/**
 * @license
 * Copyright 2023 Google Inc.
 * SPDX-License-Identifier: Apache-2.0
 */

import {spawnSync, spawn} from 'child_process';
import {createReadStream} from 'fs';
import {mkdir, readdir} from 'fs/promises';
import * as path from 'path';
import {Stream} from 'stream';

import extractZip from 'extract-zip';
import tar from 'tar-fs';
import bzip from 'unbzip2-stream';

/**
 * @internal
 */
export async function unpackArchive(
  archivePath: string,
  folderPath: string,
): Promise<void> {
  if (archivePath.endsWith('.zip')) {
    await extractZip(archivePath, {dir: folderPath});
  } else if (archivePath.endsWith('.tar.bz2')) {
    await extractTar(archivePath, folderPath);
  } else if (archivePath.endsWith('.dmg')) {
    await mkdir(folderPath);
    await installDMG(archivePath, folderPath);
  } else if (archivePath.endsWith('.exe')) {
    // Firefox on Windows.
    const result = spawnSync(archivePath, [`/ExtractDir=${folderPath}`], {
      env: {
        __compat_layer: 'RunAsInvoker',
      },
    });
    if (result.status !== 0) {
      throw new Error(
        `Failed to extract ${archivePath} to ${folderPath}: ${result.output}`,
      );
    }
  } else if (archivePath.endsWith('.tar.xz')) {
    await extractTarXz(archivePath, folderPath);
  } else {
    throw new Error(`Unsupported archive format: ${archivePath}`);
  }
}

/**
 * @internal
 */
function extractTar(tarPath: string, folderPath: string): Promise<void> {
  return new Promise((fulfill, reject) => {
    const tarStream = tar.extract(folderPath);
    tarStream.on('error', reject);
    tarStream.on('finish', fulfill);
    const readStream = createReadStream(tarPath);
    readStream.pipe(bzip()).pipe(tarStream);
  });
}

/**
 * @internal
 */
function createXzStream() {
  const child = spawn('xz', ['-d']);
  const stream = new Stream.Transform({
    transform(chunk, encoding, callback) {
      if (!child.stdin.write(chunk, encoding)) {
        child.stdin.once('drain', callback);
      } else {
        callback();
      }
    },

    flush(callback) {
      if (child.stdout.destroyed) {
        callback();
      } else {
        child.stdin.end();
        child.stdout.on('close', callback);
      }
    },
  });

  child.stdin.on('error', e => {
    if ('code' in e && e.code === 'EPIPE') {
      // finished before reading the file finished (i.e. head)
      stream.emit('end');
    } else {
      stream.destroy(e);
    }
  });

  child.stdout
    .on('data', data => {
      return stream.push(data);
    })
    .on('error', e => {
      return stream.destroy(e);
    });

  return stream;
}

/**
 * @internal
 */
function extractTarXz(tarPath: string, folderPath: string): Promise<void> {
  return new Promise((fulfill, reject) => {
    const tarStream = tar.extract(folderPath);
    tarStream.on('error', reject);
    tarStream.on('finish', fulfill);
    const readStream = createReadStream(tarPath);
    readStream.pipe(createXzStream()).pipe(tarStream);
  });
}

/**
 * @internal
 */
async function installDMG(dmgPath: string, folderPath: string): Promise<void> {
  const {stdout} = spawnSync(`hdiutil`, [
    'attach',
    '-nobrowse',
    '-noautoopen',
    dmgPath,
  ]);

  const volumes = stdout.toString('utf8').match(/\/Volumes\/(.*)/m);
  if (!volumes) {
    throw new Error(`Could not find volume path in ${stdout}`);
  }
  const mountPath = volumes[0]!;

  try {
    const fileNames = await readdir(mountPath);
    const appName = fileNames.find(item => {
      return typeof item === 'string' && item.endsWith('.app');
    });
    if (!appName) {
      throw new Error(`Cannot find app in ${mountPath}`);
    }
    const mountedPath = path.join(mountPath!, appName);

    spawnSync('cp', ['-R', mountedPath, folderPath]);
  } finally {
    spawnSync('hdiutil', ['detach', mountPath, '-quiet']);
  }
}
