package javaCalculator;

import java.util.InputMismatchException;
import java.util.Scanner;

public class Calculator {

	public static void main (String[] args){

		int userChoice;
		Scanner userScanner = new Scanner (System.in);
		double firstNumber = 0;
		double secondNumber = 0;
		double answer = 0;
		String operation = null;
		String expression = null;

		try {

			System.out.println("Hello what would you like to do?");
			System.out.println("1)Use basic calculator (Step by step)");
			System.out.println("2)Use basic calculator (Enter an expression)");
			userChoice = userScanner.nextInt();

			if (userChoice == 1){
				System.out.println("Please enter your first number");
				firstNumber = userScanner.nextDouble();

				System.out.println("Please enter your second number");
				secondNumber = userScanner.nextDouble();

				System.out.println("Please enter an operation");
				operation = userScanner.next();

				switch (operation) {

				case "+":
					answer = (firstNumber + secondNumber);
					break;
				case "-":
					answer = (firstNumber - secondNumber);
					break;
				case "/":
					answer = (firstNumber / secondNumber);
					break;
				case "*":
					answer = (firstNumber * secondNumber);
					break;
				case "x":
					answer = (firstNumber * secondNumber);
				}

			}

			if (userChoice == 2){

				System.out.println("Please enter your expression");
				expression = userScanner.nextLine();

				if (expression.contains("/")) {
					String[] sarr = expression.split("/");
					firstNumber = Integer.parseInt(sarr[0]);
					secondNumber = Integer.parseInt(sarr[1]);
					answer = firstNumber / secondNumber;
				}else{

					if (expression.contains("-")) {
						String[] sarr = expression.split("-");
						firstNumber = Integer.parseInt(sarr[0]);
						secondNumber = Integer.parseInt(sarr[1]);
						answer = firstNumber - secondNumber;
					}else{

						if (expression.contains("*")) {
							String[] sarr = expression.split("*");
							firstNumber = Integer.parseInt(sarr[0]);
							secondNumber = Integer.parseInt(sarr[1]);
							answer = firstNumber * secondNumber;
						}else{

							if (expression.contains("+")) {
								String[] sarr = expression.split("+");
								firstNumber = Integer.parseInt(sarr[0]);
								secondNumber = Integer.parseInt(sarr[1]);
								answer = firstNumber + secondNumber;
							}

						}}}}}





		catch (InputMismatchException  NumberFormatException ) {

			System.out.println("That is not valid, please restart and enter something valid.");
			System.exit(0);
		}
		System.out.println("The answer is " + answer);
		userScanner.close();

	}
}