import { statSync } from 'fs';
import { join } from 'path';
import { getGlobalVariable } from '../../utils/env';
import { expectFileToExist, expectFileToMatch, readFile } from '../../utils/fs';
import { expectGitToBeClean } from '../../utils/git';
import { ng } from '../../utils/process';


function verifySize(bundle: string, baselineBytes: number) {
  const size = statSync(`dist/test-project/${bundle}`).size;
  const percentageBaseline = baselineBytes * 10 / 100;
  const maxSize = baselineBytes + percentageBaseline;
  const minSize = baselineBytes - percentageBaseline;

  if (size >= maxSize) {
    throw new Error(
      `Expected ${bundle} size to be less than ${maxSize / 1024}Kb but it was ${size / 1024}Kb.`,
    );
  }

  if (size <= minSize) {
    throw new Error(
      `Expected ${bundle} size to be greater than ${minSize / 1024}Kb but it was ${size / 1024}Kb.`,
    );
  }
}

export default async function () {
  // TODO(architect): Delete this test. It is now in devkit/build-angular.

  // Can't use the `ng` helper because somewhere the environment gets
  // stuck to the first build done
  const argv = getGlobalVariable('argv');
  const ivyProject = argv['ivy'];
  const bootstrapRegExp = ivyProject
    ? /bootstrapModule\([a-zA-Z]+\)\./
    : /bootstrapModuleFactory\([a-zA-Z]+\)\./;

  await ng('build', '--prod');
  await expectFileToExist(join(process.cwd(), 'dist'));
  // Check for cache busting hash script src
  await expectFileToMatch('dist/test-project/index.html', /main-es5\.[0-9a-f]{20}\.js/);
  await expectFileToMatch('dist/test-project/index.html', /main-es2015\.[0-9a-f]{20}\.js/);
  await expectFileToMatch('dist/test-project/index.html', /styles\.[0-9a-f]{20}\.css/);
  await expectFileToMatch('dist/test-project/3rdpartylicenses.txt', /MIT/);

  const indexContent = await readFile('dist/test-project/index.html');
  const mainES5Path = indexContent.match(/src="(main-es5\.[a-z0-9]{0,32}\.js)"/)[1];
  const mainES2015Path = indexContent.match(/src="(main-es2015\.[a-z0-9]{0,32}\.js)"/)[1];

  // Content checks
  await expectFileToMatch(`dist/test-project/${mainES5Path}`, bootstrapRegExp);
  await expectFileToMatch(`dist/test-project/${mainES2015Path}`, bootstrapRegExp);

  // Size checks in bytes
  if (ivyProject) {
    verifySize(mainES5Path, 147789);
    verifySize(mainES2015Path, 130153);
  } else {
    verifySize(mainES5Path, 155523);
    verifySize(mainES2015Path, 135394);
  }

  // Check that the process didn't change local files.
  await expectGitToBeClean();
}
