/*
 * SimplyHTML, a word processor based on Java, HTML and CSS
 * Copyright (C) 2002 Ulrich Hilger
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package com.lightdev.app.shtm;

import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.prefs.Preferences;

import javax.swing.Action;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JMenuItem;

/**
 * Base class for plug-ins of application SimplyHTML.
 *
 * <p>Defines some common methods for reuse in plug-ins. All
 * settings such as dockLocation or activation state
 * of a plug-in are stored persistently in a preferences file
 * with the help of class <code>Prefs</code>. The preferences
 * file is valid for the current user, so each user has own
 * plug-in settings.</p>
 *
 * <p>Menus are constructed with the help of class
 * <code>DynamicResource</code>. This class needs menu definitions
 * accessible in a .properties file as described in the API docs
 * of <code>DynamicResource</code>. I.e., methods of class
 * <code>AbstractPlugin</code> only work as defined herein when
 * accompanied by such .properties file accordingly.</p>
 *
 * @author Ulrich Hilger
 * @author Light Development
 * @author <a href="http://www.lightdev.com">http://www.lightdev.com</a>
 * @author <a href="mailto:info@lightdev.com">info@lightdev.com</a>
 * @author published under the terms and conditions of the
 *      GNU General Public License,
 *      for details see file gpl.txt in the distribution
 *      package of this software
 *
 * 
 *
 * @see com.lightdev.app.shtm.DynamicResource
 */

public abstract class AbstractPlugin implements SHTMLPlugin {

  /**
   * construct an AbstractPlugin
   *
   * <p>Constructor may not have parameters so that
   * java.lang.Class.newInstance can be used on it.</p>
   */
  public AbstractPlugin() {
    //System.out.println("AbstractPlugin constructor");
    /*SecurityManager security = System.getSecurityManager();
    if (security != null) {
      security.
    }
    */
    prefs = Preferences.userNodeForPackage( getClass() );
  }

  /**
   * init the plug-in
   *
   * this is called by the PluginManager directly after instantiating the plug-in
   */
  public void initPlugin(SHTMLPanelImpl owner) { this.owner = owner; }

  /**
   * create the plug-in menu
   */
  protected void createPluginMenu() {
    if(pluginMenuId != null) {
      pMenu = owner.dynRes.createMenu(AbstractPlugin.textResources, pluginMenuId);
    }
  }

  /**
   * create the help menu
   */
  protected void createHelpMenu() {
    if(helpMenuId != null) {
      hMenu = owner.dynRes.createMenu(AbstractPlugin.textResources, helpMenuId);
      initHelpMenu();
    }
  }

  public void initHelpMenu() {
  }

  /**
   * create a frame for the component of this plug-in, if it
   * has a JComponent to display.
   */
  protected void createFrame() {
    if(c != null) {
      frame = new JFrame(getGUIName());
      frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
      frame.setSize(300, 400);
      frame.getContentPane().add(c);
    }
    frame.pack();
  }

  /**
   * create, show or hide frame as needed, depending
   * on a given dock location
   *
   * @param location  the dock location of the plug-in, one of
   * DOCK_LOCATION_TOP, DOCK_LOCATION_BOTTOM,
   * DOCK_LOCATION.LEFT, DOCK_LOCATION_RIGHT or DOCK_LOCATION_NONE, if the
   * component shall not dock.
   */
  protected void createFrameAsNeeded(int location) {
    if(location == SHTMLPlugin.DOCK_LOCATION_NONE) {
      if((frame == null) && (c != null)) {
        createFrame();
      }
      if(frame != null) {
        frame.setVisible(true);
      }
    }
    else {
      if(frame != null) {
        frame.setVisible(false);
      }
    }
  }

  /* ----------- SimplyHTML plugin interface implementation start --------- */

  /**
   * initialize the plugin
   *
   * @param owner  the owner of this plug-in
   * @param internalName  the internal name this plug-in shall have
   * @param pluginMenuId  the id of the plug-in menu in the TextResources,
   * or null if no plugin-in menu is to be created
   * @param helpMenuId  the id of the help menu for this plug-in in the
   * TextResources, or null if no help menu is to be created
   */
  public void initPlugin(SHTMLPanel owner, String internalName, String pluginMenuId,
                        String helpMenuId) {
    this.owner = (SHTMLPanelImpl)owner; 
    this.internalName = internalName;
    this.pluginMenuId = pluginMenuId;
    this.helpMenuId = helpMenuId;
    try {
      //System.out.println("AbstractPlugin this.getClass.getName=" + this.getClass().getName());
      if(SHTMLPanelImpl.pluginManager != null) {
          ClassLoader plLoader = SHTMLPanelImpl.pluginManager.getPluginLoader();
          if(plLoader != null) {
              final ResourceBundle resourceBundle = ResourceBundle.getBundle(this.getClass().getName(), Locale.getDefault(), plLoader);
              textResources = new DefaultTextResources(resourceBundle);
              //System.out.println("AbstractPlugin plLoader != null, resources=" + resources);
        }
        else {
          DefaultTextResources  instance = new DefaultTextResources(ResourceBundle.getBundle(this.getClass().getName(), Locale.getDefault()));
        textResources = instance;
          //System.out.println("AbstractPlugin plLoader == null, resources=" + resources);
        }
      }
      else {
        DefaultTextResources  instance = new DefaultTextResources(ResourceBundle.getBundle(this.getClass().getName(), Locale.getDefault()));
        textResources = instance;
        //System.out.println("AbstractPlugin pluginManager = null, resources=" + resources);
      }
      this.active = prefs.getBoolean(internalName + PREFSID_PLUGIN_ACTIVE, true);
      dockLocation = prefs.getInt(internalName + PREFSID_PLUGIN_DOCK_LOCATION,
                                  SHTMLPlugin.DOCK_LOCATION_LEFT);
      createFrameAsNeeded(dockLocation);
    }
    catch(MissingResourceException mre) {
      Util.errMsg(null, this.getClass().getName() +
                  ".properties not found", mre);
    }

