EvoCalculator.Core/EvoCalculator.Core.Calculation/Columns/SumColumn.cs

using System;
using System.Linq;
using EvoCalculator.Core.Calculation.Post;
using EvoCalculator.Core.Models.Calculation.Models.Prepared;
using TridentGoalSeek;

namespace EvoCalculator.Core.Calculation.Columns
{
    public class SumColumn : BaseColumnWithGoalSeek
    {
        private readonly PercentPaymentColumn _percentPaymentColumn;
        private readonly PreparedValues _preparedValues;
        private readonly PostValues _postValues;

        public SumColumn(int count, DateTempColumn dateTempColumn
            , PreparedValues preparedValues
            , PercentPaymentColumn percentPaymentColumn, PostValues postValues) : base(count, dateTempColumn)
        {
            _preparedValues = preparedValues;
            _percentPaymentColumn = percentPaymentColumn;
            _postValues = postValues;
        }

        public override decimal Calculate(decimal inputVariable)
        {
            FillValues(inputVariable);
            return Convert.ToDecimal(IRR);
        }

        protected override void FillValues(decimal x)
        {
            Values[0] = -_postValues.BaseCost.Value;
            Values[1] = _preparedValues.FirstPaymentSum;

            for (var i = 2; i < Values.Length - 1; i++) Values[i] = x * (decimal) _percentPaymentColumn.Values[i] / 100;

            Values[^1] = _preparedValues.LastPaymentSum;
        }

        public void PostCheck()
        {
            new CheckTools<decimal>().CheckColumnForZeroValue(Values);

            if (Values[1] / Values.Skip(1).Sum() >= 0.5m)
            {
                throw new Exception(
                    "Первый платеж по графику более 50% от суммы лизинговых платежей. Необходимо уменьшить первый платеж");
            }
        }

        public override void ComputeValues(decimal requiredValue)
        {
            var NUMBER_OF_LARGE_PERCENTS = _percentPaymentColumn.Values
                .Skip(2)
                .Take(_percentPaymentColumn.Values.Length - 1)
                .Where(x => x >= 10).ToArray().Length;

            var goalSeek = new GoalSeek(this);
            goalSeek.SeekResult(requiredValue,
                new GoalSeekOptions(
                    startingStabPoint:
                    (_postValues.BaseCost.Value - _preparedValues.FirstPaymentSum) / NUMBER_OF_LARGE_PERCENTS
                    , maximumAttempts: 1000
                    , initialTineSpacing: (_postValues.BaseCost.Value - _preparedValues.FirstPaymentSum) / _preparedValues.Nmper
                    // , focusPercentage: 50
                ));
        }
    }
}