/*
 *  JFLAP - Formal Languages and Automata Package
 * 
 * 
 *  Susan H. Rodger
 *  Computer Science Department
 *  Duke University
 *  August 27, 2009

 *  Copyright (c) 2002-2009
 *  All rights reserved.

 *  JFLAP is open source software. Please see the LICENSE for terms.
 *
 */





package gui.environment;

import file.Codec;
import file.EncodeException;
import file.ParseException;
import gui.editor.EditBlockPane;
import gui.editor.EditorPane;
import gui.grammar.GrammarInputPane;

import java.awt.BorderLayout;
import java.awt.event.ComponentEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.File;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.filechooser.FileFilter;

/**
 * The <CODE>EnvironmentFrame</CODE> is the general sort of frame for holding
 * an environment.
 * 
 * @author Thomas Finley
 */

public class EnvironmentFrame extends JFrame {
	/**
	 * Instantiates a new <CODE>EnvironmentFrame</CODE>. This does not fill
	 * the environment with anything.
	 * 
	 * @param environment
	 *            the environment that the frame is created for
	 */
	public EnvironmentFrame(Environment environment) {
		this.environment = environment;
		environment.addFileChangeListener(new FileChangeListener() {
			public void fileChanged(FileChangeEvent e) {
				refreshTitle();
			}
		});
		initMenuBar();
		this.getContentPane().setLayout(new BorderLayout());
		this.getContentPane().add(environment, BorderLayout.CENTER);

		// Register this frame with the universe.
		myNumber = Universe.registerFrame(this);
		refreshTitle();

		this.addWindowListener(new Listener());
		this.setLocation(50, 50);
		this.setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
		resizeWatcher();
	}
	
	/**
	 * Special constructor to create grammar environment from turing converted 
	 * @param environment
	 * @param isTuring
	 */
	public EnvironmentFrame(Environment environment, int isTuring) {
		this.environment = environment;
		environment.addFileChangeListener(new FileChangeListener() {
			public void fileChanged(FileChangeEvent e) {
				refreshTitle();
			}
		});
		this.setJMenuBar(gui.menu.MenuBarCreator.getMenuBar(this, 0));
		
		this.getContentPane().setLayout(new BorderLayout());
		this.getContentPane().add(environment, BorderLayout.CENTER);

		// Register this frame with the universe.
		myNumber = Universe.registerFrame(this);
		refreshTitle();

		this.addWindowListener(new Listener());
		this.setLocation(50, 50);
		this.setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
		resizeWatcher();
	}

	/**
	 * Returns a simple identifying string for this frame.
	 * 
	 * @return a simple string that identifies this frame
	 */
	public String getDescription() {
		if (environment.getFile() == null)
			return "<untitled" + myNumber + ">";
        else if(environment.myObjects!=null  && environment.getActive()!=null && (environment.getActive() instanceof EditorPane || environment.getActive() instanceof GrammarInputPane)){
            return environment.getActive().getName();        
        }
		else
			return "(" + environment.getFile().getName() + ")";
	}

	/**
	 * Sets the title on this frame to be the name of the file for the
	 * environment, or untitled if there is no file for this environment yet.
	 */
	protected void refreshTitle() {
		String title = DEFAULT_TITLE + " : " + getDescription();
		setTitle(title);
	}

	/**
	 * Initializes the menu bar for this frame.
	 */
	protected void initMenuBar() {
		this.setJMenuBar(gui.menu.MenuBarCreator.getMenuBar(this));
	}

	/**
	 * Returns the environment for this frame.
	 * 
	 * @return the environment for this frame
	 */
	public Environment getEnvironment() {
		return environment;
	}

	/**
	 * Saves the environment's object to a file. This serializes the object
	 * found in the environment, and then writes it to the file of the
	 * environment.
	 * 
	 * @param saveAs
	 *            if <CODE>true</CODE> this will prompt the user with a save
	 *            file dialog box no matter what, otherwise the user will only
	 *            be prompted if the environment has no file
	 * @return <CODE>true</CODE> if the save was a success, <CODE>false</CODE>
	 *         if it was not
	 */
	public boolean save(boolean saveAs) {
		File file = saveAs ? null : environment.getFile();
        Codec codec = (Codec) environment.getEncoder();
        Serializable object = environment.getObject();
        if(environment.myObjects!=null  && environment.getActive()!=null && environment.getActive() instanceof EditorPane){
            EditorPane ep = (EditorPane)environment.getActive();
            File expected = new File(ep.getAutomaton().getFilePath()+ep.getAutomaton().getFileName());
            file = saveAs ? null : expected;
            object = ep.getAutomaton();
        }
        else if(environment.myObjects!=null  && environment.getActive()!=null && environment.getActive() instanceof GrammarInputPane){
            GrammarInputPane ep = (GrammarInputPane)environment.getActive();
            File expected = new File(ep.getGrammar().getFilePath()+ep.getGrammar().getFileName());
            file = saveAs ? null : expected;
            object = ep.getGrammar();
        }
		
        
		boolean blockEdit = false;
		if (environment.getActive() instanceof EditBlockPane) {
			EditBlockPane newPane = (EditBlockPane) environment.getActive();
			object = newPane.getAutomaton();
			blockEdit = true;
		}
		boolean badname = false;
		// Is this encoder valid?
		if (file != null && (codec == null || !codec.canEncode(object))) {
			JOptionPane
					.showMessageDialog(
							this,
							"We cannot write this structure in the same format\n"
									+ "it was read as!  Use Save As to select a new format.",
							"IO Error", JOptionPane.ERROR_MESSAGE);
			return false;
		}

