fildir program

import java.util.*;


public class fildir{

    int globalID;
    fildir()
    {
        Scanner input = new Scanner(System.in);

        HashMap<String, String> map;
        Directory head = null;
        Directory curr = null;
        int cse = 1;
        while(true)
        {
            String command = input.next();

            if(command.equals("end")) break;

            if(command.equals("init"))
            {
                System.out.println("File system #" + cse + ":\n");
                head = new Directory("home", 0, null);
                curr = head;
                map = new HashMap<String, String>();
                globalID++;
            }
            else if(command.equals("mkdir"))
            {
                String name = input.next();
                head = AddDirectory(head, name, curr);
            }
            else if(command.equals("mkfile"))
            {
                String name = input.next();
                head = AddFile(head, name, curr);
            }
            else if(command.equals("cd"))
            {
                String[] path = input.next().split("/");

                for(int i = 0; i < path.length; i++)
                {
                    if(path[i].equals(".."))
                    {
                        //need to move up
                        curr = curr.up;
                    }
                    else
                    {
                        //need to move forward.
                        for(int j = 0; j < curr.sublist.size(); j++)
                        {
                            if(curr.sublist.get(j).name == path[i])
                                curr = curr.sublist.get(j);
                        }

                    }
                }
            }
            else if(command.equals("ls"))
            {
                Directory temp = curr;
                String path = getPath(temp);

                System.out.println("Listing for " + path + ":");
                printDirectories(curr);
                printFiles(curr);
                System.out.println();
            }



        }
    }

    String getPath(Directory curr)
    {
        String path = "/" + curr.name;
        curr = curr.up;
        while(curr != null)
        {
            path = "/" + curr.name + path;
        }

        return path;
    }

    void printDirectories(Directory curr)
    {
        Collections.sort(curr.sublist);
        for(int i = 0; i < curr.sublist.size(); i++)
            System.out.println(curr.sublist.get(i).name);

    }

    void printFiles(Directory curr)
    {
        Collections.sort(curr.files);
        for(int i = 0; i < curr.files.size(); i++)
            System.out.println(curr.files.get(i));
    }

    Directory AddDirectory(Directory head, String name, Directory curr)
    {
        if(head.id == curr.id)
        {
            head.sublist.add(new Directory(name, globalID, head));
            globalID++;
            return head;
        }

        for(int i = 0; i < head.sublist.size(); i++)
        {
            Directory t = AddDirectory(head.sublist.get(i), name, curr);

            if(t != null)
                return head;

        }
        return null;
    }

    Directory AddFile(Directory head, String name, Directory curr)
    {
        if(head.id == curr.id)
        {
            head.files.add(name);
            return head;
        }

        for(int i = 0; i < head.sublist.size(); i++)
        {
            Directory t = AddFile(head.sublist.get(i), name, curr);

            if(t != null)
                return head;

        }
        return null;
    }
    public static void main(String[] args)
    {
        new fildir();
    }
}

class Directory implements Comparable<Directory>
{
    String name;
    ArrayList<Directory> sublist;
    ArrayList<String> files;
    int id;
    Directory up;
    Directory(String name, int id, Directory up)
    {
        this.name = name;
        this.id = id;
        this.up = up;
        sublist = new ArrayList<Directory>();
        files = new ArrayList<String>();

    }

    @Override
    public int compareTo(Directory other)
    {
        return this.name.compareTo(other.name);
    }
}

/*
init
mkfile temp
mkdir COURSES
mkfile junk
mkdir CONTESTS
ls
cd COURSES
mkdir COP4020
cd COP4020
mkfile exam1
mkfile exam3
mkfile exam2
mkfile EXAM1
ls
cd ..
mkdir COT4810
cd COT4810
cd ../../CONTESTS
mkdir REAL
mkfile scoring
mkdir PRACTICE
ls
cd REAL
mkfile temp
mkdir junk
cd ../../COURSES/COT4810
ls
cd ..
ls
init
mkfile aaa
mkfile bbb
mkdir Level1
cd Level1
mkdir Level2a
mkdir Level2b
cd Level2a
mkdir Level3
cd Level3
mkdir Level4
cd ../../..
ls
end


*/