*

Masuit.Tools.Abstractions/Models/LoanModel.cs

@@ -15,185 +15,185 @@ namespace Masuit.Tools.Models;
 /// <param name="Start">开始还款日</param>
 public record LoanModel(decimal Loan, decimal Rate, int Period, DateTime Start, LoanType LoanType = LoanType.EquivalentInterest)
 {
-	public Dictionary<DateTime, decimal?> RateAdjustments { get; set; } = new();
-
-	public List<PrepaymentOption> Prepayments { get; set; } = new();
-
-	private static decimal CumIPMT(decimal rate, decimal loan, int period)
-	{
-		double interest = 0;
-		for (int i = 1; i <= period; i++)
-		{
-			interest += Financial.IPmt((double)(rate / 12), i, period, (double)loan);
-		}
-
-		return interest.ToDecimal(2);
-	}
-
-	/// <summary>
-	/// 生成还款计划
-	/// </summary>
-	/// <returns></returns>
-	public LoanResult Payment()
-	{
-		var result = LoanType == LoanType.EquivalentPrincipal ? PrepaymentPrincipal() : PrepaymentInterest();
-		result.Plans[0].OriginRemainInterest = result.Plans[0].RemainInterest;
-		for (var i = 1; i < result.Plans.Count; i++)
-		{
-			result.Plans[i].Period = i + 1;
-			result.Plans[i].OriginRemainInterest = result.Plans[i - 1].RemainInterest - result.Plans[i].Interest;
-			if (result.Plans[i].LoanType != result.Plans[i - 1].LoanType)
-			{
-				result.Plans[i].Repayment = result.Plans[i - 1].Balance - result.Plans[i].Balance - result.Plans[i].Amount;
-			}
-		}
-
-		return result;
-	}
-
-	private LoanResult PrepaymentInterest()
-	{
-		var list = new List<PaymentPlan>()
-		{
-			new()
-			{
-				Date = Start,
-				LoanType = LoanType.EquivalentInterest
-			}
-		};
-		var pmt = -Financial.Pmt((double)(Rate / 12), Period, (double)Loan);
-		list[0].Rate = Rate;
-		list[0].Period = 1;
-		list[0].RemainPeriod = Period;
-		list[0].Payment = pmt.ToDecimal(2);
-		list[0].Interest = Math.Round(Loan * Rate / 12, 2, MidpointRounding.AwayFromZero);
-		list[0].Amount = list[0].Payment - list[0].Interest;
-		list[0].Balance = Loan - list[0].Amount;
-		for (var i = 1; i < Period; i++)
-		{
-			var current = Start.AddMonths(i);
-			var adj = RateAdjustments.FirstOrDefault(x => x.Key <= current && x.Key > current.AddMonths(-1));
-			var newRate = adj.Value ?? list[i - 1].Rate;
-			var prepayment = Prepayments.Find(x => x.Date <= current && x.Date > current.AddMonths(-1));
-			if (prepayment?.ChangeType is LoanType.EquivalentPrincipal)
-			{
-				list.AddRange(new LoanModel(list[i - 1].Balance - prepayment.Amount, newRate, list[i - 1].RemainPeriod - 1, current, LoanType.EquivalentPrincipal)
-				{
-					Prepayments = Prepayments,
-					RateAdjustments = RateAdjustments
-				}.PrepaymentPrincipal().Plans);
-				break;
-			}
-
-			list.Add(new PaymentPlan()
-			{
-				Period = i,
-				Date = current,
-				LoanType = LoanType.EquivalentInterest
-			});
-			list[i].Rate = newRate;
-			list[i].Repayment = prepayment?.Amount ?? 0;
-			if (Prepayments.FirstOrDefault(x => x.Date <= current.AddMonths(-1) && x.Date > current.AddMonths(-2))?.ReducePeriod == true)
-			{
-				var leftPeriod = (int)Math.Round(-Math.Log((double)(1 - (list[i - 1].Balance * list[i].Rate / 12) / list[i - 1].Payment)) / Math.Log((double)(1 + list[i].Rate / 12)));
-				list[i].PeriodReduce = Period - list.Count + 1 - leftPeriod;
-				list[i].RemainPeriod = leftPeriod;
-			}
-			else
-			{
-				list[i].RemainPeriod = list[i - 1].RemainPeriod - 1;
-			}
-			list[i].Payment = -Financial.Pmt((double)(list[i].Rate / 12), list[i].RemainPeriod, (double)list[i - 1].Balance).ToDecimal(2);
-			if ((current - adj.Key).TotalDays > 0 && (current - adj.Key).TotalDays < 30)
-			{
-				var days = (decimal)(list[i].Date - list[i - 1].Date).TotalDays;
-				list[i].Payment = list[i - 1].Payment / days * (decimal)Math.Abs((adj.Key - list[i - 1].Date).TotalDays) + list[i].Payment / days * (decimal)Math.Abs((current - adj.Key).TotalDays);