		// Set the file filters.
		FileFilter[] filters = Universe.CHOOSER.getChoosableFileFilters();
		for (int i = 0; i < filters.length; i++)
			Universe.CHOOSER.removeChoosableFileFilter(filters[i]);
		List encoders = Universe.CODEC_REGISTRY.getEncoders(object);
		Iterator it = encoders.iterator();
		while (it.hasNext())
			Universe.CHOOSER.addChoosableFileFilter((FileFilter) it.next());
		if (codec != null && codec.canEncode(object)) {
			Universe.CHOOSER.setFileFilter(codec);
		} else {
			Universe.CHOOSER.setFileFilter((FileFilter) encoders.get(0));
		}
        if(saveAs) Universe.CHOOSER.setDialogTitle("Save As");
		// Check the name.
		if (file != null && codec != null) {
			// Get the suggested file name.
			String filename = file.getName();
			String newname = codec.proposeFilename(filename, object);
			if (!filename.equals(newname)) {
				int result = JOptionPane.showConfirmDialog(this,
						"To save as a " + codec.getDescription() + ",\n"
								+ "JFLAP wants to save " + filename
								+ " to a new file\n" + "named " + newname
								+ ".  Is that OK?");
				switch (result) {
				case JOptionPane.CANCEL_OPTION:
					// They cancelled. Get out of here.
					return false;
				case JOptionPane.NO_OPTION:
					// No, it's not OK! Use the original name.
					break;
				case JOptionPane.YES_OPTION:
					// Yes, we want the new name! Change the file.
					file = new File(file.getParent(), newname);
					badname = true;
				}
			}
		}
		// The save as loop.
		while (badname || file == null) {
			if (!badname) {
				int result = Universe.CHOOSER.showSaveDialog(this);
				if (result != JFileChooser.APPROVE_OPTION)
					return false;
				file = Universe.CHOOSER.getSelectedFile();
                if(file != null){                   
//                  Get the suggested file name.
                    String filename = file.getName();
                    codec = (Codec) Universe.CHOOSER.getFileFilter();
                    file = new File(Universe.CHOOSER.getCurrentDirectory(), codec.proposeFilename(
                            filename, object));
                    // Check for the existing file.
                }
				else{
                    JOptionPane.showMessageDialog(null, "JFLAP could not determine the selected file name.  Try again.", "Error", JOptionPane.ERROR_MESSAGE);
                    file = null;
				    continue;             
                }
			}
			badname = false;
			if (file.exists()) {
				int result = JOptionPane.showConfirmDialog(this, "Overwrite "
						+ file.getName() + "?");
				switch (result) {
				case JOptionPane.CANCEL_OPTION:
					return false;
				case JOptionPane.NO_OPTION:
					file = null;
					continue;
				default:
				}
			}
		}
		// //System.out.println("CODEC: "+codec.getDescription());
		Universe.CHOOSER.resetChoosableFileFilters();

		// Use the codec to save the file.
		try {
			codec.encode(object, file, null);
			if (!blockEdit)
				environment.setFile(file);
			environment.setEncoder(codec);
			environment.clearDirty();
			return true;
		} catch (ParseException e) {
			JOptionPane.showMessageDialog(this, e.getMessage(), "Write Error",
					JOptionPane.ERROR_MESSAGE);
			return false;
		} catch(EncodeException e){
            JOptionPane.showMessageDialog(this, e.getMessage(), "Write Error",
                    JOptionPane.ERROR_MESSAGE);
            return false;
        }
	}

	/**
	 * Attempts to close an environment frame.
	 * 
	 * @return <CODE>true</CODE> if the window was successfully closed, <CODE>false</CODE>
	 *         if the window could not be closed at this time (probably user
	 *         intervention)
	 */
	public boolean close() {
		if (environment.isDirty()) {
			File file = environment.getFile();
			String title;
			if (file == null)
				title = "untitled";
			else
				title = file.getName();

			int result = JOptionPane.showConfirmDialog(this, "Save " + title
					+ " before closing?");
			if (result == JOptionPane.CANCEL_OPTION)
				return false;
			if (result == JOptionPane.YES_OPTION)
				save(false);
			//called by using alt-f4 in the window
			if (result==-1)
				return false;
		}
		dispose();
		Universe.unregisterFrame(this);
		return true;
	}
	
	public void resizeWatcher(){
		 this.addComponentListener(new java.awt.event.ComponentAdapter()
	                {
	                        public void componentResized(ComponentEvent event)
	                        {
	                                environment.resizeSplit();
	                        }
	                });
	}




	/**
	 * Returns the string that describes this frame.
	 * 
	 * @return the string that describes this frame
	 */
	public String toString() {
		return getDescription();
	}

	/** The environment that this frame displays. */
	private Environment environment;

	/** The number of this environment frames. */
	private int myNumber = 0xdeadbeef;

	/** The default title for these frames. */
	private static final String DEFAULT_TITLE = "JFLAP";

	/**
	 * The window listener for this frame.
	 */
	private class Listener extends WindowAdapter {
		public void windowClosing(WindowEvent event) {
			close();
		}
	}




}