/*
 * A CCNx command line utility.
 *
 * Copyright (C) 2008, 2009, 2012 Palo Alto Research Center, Inc.
 *
 * This work is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License version 2 as published by the
 * Free Software Foundation. 
 * This work 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., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */


package org.ccnx.ccn.utils.explorer;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.swing.JEditorPane;
import javax.swing.JFileChooser;
import javax.swing.JFrame;

import org.ccnx.ccn.CCNHandle;
import org.ccnx.ccn.io.CCNFileInputStream;
import org.ccnx.ccn.protocol.ContentName;


/**
 * Class for retrieving content on a separate thread.  This is called by the
 * ContentExplorer for displaying txt in the preview pane, popup windows, saving
 * content to a local filesystem and for interfacing with media players (upcoming).
 */
public class LocalSaveContentRetriever implements Runnable {

	private ContentName name = null;
	private CCNHandle handle = null;
	private int readsize = 1024;
	private JEditorPane htmlPane = null;
	
	/**
	 * Constructor for the LocalSaveContentRetriever.
	 * 
	 * @param h CCNHandle to use for downloading the content
	 * @param n ContentName of the content object name to download
	 * @param p Preview pane to show download status
	 */
	public LocalSaveContentRetriever(CCNHandle h, ContentName n, JEditorPane p){
		handle = h;
		name = n;
		htmlPane = p;
	}
	
	
	/**
	 * run() method for the thread that saves content to a filesystem.  This method
	 * creates and displays a JFileChooser.  The user selects a location to save the
	 * content.  If the selected file cannot be created or written to, the method
	 * returns and the content is not retrieved.  Status for this operation is displayed
	 * in the ContentExplorer preview pane.
	 * 
	 */
	public void run() {
		
		if (name == null) {
			System.err.println("Must set file name for retrieval");
			return;
		}
				
		if (handle == null) {
			System.err.println("Must set CCNHandle");
			return;
		}
		
		if (htmlPane == null) {
			System.err.println("Must set JEditorPane");
			return;
		}

		JFrame frame = new JFrame();
		JFileChooser chooser = new JFileChooser();
		File f = null;
		chooser.setCurrentDirectory(null);
		int returnVal = chooser.showSaveDialog(frame);

        if (returnVal == JFileChooser.APPROVE_OPTION) {
        	f = chooser.getSelectedFile();
        } else {
        	//the user hit cancel
        	htmlPane.setText("Save File cancelled");
        	return;
        }
		boolean overwrite = false;
        //check the file and make sure we can write to it
        try {
        	if (f.exists()) {
        		//the file exists...   don't need to create a new file
        		htmlPane.setText("Overwriting contents of "+f.getPath());
        		overwrite = true;
        	} else {
        	//we need to create the file
        		f.createNewFile();
        	}
        	
        	if (f.canWrite()) {
        	} else {
        		htmlPane.setText("The ContentExplorer is unable to write the content to the specified file.");
        		return;
        	}
        } catch (IOException e) {
        	System.err.println("could not create "+f.getPath() +" for saving content to filesystem");
        	htmlPane.setText("could not create "+f.getPath() +" for saving content to filesystem");
        }
        		
		try{
			if (!overwrite)
				htmlPane.setText("saving "+name+" to "+ f.getCanonicalPath());
			else
				htmlPane.setText("overwriting contents of "+ f.getCanonicalPath()+" to save "+name);
			
			CCNFileInputStream fis = new CCNFileInputStream(name, handle);
			FileOutputStream output = new FileOutputStream(f);
			
			byte [] buffer = new byte[readsize];
			
			int readcount = 0;
			while ((readcount = fis.read(buffer)) != -1){
				output.write(buffer, 0, readcount);
				output.flush();
			}
			htmlPane.setText("Saved "+name+" to "+f.getCanonicalPath());	
		} catch (Exception e) {
			htmlPane.setText("Could not save "+name+" to "+f.getPath() +" This may be a prefix for an object or just may not be available at this time.");
			System.err.println("Could not retrieve file: "+name);
		}
		
	}

}