package com.atlassian.webdriver.utils;
   
   import org.openqa.selenium.WebDriver;
   import org.openqa.selenium.chrome.ChromeDriver;
   import org.openqa.selenium.firefox.FirefoxDriver;
   import org.openqa.selenium.htmlunit.HtmlUnitDriver;
   import org.openqa.selenium.ie.InternetExplorerDriver;
   import org.openqa.selenium.internal.WrapsDriver;
   
  import javax.annotation.Nonnull;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  /**
   * @since 2.1
   */
  public final class WebDriverUtil
  {
      private WebDriverUtil()
      {
          throw new AssertionError(WebDriverUtil.class.getName() + " is not supposed to be instantiated");
      }
  
      public static boolean isFirefox(@Nonnull WebDriver driver)
      {
          return getUnderlyingDriver(driver) instanceof FirefoxDriver;
      }
  
      public static boolean isChrome(@Nonnull WebDriver driver)
      {
          return getUnderlyingDriver(driver) instanceof ChromeDriver;
      }
  
      public static boolean isHtmlUnit(@Nonnull WebDriver driver)
      {
          return getUnderlyingDriver(driver) instanceof HtmlUnitDriver;
      }
  
      public static boolean isIE(@Nonnull WebDriver driver)
      {
          return getUnderlyingDriver(driver) instanceof InternetExplorerDriver;
      }
  
      /**
       * Retrieve the underlying {@link WebDriver} instance.
       *
       * @param driver the driver to examine
       * @return the underlying web driver instance that is actually driving the test. This can be the same instance
       * as {@literal driver}, or some other instance that is wrapped by {@literal driver}.
       */
      @Nonnull
      public static WebDriver getUnderlyingDriver(@Nonnull WebDriver driver)
      {
          checkNotNull(driver, "driver");
          while (driver instanceof WrapsDriver)
          {
              driver = WrapsDriver.class.cast(driver).getWrappedDriver();
          }
          return driver;
      }
  
      /**
       * Check whether the underlying driver is instance of {@literal type}. This method attempts to retrieve the underlying
       * web driver before performing the instance check.
       *
       * @param driver driver to check
       * @param type type to check
       * @return {@literal true}, if the underlying driver is an instance of {@literal type}, in which case
       * {@link #as(WebDriver, Class)} may be safely used on it
       * @see #getUnderlyingDriver(WebDriver)
       */
      public static boolean isInstance(@Nonnull WebDriver driver, @Nonnull Class<?> type)
      {
          return type.isInstance(getUnderlyingDriver(driver));
      }
  
      /**
       * Get the underlying web driver instance from {@literal driver} as instance of {@literal type}.
       *
       * @param driver driver to examine
       * @param type type to cast to
       * @param <T> type parameter
       * @return the underlying driver instance as T
       * @throws ClassCastException if {@link #isInstance(WebDriver, Class)} for given arguments returns {@literal false}
       * @see #isInstance(org.openqa.selenium.WebDriver, Class)
       */
      public static <T> T as(@Nonnull WebDriver driver, @Nonnull Class<T> type)
      {
          return type.cast(getUnderlyingDriver(driver));
      }
  }