/*
 * The contents of this file are subject to the terms of the Common Development and
 * Distribution License (the License). You may not use this file except in compliance with the
 * License.
 *
 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
 * specific language governing permission and limitations under the License.
 *
 * When distributing Covered Software, include this CDDL Header Notice in each file and include
 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
 * Header, with the fields enclosed by brackets [] replaced by your own identifying
 * information: "Portions Copyright [year] [name of copyright owner]".
 *
 * Copyright 2006-2010 Sun Microsystems, Inc.
 * Portions Copyright 2013-2015 ForgeRock AS.
 */
package org.opends.quicksetup.ui;

import java.awt.CardLayout;
import java.awt.Component;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import java.util.HashMap;
import java.util.HashSet;

import javax.swing.Box;
import javax.swing.JEditorPane;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.event.HyperlinkEvent;
import javax.swing.event.HyperlinkListener;

import org.opends.quicksetup.event.ButtonActionListener;
import org.opends.quicksetup.event.ButtonEvent;
import org.opends.quicksetup.ProgressDescriptor;
import org.opends.quicksetup.UserData;
import org.opends.quicksetup.util.HtmlProgressMessageFormatter;
import org.opends.quicksetup.util.ProgressMessageFormatter;
import org.opends.quicksetup.util.URLWorker;
import org.forgerock.i18n.LocalizableMessage;
import static org.opends.messages.QuickSetupMessages.*;

/**
 * This is an abstract class that is extended by all the classes that are in
 * the CardLayout of CurrentStepPanel.  All the panels that appear on the
 * top-right side of the dialog extend this class: WelcomePane, ReviewPanel,
 * etc.
 *
 */
public abstract class QuickSetupStepPanel extends QuickSetupPanel
implements HyperlinkListener
{
  private static final long serialVersionUID = -1983448318085588324L;
  private JPanel inputContainer;
  private Component inputPanel;

  private HashSet<ButtonActionListener> buttonListeners = new HashSet<>();

  private ProgressMessageFormatter formatter;

  private static final String INPUT_PANEL = "input";
  private static final String CHECKING_PANEL = "checking";

  private boolean isCheckingVisible;

  /**
   * We can use a HashMap (not multi-thread safe) because all
   * the calls to this object are done in the event-thread.
  */
  private HashMap<String, URLWorker> hmURLWorkers = new HashMap<>();

  /**
   * Creates a default instance.
   * @param application Application this panel represents
   */
  public QuickSetupStepPanel(GuiApplication application) {
    super(application);
  }

  /**
   * Initializes this panel.  Called soon after creation.  In general this
   * is where maps should be populated etc.
   */
  public void initialize() {
    createLayout();
  }

  /**
   * Called just before the panel is shown: used to update the contents of the
   * panel with new UserData (used in particular in the review panel).
   *
   * @param data the new user data.
   */
  public void beginDisplay(UserData data)
  {
  }

  /**
   * Called just after the panel is shown: used to set focus properly.
   */
  public void endDisplay()
  {
  }

  /**
   * Tells whether the method beginDisplay can be long and so should be called
   * outside the event thread.
   * @return <CODE>true</CODE> if the method beginDisplay can be long and so
   * should be called outside the event thread and <CODE>true</CODE> otherwise.
   */
  public boolean blockingBeginDisplay()
  {
    return false;
  }

  /**
   * Called when a progress change must be reflected in the panels.  Only
   * ProgressPanel overwrites this method and for all the others it stays empty.
   * @param descriptor the descriptor of the Installation progress.
   */
  public void displayProgress(ProgressDescriptor descriptor)
  {
  }

  /**
   * Implements HyperlinkListener.  When the user clicks on a link we will
   * try to display the associated URL in the browser of the user.
   *
   * @param e the HyperlinkEvent.
   */
  public void hyperlinkUpdate(HyperlinkEvent e)
  {
    if (e.getEventType() == HyperlinkEvent.EventType.ACTIVATED)
    {
      String url = e.getURL().toString();
      if (!isURLWorkerRunning(url))
      {
        /*
         * Only launch the worker if there is not already a worker trying to
         * display this URL.
         */
        URLWorker worker = new URLWorker(this, url);
        startWorker(worker);
      }
    }
  }

  /**
   * Returns the value corresponding to the provided FieldName.
   * @param fieldName the FieldName for which we want to obtain the value.
   * @return the value corresponding to the provided FieldName.
   */
  public Object getFieldValue(FieldName fieldName)
  {
    return null;
  }

  /**
   * Marks as invalid (or valid depending on the value of the invalid parameter)
   * a field corresponding to FieldName.  This basically implies udpating the
   * style of the JLabel associated with fieldName (the association is done
   * using the LabelFieldDescriptor class).
   * @param fieldName the FieldName to be marked as valid or invalid.
   * @param invalid whether to mark the field as valid or invalid.
   */
  public void displayFieldInvalid(FieldName fieldName, boolean invalid)
  {
  }

