package utils

// 一些计算

// ComputeIndividualIncomeTax 计算个人所得税
func ComputeIndividualIncomeTax(income float64) float64 {
	if income <= 800 {
		return 0
	}

	if income <= 4000 {
		income = income - 800
	}

	// 实际纳税金额
	income = income * 0.8

	// 税率、速算扣除数
	var taxRate, quickDeduction float64

	if income <= 20000 {
		taxRate = 0.2
		quickDeduction = 0
	} else if income <= 50000 {
		taxRate = 0.3
		quickDeduction = 2000
	} else {
		taxRate = 0.4
		quickDeduction = 7000
	}

	incomeTax := income*taxRate - quickDeduction

	return incomeTax
}