//File:  sort.java
//CS 471 - Operating Systems Project
//Dennis Pereira, Ely Soto, John Cavalieri

//the sort command was not documented as a requirement in any of the
//specifications, however, we have implemented a version of it in this file
//sort accepts two option flags (-a) for ascending order and (-d) for descending order
//it is intended to be applied to strings

import java.util.*;

public class sort extends VMachine {
    
    public sort() {
    }
    
    public void run()
    {
        try
        {
		//if there are no option flags, then the default is ascending order
		//or if the flag is (-a)
            if(args.length == 0 || (args.length > 0 && args[0].toLowerCase().compareTo("-a")==0))
            {
			//then create a new vector used to store the strings
                Vector strvector = new Vector(2,2);
			//take input
                String str = sysapi.Read(IN);
			//while there is still input
                while(str.compareTo("") != 0)
                {
			//add the input to the vector
                    strvector.add(str);
			//wait for more input
                    str = sysapi.Read(IN);
                }
                
			//convert input to an array
                Object[] strarray = strvector.toArray();
			//sort the array
                Arrays.sort(strarray);
                
			//write the array to the desired output
                for(int i =0;i<strarray.length;i++)
                {
                    sysapi.Write(OUT,strarray[i] + "\n");
                }
            }
		//if the option flag is (-d)
		//do all the same things as above, except sort in reverse order
            else if(args.length > 0 && args[0].toLowerCase().compareTo("-d")==0)
            {
                Vector strvector = new Vector(2,2);
                
                String str = sysapi.Read(IN);
                while(str.compareTo("") != 0)
                {
                    strvector.add(str);
                    str = sysapi.Read(IN);
                }
                
                Object[] strarray = strvector.toArray();
			//sort the array in descending order
                Arrays.sort(strarray,Collections.reverseOrder());
                
                for(int i = 0; i < strarray.length; i++)
                {
                    sysapi.Write(OUT,strarray[i] + "\n");
                }
            }
        }
        catch(Exception ex)
        {
            System.out.println(ex);
        }
        sysapi.Exit(vmh,owner);
    }
}