feat: add percentage loyalti setting mode

internal/processor/earning_calculator_test.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
+	"apskel-pos-be/internal/constants"
 	"apskel-pos-be/internal/entities"
 	"apskel-pos-be/internal/models"
 )
@@ -113,6 +114,44 @@ func TestCalculateEarning_EdgeCases(t *testing.T) {
 	assert.Equal(t, int64(0), CalculateEarning(&entities.Order{Subtotal: 87500}, 0, s).Point.Amount)
 }
 
+func TestCalculateEarning_Percentage(t *testing.T) {
+	s := prdEarningSettings()
+	s.Point.EarnMode = constants.LoyaltyEarnModePercentage
+	s.Point.EarnPercent = 1
+
+	// 1% of the basis; the per-amount settings are ignored, and coin keeps its own mode.
+	got := CalculateEarning(&entities.Order{Subtotal: 97500, DiscountAmount: 10000}, 0, s)
+	assert.Equal(t, int64(875), got.Point.Amount)
+	assert.Equal(t, int64(3), got.Coin.Amount)
+	// The part paid with EnakPoint earns nothing in this mode either.
+	assert.Equal(t, int64(675), CalculateEarning(&entities.Order{Subtotal: 97500, DiscountAmount: 10000}, 20000, s).Point.Amount)
+
+	// Decimals, and floor, not round: 2.5% of 87.500 is 2187.5.
+	s.Point.EarnPercent = 2.5
+	assert.Equal(t, int64(2187), CalculateEarning(&entities.Order{Subtotal: 87500}, 0, s).Point.Amount)
+	s.Point.EarnPercent = 0.01
+	assert.Equal(t, int64(8), CalculateEarning(&entities.Order{Subtotal: 87599.99}, 0, s).Point.Amount)
+
+	// The minimum and the cap apply as in the other mode.
+	s.Point.EarnPercent = 10
+	s.Point.MinOrderAmount = 50000
+	max := int64(6000)
+	s.Point.MaxPerOrder = &max
+	assert.Equal(t, int64(0), CalculateEarning(&entities.Order{Subtotal: 49999}, 0, s).Point.Amount)
+	assert.Equal(t, int64(5000), CalculateEarning(&entities.Order{Subtotal: 50000}, 0, s).Point.Amount)
+	got = CalculateEarning(&entities.Order{Subtotal: 87500}, 0, s)
+	assert.Equal(t, int64(6000), got.Point.Amount)
+	assert.True(t, got.Point.Capped)
+
+	// The mode and percent are frozen on the ledger row.
+	assert.Equal(t, constants.LoyaltyEarnModePercentage, got.Metadata(got.Point)["earn_mode"])
+	assert.Equal(t, 10.0, got.Metadata(got.Point)["earn_percent"])
+
+	// A zero percent earns nothing even when enabled.
+	s.Point.EarnPercent = 0
+	assert.Equal(t, int64(0), CalculateEarning(&entities.Order{Subtotal: 87500}, 0, s).Point.Amount)
+}
+
 func TestCalculateEarning_MetadataSnapshot(t *testing.T) {
 	got := CalculateEarning(&entities.Order{Subtotal: 87500}, 0, prdEarningSettings())
 	assert.Equal(t, entities.Metadata{