  /**
   * Returns the minimum width of the panel.  This is used to calculate the
   * minimum width of the dialog.
   * @return the minimum width of the panel.
   */
  public int getMinimumWidth()
  {
    // Just take the preferred width of the inputPanel because the
    // instructionsPanel
    // are too wide.
    int width = 0;
    if (inputPanel != null)
    {
      width = (int) inputPanel.getPreferredSize().getWidth();
    }
    return width;
  }

  /**
   * Returns the minimum height of the panel.  This is used to calculate the
   * minimum height of the dialog.
   * @return the minimum height of the panel.
   */
  public int getMinimumHeight()
  {

    return (int) getPreferredSize().getHeight();
  }


  /**
   * Adds a button listener.  All the button listeners will be notified when
   * the buttons are clicked (by the user or programatically).
   * @param l the ButtonActionListener to be added.
   */
  public void addButtonActionListener(ButtonActionListener l)
  {
    buttonListeners.add(l);
  }

  /**
   * Removes a button listener.
   * @param l the ButtonActionListener to be removed.
   */
  public void removeButtonActionListener(ButtonActionListener l)
  {
    buttonListeners.remove(l);
  }

  /**
   * This method displays a working progress icon in the panel.
   * @param visible whether the icon must be displayed or not.
   */
  public void setCheckingVisible(boolean visible)
  {
    if (visible != isCheckingVisible && inputContainer != null)
    {
      CardLayout cl = (CardLayout) inputContainer.getLayout();
      if (visible)
      {
        cl.show(inputContainer, CHECKING_PANEL);
      }
      else
      {
        cl.show(inputContainer, INPUT_PANEL);
      }
      isCheckingVisible = visible;
    }
  }

  /**
   * Returns the text to be displayed in the progress label for a give icon
   * type.
   * @param iconType the icon type.
   * @return the text to be displayed in the progress label for a give icon
   * type.
   */
  protected LocalizableMessage getTextForIcon(UIFactory.IconType iconType)
  {
    LocalizableMessage text;
    if (iconType == UIFactory.IconType.WAIT)
    {
      text = INFO_GENERAL_CHECKING_DATA.get();
    }
    else
    {
      text = LocalizableMessage.EMPTY;
    }
    return text;
  }

  /**
   * Notifies the button action listeners that an event occurred.
   * @param ev the button event to be notified.
   */
  protected void notifyButtonListeners(ButtonEvent ev)
  {
    for (ButtonActionListener l : buttonListeners)
    {
      l.buttonActionPerformed(ev);
    }
  }
  /**
   * Creates the layout of the panel.
   *
   */
  protected void createLayout()
  {
    setLayout(new GridBagLayout());

    setOpaque(false);

    GridBagConstraints gbc = new GridBagConstraints();

    Component titlePanel = createTitlePanel();
    Component instructionsPanel = createInstructionsPanel();
    inputPanel = createInputPanel();

    boolean somethingAdded = false;

    if (titlePanel != null)
    {
      gbc.weightx = 1.0;
      gbc.weighty = 0.0;
      gbc.gridwidth = GridBagConstraints.REMAINDER;
      gbc.fill = GridBagConstraints.HORIZONTAL;
      gbc.anchor = GridBagConstraints.NORTHWEST;
      gbc.insets.left = 0;
      add(titlePanel, gbc);
      somethingAdded = true;
    }

    if (instructionsPanel != null)
    {
      if (somethingAdded)
      {
        gbc.insets.top = UIFactory.TOP_INSET_PRIMARY_FIELD;
      } else
      {
        gbc.insets.top = 0;
      }
      gbc.insets.left = 0;
      gbc.weightx = 1.0;
      gbc.weighty = 0.0;
      gbc.gridwidth = GridBagConstraints.REMAINDER;
      gbc.fill = GridBagConstraints.BOTH;
      gbc.anchor = GridBagConstraints.NORTHWEST;
      add(instructionsPanel, gbc);
      somethingAdded = true;
    }

    if (inputPanel != null)
    {
      inputContainer = new JPanel(new CardLayout());
      inputContainer.setOpaque(false);
      if (requiresScroll())
      {
        inputContainer.add(UIFactory.createBorderLessScrollBar(inputPanel),
            INPUT_PANEL);
      }
      else
      {
        inputContainer.add(inputPanel, INPUT_PANEL);
      }

