// Copyright (C) 2008 The University of Manchester, University of Southampton
// and Cardiff University
package net.sf.taverna.t2.ui.perspectives.myexperiment;

import java.awt.BorderLayout;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Vector;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JSplitPane;
import javax.swing.SwingUtilities;

import org.apache.log4j.Logger;

import net.sf.taverna.t2.ui.perspectives.myexperiment.model.Base64;
import net.sf.taverna.t2.ui.perspectives.myexperiment.model.MyExperimentClient;
import net.sf.taverna.t2.ui.perspectives.myexperiment.model.SearchEngine;
import net.sf.taverna.t2.ui.perspectives.myexperiment.model.Tag;

/*
 * @author Jiten Bhagat
 */
public class TagBrowserTabContentPanel extends JPanel implements ActionListener {
  // CONSTANTS
  private static final double TAG_CLOUD_BALANCE = 0.35;
  private static final double TAG_SIDEBAR_BALANCE = 0.4;
  private static final int TAG_SEARCH_HISTORY_LENGTH = 50;

  private MainComponent pluginMainComponent;
  private MyExperimentClient myExperimentClient;
  private Logger logger;

  // COMPONENTS
  private JSplitPane spMainSplitPane;
  private JSplitPane spTagCloudSplitPane;
  private TagCloudPanel jpMyTags;
  private TagCloudPanel jpAllTags;
  private SearchResultsPanel jpTagSearchResults;
  private JButton bLoginToSeeMyTags;
  private JPanel jpLoginToSeeMyTags;

  // STORAGE
  // last tag for which the search has been made
  private String strCurrentTagCommand;
  private ArrayList<Tag> lTagSearchHistory;

  // Search components
  private SearchEngine searchEngine; // The search engine for executing keyword
  // query searches
  private Vector<Long> vCurrentSearchThreadID; // This will keep ID of the

  // current search thread (there
  // will only be one such thread)

  @SuppressWarnings("unchecked")
  public TagBrowserTabContentPanel(MainComponent component, MyExperimentClient client, Logger logger) {
	super();

	// set main variables to ensure access to myExperiment, logger and the
	// parent component
	this.pluginMainComponent = component;
	this.myExperimentClient = client;
	this.logger = logger;

	// no tag searches have been done yet
	this.strCurrentTagCommand = null;

	// initialise the tag search history
	String strTagSearchHistory = (String) myExperimentClient.getSettings().get(MyExperimentClient.INI_TAG_SEARCH_HISTORY);
	if (strTagSearchHistory != null) {
	  Object oTagSearchHistory = Base64.decodeToObject(strTagSearchHistory);
	  this.lTagSearchHistory = (ArrayList<Tag>) oTagSearchHistory;
	} else {
	  this.lTagSearchHistory = new ArrayList<Tag>();
	}

	this.initialiseUI();

	// initialise the search engine
	vCurrentSearchThreadID = new Vector<Long>(1);
	vCurrentSearchThreadID.add(null); // this is just a placeholder, so that
	// it's possible to update this value
	// instead of adding new ones later
	this.searchEngine = new SearchEngine(vCurrentSearchThreadID, true, jpTagSearchResults, pluginMainComponent, myExperimentClient, logger);

	SwingUtilities.invokeLater(new Runnable() {
	  public void run() {
		spTagCloudSplitPane.setDividerLocation(TAG_CLOUD_BALANCE);
		spMainSplitPane.setDividerLocation(TAG_SIDEBAR_BALANCE);
		spMainSplitPane.setOneTouchExpandable(true);
		spMainSplitPane.setDoubleBuffered(true);
	  }
	});
  }

  private void initialiseUI() {
	// This panel will be used when the user is not logged in - i.e. when can't
	// show "My Tags";
	// log-in button will be shown instead
	this.bLoginToSeeMyTags = new JButton("Login to see your tags", new ImageIcon(MyExperimentPerspective.getLocalResourceURL("login_icon")));
	this.bLoginToSeeMyTags.addActionListener(this);

	this.jpLoginToSeeMyTags = new JPanel();
	this.jpLoginToSeeMyTags.setLayout(new GridBagLayout());
	this.jpLoginToSeeMyTags.add(this.bLoginToSeeMyTags);

	// Create the tag clouds
	this.jpMyTags = new TagCloudPanel("My Tags", TagCloudPanel.TAGCLOUD_TYPE_USER, this, pluginMainComponent, myExperimentClient, logger);
	this.jpAllTags = new TagCloudPanel("All Tags", TagCloudPanel.TAGCLOUD_TYPE_GENERAL, this, pluginMainComponent, myExperimentClient, logger);