-			}
-			list[i].Interest = Math.Round(list[i - 1].Balance * list[i].Rate / 12, 2);
-			list[i].Amount = Math.Round(list[i].Payment - list[i].Interest, 2);
-			list[i].Balance = Math.Round(list[i - 1].Balance - list[i].Amount - list[i].Repayment, 2);
-			if (list[i].Balance <= 0)
-			{
-				list[i].Payment += list[i].Balance;
-				break;
-			}
-		}
-
-		var totalInterest = -CumIPMT(Rate, Loan, Period);
-		return new LoanResult(totalInterest, list);
-	}
-
-	private LoanResult PrepaymentPrincipal()
-	{
-		var list = new List<PaymentPlan>()
-		{
-			new()
-			{
-				Date = Start,
-				LoanType = LoanType.EquivalentPrincipal,
-				RemainPeriod = Period
-			}
-		};
-		list[0].Rate = Rate;
-		list[0].Period = 1;
-		list[0].Interest = Math.Round(Loan * Rate / 12, 2, MidpointRounding.AwayFromZero);
-		list[0].Amount = Math.Round(Loan / Period, 2, MidpointRounding.AwayFromZero);
-		list[0].Payment = Math.Round(list[0].Amount + list[0].Interest, 2, MidpointRounding.AwayFromZero);
-		list[0].Balance = Math.Round(Loan - list[0].Amount, 2, MidpointRounding.AwayFromZero);
-		for (var i = 1; i < Period; i++)
-		{
-			var current = Start.AddMonths(i);
-			var adj = RateAdjustments.FirstOrDefault(x => x.Key <= current && x.Key > current.AddMonths(-1));
-			var newRate = adj.Value ?? list[i - 1].Rate;
-			var prepayment = Prepayments.Find(x => x.Date <= current && x.Date > current.AddMonths(-1));
-			if (prepayment?.ChangeType is LoanType.EquivalentInterest)
-			{
-				list.AddRange(new LoanModel(list[i - 1].Balance - prepayment.Amount, newRate, list[i - 1].RemainPeriod, current)
-				{
-					Prepayments = Prepayments,
-					RateAdjustments = RateAdjustments
-				}.PrepaymentInterest().Plans);
-				break;
-			}
-
-			list.Add(new PaymentPlan()
-			{
-				Period = i,
-				Date = current,
-				LoanType = LoanType.EquivalentPrincipal
-			});
-			list[i].Rate = newRate;
-			list[i].Repayment = prepayment?.Amount ?? 0;
-			list[i].Interest = Math.Round(list[i - 1].Balance * list[i].Rate / 12, 2, MidpointRounding.AwayFromZero);
-			if ((current - adj.Key).TotalDays > 0 && (current - adj.Key).TotalDays < 30)
-			{
-				var days = (decimal)(list[i].Date - list[i - 1].Date).TotalDays;
-				list[i].Interest = list[i - 1].Interest / days * (decimal)Math.Abs((adj.Key - list[i - 1].Date).TotalDays) + list[i].Interest / days * (decimal)Math.Abs((current - adj.Key).TotalDays);
-			}
-
-			if (prepayment?.ReducePeriod == true)
-			{
-				list[i].PeriodReduce = (int)Math.Round(list[i].Repayment / (Loan / Period));
-				list[i].RemainPeriod = list[i - 1].RemainPeriod - list[i].PeriodReduce - 1;
-			}
-			else
-			{
-				list[i].RemainPeriod = list[i - 1].RemainPeriod - 1;
-			}
-
-			list[i].Amount = Math.Round(list[i - 1].Balance / (Period - i - list.Sum(p => p.PeriodReduce)), 2, MidpointRounding.AwayFromZero);
-			list[i].Payment = Math.Round(list[i].Amount + list[i].Interest, 2, MidpointRounding.AwayFromZero);
-			list[i].Balance = Math.Round(list[i - 1].Balance - list[i].Amount - list[i].Repayment, 2, MidpointRounding.AwayFromZero);
-			if (list[i].Balance <= 0)
-			{
-				list[i].Payment += list[i].Balance;
-				break;
-			}
-		}
-
-		var totalInterest = Loan * Rate / 12 * (Period + 1) / 2;
-		return new LoanResult(totalInterest, list);
-	}
+    public Dictionary<DateTime, decimal?> RateAdjustments { get; set; } = new();
+
+    public List<PrepaymentOption> Prepayments { get; set; } = new();
+
+    private static decimal CumIPMT(decimal rate, decimal loan, int period)
+    {
+        double interest = 0;
+        for (int i = 1; i <= period; i++)
+        {
+            interest += Financial.IPmt((double)(rate / 12), i, period, (double)loan);
+        }
+
