/**
 * This source file is available under the terms of the
 * Pimcore Open Core License (POCL)
 * Full copyright and license information is available in
 * LICENSE.md which is distributed with this source code.
 *
 *  @copyright  Copyright (c) Pimcore GmbH (https://www.pimcore.com)
 *  @license    Pimcore Open Core License (POCL)
 */

import { createHash, type Hash } from 'node:crypto';
import fs from 'node:fs';
import path from 'node:path';

/**
 * Deterministic build id derived from a source tree (excluding installed dependencies and
 * generated output). It is a sha256 over every file's normalized relative path + content, so
 * identical source — including configs (rsbuild, tsconfig, …), fonts and the API spec —
 * yields the same id regardless of checkout location, and any change to them bumps it. Both
 * the SDK and app builds of one `build-app` run resolve the same id (used as the archive
 * filename and the grouping key).
 *
 * Shared across bundles: the source dir is passed by the caller so consumers installed via
 * npm (e.g. collab-bundle importing this via `@pimcore/studio-ui-bundle/bundler/build-id`)
 * can point it at their own assets root. If omitted, defaults to the parent of this file —
 * correct only when the script runs from within the studio-ui-bundle source repo.
 */

// Installed dependencies and generated output — not part of the source fingerprint.
const EXCLUDED_DIRS = new Set(['node_modules', 'dist']);

const cache = new Map<string, string>();

function hashTree(dir: string, base: string, hash: Hash): void {
  const entries = fs
    .readdirSync(dir, { withFileTypes: true })
    .sort((a, b) => a.name.localeCompare(b.name));

  for (const entry of entries) {
    if (entry.isDirectory()) {
      if (!EXCLUDED_DIRS.has(entry.name)) {
        hashTree(path.join(dir, entry.name), base, hash);
      }
    } else if (entry.isFile()) {
      const abs = path.join(dir, entry.name);
      // relative + normalized path keeps the id stable across checkout locations / OSes
      hash.update(path.relative(base, abs).split(path.sep).join('/'));
      hash.update(fs.readFileSync(abs));
    }
  }
}

function sourceFingerprint(sourceDir: string): string {
  const resolved = path.resolve(sourceDir);
  const cached = cache.get(resolved);
  if (cached !== undefined) {
    return cached;
  }

  const hash = createHash('sha256');
  hashTree(resolved, resolved, hash);
  const fingerprint = hash.digest('hex');
  cache.set(resolved, fingerprint);

  return fingerprint;
}

/**
 * Shared id for one build (the SDK + app pair). Used as the archive filename
 * (`build-<id>.zip`) and written into each output dir as `.build-id` so the dirs of a
 * single build can be grouped and stale builds ignored at serve time.
 *
 * @param sourceDir absolute path to the source tree to fingerprint (e.g. `assets/` in
 *   studio-ui-bundle, `assets/studio/` in collab-bundle). Defaults to the parent of this
 *   file — correct only for in-repo use, not when installed as a dependency.
 */
export function getBuildGroupId(sourceDir: string = path.resolve(__dirname, '..')): string {
  return sourceFingerprint(sourceDir).slice(0, 12);
}