import { join } from 'path';
// import { join, dirname } from 'path';
import execa from 'execa';
import fs from 'fs';
import { ensureDir } from 'fs-extra';
import { promisify } from 'util';
const readFile = promisify(fs.readFile);
const writeFile = promisify(fs.writeFile);
import {
  getWriteableDirectory,
  download,
  glob,
  createLambda,
  BuildOptions,
} from '@now/build-utils';
import { downloadAndInstallBundler } from './gem-install';

async function gemInstall(gemPath: string, workDir: string, vendorDir: string, ...gems: string[]) {
  console.log(`running "gem install ${gems.join(' ')}"...`);
  await execa(gemPath, ['help', 'install'], { stdio: 'inherit' })
  try {
    await execa(gemPath, ['install', ...gems, '-​-install-dir', vendorDir, '-​-no-document'], {
      cwd: workDir,
      stdio: 'inherit',
    });
  } catch (err) {
    console.log(`failed to run "gem install ${gems.join(' ')}"...`);
    throw err;
  }
}

// async function bundleInstall(bundlePath: string, workDir: string, ...args: string[]) {
//   console.log(`running "bundle ${args.join(' ')}"...`);
//   try {
//     await execa(bundlePath, args, {
//       cwd: workDir,
//       stdio: 'inherit',
//       env: {
//         'BUNDLE_SILENCE_ROOT_WARNING': '1',
//       }
//     });
//   } catch (err) {
//     console.log(`failed to run "bundle ${args.join(' ')}"...`);
//     throw err;
//   }
// }

export const config = {
  maxLambdaSize: '5mb',
};

export const build = async ({ workPath, files, entrypoint }: BuildOptions) => {
  console.log('downloading files...');

  // eslint-disable-next-line no-param-reassign
  files = await download(files, workPath);

  // this is where `ruby, gem and bundler` will be installed to
  // we need it to be under `/tmp`
  const gemHome = await getWriteableDirectory();
  process.env.GEM_HOME = gemHome;
  const { gemPath } = await downloadAndInstallBundler();
  // const { gemPath, bundlerPath } = await downloadAndInstallBundler();

  // reuse existing vendor directory if available
  const vendorFiles = await glob('vendor/bundle/ruby/*', workPath)
  let vendorDir: string
  if (Object.keys(vendorFiles).length) {
    vendorDir = vendorFiles[Object.keys(vendorFiles)[0]].fsPath
  } else {
    vendorDir = join(workPath, 'vendor', 'bundle', 'ruby', '2.5.3')
  }

  await ensureDir(vendorDir)
  console.log('Using vendor dir', vendorDir);

  // install single requirement for http
  await gemInstall(gemPath, workPath, vendorDir, 'httparty');

  // const fsFiles = await glob('**', workPath);

  // const entryDirectory = dirname(entrypoint);
  // const gemFile = join(entryDirectory, 'Gemfile');

  // if (fsFiles[gemFile]) {
  //   console.log('found "Gemfile"');
  //   const gemFilePath = fsFiles[gemFile].fsPath;
  //   await bundleInstall(bundlerPath, workPath, 'package', '--no-install', '--gemfile', gemFilePath);
  // }

  const originalRbPath = join(__dirname, 'now_init.rb');
  const originalNowHandlerRbContents = await readFile(originalRbPath, 'utf8');

  // will be used on `from $here import handler`
  // for example, `from api.users import handler`
  console.log('entrypoint is', entrypoint);
  const userHandlerFilePath = entrypoint.replace(/\.rb$/, '');
  const nowHandlerRbContents = originalNowHandlerRbContents.replace(
    /__NOW_HANDLER_FILENAME/g,
    userHandlerFilePath,
  );

  // in order to allow the user to have `server.rb`, we need our `server.rb` to be called
  // somethig else
  const nowHandlerRbFilename = 'now__handler__ruby';

  await writeFile(
    join(workPath, `${nowHandlerRbFilename}.rb`),
    nowHandlerRbContents,
  );

  const lambda = await createLambda({
    files: await glob('**', workPath),
    handler: `${nowHandlerRbFilename}.handler`,
    runtime: 'ruby2.5',
    environment: {},
  });

  return {
    [entrypoint]: lambda,
  };
};