63d1860dc0
Add a full payment and subscription system supporting EasyPay (Alipay/WeChat), Stripe, and direct Alipay/WeChat Pay providers with multi-instance load balancing.
20 lines
714 B
Go
20 lines
714 B
Go
package payment
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import (
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"github.com/shopspring/decimal"
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)
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// CalculatePayAmount computes the total pay amount given a recharge amount and
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// fee rate (percentage). Fee = amount * feeRate / 100, rounded UP (away from zero)
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// to 2 decimal places. The returned string is formatted to exactly 2 decimal places.
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// If feeRate <= 0, the amount is returned as-is (formatted to 2 decimal places).
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func CalculatePayAmount(rechargeAmount float64, feeRate float64) string {
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amount := decimal.NewFromFloat(rechargeAmount)
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if feeRate <= 0 {
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return amount.StringFixed(2)
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}
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rate := decimal.NewFromFloat(feeRate)
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fee := amount.Mul(rate).Div(decimal.NewFromInt(100)).RoundUp(2)
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return amount.Add(fee).StringFixed(2)
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}
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