  }


  /**
   * set the owner of this plug-in
   *
   * @param owner  the main frame of the instance of SimplyHTML creating the plug-in
   */
  public void setOwner(SHTMLPanelImpl owner) {
    this.owner = owner;
  }

  /**
   * get the owner of this plug-in
   *
   * @return the owner of this plug-in
   */
  public SHTMLPanelImpl getOwner() {
    return owner;
  }

  /**
   * set status of plug-in and persistently store setting in
   * a preferences file
   *
   * @param isActive  indicates whether or not the plug-in shall be activated
   */
  public void setStatus(boolean isActive) {
    this.active = isActive;
    prefs.putBoolean(getInternalName() + PREFSID_PLUGIN_ACTIVE, isActive);
    try {
      prefs.flush();
    }
    catch(Exception e) {
      Util.errMsg(null, e.getMessage(), e);
    }
  }

  /**
   * set the location the component returned by getDockComponent()
   * shall be docked at. Persistently store setting in
   * a preferences file.
   *
   * @param location the dock location, one of DOCK_LOCATION_TOP, DOCK_LOCATION_BOTTOM,
   * DOCK_LOCATION.LEFT, DOCK_LOCATION_RIGHT or DOCK_LOCATION_NONE, if the
   * component shall not dock.
   */
  public void setDockLocation(int location) {
    dockLocation = location;
    prefs.putInt(getInternalName() + PREFSID_PLUGIN_DOCK_LOCATION, location);
    try {
      prefs.flush();
    }
    catch(Exception e) {
      Util.errMsg(null, e.getMessage(), e);
    }
    createFrameAsNeeded(location);
  }

  /**
   * get a menu of actions this plug-in provides.
   *
   * <p><code>JMenu</code> is a decendant of <code>JMenuItem</code>
   * so this method may return a single menu item up to a whole
   * structure of submenus in its return value.</p>
   *
   * @return the plug-in menu
   */
  public JMenuItem getPluginMenu() {
    return pMenu;
  }

  /**
   * get a menu item providing documentation about this
   * plug-in.
   *
   * <p><code>JMenu</code> is a decendant of <code>JMenuItem</code>
   * so this method may return a single menu item up to a whole
   * structure of submenus in its return value.</p>
   *
   * @return a menu item with help for this plug-in
   */
  public JMenuItem getHelpMenu() {
    return hMenu;
  }

  /**
   * get the name of the plug-in as it shall appear
   * on a GUI.
   *
   * @return the name of the plug-in
   */
  public String getGUIName() {
    return "AbstractPlugin";
  }

  /**
   * get the name used internally for this plug-in
   *
   * @return the internal name of this plug-in
   */
  public String getInternalName() {
    return internalName;
  }

  /**
   * get the location the component returned by getDockComponent()
   * shall be docked at.
   *
   * @return the dock location, one of DOCK_LOCATION_TOP, DOCK_LOCATION_BOTTOM,
   * DOCK_LOCATION.LEFT, DOCK_LOCATION_RIGHT or DOCK_LOCATION_NONE, if the
   * component shall not dock.
   */
  public int getDockLocation() {
    return dockLocation;
  }

  /**
   * get the component that this plug-in produces, if any
   *
   * @return the component produced by this plug-in, or null if none
   * is produced
   */
  public JComponent getComponent() {
    return c;
  }

  /**
   * get the status of the plug-in
   *
   * @return true, if activated, false if not
   */
  public boolean isActive() {
    return this.active;
  }

  /**
   * get a string from the resource bundle of the owner of this plug-in
   *
   * @param nm  the name of the string resource to get
   *
   * @return the string with the given name or null, if none is found
   */
  public String getOwnerResString(String nm) {
    return Util.getResourceString(SHTMLPanelImpl.getResources(), nm);
  }

  /**
   * get an action from the resource bundle of the owner of this plug-in
   *
   * @param cmd  the name of the action to get
   *
   * @return the action with the given name or null, if none is found
   */
  public Action getOwnerAction(String cmd) {
    return owner.getDynRes().getAction(cmd);
  }

  /* ----------- SimplyHTML plugin interface implementation end --------- */

  /* --------------- class fields start --------------------- */

  /** TextResources of plug-in */
  public static TextResources textResources;

  /** constant for active setting in preferences file */
  public static final String PREFSID_PLUGIN_ACTIVE = "Active";

  /** constant for dock location setting in preferences file */
  public static final String PREFSID_PLUGIN_DOCK_LOCATION = "DockLocation";

  /** the internal name of this plug-in */
  protected String internalName;

  /** the id in the ResourceFile for the menu of this plug-in */
  protected String pluginMenuId;

  /** the id in the ResourceFile for the help menu of this plug-in */
  protected String helpMenuId;

  /** the plug-in menu provided by this plug-in */
  protected JMenuItem pMenu = null;

  /** the help menu provided by this plug-in */
  protected JMenuItem hMenu = null;

  /** status of plug-in */
  protected boolean active = true;

  /** current dock location */
  protected int dockLocation = SHTMLPlugin.DOCK_LOCATION_LEFT;

  /** component of this plug-in */
  protected JComponent c = null;

  /** JFrame for dockLocation=none */
  protected JFrame frame = null;

  /** reference for user preferences for this class */
  protected Preferences prefs;

  /** the owner of this plug in */
  protected SHTMLPanelImpl owner;

  /* ------------- class fields end ------------------ */
}