+        return interest.ToDecimal(2);
+    }
+
+    /// <summary>
+    /// 生成还款计划
+    /// </summary>
+    /// <returns></returns>
+    public LoanResult Payment()
+    {
+        var result = LoanType == LoanType.EquivalentPrincipal ? PrepaymentPrincipal() : PrepaymentInterest();
+        result.Plans[0].OriginRemainInterest = result.Plans[0].RemainInterest;
+        for (var i = 1; i < result.Plans.Count; i++)
+        {
+            result.Plans[i].Period = i + 1;
+            result.Plans[i].OriginRemainInterest = result.Plans[i - 1].RemainInterest - result.Plans[i].Interest;
+            if (result.Plans[i].LoanType != result.Plans[i - 1].LoanType)
+            {
+                result.Plans[i].Repayment = result.Plans[i - 1].Balance - result.Plans[i].Balance - result.Plans[i].Amount;
+            }
+        }
+
+        return result;
+    }
+
+    private LoanResult PrepaymentInterest()
+    {
+        var list = new List<PaymentPlan>()
+        {
+            new()
+            {
+                Date = Start,
+                LoanType = LoanType.EquivalentInterest
+            }
+        };
+        var pmt = -Financial.Pmt((double)(Rate / 12), Period, (double)Loan);
+        list[0].Rate = Rate;
+        list[0].Period = 1;
+        list[0].RemainPeriod = Period;
+        list[0].Payment = pmt.ToDecimal(2);
+        list[0].Interest = Math.Round(Loan * Rate / 12, 2, MidpointRounding.AwayFromZero);
+        list[0].Amount = list[0].Payment - list[0].Interest;
+        list[0].Balance = Loan - list[0].Amount;
+        for (var i = 1; i < Period; i++)
+        {
+            var current = Start.AddMonths(i);
+            var adj = RateAdjustments.FirstOrDefault(x => x.Key.AddMonths(1) <= current && x.Key.AddMonths(1) > current.AddMonths(-1));
+            var newRate = adj.Value ?? list[i - 1].Rate;
+            var prepayment = Prepayments.Find(x => x.Date <= current && x.Date > current.AddMonths(-1));
+            if (prepayment?.ChangeType is LoanType.EquivalentPrincipal)
+            {
+                list.AddRange(new LoanModel(list[i - 1].Balance - prepayment.Amount, newRate, list[i - 1].RemainPeriod - 1, current, LoanType.EquivalentPrincipal)
+                {
+                    Prepayments = Prepayments,
+                    RateAdjustments = RateAdjustments
+                }.PrepaymentPrincipal().Plans);
+                break;
+            }
+
+            list.Add(new PaymentPlan()
+            {
+                Period = i,
+                Date = current,
+                LoanType = LoanType.EquivalentInterest
+            });
+            list[i].Rate = newRate;
+            list[i].Repayment = prepayment?.Amount ?? 0;
+            if (Prepayments.FirstOrDefault(x => x.Date <= current.AddMonths(-1) && x.Date > current.AddMonths(-2))?.ReducePeriod == true)
+            {
+                var leftPeriod = (int)Math.Round(-Math.Log((double)(1 - (list[i - 1].Balance * list[i].Rate / 12) / list[i - 1].Payment)) / Math.Log((double)(1 + list[i].Rate / 12)));
+                list[i].PeriodReduce = Period - list.Count + 1 - leftPeriod;
+                list[i].RemainPeriod = leftPeriod;
+            }
+            else
+            {
+                list[i].RemainPeriod = list[i - 1].RemainPeriod - 1;
+            }
+            list[i].Payment = -Financial.Pmt((double)(list[i].Rate / 12), list[i].RemainPeriod, (double)list[i - 1].Balance).ToDecimal(2);
+            if ((current - adj.Key).TotalDays > 0 && (current - adj.Key).TotalDays < 30)
+            {
+                var days = (decimal)(list[i].Date - list[i - 1].Date).TotalDays;
+                list[i].Payment = list[i - 1].Payment / days * (decimal)Math.Abs((adj.Key - list[i - 1].Date).TotalDays) + list[i].Payment / days * (decimal)Math.Abs((current - adj.Key).TotalDays);
