/*
 * Copyright 2008 Google Inc.
 * 
 * Licensed 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 com.google.gwt.user.client.ui;

import com.google.gwt.dom.client.Element;
import com.google.gwt.junit.client.GWTTestCase;
import com.google.gwt.safehtml.shared.SafeHtmlUtils;
import com.google.gwt.user.client.ui.HasWidgetsTester.WidgetAdder;

import java.util.Locale;

/**
 * Tests {@link CaptionPanel}.
 */
public class CaptionPanelTest extends GWTTestCase {

  private static final String html = "<b>hello</b><i>world</i>";

  @Override
  public String getModuleName() {
    return "com.google.gwt.user.User";
  }

  /**
   * Tests {@link CaptionPanel#add(IsWidget)}.
   */
  public void testAddAsIsWidget() {
    CaptionPanel panel = createEmptyCaptionPanel();
    Widget widget = new Label("foo");
    
    // IsWidget cast to call the overloaded version
    panel.add((IsWidget) widget);
    
    assertSame(widget,panel.getContentWidget());
  }
  
  /**
   * Ensures that {@link CaptionPanel#add(IsWidget)} does <b>NOT</b> fail
   * when the IsWidget argument is <code>null</code>. Not that this is
   * a great thing, but it works in the add(Widget) case so...
   */
  public void testAddNullAsIsWidget() {
    CaptionPanel panel = createEmptyCaptionPanel();
    // IsWidget reference to call the overloaded version
    IsWidget widget = null;
    
    panel.add(widget);
    // ta da...
  }

  public void testHasWidgets() {
    WidgetAdder adder = new HasWidgetsTester.DefaultWidgetAdder();

    // With no caption.
    HasWidgetsTester.testAll(createEmptyCaptionPanel(), adder, false);

    // With a text caption.
    HasWidgetsTester.testAll(new CaptionPanel("some text"), adder, false);

    // With a complex HTML caption.
    HasWidgetsTester.testAll(new CaptionPanel(
        "<legend>not the <i>actual</i> legend<legend>", true), adder, false);
  }

  public void testCaptionAcceptsEmptyStringAndRemovesLegendElement() {
    // Ctor/HTML.
    {
      CaptionPanel panel = new CaptionPanel("");
      assertEquals("", panel.getCaptionHTML());
      assertNull(panel.getElement().getFirstChild());
    }

    // Setter/HTML.
    {
      CaptionPanel panel = new CaptionPanel("not null");
      assertEquals("not null", panel.getCaptionHTML());

      panel.setCaptionHTML("");
      assertEquals("", panel.getCaptionHTML());
      assertNull(panel.getElement().getFirstChild());
    }

    // Setter/Text.
    {
      CaptionPanel panel = new CaptionPanel("not null");
      assertEquals("not null", panel.getCaptionHTML());

      panel.setCaptionText("");
      assertEquals("", panel.getCaptionHTML());
      assertNull(panel.getElement().getFirstChild());
    }
  }

  // TODO(bruce): re-active when we ensure that assertions are enabled during
  // unit test runs
  // /**
  // * When the caption is null, it needs to be actually removed from the DOM
  // (to
  // * compensate for browser bugs). This formulation requires no widget to have
  // * been set first.
  // */
  // public void testCaptionAssertsAgainstNull() {
  // // Ctor.
  // {
  // try {
  // new CaptionPanel(null);
  // fail("Should've asserted!");
  // } catch (AssertionError e) {
  // // good to make it here
  // }
  // }
  //
  // // Setter/HTML.
  // {
  // try {
  // CaptionPanel panel = new CaptionPanel("stuff");
  // panel.setCaptionHTML(null);
  // fail("Should've asserted!");
  // } catch (AssertionError e) {
  // // good to make it here
  // }
  // }
  //
  // // Setter/Text.
  // {
  // try {
  // CaptionPanel panel = new CaptionPanel("stuff");
  // panel.setCaptionText(null);
  // fail("Should've asserted!");
  // } catch (AssertionError e) {
  // // good to make it here
  // }
  // }
  // }

  public void testCtorAsHtmlFlag() {
    String s = "this is <b>not</b> null";

    // Ctor/Text.
    {
      CaptionPanel panel = new CaptionPanel(s, false);
      // Check without regard to the case of tags; some browsers change tag case
      // against your will.
      assertEqualsIgnoreCase(s, panel.getCaptionText());
      assertNotEquals(s, panel.getCaptionHTML());
    }

    // Ctor/HTML.
    {
      CaptionPanel panel = new CaptionPanel(s, true);
      assertEquals("this is not null", panel.getCaptionText());
      assertEqualsIgnoreCase(s, panel.getCaptionHTML());
    }
  }

  private void assertEqualsIgnoreCase(String expected, String actual) {
    String expectedLc = expected != null ? expected.toLowerCase(Locale.ROOT) : null;
    String actualLc = actual != null ? actual.toLowerCase(Locale.ROOT) : null;
    assertEquals(expectedLc, actualLc);
  }

