code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  
  package org.openqa.selenium.firefox;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import org.openqa.selenium.Platform;
  import org.openqa.selenium.WebDriverException;
  import org.openqa.selenium.internal.Require;
  
  /** Wrapper around Firefox executable. */
  class Executable {
  
    private final File binary;
    private String version;
    private FirefoxBinary.Channel channel;
  
    public Executable(File userSpecifiedBinaryPath) {
      Require.argument("Path to the firefox binary", (Object) userSpecifiedBinaryPath).nonNull();
      binary = userSpecifiedBinaryPath;
    }
  
    public File getDirectory() {
      return binary.getAbsoluteFile().getParentFile();
    }
  
    public File getFile() {
      return binary;
    }
  
    public String getPath() {
      return binary.getAbsolutePath();
    }
  
    public String getVersion() {
      if (version == null) {
        loadApplicationIni();
      }
      return version;
    }
  
    public FirefoxBinary.Channel getChannel() {
      if (channel == null) {
        loadChannelPref();
      }
      return channel;
    }
  
    private void loadApplicationIni() {
      Path applicationIni = getResource("application.ini");
      if (Files.exists(applicationIni)) {
        try (BufferedReader reader = Files.newBufferedReader(applicationIni)) {
          version =
              reader
                  .lines()
                  .map(String::trim)
                  .filter(line -> line.startsWith("Version="))
                  .findFirst()
                  .map(line -> line.substring("Version=".length()))
                  .orElseThrow(
                      () ->
                          new WebDriverException(
                              "Cannot get version info for Firefox binary " + binary));
        } catch (IOException e) {
          throw new WebDriverException("Cannot get version info for Firefox binary " + binary, e);
        }
      } else {
        // Set version to something with a ridiculously high number.
        version = "1000.0 unknown";
      }
    }
  
    private void loadChannelPref() {
      Path channelPrefs = getResource("defaults/pref/channel-prefs.js");
  
      if (Files.exists(channelPrefs)) {
        try (BufferedReader reader = Files.newBufferedReader(channelPrefs)) {
          channel =
              reader
                  .lines()
                  .map(String::trim)
                  .filter(line -> line.startsWith("pref(\"app.update.channel\""))
                  .findFirst()
                  .map(
                      line ->
                          FirefoxBinary.Channel.fromString(
                              line.substring(
                                  "pref(\"app.update.channel\", \"".length(),
                                  line.length() - "\");".length())))
                  .orElseThrow(
                      () ->
                          new WebDriverException(
                              "Cannot get channel info for Firefox binary " + binary));
        } catch (IOException e) {
          throw new WebDriverException("Cannot get channel info for Firefox binary " + binary, e);
        }
      } else {
        // Pick a sane default
        channel = FirefoxBinary.Channel.RELEASE;
      }
    }
  
    private Path getResource(String resourceName) {
      Path binaryLocation = binary.getAbsoluteFile().toPath();
      if (Platform.getCurrent().is(Platform.MAC)) {
        return binaryLocation.getParent().getParent().resolve("Resources").resolve(resourceName);
      } else {
        return binaryLocation.getParent().resolve(resourceName);
      }
    }
  }
  