调整项目结构,factory只负责暴露方法，不实现业务细节

tools/money.go

@@ -0,0 +1,173 @@
+package tools
+
+import (
+	"fmt"
+	"math"
+)
+
+// MoneyCalculator 金额计算工具（以分为单位）
+type MoneyCalculator struct{}
+
+// NewMoneyCalculator 创建金额计算器
+func NewMoneyCalculator() *MoneyCalculator {
+	return &MoneyCalculator{}
+}
+
+// YuanToCents 元转分
+func (m *MoneyCalculator) YuanToCents(yuan float64) int64 {
+	return int64(math.Round(yuan * 100))
+}
+
+// CentsToYuan 分转元
+func (m *MoneyCalculator) CentsToYuan(cents int64) float64 {
+	return float64(cents) / 100
+}
+
+// FormatYuan 格式化显示金额（分转元，保留2位小数）
+func (m *MoneyCalculator) FormatYuan(cents int64) string {
+	return fmt.Sprintf("%.2f", m.CentsToYuan(cents))
+}
+
+// Add 金额相加
+func (m *MoneyCalculator) Add(amount1, amount2 int64) int64 {
+	return amount1 + amount2
+}
+
+// Subtract 金额相减
+func (m *MoneyCalculator) Subtract(amount1, amount2 int64) int64 {
+	return amount1 - amount2
+}
+
+// Multiply 金额乘法（金额 * 数量）
+func (m *MoneyCalculator) Multiply(amount int64, quantity int) int64 {
+	return amount * int64(quantity)
+}
+
+// MultiplyFloat 金额乘法（金额 * 浮点数，如折扣）
+func (m *MoneyCalculator) MultiplyFloat(amount int64, rate float64) int64 {
+	return int64(math.Round(float64(amount) * rate))
+}
+
+// Divide 金额除法（平均分配）
+func (m *MoneyCalculator) Divide(amount int64, count int) int64 {
+	if count <= 0 {
+		return 0
+	}
+	return amount / int64(count)
+}
+
+// CalculateDiscount 计算折扣金额
+func (m *MoneyCalculator) CalculateDiscount(originalAmount int64, discountRate float64) int64 {
+	if discountRate <= 0 || discountRate >= 1 {
+		return 0
+	}
+	return int64(math.Round(float64(originalAmount) * discountRate))
+}
+
+// CalculatePercentage 计算百分比金额
+func (m *MoneyCalculator) CalculatePercentage(amount int64, percentage float64) int64 {
+	return int64(math.Round(float64(amount) * percentage / 100))
+}
+
+// Max 取最大金额
+func (m *MoneyCalculator) Max(amounts ...int64) int64 {
+	if len(amounts) == 0 {
+		return 0
+	}
+	max := amounts[0]
+	for _, amount := range amounts[1:] {
+		if amount > max {
+			max = amount
+		}
+	}
+	return max
+}
+
+// Min 取最小金额
+func (m *MoneyCalculator) Min(amounts ...int64) int64 {
+	if len(amounts) == 0 {
+		return 0
+	}
+	min := amounts[0]
+	for _, amount := range amounts[1:] {
+		if amount < min {
+			min = amount
+		}
+	}
+	return min
+}
+
+// IsPositive 判断是否为正数
+func (m *MoneyCalculator) IsPositive(amount int64) bool {
+	return amount > 0
+}
+
+// IsZero 判断是否为零
+func (m *MoneyCalculator) IsZero(amount int64) bool {
+	return amount == 0
+}
+
+// IsNegative 判断是否为负数
+func (m *MoneyCalculator) IsNegative(amount int64) bool {
+	return amount < 0
+}
+
+// Equal 判断金额是否相等
+func (m *MoneyCalculator) Equal(amount1, amount2 int64) bool {
+	return amount1 == amount2
+}
+
+// Greater 判断第一个金额是否大于第二个
+func (m *MoneyCalculator) Greater(amount1, amount2 int64) bool {
+	return amount1 > amount2
+}
+
+// Less 判断第一个金额是否小于第二个
+func (m *MoneyCalculator) Less(amount1, amount2 int64) bool {
+	return amount1 < amount2
+}
+
+// Sum 计算金额总和
+func (m *MoneyCalculator) Sum(amounts ...int64) int64 {
+	var total int64
+	for _, amount := range amounts {
+		total += amount
+	}
+	return total
+}
+
+// SplitAmount 金额分摊（处理分摊不均的情况）
+func (m *MoneyCalculator) SplitAmount(totalAmount int64, count int) []int64 {
+	if count <= 0 {
+		return []int64{}
+	}
+
+	baseAmount := totalAmount / int64(count)
+	remainder := totalAmount % int64(count)
+
+	amounts := make([]int64, count)
+	for i := 0; i < count; i++ {
+		amounts[i] = baseAmount
+		if int64(i) < remainder {
+			amounts[i]++
+		}
+	}
+
+	return amounts
+}
+
+// 全局金额计算器实例
+var Money = NewMoneyCalculator()
+
+// 便捷函数
+func YuanToCents(yuan float64) int64 {
+	return Money.YuanToCents(yuan)
+}
+
+func CentsToYuan(cents int64) float64 {
+	return Money.CentsToYuan(cents)
+}
+
+func FormatYuan(cents int64) string {
+	return Money.FormatYuan(cents)
+}