using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace ChrisMayor.codechallenge
{
    class Program
    {
        static void Main(string[] args)
        {
            var program = new Program();
            program.CountChange();
        }


        private void CountChange()
        {
            var calculators = GetCalculators();
            var changeCalculations = ReadFile().Select(l => CountChangePerCustomer(int.Parse(l), calculators));
            var coincount = changeCalculations.ToList().SelectMany(c => c).Sum(c => c.CoinCount);
            Console.WriteLine($"Coins needed: {coincount}");
        }

        private IEnumerable<CoinCalculation> CountChangePerCustomer(int centinput, Dictionary<int, Func<int, CoinCalculation>> calculators)
        {
            var remainingvalue = centinput;
            var count = 0;
            while (remainingvalue > 0)
            {
                count++;
                var calculationPerCoin = calculators[count].Invoke(remainingvalue);
                remainingvalue = calculationPerCoin.Rest;
                yield return calculationPerCoin;
            }

        }

        private Dictionary<int, Func<int, CoinCalculation>> GetCalculators()
        {
            var dictionary = new Dictionary<int, Func<int, CoinCalculation>>();
            // key is order
            dictionary.Add(1, GetCalculator(50));
            dictionary.Add(2, GetCalculator(20));
            dictionary.Add(3, GetCalculator(10));
            dictionary.Add(4, GetCalculator(5));
            dictionary.Add(5, GetCalculator(2));
            dictionary.Add(6, GetCalculator(1));
            return dictionary;
        }

        public Func<int, CoinCalculation> GetCalculator(int coinValue)
        {
            Func<int, CoinCalculation> calculator = cents => new CoinCalculation { CoinValue = coinValue, CoinCount = cents / coinValue, Rest = cents % coinValue };
            return calculator;
        }

        public struct CoinCalculation
        {
            public int CoinValue { get; set; }
            public int CoinCount { get; set; }
            public int Rest { get; set; }
        }



        private string[] ReadFile()
        {
            return File.ReadAllLines(@"C:\Projekt\challange\OwR3bW9NuaZNNLtukKN5GeGPOnH2_cash-register_input (1).txt");
        }
    }
}