      JPanel checkingPanel = UIFactory.makeJPanel();
      checkingPanel.setLayout(new GridBagLayout());
      checkingPanel.add(UIFactory.makeJLabel(UIFactory.IconType.WAIT,
          INFO_GENERAL_CHECKING_DATA.get(),
          UIFactory.TextStyle.PRIMARY_FIELD_VALID),
          new GridBagConstraints());
      inputContainer.add(checkingPanel, CHECKING_PANEL);

      if (somethingAdded)
      {
        gbc.insets.top = UIFactory.TOP_INSET_INPUT_SUBPANEL;
      } else
      {
        gbc.insets.top = 0;
      }
      gbc.weightx = 1.0;
      gbc.weighty = 1.0;
      gbc.gridwidth = GridBagConstraints.REMAINDER;
      gbc.fill = GridBagConstraints.BOTH;
      gbc.anchor = GridBagConstraints.NORTHWEST;
      gbc.insets.left = 0;
      add(inputContainer, gbc);
    }
    else
    {
      addVerticalGlue(this);
    }
  }

  /**
   * Creates and returns the panel that contains the layout specific to the
   * panel.
   * @return the panel that contains the layout specific to the
   * panel.
   */
  protected abstract Component createInputPanel();

  /**
   * Returns the title of this panel.
   * @return the title of this panel.
   */
  protected abstract LocalizableMessage getTitle();

  /**
   * Returns the instruction of this panel.
   * @return the instruction of this panel.
   */
  protected abstract LocalizableMessage getInstructions();

  /**
   * Commodity method that adds a vertical glue at the bottom of a given panel.
   * @param panel the panel to which we want to add a vertical glue.
   */
  protected void addVerticalGlue(JPanel panel)
  {
    GridBagConstraints gbc = new GridBagConstraints();
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gbc.insets = UIFactory.getEmptyInsets();
    gbc.weighty = 1.0;
    gbc.fill = GridBagConstraints.VERTICAL;
    panel.add(Box.createVerticalGlue(), gbc);
  }

  /**
   * This method is called by the URLWorker when it has finished its task.
   * @param worker the URLWorker that finished its task.
   */
  public void urlWorkerFinished(URLWorker worker)
  {
    hmURLWorkers.remove(worker.getURL());
  }

  /**
   * Tells whether the input panel should have a scroll or not.
   * @return <CODE>true</CODE> if the input panel should have a scroll and
   * <CODE>false</CODE> otherwise.
   */
  protected boolean requiresScroll()
  {
    return true;
  }

  /**
   * Returns the formatter that will be used to display the messages in this
   * panel.
   * @return the formatter that will be used to display the messages in this
   * panel.
   */
  ProgressMessageFormatter getFormatter()
  {
    if (formatter == null)
    {
      formatter = new HtmlProgressMessageFormatter();
    }
    return formatter;
  }

  /**
   * Creates and returns the title panel.
   * @return the title panel.
   */
  private Component createTitlePanel()
  {
    Component titlePanel = null;
    LocalizableMessage title = getTitle();
    if (title != null)
    {
      JPanel p = new JPanel(new GridBagLayout());
      p.setOpaque(false);
      GridBagConstraints gbc = new GridBagConstraints();
      gbc.anchor = GridBagConstraints.NORTHWEST;
      gbc.fill = GridBagConstraints.HORIZONTAL;
      gbc.weightx = 0.0;
      gbc.gridwidth = GridBagConstraints.RELATIVE;

      JLabel l =
          UIFactory.makeJLabel(UIFactory.IconType.NO_ICON, title,
              UIFactory.TextStyle.TITLE);
      p.add(l, gbc);

      gbc.weightx = 1.0;
      gbc.gridwidth = GridBagConstraints.REMAINDER;
      p.add(Box.createHorizontalGlue(), gbc);

      titlePanel = p;
    }
    return titlePanel;
  }

  /**
   * Creates and returns the instructions panel.
   * @return the instructions panel.
   */
  protected Component createInstructionsPanel()
  {
    Component instructionsPanel = null;
    LocalizableMessage instructions = getInstructions();
    if (instructions != null)
    {
      JEditorPane p =
          UIFactory.makeHtmlPane(instructions, UIFactory.INSTRUCTIONS_FONT);
      p.setOpaque(false);
      p.setEditable(false);
      p.addHyperlinkListener(this);
      instructionsPanel = p;
    }
    return instructionsPanel;
  }

  /**
   * Returns <CODE>true</CODE> if there is URLWorker running for the given url
   * and <CODE>false</CODE> otherwise.
   * @param url the url.
   * @return <CODE>true</CODE> if there is URLWorker running for the given url
   * and <CODE>false</CODE> otherwise.
   */
  private boolean isURLWorkerRunning(String url)
  {
    return hmURLWorkers.get(url) != null;
  }

  /**
   * Starts a worker.
   * @param worker the URLWorker to be started.
   */
  private void startWorker(URLWorker worker)
  {
    hmURLWorkers.put(worker.getURL(), worker);
    worker.startBackgroundTask();
  }
}