//********************************************************************
//  TextCalculator.java       Author: Sophie Quigley
//
//  Provides a textual input user interface for the Calculator Class
//
//********************************************************************

import cs1.Keyboard;

public class TextCalculator
{
   private Calculator calculator;
   public TextCalculator ()
   {
        String entry;
        char letter1;
        
        calculator = new Calculator();
        calculator.addViewer(Calculator.TEXTVIEWER);     
        
        while (true)
        {
            System.out.println("Enter a float, operator, or e to erase last entry, c to clear all entries, or s for stop:");
            entry = Keyboard.readString();
            letter1 = entry.toLowerCase().charAt(0);
            switch (letter1)
            {
                case 's':   // Stop
                    return;
                case 'e':   // Erase last entry
                    calculator.eraseLast();
                    break;
                case 'c':   // Clear
                    calculator.clear();
                    break;
                case '+':   // Handle unary and binary +
                    if (entry.length() == 1)
                        calculator.operation(Calculator.PLUS);
                    else
                        parseNumber(entry);
                    break;
                case '-':   // Handle unary and binary -
                    if (entry.length() == 1)
                        calculator.operation(Calculator.MINUS);
                    else
                        parseNumber(entry);
                    break;
                case '*':
                    calculator.operation(Calculator.TIMES);
                    break;
                case '/':
                    calculator.operation(Calculator.DIVIDES);
                    break;
                default:    // Numbers
                    parseNumber(entry);
            }
        }
   }
   private void parseNumber (String number)
   {
       calculator.number(new Float(number));
   }
}