using System;
namespace Calculator
{


    public class Calculator
    {
        public decimal currentValue;
        public decimal operand1;
        public decimal operand2;
        char opCode;

        public Calculator()
        {
            this.currentValue = 0;
            this.operand1 = 0;
            this.operand2 = 0;
            this.opCode = ' ';
        }


        public void Clear()
        {
            this.currentValue = 0;
            this.operand1 = 0;
            this.operand2 = 0;
            this.opCode = ' ';
        }

        public void Add(decimal value)
        {
            this.operand1 = value;
            this.currentValue = value;
            this.opCode = '+';
        }

        public void Subtract(decimal value)
        {
            this.operand1 = value;
            this.currentValue = value;
            this.opCode = '-';
        }

        public void Multiply(decimal value)
        {
            this.operand1 = value;
            this.currentValue = value;
            this.opCode = '*';
        }

        public void Divide(decimal value)
        {
            this.operand1 = value;
            this.currentValue = value;
            this.opCode = '/';
        }

        public void Equals()
        {
            switch (this.opCode)
            {
                case '+':
                    currentValue = operand1 + operand2;
                    break;
                case '-':
                    currentValue = operand1 - operand2;
                    break;
                case '*':
                    currentValue = operand1 * operand2;
                    break;
                case '/':
                    currentValue = operand1 / operand2;
                    break;
            }

            operand1 = currentValue;
        }

        public void Equals(decimal value)
        {
            operand2 = value;

            switch (this.opCode)
            {
                case '+':
                    currentValue = operand1 + operand2;
                    break;
                case '-':
                    currentValue = operand1 - operand2;
                    break;
                case '*':
                    currentValue = operand1 * operand2;
                    break;
                case '/':
                    currentValue = operand1 / operand2;
                    break;
            }

            operand1 = currentValue;
        }


        public void squareRoot(decimal value)
        {
            this.operand1 = value;
            currentValue = (decimal)Math.Sqrt(Convert.ToDouble(operand1));
            opCode = ' ';
        }

        public void Fraction(decimal value)
        {
            this.operand1 = value;
            currentValue = 1 / operand1;
            opCode = ' ';
        }
    }
}