feat: add percentage loyalti setting mode

internal/processor/loyalty_settings_processor.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"math"
 	"strconv"
 	"strings"
 	"time"
@@ -240,14 +241,20 @@ func loyaltySettingChangeModel(row entities.LoyaltySettingChange) models.Loyalty
 func outletLoyaltyFields(s *models.OutletLoyaltySettings) []loyaltyField {
 	return []loyaltyField{
 		boolLoyaltyField(constants.LoyaltyPointEnabledKey, &s.Point.Enabled, false),
+		enumLoyaltyField(constants.LoyaltyPointEarnModeKey, &s.Point.EarnMode, constants.LoyaltyEarnModeDefault,
+			constants.LoyaltyEarnModePerAmount, constants.LoyaltyEarnModePercentage),
 		intLoyaltyField(constants.LoyaltyPointEarnPerAmountKey, &s.Point.EarnPerAmount, constants.LoyaltyPointEarnPerAmountDefault, 1, noLoyaltyMax),
 		intLoyaltyField(constants.LoyaltyPointEarnValueKey, &s.Point.EarnValue, constants.LoyaltyEarnValueDefault, 0, noLoyaltyMax),
+		percentLoyaltyField(constants.LoyaltyPointEarnPercentKey, &s.Point.EarnPercent, constants.LoyaltyEarnPercentDefault),
 		intLoyaltyField(constants.LoyaltyPointMinOrderAmountKey, &s.Point.MinOrderAmount, 0, 0, noLoyaltyMax),
 		optionalIntLoyaltyField(constants.LoyaltyPointMaxPerOrderKey, &s.Point.MaxPerOrder, 0),
 
 		boolLoyaltyField(constants.LoyaltyCoinEnabledKey, &s.Coin.Enabled, false),
+		enumLoyaltyField(constants.LoyaltyCoinEarnModeKey, &s.Coin.EarnMode, constants.LoyaltyEarnModeDefault,
+			constants.LoyaltyEarnModePerAmount, constants.LoyaltyEarnModePercentage),
 		intLoyaltyField(constants.LoyaltyCoinEarnPerAmountKey, &s.Coin.EarnPerAmount, constants.LoyaltyCoinEarnPerAmountDefault, 1, noLoyaltyMax),
 		intLoyaltyField(constants.LoyaltyCoinEarnValueKey, &s.Coin.EarnValue, constants.LoyaltyEarnValueDefault, 0, noLoyaltyMax),
+		percentLoyaltyField(constants.LoyaltyCoinEarnPercentKey, &s.Coin.EarnPercent, constants.LoyaltyEarnPercentDefault),
 		intLoyaltyField(constants.LoyaltyCoinMinOrderAmountKey, &s.Coin.MinOrderAmount, 0, 0, noLoyaltyMax),
 		optionalIntLoyaltyField(constants.LoyaltyCoinMaxPerOrderKey, &s.Coin.MaxPerOrder, 0),
 
@@ -329,6 +336,35 @@ func intLoyaltyField(key string, v *int64, def, min, max int64) loyaltyField {
 	}
 }
 
+// percentLoyaltyField is a percentage from 0 to 100 with at most two decimals, so it
+// is whole in hundredths and calculations with it stay in integers.
+func percentLoyaltyField(key string, v *float64, def float64) loyaltyField {
+	check := func(n float64) error {
+		// The negated form also rejects NaN.
+		if !(n >= 0 && n <= 100) {
+			return fmt.Errorf("%w: %s must be between 0 and 100", ErrInvalidLoyaltySettings, key)
+		}
+		if math.Abs(n*100-math.Round(n*100)) > 1e-6 {
+			return fmt.Errorf("%w: %s must have at most two decimals", ErrInvalidLoyaltySettings, key)
+		}
+		return nil
+	}
+	return loyaltyField{
+		key: key,
+		parse: func(raw string) bool {
+			n, err := strconv.ParseFloat(strings.TrimSpace(raw), 64)
+			if err != nil || check(n) != nil {
+				return false
+			}
+			*v = n
+			return true
+		},
+		reset:    func() { *v = def },
+		validate: func() error { return check(*v) },
+		format:   func() *string { s := strconv.FormatFloat(*v, 'f', -1, 64); return &s },
+	}
+}
+
 // optionalIntLoyaltyField is a limit that may be unset, meaning no limit.
 func optionalIntLoyaltyField(key string, v **int64, min int64) loyaltyField {
 	return loyaltyField{