+            }
+            list[i].Interest = Math.Round(list[i - 1].Balance * list[i].Rate / 12, 2);
+            list[i].Amount = Math.Round(list[i].Payment - list[i].Interest, 2);
+            list[i].Balance = Math.Round(list[i - 1].Balance - list[i].Amount - list[i].Repayment, 2);
+            if (list[i].Balance <= 0)
+            {
+                list[i].Payment += list[i].Balance;
+                break;
+            }
+        }
+
+        var totalInterest = -CumIPMT(Rate, Loan, Period);
+        return new LoanResult(totalInterest, list);
+    }
+
+    private LoanResult PrepaymentPrincipal()
+    {
+        var list = new List<PaymentPlan>()
+        {
+            new()
+            {
+                Date = Start,
+                LoanType = LoanType.EquivalentPrincipal,
+                RemainPeriod = Period
+            }
+        };
+        list[0].Rate = Rate;
+        list[0].Period = 1;
+        list[0].Interest = Math.Round(Loan * Rate / 12, 2, MidpointRounding.AwayFromZero);
+        list[0].Amount = Math.Round(Loan / Period, 2, MidpointRounding.AwayFromZero);
+        list[0].Payment = Math.Round(list[0].Amount + list[0].Interest, 2, MidpointRounding.AwayFromZero);
+        list[0].Balance = Math.Round(Loan - list[0].Amount, 2, MidpointRounding.AwayFromZero);
+        for (var i = 1; i < Period; i++)
+        {
+            var current = Start.AddMonths(i);
+            var adj = RateAdjustments.FirstOrDefault(x => x.Key.AddMonths(1) <= current && x.Key.AddMonths(1) > current.AddMonths(-1));
+            var newRate = adj.Value ?? list[i - 1].Rate;
+            var prepayment = Prepayments.Find(x => x.Date <= current && x.Date > current.AddMonths(-1));
+            if (prepayment?.ChangeType is LoanType.EquivalentInterest)
+            {
+                list.AddRange(new LoanModel(list[i - 1].Balance - prepayment.Amount, newRate, list[i - 1].RemainPeriod, current)
+                {
+                    Prepayments = Prepayments,
+                    RateAdjustments = RateAdjustments
+                }.PrepaymentInterest().Plans);
+                break;
+            }
+
+            list.Add(new PaymentPlan()
+            {
+                Period = i,
+                Date = current,
+                LoanType = LoanType.EquivalentPrincipal
+            });
+            list[i].Rate = newRate;
+            list[i].Repayment = prepayment?.Amount ?? 0;
+            list[i].Interest = Math.Round(list[i - 1].Balance * list[i].Rate / 12, 2, MidpointRounding.AwayFromZero);
+            if ((current - adj.Key).TotalDays > 0 && (current - adj.Key).TotalDays < 30)
+            {
+                var days = (decimal)(list[i].Date - list[i - 1].Date).TotalDays;
+                list[i].Interest = list[i - 1].Interest / days * (decimal)Math.Abs((adj.Key - list[i - 1].Date).TotalDays) + list[i].Interest / days * (decimal)Math.Abs((current - adj.Key).TotalDays);
+            }
+
+            if (prepayment?.ReducePeriod == true)
+            {
+                list[i].PeriodReduce = (int)Math.Round(list[i].Repayment / (Loan / Period));
+                list[i].RemainPeriod = list[i - 1].RemainPeriod - list[i].PeriodReduce - 1;
+            }
+            else
+            {
+                list[i].RemainPeriod = list[i - 1].RemainPeriod - 1;
+            }
+
+            list[i].Amount = Math.Round(list[i - 1].Balance / (Period - i - list.Sum(p => p.PeriodReduce)), 2, MidpointRounding.AwayFromZero);
+            list[i].Payment = Math.Round(list[i].Amount + list[i].Interest, 2, MidpointRounding.AwayFromZero);
+            list[i].Balance = Math.Round(list[i - 1].Balance - list[i].Amount - list[i].Repayment, 2, MidpointRounding.AwayFromZero);
