/// <summary>
/// 总利息
/// </summary>
/// <param name="principal">本金</param>
/// <param name="rateType">利率计算方式</param>
/// <param name="rate">利率</param>
/// <param name="deadline">期限</param>
/// <param name="periods">期数</param>
/// <returns></returns>
public decimal GetTotalInterest(decimal principal, RepaymentRateType rateType, decimal rate, decimal deadline, int periods = 1)
{
var list = this.GetRepayments(principal, rateType, rate, deadline, periods);
if (list == null)
{
return(0);
}
return(list.Sum(r => r.Interest));
}
/// <summary>
/// 单元金额
/// </summary>
/// <param name="rateType">利率计算方式</param>
/// <returns></returns>
public decimal GetUnitAmount(RepaymentRateType rateType = RepaymentRateType.年利率)
{
switch (rateType)
{
case RepaymentRateType.天利率:
return(1m);
case RepaymentRateType.月利率:
return(1m / 30);
case RepaymentRateType.季利率:
return(1m / 90);
default:
case RepaymentRateType.年利率:
return(1m / 360);
}
}
/// <summary>
/// 获取N倍的单元金额
/// </summary>
/// <param name="amount">总金额</param>
/// <param name="rateType">利率计算方式</param>
/// <returns></returns>
public decimal GetNUnitAmount(decimal amount, RepaymentRateType rateType = RepaymentRateType.年利率)
{
switch (rateType)
{
case RepaymentRateType.天利率:
return(amount * 1m * 30);
case RepaymentRateType.月利率:
return(amount * 1m);
case RepaymentRateType.季利率:
return(amount * 1m / 3);
default:
case RepaymentRateType.年利率:
return(amount * 1m / 12);
}
}
/// <summary>
/// 还款列表
/// </summary>
/// <param name="principal">本金</param>
/// <param name="rateType">利率计算方式</param>
/// <param name="rate">利率</param>
/// <param name="deadline">期限</param>
/// <param name="periods">期数</param>
/// <param name="autoFixPrincipalToInteger">是否为自动修正本金整数</param>
/// <returns></returns>
public override IEnumerable <RepaymentModel> GetRepayments(decimal principal, RepaymentRateType rateType, decimal rate, decimal deadline, int periods = 1, bool autoFixPrincipalToInteger = true)
{
if (periods <= 0)
{
throw new DomainException("还款期数不能小于0");
}
/*总利息*/
var totalInterest = this.Strategy.GetNUnitAmount(principal * rate * deadline, rateType);
var list = new List <RepaymentModel>(periods);
/*不用修正本金或进要修正本金但能整除*/
if (!autoFixPrincipalToInteger || (autoFixPrincipalToInteger && principal % periods == 0))
{
for (var i = 1; i <= periods; i++)
{
var model = new RepaymentModel()
{
Principal = principal / periods, Interest = totalInterest / periods, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, deadline * i / periods)
};
list.Add(model);
}
}
else
{
var fixPrincipal = principal - principal % periods;
var firstPrinciapl = principal - (periods - 1) * fixPrincipal / periods;
var firstModel = new RepaymentModel()
{
Principal = firstPrinciapl, Interest = totalInterest / periods, Period = 1, PayDate = this.Strategy.GetPayTime(this.StartDate, deadline * 1 / periods)
};
list.Add(firstModel);
/*只有大于1期后才可能重新计算本金与利息*/
if (periods > 1)
{
var changeAvg = (principal - firstPrinciapl) / (periods - 1);
for (var i = 2; i <= periods; i++)
{
var model = new RepaymentModel()
{
Principal = changeAvg, Interest = totalInterest / periods, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, deadline * i / periods)
};
list.Add(model);
}
}
}
return(list);
}
/// <summary>
/// 还款列表
/// </summary>
/// <param name="principal">本金</param>
/// <param name="rateType">利率计算方式</param>
/// <param name="rate">利率</param>
/// <param name="deadline">期限</param>
/// <param name="periods">期数</param>
/// <param name="autoFixPrincipalToInteger">是否为自动修正本金整数</param>
