ZCW-MacroLabs-OOP-ScientificCalculator-copy/Calculations.java

import java.util.ArrayList;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Calculations
{
    public static Console console = new Console();
    public static ArrayList<String> library = new ArrayList<String>();
    public static String invalidArgumentsAmountError = "You have entered an invalid amount of arguments. Please only use two arguments, or switch to PEMDAS";
    public static Pemdas pemdas = new Pemdas();

    public Calculations(){

    library.add("multiply");
    library.add("divide");
    library.add("subtract");
    library.add("add");
    library.add("COS");
    library.add("SIN");
    library.add("TAN");
    library.add("invertS");
    library.add("invertN");
    library.add("factorial");
    library.add("switchunit");
    library.add("clear");
    library.add("storeM");
    library.add("resetM");
    library.add("recallM");
    library.add("displayM");

    }

    public static String getCommand(String userInput)
    {
        boolean foundCommand = false;
        String command = "";
        String result = "";

        String[] inputArr = userInput.split(" ");
        for(int i = 0; i < library.size(); i ++)
        {
            String currCommand = library.get(i);
            if(currCommand.equalsIgnoreCase(inputArr[0]))
            {
                command = currCommand;
                foundCommand = true;
                break;
            }
        }

        switch(command)
        {
            case "multiply":
                result = Multiply(userInput);
            break;

            case "divide":
                result = Divide(userInput);
            break;

            case "add":
                result = Add(userInput);
            break;

            case "subtract":
                result = Subtract(userInput);
            break;

            case "invertS":
                result = InvertSign(userInput);
            break;

            case "invertN":
                result = InvertNumber(userInput);
            break;

            case "clear":
                 Clear();
            break;
        }
        return result;
    }

    public static ArrayList<Double> getNumbers(String userInput){
        ArrayList<Double> results = new ArrayList<Double>();

        //takes in a string
        //finds the first occurence of a number
        //store it as a double ( left )
        //add this to the arraylist
        //find the second occurence of a number
        //store it as a double (right)
        //add this to the array list
        //if the size of the arraylist is 2
            //return the array list
        //else return null'

        Pattern pattern = Pattern.compile("\\s?\\-?\\.?\\d+\\.?(\\d+)?\\s?");
        Matcher matcher = pattern.matcher(userInput);

        while(matcher.find()){
            String number = matcher.group().trim();
            Double deci = Double.valueOf(number);

            results.add(deci);
        }

        if(results.size() == 2)
        {
            return results;
        }
        return null;
    }

    public static ArrayList<Double> getNumber(String userInput){
        ArrayList<Double> results = new ArrayList<Double>();

        //takes in a string
        //finds the first occurence of a number
        //store it as a double ( left )
        //add this to the arraylist
        //find the second occurence of a number
        //store it as a double (right)
        //add this to the array list
        //if the size of the arraylist is 2
            //return the array list
        //else return null'

        Pattern pattern = Pattern.compile("\\s?\\-?\\.?\\d+\\.?(\\d+)?\\s?");
        Matcher matcher = pattern.matcher(userInput);

        while(matcher.find()){
            String number = matcher.group().trim();
            Double deci = Double.valueOf(number);

            results.add(deci);

        }

        if(results.size() == 1)
        {
            System.out.println(results.get(0));
            return results;
        }

        return null;
    }

    public static String Multiply(String userInput)
    {
        String result = "";
        ArrayList<Double> results = getNumbers(userInput);
        if(results != null)
        {
            Double product = results.get(0) * results.get(1);
            result = String.valueOf(product);
            return result;
        } else {
            return invalidArgumentsAmountError;
        }
    }

    public static String Divide(String userInput)
    {
        //perform the operation
        //convert to string
        //return string
        String result = "";
        ArrayList<Double> results = getNumbers(userInput);
        if(results != null)
        {
            Double quotient = results.get(0) / results.get(1);
            result = String.valueOf(quotient);
            return result;
        } else {
            return invalidArgumentsAmountError;
        }


    }

        public static String Add(String userInput)
    {
        String result = "";
        ArrayList<Double> results = getNumbers(userInput);
        if(results != null)
        {
            Double sum = results.get(0) + results.get(1);
            result = String.valueOf(sum);
            return result;
        } else {
            return invalidArgumentsAmountError;
        }

    }

    public static String Subtract(String userInput)
    {
        //perform the operation
        //convert to string
        //return string
        String result = "";
        ArrayList<Double> results = getNumbers(userInput);
        if(results != null)
        {
            Double difference = results.get(0) - results.get(1);
            result = String.valueOf(difference);
            return result;
        } else {
            return invalidArgumentsAmountError;
        }

    }

    public static String InvertSign(String userInput)
    {
      ArrayList <Double> number1 = getNumber(userInput);
      return number.get(0) * -1;
        //perform the operation
        //convert to string
        //return string
        return null;
    }

    public static String InvertNumber(String userInput)
    {
        //perform the operation
        //convert to string
        //return string
        return null;
    }

    public static void Clear()
    {
        //reset the default value to 0
    }
}