/* 
 *Johnny A. Shaieb
 *Program 3
 *CS2003
*/


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

public class Program3
{
    StackArrayBased stack = new StackArrayBased();
    private String filename = "";
    private String postfix = "";
    private int count = 0;
    
    public static void main(String args[])
    {
	//A + B * C * D * ( E + F * ( A - B ) )
	Program3 p = new Program3();
	p.requestFile();
	p.InfixToPostfix();
	//System.out.println(p.getPostFix());
    }
    
    public String getPostFix()
    {
	return postfix;
    }
    
    public void InfixToPostfix()
    {
	String line = "";
	int oper_value = 0;
	try
	{
	    BufferedReader br = new BufferedReader(new FileReader(getFilename()));
	    while((line = br.readLine()) != null)
	    {
		StringTokenizer tok = new StringTokenizer(line);
		while(tok.hasMoreTokens())
		{
		    String tokLine = tok.nextToken();
                    System.out.println("Working on: " + tokLine);
		    if( (tokLine.equalsIgnoreCase("+")) || 
		        (tokLine.equalsIgnoreCase("-")) || 
		        (tokLine.equalsIgnoreCase("*")) || 
		        (tokLine.equalsIgnoreCase("/")) ||
			(tokLine.equalsIgnoreCase("(")) ||
		        (tokLine.equalsIgnoreCase("$")) )
		    {
			oper_value = assignValue(tokLine);

			if(stack.isEmpty())
			{
			    stack.push((String)tokLine);
			    System.out.println("PUSHED> " + tokLine);
			    count++;
			}
			else
			{
			    String look = (String)stack.peek();
			    int peek_value = assignValue(look);
			    System.out.println("OPERVAL: " + oper_value + " PEEKVAL: " + peek_value);
			    if(oper_value == 0)
			    {
				stack.push((String)tokLine);
				System.out.println("PUSHED> " + tokLine);
				count++;
			    }
			    else if(peek_value < oper_value)
			    {
				stack.push((String)tokLine);
				System.out.println("PUSHED> " + tokLine);
				count++;
			    }
			    else
			    {
				String temp = (String)stack.pop();
				createPostfix(temp);
				stack.push((String)tokLine);
			    }
			}
			
		    }//First IF
		    else if(tokLine.equalsIgnoreCase(")"))
		    {
			System.out.println("Encountered a ')'");
			boolean cont = true;
			while(!stack.isEmpty() && cont)
			{
			    String temp = (String)stack.peek();
			    System.out.println("Inside While Peek Value: " + temp);
			    if(!temp.equalsIgnoreCase("("))
			    {
				temp = (String)stack.pop();
				count--;
				createPostfix(temp);
			    }
			    else
			    {
				//get out off loop
				stack.pop();
				count--;
				System.out.println("Get out of while loop");
				cont = false;
			    }
			    
			}
		    }
		    else
		    {
			createPostfix(tokLine);
		    }
		    
		}//while
		while(!stack.isEmpty())
		{
		    String temp = (String)stack.pop();
		    count--;
		    createPostfix(temp);
		}
		System.out.println("Infix  : " + line);
		System.out.println("Postfix: " + getPostFix());
		postfixToValue(getPostFix());
		postfix = "";
	    }   
	}
	catch(Exception e)
	{
	    System.out.println("Error> " + e);
	}
    }
    
    public void createPostfix(String s)
    {
	if(postfix.equalsIgnoreCase(""))
	{
	    postfix = s;
	}
	else
	{
	    postfix += " " + s;
	}
        System.out.println("Called createPostfix: " + postfix);
    }
    
