#!/usr/bin/env node

'use strict';

const {exec} = require('child-process-promise');

const chalk = require('chalk');

const {join} = require('path');

const semver = require('semver');

const yargs = require('yargs');

const fs = require('fs');

const INSTALL_PACKAGES = ['react-dom', 'react', 'react-test-renderer'];

const REGRESSION_FOLDER = 'build-regression';

const ROOT_PATH = join(__dirname, '..', '..');

const buildPath = join(ROOT_PATH, `build`, 'oss-experimental');

const regressionBuildPath = join(ROOT_PATH, REGRESSION_FOLDER);

const argv = yargs(process.argv.slice(2)).argv;

const version = process.argv[2];

const shouldReplaceBuild = !!argv.replaceBuild;

async function downloadRegressionBuild() {

  console.log(chalk.bold.white(`Downloading React v${version}\n`));

  // Make build directory for temporary modules we're going to download

  // from NPM

  console.log(

    chalk.white(

      `Make Build directory at ${chalk.underline.blue(regressionBuildPath)}\n`

    )

  );

  await exec(`mkdir ${regressionBuildPath}`);

  // Install all necessary React packages that have the same version

  const downloadPackagesStr = INSTALL_PACKAGES.reduce(

    (str, name) => `${str} ${name}@${version}`,

    ''

  );

  await exec(

    `npm install --prefix ${REGRESSION_FOLDER} ${downloadPackagesStr}`

  );

  // If we shouldn't replace the build folder, we can stop here now

  // before we modify anything

  if (!shouldReplaceBuild) {

    return;

  }

  // Remove all the packages that we downloaded in the original build folder

  // so we can move the modules from the regression build over

  const removePackagesStr = INSTALL_PACKAGES.reduce(

    (str, name) => `${str} ${join(buildPath, name)}`,

    ''

  );

  console.log(

    chalk.white(

      `Removing ${removePackagesStr

        .split(' ')

        .map(str => chalk.underline.blue(str) + '\n')

        .join(' ')}\n`

    )

  );

  await exec(`rm -r ${removePackagesStr}`);

  // Move all packages that we downloaded to the original build folder

  // We need to separately move the scheduler package because it might

  // be called schedule

  const movePackageString = INSTALL_PACKAGES.reduce(

    (str, name) => `${str} ${join(regressionBuildPath, 'node_modules', name)}`,

    ''

  );

  console.log(

    chalk.white(

      `Moving ${movePackageString

        .split(' ')

        .map(str => chalk.underline.blue(str) + '\n')

        .join(' ')} to ${chalk.underline.blue(buildPath)}\n`

    )

  );

  await exec(`mv ${movePackageString} ${buildPath}`);

  // For React versions earlier than 18.0.0, we explicitly scheduler v0.20.1, which

  // is the first version that has unstable_mock, which DevTools tests need, but also

  // has Scheduler.unstable_trace, which, although we don't use in DevTools tests

  // is imported by older React versions and will break if it's not there

  if (semver.lte(semver.coerce(version).version, '18.0.0')) {

    await exec(`npm install --prefix ${REGRESSION_FOLDER} [email protected]`);

  }

  // In v16.5, scheduler is called schedule. We need to make sure we also move

  // this over. Otherwise the code will break.

  if (fs.existsSync(join(regressionBuildPath, 'node_modules', 'schedule'))) {

    console.log(chalk.white(`Downloading schedule\n`));

    await exec(

      `mv ${join(regressionBuildPath, 'node_modules', 'schedule')} ${buildPath}`

    );

  } else {

    console.log(chalk.white(`Downloading scheduler\n`));

    await exec(`rm -r ${join(buildPath, 'scheduler')}`);

    await exec(

      `mv ${join(

        regressionBuildPath,

        'node_modules',

        'scheduler'

      )} ${buildPath}`

    );

  }

}

async function main() {

  try {

    if (!version) {

      console.log(chalk.red('Must specify React version to download'));

      return;

    }

    await downloadRegressionBuild();

  } catch (e) {

    console.log(chalk.red(e));

  } finally {

    // We shouldn't remove the regression-build folder unless we're using

    // it to replace the build folder

    if (shouldReplaceBuild) {

      console.log(chalk.bold.white(`Removing regression build`));

      await exec(`rm -r ${regressionBuildPath}`);

    }

  }

}

main();