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

import java.io.*;
import java.text.DateFormat;
import java.util.Date;

// This file is used to output the contents of a directory

public class ls extends VMachine
{
    public ls()
    {
    }
    
    public void run()
    {
        
        try
        {
            File fileObject;
            String bytelength;
            String time,date;
            int dircount = 0;
            int filecount = 0;
            long totalbytecount = 0;
            
            if (args.length == 0)			// If no argument get the current path
            {
                fileObject = new File(sysapi.findUser(owner).getcurrentPath());		
            }
            else						// If it has arguments add the argument to the current path
            {
                fileObject = new File(sysapi.findUser(owner).getcurrentPath() + args[0]);
            }
            
            if(fileObject.isDirectory())		// Only if it's a directoy continue
            {
                File[] listing = fileObject.listFiles();
                for(int x = 0; x < listing.length; x++)
                {
                    if(listing[x].isDirectory())		// If it's a directory found
                    {
                        dircount++;					// Increment directory count
										// Get time the directory was created
                        time = new String(DateFormat.getTimeInstance().format(new Date(listing[x].lastModified())));
                        for(int i=0;time.length() < 11;i++)
                        {
                            time = " " + time;			// output the time
                        }
                        date = new String(DateFormat.getDateInstance().format(new Date(listing[x].lastModified())));
                        for(int i=0;date.length() < 12;i++)
                        {
                            date = " " + date;			// Output the date
                        }
                        sysapi.Write(OUT,time + "  " +  date + "   [DIR]  " + "        " + listing[x].getName() + "\n");
                    }
                    else if(listing[x].isFile())		// If it's a file that is found
                    {
                        filecount++;				// Increment file count
                        totalbytecount += listing[x].length();	// Get byte count
                        
                        bytelength = new String().valueOf(listing[x].length());
                        for(int i=0;bytelength.length() < 8;i++)
                        {
                            bytelength = " " + bytelength;
                        }
                        time = new String(DateFormat.getTimeInstance().format(new Date(listing[x].lastModified())));
                        for(int i=0;time.length() < 11;i++)
                        {
                            time = " " + time;			// output the time
                        }
                        date = new String(DateFormat.getDateInstance().format(new Date(listing[x].lastModified())));
                        for(int i=0;date.length() < 12;i++)
                        {
                            date = " " + date;			// output the date
                        }
                        sysapi.Write(OUT, time + "  " + date + "         " + bytelength + " " + listing[x].getName() + "\n");
                    }
                }
                if(filecount > 0)					// if files are found print the total number of bytes for all the files 
                {
                    sysapi.Write(OUT,new String().valueOf(totalbytecount) + " Bytes in " + new String().valueOf(filecount) + " File(s)\n");
                }
                if(dircount > 0)					// output number of directories
                {
                    sysapi.Write(OUT,new String().valueOf(dircount) + " Directories(s)\n");
                }
            }
            else								// Error statement if directory doesn't exist.
            {
                sysapi.Write(OUT,"Error -- Directory does not exist.\n");
            }
            sysapi.Exit(vmh,owner);
        }
        catch (Exception err)
        {
            System.out.println("ls threw Exception: " + err);
        }
    }
    
}