/*=========================================================================

  Program:   FusionViewer
  Module:    $RCSfile: FilePair.java,v $
  Language:  Java
  Date:      $Date: 2007/02/02 19:26:29 $
  Version:   $Revision: 1.2 $
  
  Copyright (c) Insightful Corporation.  All rights reserved.
  See Copyright.txt for details.
  
  This software is distributed WITHOUT ANY WARRANTY; without even
  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

package org.fusionviewer.io;

import java.io.File;


/**\class FilePair
 *\brief A pair of files.
 */
public class FilePair {
	private String file1, file2;
	
	/**
	 * Construct a file pair from 2 file paths
	 * 
	 * @param file1 the first file
	 * @param file2 the second file
	 */
	public FilePair(String file1, String file2) {
		this.file1 = file1;
		this.file2 = file2;
	}
	
	/**
	 * Construct this file pair as a duplicate of another file pair
	 * 
	 * @param p file pair to copy
	 */
	public FilePair(FilePair p) {
		file1 = p.file1;
		file2 = p.file2;
	}
	
	/**
	 * Return a human-readable representation
	 */
	public String toString() {
		return getFilename(file1) + " / " + getFilename(file2);
	}
	
	/*
	 * Return only the name part of a file path.
	 */
	private String getFilename(String path) {
		if (path.length() <= 0)
			return "";
		
		int pos = path.lastIndexOf(File.separatorChar);
		if (pos < 0)
			return path;
		
		return path.substring(pos + 1);
	}
	
	/**
	 * Access file 1 of the pair
	 * 
	 * @return file 1
	 */
	public String getFile1() {
		return file1;
	}
	
	/**
	 * Access file 2 of the pair
	 * 
	 * @return file 2
	 */
	public String getFile2() {
		return file2;
	}
	
	/**
	 * Determine if this object is equivalent to another FilePair.
	 */
	public boolean equals(Object o) {
		if (o == this)
			return true;
		
		if (!(o instanceof FilePair))
			return false;
		
		FilePair p = (FilePair) o;
		return file1.equals(p.file1) && file2.equals(p.file2);
	}
	
	/**
	 * Compute the hash code for this object.
	 */
	public int hashCode() {
		// Hash code computation from Effective Java by Joshua Block
		int result = 17;
		result = 37 * result + file1.hashCode();
		result = 37 * result + file2.hashCode();
		
		return result;
	}
}