/// <returns></returns>
public override IEnumerable <RepaymentModel> GetRepayments(decimal principal, RepaymentRateType rateType, decimal rate, decimal deadline, int periods = 1, bool autoFixPrincipalToInteger = true)
{
if (periods <= 0)
{
throw new ArgumentException("还款期数不能小于0");
}
return(new[] { new RepaymentModel()
{
Principal = principal, Interest = this.Strategy.GetNUnitAmount(principal * rate * deadline, rateType), Period = 1, PayDate = this.Strategy.GetPayTime(this.StartDate, deadline)
} });
}
/// <summary>
/// 还款列表
/// </summary>
/// <param name="principal">本金</param>
/// <param name="rateType">利率计算方式</param>
/// <param name="rate">利率</param>
/// <param name="deadline">期限</param>
/// <param name="periods">期数</param>
/// <param name="autoFixPrincipalToInteger">是否为自动修正本金整数</param>
/// <returns></returns>
public override IEnumerable <RepaymentModel> GetRepayments(decimal principal, RepaymentRateType rateType, decimal rate, decimal deadline, int periods = 1, bool autoFixPrincipalToInteger = true)
{
if (periods <= 0)
{
throw new ArgumentException("还款期数不能小于0");
}
var list = new List <RepaymentModel>(periods);
for (var i = 1; i < periods; i++)
{
list.Add(new RepaymentModel()
{
Principal = 0, Interest = this.Strategy.GetNUnitAmount(principal * rate * deadline, rateType) / periods, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, i * deadline / periods)
});
}
list.Add(new RepaymentModel()
{
Principal = principal, Interest = this.Strategy.GetNUnitAmount(principal * rate * deadline, rateType) / periods, Period = periods, PayDate = this.Strategy.GetPayTime(this.StartDate, deadline)
});
return(list);
}
/// <summary> /// 还款列表 /// </summary> /// <param name="principal">本金</param> /// <param name="rateType">利率计算方式</param> /// <param name="rate">利率</param> /// <param name="deadline">期限</param> /// <param name="periods">期数</param> /// <param name="autoFixPrincipalToInteger">是否为自动修正本金整数</param> /// <returns></returns> public abstract IEnumerable <RepaymentModel> GetRepayments(decimal principal, RepaymentRateType rateType, decimal rate, decimal deadline, int periods = 1, bool autoFixPrincipalToInteger = true);
/// <summary>
/// 还款列表
/// </summary>
/// <param name="principal">本金</param>
/// <param name="rateType">利率计算方式</param>
/// <param name="rate">利率</param>
/// <param name="deadline">期限</param>
/// <param name="periods">期数</param>
/// <param name="autoFixPrincipalToInteger">是否为自动修正本金整数</param>
/// <returns></returns>
public override IEnumerable <RepaymentModel> GetRepayments(decimal principal, RepaymentRateType rateType, decimal rate, decimal deadline, int periods = 1, bool autoFixPrincipalToInteger = true)
{
if (periods <= 0)
{
throw new DomainException("还款期数不能小于0");
}
switch (this.DateType)
{
case RepaymentTimeUnitType.天:
{
if (deadline / 30 != periods)
{
throw new ArgumentException(string.Format("当前以天计算，共{0}天，期数应为{1}，但参数的期数却为{2}", deadline, deadline / 30, periods));
}
}
break;
case RepaymentTimeUnitType.季:
{
if (deadline * 4 != periods)
{
throw new ArgumentException(string.Format("当前以季计算，共{0}季，期数应为{1}，但参数的期数却为{2}", deadline, deadline * 4, periods));
}
}
break;
case RepaymentTimeUnitType.年:
{
if (deadline * 12 != periods)
{
throw new ArgumentException(string.Format("当前以年计算，共{0}年，期数应为{1}，但参数的期数却为{2}", deadline, deadline * 12, periods));
}
}
break;
case RepaymentTimeUnitType.月:
{
if (deadline != periods)
{
throw new ArgumentException(string.Format("当前以月计算，共{0}月，期数应为{1}，但参数的期数却为{2}", deadline, deadline, periods));
