package com.atlassian.webdriver.visualcomparison;
   
   import com.atlassian.selenium.visualcomparison.ScreenElement;
   import com.atlassian.selenium.visualcomparison.VisualComparableClient;
   import com.atlassian.selenium.visualcomparison.utils.ScreenResolution;
   import com.atlassian.webdriver.AtlassianWebDriver;
   import com.google.common.base.Function;
   import org.openqa.selenium.By;
   import org.openqa.selenium.Dimension;
  import org.openqa.selenium.JavascriptExecutor;
  import org.openqa.selenium.SearchContext;
  import org.openqa.selenium.WebDriver;
  import org.openqa.selenium.WebElement;
  
  import javax.annotation.Nonnull;
  import java.io.File;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * @since 2.1
   */
  public class WebDriverVisualComparableClient implements VisualComparableClient
  {
      private final AtlassianWebDriver driver;
      private Dimension documentSize;
      private Dimension viewportSize;
  
      public WebDriverVisualComparableClient(final AtlassianWebDriver driver)
      {
          this.driver = driver;
      }
  
      public void captureEntirePageScreenshot (String filePath)
      {
          driver.takeScreenshotTo(new File(filePath));
          documentSize = getDimensionsFor("document");
          viewportSize = getDimensionsFor("window");
      }
  
      private Dimension getDimensionsFor(String selector)
      {
          int x = Integer.parseInt(execute("return jQuery(" + selector + ").width();").toString());
          int y = Integer.parseInt(execute("return jQuery(" + selector + ").height();").toString());
          return new Dimension(x,y);
      }
  
      public ScreenElement getElementAtPoint(int x, int y)
      {
          int deltaY = documentSize.height - viewportSize.height;
          int scrollY = Math.min(deltaY, y);
          int relY = y - scrollY; // number between 0 and viewportSize.height
  
          int deltaX = documentSize.width - viewportSize.width;
          int scrollX = Math.min(deltaX, x);
          int relX = x - scrollX; // number between 0 and viewportSize.width
  
          execute(String.format("window.scrollTo(%d,%d)",scrollX,scrollY));
          WebElement el = driver.findElement(atPointInDom(relX,relY));
          return new WebDriverScreenElement(el);
      }
  
      private By atPointInDom(int relX, int relY)
      {
          final String domSel = String.format("return document.elementFromPoint(%d,%d);",relX,relY);
          final Object o = driver.executeScript(domSel);
  
          if (o instanceof WebElement) {
              return new By() {
                  @Override
                  public List<WebElement> findElements(SearchContext searchContext) {
                      return new ArrayList<WebElement>() {
                          {
                              add((WebElement) o);
                          }
                      };
                  }
              };
          }
  
          return null;
      }
  
      public void evaluate (String command)
      {
          execute(command);
      }
  
      public Object execute (String command, Object... arguments)
      {
          return driver.executeScript(command, arguments);
      }
  
      public boolean resizeScreen(ScreenResolution resolution, boolean refresh)
      {
          driver.getDriver().manage().window().setSize(new Dimension(resolution.width, resolution.height));
          viewportSize = getDimensionsFor("window");
          if (refresh)
          {
             refreshAndWait();
         }
         return true;
     }
 
     public void refreshAndWait ()
     {
         // WebDriver automatically waits, or so the docs say.
         driver.navigate().refresh();
     }
 
     public boolean waitForJQuery (long waitTimeMillis)
     {
         try
         {
             driver.waitUntil(new Function<WebDriver, Boolean>() {
                 public Boolean apply(WebDriver webDriver) {
                     String jQueryActive = ((JavascriptExecutor)webDriver).executeScript("return (window.jQuery.active)").toString();
                     return (jQueryActive).equals ("0");
                 }
             }, (int)waitTimeMillis);
             Thread.sleep(400);
         }
         catch (InterruptedException e)
         {
             return false;
         }
         return true;
     }
 
     private class WebDriverScreenElement implements ScreenElement
     {
         private final WebElement element;
 
         WebDriverScreenElement(WebElement el)
         {
             this.element = el;
         }
 
         @Override
         @Nonnull
         public String getHtml()
         {
             return (String) execute("var d = document.createElement('div'); d.appendChild(arguments[0].cloneNode(true)); return d.innerHTML;", element);
         }
     }
 
 }