+            if (list[i].Balance <= 0)
+            {
+                list[i].Payment += list[i].Balance;
+                break;
+            }
+        }
+
+        var totalInterest = Loan * Rate / 12 * (Period + 1) / 2;
+        return new LoanResult(totalInterest, list);
+    }
 }
 
 /// <summary>
@@ -201,17 +201,17 @@ public record LoanModel(decimal Loan, decimal Rate, int Period, DateTime Start,
 /// </summary>
 public enum LoanType
 {
-	/// <summary>
-	/// 等额本息
-	/// </summary>
-	[Description("等额本息")]
-	EquivalentInterest,
-
-	/// <summary>
-	/// 等额本金
-	/// </summary>
-	[Description("等额本金")]
-	EquivalentPrincipal,
+    /// <summary>
+    /// 等额本息
+    /// </summary>
+    [Description("等额本息")]
+    EquivalentInterest,
+
+    /// <summary>
+    /// 等额本金
+    /// </summary>
+    [Description("等额本金")]
+    EquivalentPrincipal,
 }
 
 /// <summary>
@@ -230,125 +230,125 @@ public record PrepaymentOption(DateTime Date, decimal Amount, bool ReducePeriod
 /// <param name="Plans">还款计划</param>
 public record LoanResult(decimal TotalInterest, List<PaymentPlan> Plans)
 {
-	/// <summary>
-	/// 总提前还款额
-	/// </summary>
-	public decimal TotalRepayment => Plans.Sum(e => e.Repayment);
-
-	/// <summary>
-	/// 实际总利息
-	/// </summary>
-	public decimal ActualInterest => Plans.Sum(e => e.Interest);
-
-	/// <summary>
-	/// 实际还款总额
-	/// </summary>
-	public decimal ActualPayment => Plans.Sum(e => e.Payment + e.Repayment);
-
-	/// <summary>
-	/// 节省利息
-	/// </summary>
-	public decimal SavedInterest => TotalInterest - ActualInterest;
-
-	public void Deconstruct(out decimal totalInterest, out decimal actualInterest, out decimal totalRepayment, out List<PaymentPlan> paymentPlans)
-	{
-		totalInterest = TotalInterest;
-		actualInterest = ActualInterest;
-		totalRepayment = TotalRepayment;
-		paymentPlans = Plans;
-	}
-
-	public void Deconstruct(out decimal totalInterest, out decimal actualInterest, out decimal savedInterest, out decimal totalRepayment, out List<PaymentPlan> paymentPlans)
-	{
-		totalInterest = TotalInterest;
-		actualInterest = ActualInterest;
-		totalRepayment = TotalRepayment;
-		paymentPlans = Plans;
-		savedInterest = SavedInterest;
-	}
-
-	public void Deconstruct(out decimal totalInterest, out decimal actualInterest, out decimal savedInterest, out decimal totalRepayment, out decimal actualPayment, out List<PaymentPlan> paymentPlans)
-	{
-		totalInterest = TotalInterest;
-		actualInterest = ActualInterest;
-		totalRepayment = TotalRepayment;
-		paymentPlans = Plans;
-		savedInterest = SavedInterest;
-		actualPayment = ActualPayment;
-	}
+    /// <summary>
+    /// 总提前还款额
+    /// </summary>
+    public decimal TotalRepayment => Plans.Sum(e => e.Repayment);
+
+    /// <summary>
+    /// 实际总利息
+    /// </summary>
+    public decimal ActualInterest => Plans.Sum(e => e.Interest);
+
+    /// <summary>
+    /// 实际还款总额
+    /// </summary>
+    public decimal ActualPayment => Plans.Sum(e => e.Payment + e.Repayment);
+
+    /// <summary>
+    /// 节省利息
+    /// </summary>
+    public decimal SavedInterest => TotalInterest - ActualInterest;
+
+    public void Deconstruct(out decimal totalInterest, out decimal actualInterest, out decimal totalRepayment, out List<PaymentPlan> paymentPlans)
+    {
+        totalInterest = TotalInterest;
+        actualInterest = ActualInterest;
+        totalRepayment = TotalRepayment;
+        paymentPlans = Plans;
+    }
+
+    public void Deconstruct(out decimal totalInterest, out decimal actualInterest, out decimal savedInterest, out decimal totalRepayment, out List<PaymentPlan> paymentPlans)
+    {
+        totalInterest = TotalInterest;
+        actualInterest = ActualInterest;
+        totalRepayment = TotalRepayment;
