const test = require('node:test');
const assert = require('node:assert/strict');
const { detectDistro } = require('../lib/distro.js');

test('detectDistro returns null for null, undefined, or empty input', () => {
  assert.equal(detectDistro(null), null);
  assert.equal(detectDistro(undefined), null);
  assert.equal(detectDistro(''), null);
  assert.equal(detectDistro('{}'), null);
});

test('detectDistro extracts distro from parsed SPDX object with package PURLs', () => {
  const spdx = {
    packages: [
      {
        name: 'acl',
        externalRefs: [
          {
            referenceType: 'purl',
            referenceLocator: 'pkg:deb/debian/acl@2.3.1-3?os_distro=bookworm&os_name=debian&os_version=12',
          },
        ],
      },
    ],
  };

  assert.equal(detectDistro(spdx), 'debian/12');
});

test('detectDistro extracts distro from JSON string containing escaped unicode \\u0026', () => {
  const jsonStr = JSON.stringify({
    packages: [
      {
        name: 'adduser',
        externalRefs: [
          {
            referenceType: 'purl',
            referenceLocator: 'pkg:deb/debian/adduser@3.134?os_distro=bullseye&os_name=debian&os_version=11',
          },
        ],
      },
    ],
  }).replace(/&/g, '\\u0026');

  assert.ok(jsonStr.includes('\\u0026'));
  assert.equal(detectDistro(jsonStr), 'debian/11');
});

test('detectDistro handles non-debian distributions (e.g. ubuntu, alpine)', () => {
  const spdx = {
    packages: [
      {
        externalRefs: [
          {
            referenceType: 'purl',
            referenceLocator: 'pkg:apk/alpine/alpine-baselayout@3.4.3-r2?os_name=alpine&os_version=3.20',
          },
        ],
      },
    ],
  };

  assert.equal(detectDistro(spdx), 'alpine/3.20');
});

test('detectDistro returns null when PURLs lack os_name or os_version', () => {
  const spdx = {
    packages: [
      {
        externalRefs: [
          {
            referenceType: 'purl',
            referenceLocator: 'pkg:generic/foo@1.0.0',
          },
        ],
      },
    ],
  };

  assert.equal(detectDistro(spdx), null);
});