package com.atlassian.webdriver.testing.rule;
   
   import com.atlassian.webdriver.testing.annotation.WindowSize;
   import com.google.common.base.Supplier;
   import org.junit.rules.TestWatcher;
   import org.junit.runner.Description;
   import org.openqa.selenium.Dimension;
   import org.openqa.selenium.WebDriver;
   import org.openqa.selenium.WebDriverException;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.inject.Inject;
  
  import static com.google.common.base.Preconditions.checkState;
  
  /**
   * <p/>
   * Implements support for the {@link com.atlassian.webdriver.testing.annotation.WindowSize} annotation.
   *
   * <p/>
   * If this rule is used in a test and the {@link com.atlassian.webdriver.testing.annotation.WindowSize} annotation is
   * not present on either the test method, or the test class, the window will be maximized by default.
   *
   * <p/>
   * Otherwise the directives present on the annotation found (with method-level annotation superseding the class-level
   * one) will be applied to the current driver's window in a following manner:
   * <ul>
   *     <li>if the <tt>maximize</tt> flag is set to <code>true</code>, the window will be maximized</li>
   *     <li>otherwise the properties <tt>height</tt> and <tt>width</tt> will be used to set the window size. In such
   *     case those properties must have positive integer value, or an exception will be raised</li>
   * </ul>
   *
   * <p/>
   * Example:
   *
   *
   * <pre>
   *      public class MyWebDriverTest
   *      {
   *          &#064;Rule public WindowSizeRule windowSizeRule = //...
   *
   *          &#064;Test
   *          public void myTest()
   *          {
   *              // at this stage the window will be maximized
   *          }
   *      }
   * </pre>
   *
   * <pre>
   *      public class MyWebDriverTest
   *      {
   *          &#064;Rule public WindowSizeRule windowSizeRule = //...
   *
   *          &#064;Test
   *          &#064;WindowSize(width=1024,height=768)
   *          public void myTest()
   *          {
   *              // at this stage the window will be set to 1024x768
   *          }
   *      }
   * </pre>
   *
   * @since 2.1
   */
  public class WindowSizeRule extends TestWatcher
  {
      private final static Logger log = LoggerFactory.getLogger(WindowSizeRule.class);
  
      private final WebDriverSupport<? extends WebDriver> support;
  
      @Inject
      public WindowSizeRule(WebDriver webDriver)
      {
          this.support = WebDriverSupport.forInstance(webDriver);
      }
  
      public WindowSizeRule(Supplier<? extends WebDriver> driverSupplier)
      {
          this.support = WebDriverSupport.forSupplier(driverSupplier);
      }
  
      public WindowSizeRule()
      {
          this.support = WebDriverSupport.fromAutoInstall();
      }
  
      @Override
      protected void starting(Description description)
      {
          try
          {
              WindowSize windowSize = findAnnotation(description);
              if (windowSize != null)
              {
                  handleWindowSize(windowSize);
              }
              else
             {
                 maximizeWindow();
             }
         }
         catch (WebDriverException e)
         {
             // half of the drivers does not support it, let's not break because of this
             log.warn("Caught exception while trying to adjust window size.");
             log.debug("Exception while trying to adjust window size", e);
         }
     }
 
     private WindowSize findAnnotation(Description description)
     {
         if (description.getAnnotation(WindowSize.class) != null)
         {
             return description.getAnnotation(WindowSize.class);
         }
         else if (description.getTestClass() != null && description.getTestClass().isAnnotationPresent(WindowSize.class))
         {
             return description.getTestClass().getAnnotation(WindowSize.class);
         }
         else
         {
             return null;
         }
     }
 
     private void handleWindowSize(WindowSize windowSize)
     {
         if (windowSize.maximize())
         {
             maximizeWindow();
         }
         else
         {
             setSize(computeDimension(windowSize));
         }
     }
 
     private void maximizeWindow()
     {
         support.getDriver().manage().window().maximize();
     }
 
     private void setSize(Dimension dimension)
     {
         support.getDriver().manage().window().setSize(dimension);
     }
 
     private Dimension computeDimension(WindowSize windowSize)
     {
         checkState(windowSize.width() > 0, "@WindowSize width must be greater than 0, was: " + windowSize.width());
         checkState(windowSize.height() > 0, "@WindowSize height must be greater than 0, was: " + windowSize.height());
         return new Dimension(windowSize.width(), windowSize.height());
     }
 }