/*
 * Copyright 2009 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.DivElement;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.junit.client.GWTTestCase;
import com.google.gwt.user.client.DOM;

/**
 * Tests {@link RootPanel}.
 */
public class RootPanelTest extends GWTTestCase {

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

  public void testClearRootPanelAndDOM() {

    RootPanel rootPanel = createDOM("testClearRootPanelAndDOM");

    rootPanel.add(new Button("a"));
    rootPanel.add(new Button("b"));

    Element newDiv = DOM.createDiv();
    newDiv.setInnerText("c");
    rootPanel.getElement().appendChild(newDiv);

    assertEquals(3, rootPanel.getElement().getChildCount());

    rootPanel.clear(true);
    assertEquals(0, rootPanel.getElement().getChildCount());
  }

  public void testClearRootPanel() {

    RootPanel rootPanel = createDOM("testClearRootPanel");

    rootPanel.add(new Button("a"));
    rootPanel.add(new Button("b"));

    Element newDiv = DOM.createDiv();
    newDiv.setInnerText("c");
    rootPanel.getElement().appendChild(newDiv);

    assertEquals(3, rootPanel.getElement().getChildCount());

    rootPanel.clear(false);
    assertEquals(1, rootPanel.getElement().getChildCount());

    // clean up
    rootPanel.clear(true);
    assertEquals(0, rootPanel.getElement().getChildCount());
  }

  public void testClearRootPanelContainingTextNodes() {

    RootPanel rootPanel = createDOM("testClearRootPanelAndDOM");

    rootPanel.getElement().setInnerHTML("Some <i>mixed</i> content");

    assertEquals(3, rootPanel.getElement().getChildCount());

    rootPanel.clear(true);
    assertEquals(0, rootPanel.getElement().getChildCount());
  }

  public void testDetachNowWithErrorOnDetach() {
    BadWidget w = BadWidget.wrap(createAttachedDivElement());
    w.setFailOnUnload(true);
    assertTrue(RootPanel.isInDetachList(w));
    assertTrue(RootPanel.getBodyElement().isOrHasChild(w.getElement()));

    try {
      RootPanel.detachNow(w);
      fail("Expected IllegalArgumentException");
    } catch (IllegalArgumentException e) {
      // Expected.
    }
    assertFalse(RootPanel.isInDetachList(w));
  }

  public void testDetachWidgetsWithErrorOnDetach() {
    BadWidget bad0 = BadWidget.wrap(createAttachedDivElement());
    bad0.setFailOnUnload(true);
    BadWidget bad1 = BadWidget.wrap(createAttachedDivElement());
    bad1.setFailOnUnload(true);
    assertTrue(RootPanel.isInDetachList(bad0));
    assertTrue(RootPanel.isInDetachList(bad1));
    assertTrue(RootPanel.getBodyElement().isOrHasChild(bad0.getElement()));
    assertTrue(RootPanel.getBodyElement().isOrHasChild(bad1.getElement()));

    try {
      RootPanel.detachWidgets();
      fail("Expected AttachDetachException");
    } catch (AttachDetachException e) {
      // Expected.
      assertEquals(2, e.getCauses().size());
    }
    assertFalse(RootPanel.isInDetachList(bad0));
    assertFalse(RootPanel.isInDetachList(bad1));
  }

  /**
   * Ensures that {@link RootPanel#get(String)} behaves properly.
   */
  public void testGetById() {
    Document doc = Document.get();
    DivElement div = doc.createDivElement();
    doc.getBody().appendChild(div);
    div.setInnerHTML("<div id='a'></div><div id='b'></div>");

    // You should get the same RootPanel for subsequent calls to get() with the
    // same id. But you should get *different* RootPanels for calls with
    // different ids.
    RootPanel aRoot = RootPanel.get("a");
    RootPanel bRoot = RootPanel.get("b");

    assertSame(
        "RootPanel.get() should return the same instancefor the same id",
        aRoot, RootPanel.get("a"));
    assertSame(
        "RootPanel.get() should return the same instancefor the same id",
        bRoot, RootPanel.get("b"));
    assertNotSame("RootPanels a and b should be different", aRoot, bRoot);

    // If a RootPanel's element is replaced in the DOM, you should get a
    // new RootPanel instance if you ask for it again (see issue 1937).
    Element aElem = doc.getElementById("a");
    Element newAElem = doc.createDivElement();
    newAElem.setId("a");
    aElem.getParentElement().replaceChild(newAElem, aElem);

    RootPanel newARoot = RootPanel.get("a");
    assertNotSame("New RootPanel should not be same as old", newARoot, aRoot);
  }

  public void testRemoveWithError() {
    // Create a widget that will throw an exception onUnload.
    BadWidget badWidget = new BadWidget();
    badWidget.setFailOnUnload(true);

    // Add the widget to a panel.
    RootPanel.get().add(badWidget);
    assertTrue(badWidget.isAttached());

    // Remove the widget from the panel.
    try {
      RootPanel.get().remove(badWidget);
      fail("Expected IllegalArgumentException");
    } catch (IllegalArgumentException e) {
      // Expected.
    }
    assertFalse(badWidget.isAttached());
    assertNull(badWidget.getParent());
    assertNull(badWidget.getElement().getParentElement());
  }

  /**
   * Create a div and attach it to the {@link RootPanel}.
   * 
   * @return the new div
   */
  private Element createAttachedDivElement() {
    DivElement elem = Document.get().createDivElement();
    RootPanel.getBodyElement().appendChild(elem);
    return elem;
  }

  private RootPanel createDOM(String id) {
    // create our own part in the document
    Element div = DOM.createDiv();
    div.setId(id);
    Document.get().getBody().appendChild(div);

    // get it via RootPanel
    RootPanel rootPanel = RootPanel.get(id);

    // no elements in the DOM prior to test
    assertEquals(0, rootPanel.getElement().getChildCount());
    return rootPanel;
  }
}