}
}
break;
}
switch (rateType)
{
case RepaymentRateType.天利率:
{
rate = rate * 30;
}
break;
case RepaymentRateType.季利率:
{
rate = rate / 4;
}
break;
case RepaymentRateType.年利率:
{
rate = rate / 12;
}
break;
case RepaymentRateType.月利率:
break;
}
var list = new List <RepaymentModel>(periods);
/*算法中row第二个参数是指期数*/
var factor = (decimal)Math.Pow((double)(1m + rate), periods);
var avg = principal * rate * factor / (factor - 1);
//if (periods == 1)
// return new RepaymentModel[] { new RepaymentModel((avg - principal * rate * this.Strategy.GetUnitAmount()) * deadline, principal * rate * this.Strategy.GetUnitAmount() * deadline, 1, this.Strategy.GetPayTime(this.StartDate, deadline)) };
var avgd = deadline / periods;
if (!autoFixPrincipalToInteger || (autoFixPrincipalToInteger && principal % periods == 0))
{
for (var i = 1; i <= periods; i++)
{
var interest = this.Strategy.GetNUnitAmount((principal - list.Sum(o => o.Principal)) * rate * deadline, RepaymentRateType.月利率) / periods;
var model = new RepaymentModel()
{
Principal = (avg - interest), Interest = interest, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, deadline * i / periods)
};
list.Add(model);
}
}
else
{
for (var i = 1; i <= periods; i++)
{
var interest = this.Strategy.GetNUnitAmount((principal - list.Sum(o => o.Principal)) * rate * deadline, RepaymentRateType.月利率) / periods;
var fixPrincipal = (avg - interest).FormatC(0);
var model = new RepaymentModel()
{
Principal = fixPrincipal, Interest = interest + (avg - interest - fixPrincipal), Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, deadline * i / periods)
};
list.Add(model);
}
}
//list.Add(new RepaymentModel((avg - principal * rate) * avgd, principal * rate * avgd, 1, this.Strategy.GetPayTime(this.StartDate, avgd * 1)));
//for (var i = 2; i <= periods; i++)
//{
// var interest = (principal - list.Sum(o => o.Principal)) * rate * avgd;
// var model = new RepaymentModel((avg - interest) * avgd, interest * avgd, i, this.Strategy.GetPayTime(this.StartDate, avgd * i));
// list.Add(model);
//}
return(list);
}
/// <summary>
/// 还款列表
/// </summary>
/// <param name="principal">本金</param>
/// <param name="rateType">利率计算方式</param>
/// <param name="rate">利率</param>
/// <param name="deadline">期限</param>
/// <param name="periods">期数</param>
/// <param name="autoFixPrincipalToInteger">是否为自动修正本金整数</param>
/// <returns></returns>
public override IEnumerable <RepaymentModel> GetRepayments(decimal principal, RepaymentRateType rateType, decimal rate, decimal deadline, int periods = 1, bool autoFixPrincipalToInteger = true)
{
if (periods <= 0)
{
throw new ArgumentException("还款期数不能小于0");
}
var avgPrincipalPeriod = this.principalPeriods.Count(o => o.PayPrincipal);
if (periods != this.principalPeriods.Count())
{
throw new ArgumentException("还款总期数不等于剩余还款本金期数");
}
/*先平均分出本金，在还了本金后要重新减去已经还的本金*/
var prinList = new List <decimal>(avgPrincipalPeriod);
var list = new List <RepaymentModel>(periods);
var hadPayPrincipal = 0m;
/*不用修正本金*/
if (!autoFixPrincipalToInteger)
{
for (var i = 0; i < avgPrincipalPeriod; i++)
{
prinList.Add(principal / avgPrincipalPeriod);
}
int j = 0;
for (var i = 1; i <= periods; i++)
{
if (this.principalPeriods.ElementAt(i - 1).PayPrincipal)
{
list.Add(new RepaymentModel()
{
Principal = prinList[j], Interest = this.Strategy.GetNUnitAmount((principal - hadPayPrincipal) * rate * deadline, rateType) / periods, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, i * deadline / periods)
});