  /**
   * Browsers all seem escape text differently, so we use this function to deal
   * with cases where we can't say exactly *what* reading element HTML will
   * return, but we can say for sure that at least it's different somehow than
   * some original text (due to escaping).
   */
  private void assertNotEquals(String mustNotBe, String actual) {
    assertFalse(mustNotBe != null ? mustNotBe.equals(actual) : actual == null);
  }

  public void testDefaultCaptionIsEmptyString() {
    CaptionPanel panel = createEmptyCaptionPanel();
    assertEquals("", panel.getCaptionText());
    assertEquals("", panel.getCaptionHTML());
    // Widgets may be supported in the future.
    // assertNull(panel.getCaptionWidget());
    assertNull(panel.getElement().getFirstChild());
  }

  public void testGetSetHTMLCaption() {
    CaptionPanel panel = createEmptyCaptionPanel();
    panel.setCaptionHTML("<b>bold</b>");
    assertEqualsIgnoreCase("<b>bold</b>", panel.getCaptionHTML());
    assertEquals("bold", panel.getCaptionText());
  }

  public void testGetSetTextCaption() {
    String s = "this is <b>not</b> null";
    CaptionPanel panel = createEmptyCaptionPanel();
    panel.setCaptionText(s);
    assertEquals(s, panel.getCaptionText());
    assertNotEquals(s, panel.getCaptionHTML());
  }

  public void testOneArgCtorIsTextCaption() {
    String s = "this is <b>not</b> null";
    CaptionPanel panel = new CaptionPanel(s);
    assertEquals(s, panel.getCaptionText());
    assertNotEquals(s, panel.getCaptionHTML());
  }

  public void testGetSetContentWidget() {
    {
      // No Widget set in the default ctor.
      CaptionPanel panel = new CaptionPanel("no widget");
      assertNull(panel.getContentWidget());
    }

    {
      // Set widget and remove() it.
      CaptionPanel panel = new CaptionPanel("no widget yet");
      assertNull(panel.getContentWidget());

      HTML widget = new HTML("widget");
      panel.setContentWidget(widget);
      assertSame(widget, panel.getContentWidget());

      panel.remove(widget);
      assertNull(panel.getContentWidget());
    }

    {
      // Set widget and clear() it.
      CaptionPanel panel = new CaptionPanel("no widget yet");
      assertNull(panel.getContentWidget());

      HTML widget = new HTML("widget");
      panel.setContentWidget(widget);
      assertSame(widget, panel.getContentWidget());

      panel.clear();
      assertNull(panel.getContentWidget());
    }

    {
      // Set widget and replace it.
      CaptionPanel panel = new CaptionPanel("no widget yet");
      assertNull(panel.getContentWidget());

      HTML widget1 = new HTML("widget1");
      panel.setContentWidget(widget1);
      assertSame(widget1, panel.getContentWidget());

      HTML widget2 = new HTML("widget2");
      panel.setContentWidget(widget2);
      assertSame(widget2, panel.getContentWidget());
    }
  }

  public void testGetSetCaptionAmidstContentWidget() {
    CaptionPanel panel = new CaptionPanel("caption");
    HTML widget = new HTML("widget");
    panel.setContentWidget(widget);
    assertEquals("caption", panel.getCaptionText());
    assertSame(widget, panel.getContentWidget());

    {
      // Set the caption to an empty string and verify that the legend element
      // is removed
      panel.setCaptionText("");
      assertEquals("", panel.getCaptionText());
      assertSame(widget, panel.getContentWidget());
      Element panelFirstChild = panel.getElement().getFirstChildElement();
      // The legend element ought to be removed from the DOM at this point.
      assertNotEquals("legend", panelFirstChild.getTagName().toLowerCase(Locale.ROOT));
      // (Perhaps redundantly) check that the one child is the content widget.
      assertSame(panelFirstChild, widget.getElement());
      assertNull(panelFirstChild.getNextSibling());
    }

    {
      // Set the caption to a non-empty string and verify that the legend
      // element is readded to the
      // 0th index
      panel.setCaptionText("new caption");
      assertEquals("new caption", panel.getCaptionText());
      assertSame(widget, panel.getContentWidget());
      Element panelFirstChild = panel.getElement().getFirstChildElement();
      // The legend element ought to be the 0th element in the DOM at this
      // point.
      assertTrue("legend".equalsIgnoreCase(panelFirstChild.getTagName()));
      // Check that the second child is the content widget.
      assertSame(panelFirstChild.getNextSibling(), widget.getElement());
    }

    {
      // Set the caption to a non-empty string and verify that the legend
      // element remains at the 0th
      // index
      panel.setCaptionText("newer caption");
      assertEquals("newer caption", panel.getCaptionText());
      assertSame(widget, panel.getContentWidget());
      Element panelFirstChild = panel.getElement().getFirstChildElement();
      // The legend element ought to be the 0th element in the DOM at this
      // point.
      assertTrue("legend".equalsIgnoreCase(panelFirstChild.getTagName()));
      // Check that the second child is the content widget.
      assertSame(panelFirstChild.getNextSibling(), widget.getElement());
    }

    {
      // Remove the widget and verify the caption remains at the 0th index
      panel.remove(widget);
      assertEquals("newer caption", panel.getCaptionText());
      assertNull(panel.getContentWidget());
      Element panelFirstChild = panel.getElement().getFirstChildElement();
      // The legend element ought to be the 0th element in the DOM at this
      // point.
      assertTrue("legend".equalsIgnoreCase(panelFirstChild.getTagName()));
      // (Perhaps redundantly) check that the one child is the legend element.
      assertNull(panelFirstChild.getNextSibling());
    }
  }

  public void testSafeHtmlConstructor() {
    CaptionPanel panel = new CaptionPanel(SafeHtmlUtils.fromSafeConstant(html));

    assertEquals(html, panel.getCaptionHTML().toLowerCase(Locale.ROOT));
  }

  public void testSetCaptionSafeHtml() {
    CaptionPanel panel = new CaptionPanel("hiworld");
    panel.setCaptionHTML(SafeHtmlUtils.fromSafeConstant(html));

    assertEquals(html, panel.getCaptionHTML().toLowerCase(Locale.ROOT));
  }

  private CaptionPanel createEmptyCaptionPanel() {
    return new CaptionPanel();
  }
}