using System;

using System.Linq;

using System.Collections.Generic;

using System.ComponentModel.DataAnnotations;

​

public class Program

{

    public static void Main()

    {

        var payments = new List<Payment> 

        {

            new Payment { TotalAmount = 3000m, UkWorkdayCount = 15, ForeignWorkdayCount = 5 },

            new Payment { TotalAmount = 1281.50m, UkWorkdayCount = 3, ForeignWorkdayCount = 18 }, 

            new Payment { TotalAmount = 250m, UkWorkdayCount = 31, ForeignWorkdayCount = 0 },

            new Payment { TotalAmount = 50.63m, UkWorkdayCount = 0, ForeignWorkdayCount = 4 },

​

        };

        var totalTaxableAmount = CalculateUkTaxableAmount(payments);

        Console.WriteLine(string.Format("Total UK taxable amount is: {0} GBP", totalTaxableAmount));

    }

​

    /* 

    Coding Task - implement CalculateUkTaxableAmount method

    A UK company sends their employees regularly on business trips all over the world. This has some tax implications for the employees. 

    When an employee receives their pay it needs to be determined how much of the pay is liable to UK tax (this is also called UK taxable amount) 

    The employee is liable to pay UK tax only on the part of salary and benefits earned by working from the UK. No UK tax is paid on the part of salary and benefits earned by working from abroad. 

    Effectively, the UK taxable amount is the payment amount multiplied by the ratio of the number of days the employee was working in the UK to the total number of days the employee was working during the period.

    Given a list of payments made from the employer to the employee calculate the total UK taxable amount which will be reported to UK tax authority. The result should be rounded as an amount to prevent errors in the banking

    systems.

    Think carefully what kind of input data would be considered invalid or not make good sense in the calculations. In these cases throw a ValidationException with message "Invalid payment.". The method should not throw any 

    other type of exception.

    Feel free to write any comments for your solution

    To complete the task with a login account click "Fork" before you start coding. This will generate a new link and show "Save" button so you can update your code on the link. Don't forget to save your solution at the end!

    To complete the task without an account just write your code on the page and once you're done click "Share" button to get a link to your solution. In anonymous mode the Share link changes every time you update the code 

    so to keep your progress just take a note of the latest link.

    */

    public static decimal CalculateUkTaxableAmount(List<Payment> payments)

    {

        decimal result = 0;

        payments.ForEach(pay => {

            if (pay.TotalAmount < 0){

                throw new ValidationException("Invalid payment. TotalAmount is lower than zero");

            }

            int allWorkingDays = pay.ForeignWorkdayCount + pay.UkWorkdayCount;

            decimal payForADay = pay.TotalAmount / allWorkingDays;

            result += (payForADay * pay.UkWorkdayCount);

        });

        return (decimal)System.Math.Round(result,2); 

    }

​

    public class Payment

    {

        // total amount in GBP earned by the employee during an unspecified period (can be monthly salary, quarterly bonus, weekly laundry benefit etc.)

        public decimal TotalAmount { get; set; }

​

        // number of days employee was working from the UK during the period the payment is for

        public int UkWorkdayCount { get; set; }

​

        // number of days employee was working from a country other than the UK during period the payment is for

        public int ForeignWorkdayCount { get; set; }

    }

}