+        paymentPlans = Plans;
+        savedInterest = SavedInterest;
+    }
+
+    public void Deconstruct(out decimal totalInterest, out decimal actualInterest, out decimal savedInterest, out decimal totalRepayment, out decimal actualPayment, out List<PaymentPlan> paymentPlans)
+    {
+        totalInterest = TotalInterest;
+        actualInterest = ActualInterest;
+        totalRepayment = TotalRepayment;
+        paymentPlans = Plans;
+        savedInterest = SavedInterest;
+        actualPayment = ActualPayment;
+    }
 }
 
 public record PaymentPlan
 {
-	/// <summary>
-	/// 期数
-	/// </summary>
-	public int Period { get; internal set; } = 12;
-
-	/// <summary>
-	/// 还款日
-	/// </summary>
-	public DateTime Date { get; internal set; } = DateTime.Now;
-
-	/// <summary>
-	/// 月供
-	/// </summary>
-	public decimal Payment { get; internal set; }
-
-	/// <summary>
-	/// 年利率
-	/// </summary>
-	public decimal Rate { get; internal set; }
-
-	/// <summary>
-	/// 月还利息
-	/// </summary>
-	public decimal Interest { get; internal set; }
-
-	/// <summary>
-	/// 月还本金
-	/// </summary>
-	public decimal Amount { get; internal set; }
-
-	/// <summary>
-	/// 当期提前还款额
-	/// </summary>
-	public decimal Repayment { get; internal set; }
-
-	/// <summary>
-	/// 当期剩余本金
-	/// </summary>
-	public decimal Balance { get; internal set; }
-
-	/// <summary>
-	/// 当期剩余利息
-	/// </summary>
-	public decimal RemainInterest => LoanType switch
-	{
-		LoanType.EquivalentInterest => Payment * (RemainPeriod - 1) - Balance - Repayment,
-		LoanType.EquivalentPrincipal => RemainPeriod * Interest - (RemainPeriod - 1) * RemainPeriod * Amount * (Rate / 12) / 2 - Interest,
-		_ => 0
-	};
-
-	/// <summary>
-	/// 当期剩余利息(提前还款/利率调整前)
-	/// </summary>
-	public decimal OriginRemainInterest { get; internal set; }
-
-	/// <summary>
-	/// 贷款类型（默认等额本息）
-	/// </summary>
-	public LoanType LoanType { get; internal set; }
-
-	/// <summary>
-	/// 期数减少
-	/// </summary>
-	internal int PeriodReduce { get; set; }
-
-	/// <summary>
-	/// 剩余期数
-	/// </summary>
-	internal int RemainPeriod { get; set; }
+    /// <summary>
+    /// 期数
+    /// </summary>
+    public int Period { get; internal set; } = 12;
+
+    /// <summary>
+    /// 还款日
+    /// </summary>
+    public DateTime Date { get; internal set; } = DateTime.Now;
+
+    /// <summary>
+    /// 月供
+    /// </summary>
+    public decimal Payment { get; internal set; }
+
+    /// <summary>
+    /// 年利率
+    /// </summary>
+    public decimal Rate { get; internal set; }
+
+    /// <summary>
+    /// 月还利息
+    /// </summary>
+    public decimal Interest { get; internal set; }
+
+    /// <summary>
+    /// 月还本金
+    /// </summary>
+    public decimal Amount { get; internal set; }
+
+    /// <summary>
+    /// 当期提前还款额
+    /// </summary>
+    public decimal Repayment { get; internal set; }
+
+    /// <summary>
+    /// 当期剩余本金
+    /// </summary>
+    public decimal Balance { get; internal set; }
+
+    /// <summary>
+    /// 当期剩余利息
+    /// </summary>
+    public decimal RemainInterest => LoanType switch
+    {
+        LoanType.EquivalentInterest => Payment * (RemainPeriod - 1) - Balance - Repayment,
+        LoanType.EquivalentPrincipal => RemainPeriod * Interest - (RemainPeriod - 1) * RemainPeriod * Amount * (Rate / 12) / 2 - Interest,
+        _ => 0
+    };
+
+    /// <summary>
+    /// 当期剩余利息(提前还款/利率调整前)
+    /// </summary>
+    public decimal OriginRemainInterest { get; internal set; }
+
+    /// <summary>
+    /// 贷款类型（默认等额本息）
+    /// </summary>
+    public LoanType LoanType { get; internal set; }
+
+    /// <summary>
+    /// 期数减少
+    /// </summary>
+    internal int PeriodReduce { get; set; }
+
+    /// <summary>
+    /// 剩余期数
+    /// </summary>
+    internal int RemainPeriod { get; set; }
 }
 
-#endif
+#endif