/**
 * WordSorter.java
 *
 * @author Jeff Ondich
 * @version 2/23/05
 *
 * Illustrates three new concepts: ArrayList, file input,
 *  and the use of main() as a unit test.
 *
 * A WordSorter object reads a list of words from a file
 * and can print and sort the list.
 */

import java.util.*;
import java.io.*;

public class WordSorter
{
    ArrayList<String>   wordList;

    public WordSorter( String fileName ) throws IOException
    {
        String line;

        wordList = new ArrayList<String>();

        Scanner fileScanner = new Scanner( new File( fileName ) );

        while( fileScanner.hasNext() )
        {
            line = fileScanner.nextLine();
            wordList.add( (String)line );
        }
    } 


    public void sort()
    {
        int j, k;

        for( j=1; j < wordList.size(); j++ )
        {
            String temp = wordList.get( j );
            for( k=j-1; k >= 0
                    &&  temp.compareTo( wordList.get( k ) ) < 0; k-- )
            {
                wordList.set( k+1, wordList.get( k ) );
            }

            wordList.set( k + 1, temp );
        }
    }


    public void print()
    {
        int nWords = wordList.size();
        for( int k=0; k < nWords; k++ )
        {
            System.out.println( wordList.get( k ) );
        }
    }


    // When you have a class that you intend to instantiate in a complex program,
    // it's a good idea to write some testing code that tests just the features
    // of your class.  For example, WordSorter might easily get used in a more
    // complex program.  Yet we should definitely test its features (sort and print,
    // in particular) in isolation to ferret out local bugs.  This testing of a 
    // small piece of code in isolation from the larger system it's in is called
    // "unit testing".
    //
    // A great place to put unit testing code for a Java class is in main within
    // the class itself.  Thus, if you want to run the unit test, you use
    // the command "java WordSorter".  But if you have a bigger program, you
    // might write a class called "BigWordProgram" with its own main method,
    // and then invoke the bigger program via "java BigWordProgram".  The
    // unit test for WordSorter is never invoked in this context, which is as
    // it should be.

    public static void main( String[] args ) throws IOException
    {
        if( args.length == 0 )
        {
            System.out.println( "Usage: java WordSorter wordFile" );
            return;
        }


        WordSorter ws = new WordSorter( args[0] );

        System.out.println( "---- Unsorted ----" );
        ws.print();

        System.out.println( "\n\n---- Sorted ----" );
        ws.sort();
        ws.print();
    }
}