    public int assignValue(String s)
    {
	int oper_value = 0;
	if(s.equalsIgnoreCase("+"))
	{
	    oper_value = 1;
	}
	else if(s.equalsIgnoreCase("-"))
	{
	    oper_value = 1;
	}
	else if(s.equalsIgnoreCase("*"))
	{
	    oper_value = 2;
	}
	else if(s.equalsIgnoreCase("/"))
	{
	    oper_value = 2;
	}
	else if(s.equalsIgnoreCase("$"))
	{
	    oper_value = 3;
	}
	else if(s.equalsIgnoreCase("("))
	{
	    oper_value = 0;
	}
	else
	{
	    System.out.println("Strange Operator encountered");
	    System.exit(-1);
	}
	return oper_value;
    }
    
    
    public void setFilename(String f)
    {
	filename = f;
    }
    
    public String getFilename()
    {
	return filename;
    }
    
    public void requestFile()
    {
	String file = "";
	try
	{
	    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	    //System.out.print("Enter Filename> ");
	    //file = br.readLine();
	    file = "C:\\Johnny\\School\\cs2003\\lab7\\infix_4line.txt";
	    setFilename(file);
	}
	catch(Exception e)
	{
	    System.out.println("Error> " + e);
	}
    }    
    public void postfixToValue(String str)
    {
	try
	{

		String line = "";

		boolean goodline = true;
		StackArrayBased s = new StackArrayBased();
		String tokLine = "";
		StringTokenizer tok = new StringTokenizer(str);
		while(tok.hasMoreTokens())
		{
		    tokLine = tok.nextToken().trim();
		    //System.out.println("tok> " + tokLine);
		    if( (tokLine.equalsIgnoreCase("+")) || 
		        (tokLine.equalsIgnoreCase("-")) || 
		        (tokLine.equalsIgnoreCase("*")) || 
		        (tokLine.equalsIgnoreCase("/")) || 
		        (tokLine.equalsIgnoreCase("$")) )
		    {
			//System.out.println("Symbol> " + tokLine);
			//
			if(!s.isEmpty())
			{	
			    //6 4 3 + + 3 8 2 * + * 2 + 3 +
			    Integer i = (Integer)s.pop();
			    int temp1 = i.intValue();
			    //System.out.println("POP> " + i);
			    
			    if(!s.isEmpty())
			    {
				i = (Integer)s.pop();
			    }
			    else
			    {
				System.out.println("Stack is empty,,, program terminated");
				System.exit(-1);
			    }
			    int temp2 = i.intValue();
			    //System.out.println("POP> " + i);
			    int temp3 = 0;
			    
			    if(tokLine.equalsIgnoreCase("+"))
			    {
				temp3 = temp2 + temp1;
			    }
			    else if(tokLine.equalsIgnoreCase("-"))
			    {
				temp3 = temp2 - temp1;
			    }
			    else if(tokLine.equalsIgnoreCase("*"))
			    {
				temp3 = temp2 * temp1;
			    }
			    else if(tokLine.equalsIgnoreCase("/"))
			    {
				temp3 = temp2 / temp1;
			    }
			    else if(tokLine.equalsIgnoreCase("$"))
			    {
				temp3 = (int)Math.pow((double)temp2,(double)temp1);
			    }
			    else
			    {
				System.out.println("Incorrect Symbol");
			    }
			    s.push(new Integer(temp3));			    
			}
			//
			
		    }
		    else if(tokLine.equalsIgnoreCase(""))
		    {
			System.out.println("End of line reached");
			goodline = false;
		    }
		    else
		    {
			if(!s.isFull())
			{
			    int t = Integer.parseInt(tokLine);
			    //System.out.println("PUSH> " + t);
			    s.push(new Integer(t));
			}
			
		    }
		    
		    
		}
		
		if(goodline)
		{
		    ///this is the last one
		    Integer j = (Integer)s.pop();
		    int temp4 = j.intValue();
		    System.out.println("Value of postfix expression> " + temp4);
		    System.out.println();
		    //System.out.println("Value Is> " + temp4);
		}
		else
		{
		    System.out.println("a blank line was encountered");
		}

	}
	catch(Exception e)
	{
	    System.out.println("Error> " + e);
	}
    	
    }
}