:splat 301
/docs/api/reference /docs/api 301

/docs/contributor-guides /docs/guides/contributing 301
/docs/contributor-guides/* /docs/guides/contributing/:splat 301

/docs/self-hosted/configuration/sso /docs/self-hosted/enterprise 301
${GUIDE_REDIRECTS}
`;

await rm(out, { recursive: true, force: true });
await mkdir(out, { recursive: true });

await cp(dist, resolve(out, 'docs'), { recursive: true });
await writeFile(resolve(out, '_redirects'), REDIRECTS);

console.log('[docs] Packaged dist/ -> build/docs/ with _redirects');