	// add the two tag clouds to the left-hand side sidebar
	this.spTagCloudSplitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT);
	this.spTagCloudSplitPane.setTopComponent(this.myExperimentClient.isLoggedIn() ? jpMyTags : jpLoginToSeeMyTags);
	this.spTagCloudSplitPane.setBottomComponent(jpAllTags);

	// create panel for tag search results
	this.jpTagSearchResults = new SearchResultsPanel(this, pluginMainComponent, myExperimentClient, logger);

	this.spMainSplitPane = new JSplitPane();
	this.spMainSplitPane.setLeftComponent(spTagCloudSplitPane);
	this.spMainSplitPane.setRightComponent(this.jpTagSearchResults);

	this.setLayout(new BorderLayout());
	this.add(this.spMainSplitPane, BorderLayout.CENTER);
  }

  // this helper is called when the user logs in / out to swap the
  // view accordingly; 'refresh' on "My Tags" panel should be called
  // immediately after changing the view
  public void setMyTagsShown(boolean bShow) {
	if (bShow) {
	  this.spTagCloudSplitPane.setTopComponent(this.jpMyTags);
	} else {
	  this.spTagCloudSplitPane.setTopComponent(this.jpLoginToSeeMyTags);
	}

	// in either case apply element balance again
	this.spTagCloudSplitPane.setDividerLocation(TAG_CLOUD_BALANCE);
  }

  public void refresh() {
	if (this.myExperimentClient.isLoggedIn()) {
	  // "My Tags" are only accessible when the user has logged in
	  this.jpMyTags.refresh();
	}
	this.jpAllTags.refresh();
  }

  // re-executes the search for the most recent tag
  // (if tag searches have already been done before)
  public void rerunLastTagSearch() {
	if (this.strCurrentTagCommand != null) {
	  this.actionPerformed(new ActionEvent(this.jpAllTags, 0, this.strCurrentTagCommand));
	}
  }

  public TagCloudPanel getMyTagPanel() {
	return (this.jpMyTags);
  }

  public TagCloudPanel getAllTagPanel() {
	return (this.jpAllTags);
  }

  public SearchResultsPanel getTagSearchResultPanel() {
	return (this.jpTagSearchResults);
  }

  public ArrayList<Tag> getTagSearchHistory() {
	return (this.lTagSearchHistory);
  }

  public void actionPerformed(ActionEvent e) {
	if (e.getSource().equals(this.jpTagSearchResults.bRefresh)) {
	  // disable clearing results and re-run last tag search
	  this.getTagSearchResultPanel().bClear.setEnabled(false);
	  this.rerunLastTagSearch();
	} else if (e.getSource().equals(this.jpTagSearchResults.bClear)) {
	  // clear last search and disable re-running it
	  this.strCurrentTagCommand = null;
	  vCurrentSearchThreadID.set(0, null);
	  this.getTagSearchResultPanel().clear();
	  this.getTagSearchResultPanel().setStatus(SearchResultsPanel.NO_SEARCHES_STATUS);
	  this.getTagSearchResultPanel().bClear.setEnabled(false);
	  this.getTagSearchResultPanel().bRefresh.setEnabled(false);
	} else if (e.getSource() instanceof JClickableLabel
		|| e.getSource() instanceof TagCloudPanel) {
	  // one of the tags was clicked as a hyperlink in any TagCloudPanel
	  // (in Resource Preview Browser or in Tag Browser tab) or as a
	  // JClickableLabel
	  if (e.getActionCommand().startsWith("tag:")) {
		// record the tag search command and run the search
		this.strCurrentTagCommand = e.getActionCommand();
		this.searchEngine.searchAndPopulateResults(strCurrentTagCommand);

		// update tag search history making sure that:
		// - there's only one occurrence of this tag in the history;
		// - if this tag was in the history before, it is moved to the 'top'
		// now;
		// - predefined history size is not exceeded
		Tag t = Tag.instantiateTagFromActionCommand(strCurrentTagCommand);
		this.lTagSearchHistory.remove(t);
		this.lTagSearchHistory.add(t);
		if (this.lTagSearchHistory.size() > TAG_SEARCH_HISTORY_LENGTH)
		  this.lTagSearchHistory.remove(0);

		// now update the tag search history panel in 'History' tab
		if (this.pluginMainComponent.getHistoryBrowser() != null) {
		  this.pluginMainComponent.getHistoryBrowser().refreshTagSearchHistory();
		}
	  }
	} else if (e.getSource().equals(this.bLoginToSeeMyTags)) {
	  // set the return "link"
	  this.pluginMainComponent.getMyStuffTab().cTabContentComponentToSwitchToAfterLogin = this;

	  // switch to login tab
	  this.pluginMainComponent.getMainTabs().setSelectedComponent(this.pluginMainComponent.getMyStuffTab());
	}
  }

}