package jas2.util.pluginmanager;

import java.util.*;
/**This class is used to compare version numbers.
 * The only method in this class converts both the currentversion  and the latest version (method arguments)
 * strings into string chunks (i.e. if string = 2.0.4, then ints are 2,0,4).
 * The string chunks are then converted to ints and compared one at a time. If a latest version chunk
 * is > than a current version chunk an update is available and UPDATEVERSION is returned. If all chunks are
 * equal then NOUPDATEVERSION is available. If a latest chunk is < current chunk or Strings can't be converted
 * to ints an Exception is thrown.
 */
public class VersionNumberCompare
{

	public final static int VERSIONCHECKERROR =0;
    public final static int UPDATEVERSION =1;
	public final static int NOUPDATEVERSION =2; 
	
	/**This method converts both the currentversion  and the latest version (method arguments)
	 * strings into string chunks (i.e. if string = 2.0.4, then ints are 2,0,4).
	 * The string chunks are then converted to ints and compared one at a time. If a latest version chunk
	 * is > than a current version chunk an update is available and UPDATEVERSION is returned. If all chunks are
	 * equal then NOUPDATEVERSION is available. The boolean throw exception controls whether the VersionNumberCompare
	 * exception will be thrown when a latestversion chunk is less than a current version chunk.
	 */
	public int compareVersions(String currentversion, String latestversion, boolean throwexception) throws VersionCompareException {
				
		Vector currentversionchunks = new Vector();
		Vector latestversionchunks = new Vector();
				
		String chunk = "";
		for(int i=0;i latestversionchunks.size()){
				latestversionchunks.addElement("0");
			}else if(currentversionchunks.size() < latestversionchunks.size()){
				currentversionchunks.addElement("0");
			}
		}
		
		int latestversionnum=0;
		int currentversionnum=0;
		
		//compare chunks as ints
		for(int i=0;i currentversionnum){
					return UPDATEVERSION;
			}else if(latestversionnum < currentversionnum & throwexception){
				throw new VersionCompareException();
				
			}
				
		}
			//if made it this far then are running current version
		return NOUPDATEVERSION;
				
    }
	
	class VersionCompareException extends Exception{
	
	}
	

}