import { afterEach, beforeEach, describe, expect, test } from 'bun:test';
import { execSync } from 'node:child_process';
import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';

import {
  buildPackument,
  computeIntegrity,
  highestVersion,
  indexTarballs,
  loadTarball,
  loadTarballsFromDir,
  readPackageJsonFromTarball,
} from './packument';

let tmp: string;

beforeEach(() => {
  tmp = mkdtempSync(join(tmpdir(), 'npm-sim-test-'));
});

afterEach(() => {
  rmSync(tmp, { recursive: true, force: true });
});

function packFixture(name: string, version: string): string {
  const slug = `${name.replace(/[@/]/g, '_')}-${version}`;
  const pkgDir = join(tmp, 'pkg', slug);
  mkdirSync(pkgDir, { recursive: true });
  writeFileSync(join(pkgDir, 'package.json'), JSON.stringify({ name, version, main: 'index.js' }));
  writeFileSync(join(pkgDir, 'index.js'), `module.exports = '${name}@${version}';\n`);

  const stagingDir = join(tmp, 'staging', slug);
  mkdirSync(stagingDir, { recursive: true });
  execSync(`bun pm pack --destination=${stagingDir}`, { cwd: pkgDir, stdio: 'pipe' });

  const filename = execSync(`ls ${stagingDir}`, { encoding: 'utf-8' })
    .split('\n')
    .find((f) => f.endsWith('.tgz'));
  if (!filename) throw new Error(`bun pm pack produced no tarball in ${stagingDir}`);
  return join(stagingDir, filename);
}

describe('packument', () => {
  test('readPackageJsonFromTarball extracts the package.json', () => {
    const tgz = packFixture('@testorg/foo', '1.2.3');
    const { pkg } = readPackageJsonFromTarball(tgz);
    expect(pkg.name).toBe('@testorg/foo');
    expect(pkg.version).toBe('1.2.3');
  });

  test('computeIntegrity yields stable sha1 + sha512', () => {
    const buf = Buffer.from('hello');
    const a = computeIntegrity(buf);
    const b = computeIntegrity(buf);
    expect(a).toEqual(b);
    expect(a.shasum).toMatch(/^[0-9a-f]{40}$/);
    expect(a.integrity).toMatch(/^sha512-/);
  });

  test('highestVersion picks the largest semver-ish version', () => {
    expect(highestVersion(['1.0.0', '1.10.0', '1.2.0'])).toBe('1.10.0');
    expect(highestVersion(['0.7.7'])).toBe('0.7.7');
  });

  test('loadTarball populates path, filename, integrity, pkg', () => {
    const tgz = packFixture('@testorg/foo', '1.2.3');
    const filename = tgz.split('/').pop() as string;
    const meta = loadTarball(tgz, filename);
    expect(meta.pkg.name).toBe('@testorg/foo');
    expect(meta.filename).toBe(filename);
    expect(meta.integrity).toMatch(/^sha512-/);
  });

  test('loadTarballsFromDir + indexTarballs groups by name', () => {
    const tgz1 = packFixture('@testorg/foo', '1.0.0');
    const tgz2 = packFixture('@testorg/foo', '2.0.0');

    const dir = join(tmp, 'all');
    mkdirSync(dir);
    execSync(`cp ${tgz1} ${tgz2} ${dir}/`);

    const tarballs = loadTarballsFromDir(dir);
    expect(tarballs).toHaveLength(2);

    const byName = indexTarballs(tarballs);
    expect(byName.get('@testorg/foo')).toHaveLength(2);
  });

  test('buildPackument emits dist-tags.latest and full version map', () => {
    const tgz = packFixture('@testorg/foo', '1.2.3');
    const filename = tgz.split('/').pop() as string;
    const meta = loadTarball(tgz, filename);

    const packument = buildPackument('@testorg/foo', [meta], {
      registryUrl: 'http://npm-registry.lab',
    }) as {
      name: string;
      'dist-tags': { latest: string; alpha: string };
      versions: Record<string, { dist: { tarball: string; integrity: string } }>;
    };

    expect(packument.name).toBe('@testorg/foo');
    expect(packument['dist-tags'].latest).toBe('1.2.3');
    // alpha resolves to the same single build so `@pkg@alpha` installs work in
    // the install-sh / bootstrap-apt e2e tests (the install paths track @alpha).
    expect(packument['dist-tags'].alpha).toBe('1.2.3');
    expect(packument.versions['1.2.3'].dist.tarball).toBe(
      `http://npm-registry.lab/@testorg/foo/-/${filename}`,
    );
    expect(packument.versions['1.2.3'].dist.integrity).toMatch(/^sha512-/);
  });
});