/*
 * Copyright 2013 Corpuslinguistic working group Humboldt University Berlin.
 *
 * 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 annis.gui.components;

import annis.gui.AnnisUI;
import annis.libgui.Helper;
import com.google.common.base.Preconditions;
import com.vaadin.server.FontAwesome;
import com.vaadin.shared.ui.label.ContentMode;
import com.vaadin.ui.Alignment;
import com.vaadin.ui.Button;
import com.vaadin.ui.HorizontalLayout;
import com.vaadin.ui.Label;
import com.vaadin.ui.Panel;
import com.vaadin.ui.UI;
import com.vaadin.ui.VerticalLayout;
import com.vaadin.ui.Window;
import com.vaadin.ui.themes.BaseTheme;

/**
 * A dialog that displays the message of an exception and allows to show
 * the stack trace if requested.
 * 
 * @author Thomas Krause <krauseto@hu-berlin.de>
 */
public class ExceptionDialog extends Window implements Button.ClickListener
{
  private Panel detailsPanel;
  private Label lblStacktrace;
  private Button btDetails;
  private Button btClose;
  private Button btReportBug;
  private Throwable cause;
  private VerticalLayout layout;
  private HorizontalLayout actionsLayout;
  
  public ExceptionDialog(Throwable ex)
  {
    this(ex, null);
  }
  
  public ExceptionDialog(Throwable ex, String caption)
  {
    this.cause = ex;
    Preconditions.checkNotNull(ex);
    
    layout = new VerticalLayout();
    setContent(layout);
    layout.setWidth("100%");
    layout.setHeight("-1");
    
    if(caption == null)
    {
      setCaption("Unexpected error");
    }
    else
    {
      setCaption(caption);
    }
    
    Label lblInfo = new Label("An unexpected error occured.<br />The error message was:", 
      ContentMode.HTML);
    lblInfo.setHeight("-1px");
    lblInfo.setWidth("100%");
    layout.addComponent(lblInfo);
    lblInfo.addStyleName("exception-message-caption");
    
    String message = ex.getMessage();
    if(message == null || message.isEmpty())
    {
      message = "<no message>";
    }
    Label lblMessage = new Label(message);
    lblMessage.addStyleName("exception-message-content");
    lblMessage.setHeight("-1px");
    lblMessage.setWidth("100%");
    layout.addComponent(lblMessage);
    
    actionsLayout = new HorizontalLayout();
    actionsLayout.addStyleName("exception-dlg-details");
    actionsLayout.setWidth("100%");
    actionsLayout.setHeight("-1px");
    layout.addComponent(actionsLayout);
    
    btDetails = new Button("Show Details", this);
    btDetails.setStyleName(BaseTheme.BUTTON_LINK);
    actionsLayout.addComponent(btDetails);
    
    btReportBug = new Button("Report Problem", this);
    btReportBug.setStyleName(BaseTheme.BUTTON_LINK);
    btReportBug.setVisible(false);
    btReportBug.setIcon(FontAwesome.ENVELOPE_O);
    UI ui = UI.getCurrent();
    if(ui instanceof AnnisUI)
    {
      btReportBug.setVisible(((AnnisUI) ui).canReportBugs());
    }
    actionsLayout.addComponent(btReportBug);
    actionsLayout.setComponentAlignment(btDetails, Alignment.TOP_LEFT);
    actionsLayout.setComponentAlignment(btReportBug, Alignment.TOP_RIGHT);
    
    lblStacktrace = new Label(Helper.convertExceptionToMessage(ex), ContentMode.PREFORMATTED);
    detailsPanel = new Panel(lblStacktrace);
    detailsPanel.setWidth("100%");
    detailsPanel.setHeight("300px");
    detailsPanel.setVisible(false);
    lblStacktrace.setSizeUndefined();
    lblStacktrace.setVisible(true);
    layout.addComponent(detailsPanel);
    
    btClose = new Button("OK", this);
    layout.addComponent(btClose);
    
    layout.setComponentAlignment(btClose, Alignment.BOTTOM_CENTER);
    layout.setExpandRatio(detailsPanel, 0.0f);
    layout.setExpandRatio(actionsLayout, 1.0f);
  }

  @Override
  public void buttonClick(Button.ClickEvent event)
  {
    if(event.getButton() == btDetails)
    {
      if(detailsPanel.isVisible())
      {
        detailsPanel.setVisible(false);
        btDetails.setCaption("Show Details");
        layout.setExpandRatio(detailsPanel, 0.0f);
        layout.setExpandRatio(actionsLayout, 1.0f);
      }
      else
      {
        detailsPanel.setVisible(true);
        btDetails.setCaption("Hide Details");
        layout.setExpandRatio(detailsPanel, 1.0f);
        layout.setExpandRatio(actionsLayout, 0.0f);
      }
    }
    else if(event.getButton() == btClose)
    {
      this.close();
    }
    else if(event.getButton() == btReportBug)
    {
      this.close();
      UI ui = UI.getCurrent();
      if(ui instanceof AnnisUI)
      {
        ((AnnisUI) ui).reportBug(cause);
      }
    }
  }
  
  
  public static void show(Throwable ex)
  {
    show(ex, null);
  }
  
  public static void show(Throwable ex, String caption)
  {
    ExceptionDialog dlg = new ExceptionDialog(ex);
    dlg.setClosable(true);
    dlg.setModal(true);
    dlg.setResizable(true);
    dlg.setWidth("500px");
    dlg.setHeight("-1");
    
    UI.getCurrent().addWindow(dlg);
    dlg.center();
  }
}