hadPayPrincipal += prinList[j];
j++;
}
else
{
list.Add(new RepaymentModel()
{
Principal = 0, Interest = this.Strategy.GetNUnitAmount((principal - hadPayPrincipal) * rate * deadline, rateType) / periods, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, i * deadline / periods)
});
}
}
return(list);
}
if (principal % avgPrincipalPeriod == 0)
{
for (var i = 0; i < avgPrincipalPeriod; i++)
{
prinList.Add(principal / avgPrincipalPeriod);
}
}
else
{
var fixPrincipal = principal - principal % avgPrincipalPeriod;
var firstPrinciapl = principal - (avgPrincipalPeriod - 1) * fixPrincipal / avgPrincipalPeriod;
prinList.Add(firstPrinciapl);
if (avgPrincipalPeriod > 1)
{
for (var i = 1; i < avgPrincipalPeriod; i++)
{
prinList.Add((principal - firstPrinciapl) / (avgPrincipalPeriod - 1));
}
}
}
int k = 0;
for (var i = 1; i <= periods; i++)
{
if (this.principalPeriods.ElementAt(i - 1).PayPrincipal)
{
list.Add(new RepaymentModel()
{
Principal = prinList[k], Interest = this.Strategy.GetNUnitAmount((principal - hadPayPrincipal) * rate * deadline, rateType) / periods, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, i * deadline / periods)
});
hadPayPrincipal += prinList[k];
k++;
}
else
{
list.Add(new RepaymentModel()
{
Principal = 0, Interest = this.Strategy.GetNUnitAmount((principal - hadPayPrincipal) * rate * deadline, rateType) / periods, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, i * deadline / periods)
});
}
}
return(list);
}
/// <summary>
/// 还款列表
/// </summary>
/// <param name="principal">本金</param>
/// <param name="rateType">利率计算方式</param>
/// <param name="rate">利率</param>
/// <param name="deadline">期限</param>
/// <param name="periods">期数</param>
/// <param name="autoFixPrincipalToInteger">是否为自动修正本金整数</param>
/// <returns></returns>
public override IEnumerable <RepaymentModel> GetRepayments(decimal principal, RepaymentRateType rateType, decimal rate, decimal deadline, int periods = 1, bool autoFixPrincipalToInteger = true)
{
if (periods <= 0)
{
throw new ArgumentException("还款期数不能小于0");
}
if (periods != this.principalPeriods.Count() || periods != this.principalPeriods.Max(p => p.Period))
{
throw new ArgumentException("还款总期数不等于剩余还款本金期数");
}
var list = new List <RepaymentModel>(periods);
var hadPayPrincipal = 0m;
/*不用修正本金*/
if (!autoFixPrincipalToInteger)
{
for (var i = 1; i <= periods; i++)
{
var percent = this.principalPeriods.ElementAt(i - 1);
list.Add(new RepaymentModel()
{
Principal = principal * percent.Percent / 100, Interest = this.Strategy.GetNUnitAmount((principal - hadPayPrincipal) * rate * deadline, rateType) / periods, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, i * deadline / periods)
});
hadPayPrincipal += principal * percent.Percent / 100;
}
return(list);
}
for (var i = 1; i <= periods; i++)
{
var percent = this.principalPeriods.ElementAt(i - 1);
if (i != periods)
{
list.Add(new RepaymentModel()
{
Principal = principal * percent.Percent / 100, Interest = this.Strategy.GetNUnitAmount((principal - hadPayPrincipal) * rate * deadline, rateType) / periods, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, i * deadline / periods)
});
}
else
{
list.Add(new RepaymentModel()
{
Principal = principal - hadPayPrincipal, Interest = this.Strategy.GetNUnitAmount((principal - hadPayPrincipal) * rate * deadline, rateType) / periods, Period = i, PayDate = this.Strategy.GetPayTime(this.StartDate, i * deadline / periods)
});
}
hadPayPrincipal += principal * percent.Percent / 100;
}
return(list);
}
