chore: simplify lineservice

Author: turip

openmeter/billing/errors.go

@@ -152,3 +152,18 @@ type AppError struct {
 func (e AppError) Error() string {
 	return fmt.Sprintf("app %s type with id %s in namespace %s: %s", e.AppType, e.AppID.ID, e.AppID.Namespace, e.Err.Error())
 }
+
+// ErrSnapshotInvalidDatabaseState is returned when the database state is invalid for snapshotting the line quantity.
+// This can happen if the feature or meter is not found. In such cases we should transition the invoice to
+// draft.invalid state.
+type ErrSnapshotInvalidDatabaseState struct {
+	Err error
+}
+
+func (e ErrSnapshotInvalidDatabaseState) Error() string {
+	return fmt.Sprintf("snapshotting line quantity: %s", e.Err.Error())
+}
+
+func (e ErrSnapshotInvalidDatabaseState) Unwrap() error {
+	return e.Err
+}

openmeter/billing/featuremeter.go

@@ -0,0 +1,32 @@
+package billing
+
+import (
+	"fmt"
+
+	"github.com/openmeterio/openmeter/openmeter/meter"
+	"github.com/openmeterio/openmeter/openmeter/productcatalog/feature"
+)
+
+type FeatureMeter struct {
+	Feature feature.Feature
+	Meter   *meter.Meter
+}
+
+type FeatureMeters map[string]FeatureMeter
+
+func (f FeatureMeters) Get(featureKey string, dependsOnMeteredQuantity bool) (FeatureMeter, error) {
+	featureMeter, exists := f[featureKey]
+	if !exists {
+		return FeatureMeter{}, &ErrSnapshotInvalidDatabaseState{
+			Err: fmt.Errorf("feature[%s] not found", featureKey),
+		}
+	}
+
+	if dependsOnMeteredQuantity && featureMeter.Meter == nil {
+		return FeatureMeter{}, &ErrSnapshotInvalidDatabaseState{
+			Err: fmt.Errorf("feature[%s] has no meter associated, but the line depends on metered quantity", featureMeter.Feature.Key),
+		}
+	}
+
+	return featureMeter, nil
+}

openmeter/billing/service/featuremeter.go

@@ -0,0 +1,172 @@
+package billingservice
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/samber/lo"
+
+	"github.com/openmeterio/openmeter/openmeter/billing"
+	"github.com/openmeterio/openmeter/openmeter/meter"
+	"github.com/openmeterio/openmeter/openmeter/productcatalog/feature"
+)
+
+func (s *Service) resolveFeatureMeters(ctx context.Context, lines billing.StandardLines) (billing.FeatureMeters, error) {
+	namespaces := lo.Uniq(lo.Map(lines, func(line *billing.StandardLine, _ int) string {
+		return line.Namespace
+	}))
+
+	if len(namespaces) != 1 {
+		return nil, fmt.Errorf("all lines must be in the same namespace")
+	}
+
+	namespace := namespaces[0]
+
+	featuresToResolve := lo.Uniq(
+		lo.Filter(
+			lo.Map(lines, func(line *billing.StandardLine, _ int) string {
+				return line.UsageBased.FeatureKey
+			}),
+			func(featureKey string, _ int) bool {
+				return featureKey != ""
+			},
+		),
+	)
+
+	// Let's resolve the features
+	features, err := s.featureService.ListFeatures(ctx, feature.ListFeaturesParams{
+		IDsOrKeys:       featuresToResolve,
+		Namespace:       namespace,
+		IncludeArchived: true,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("listing features: %w", err)
+	}
+
+	featuresByKey := getLastFeatures(features.Items)
+
+	metersToResolve := lo.Uniq(
+		lo.Filter(
+			lo.Map(lo.Values(featuresByKey), func(feature feature.Feature, _ int) string {
+				if feature.MeterSlug == nil {
+					return ""
+				}
+
+				return *feature.MeterSlug
+			}),
+			func(meterSlug string, _ int) bool {
+				return meterSlug != ""
+			},
+		),
+	)
+
+	meters, err := s.meterService.ListMeters(ctx, meter.ListMetersParams{
+		SlugFilter:     lo.ToPtr(metersToResolve),
+		Namespace:      namespace,
+		IncludeDeleted: true,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("listing meters: %w", err)
+	}
+
+	metersByKey := getLastMeters(meters.Items)
+
+	out := make(billing.FeatureMeters, len(featuresByKey))
+	for featureKey, feature := range featuresByKey {
+		if feature.MeterSlug == nil {
+			out[featureKey] = billing.FeatureMeter{
+				Feature: feature,
+			}
+
+			continue
+		}
+
+		meter, exists := metersByKey[*feature.MeterSlug]
+		if !exists {
+			out[featureKey] = billing.FeatureMeter{
+				Feature: feature,
+			}
+
+			continue
+		}
+
+		out[featureKey] = billing.FeatureMeter{
+			Feature: feature,
+			Meter:   &meter,
+		}
+	}
+
+	return out, nil
+}
+
+type lastEntityAccessor[T any] interface {
+	GetKey(T) string
+	GetDeletedAt(T) *time.Time
+}
+
+func getLastEntity[T any](entities []T, accessor lastEntityAccessor[T]) map[string]T {
+	featuresByKey := lo.GroupBy(entities, func(entity T) string {
+		return accessor.GetKey(entity)
+	})
+
+	out := make(map[string]T, len(featuresByKey))
+	for key, features := range featuresByKey {
+		// Let's try to find an unarchived feature
+		out[key] = latestEntity(features, accessor)
+	}
+
+	return out
+}
+
+func latestEntity[T any](entities []T, accessor lastEntityAccessor[T]) T {
+	for _, entity := range entities {
+		if accessor.GetDeletedAt(entity) == nil {
+			return entity
+		}
+	}
+
+	// Otherwise, let's find the most recently archived feature:
+	// - all entities have non-nil deleted at (or we would have returned already)
+	// - and we have at least one entity due to the definition of the groupBy
+	mostRecentlyArchivedFeature := entities[0]
+	for _, entity := range entities {
+		if accessor.GetDeletedAt(entity).After(*accessor.GetDeletedAt(mostRecentlyArchivedFeature)) {
+			mostRecentlyArchivedFeature = entity
+		}
+	}
+
+	return mostRecentlyArchivedFeature
+}
+
+type featureAccessor struct{}
+
+var _ lastEntityAccessor[feature.Feature] = (*featureAccessor)(nil)
+
+func (a featureAccessor) GetKey(feature feature.Feature) string {
+	return feature.Key
+}
+
+func (a featureAccessor) GetDeletedAt(feature feature.Feature) *time.Time {
+	return feature.ArchivedAt
+}
+
+func getLastFeatures(features []feature.Feature) map[string]feature.Feature {
+	return getLastEntity(features, featureAccessor{})
+}
+
+type meterAccessor struct{}
+
+var _ lastEntityAccessor[meter.Meter] = (*meterAccessor)(nil)
+
+func (a meterAccessor) GetKey(meter meter.Meter) string {
+	return meter.Key
+}
+
+func (a meterAccessor) GetDeletedAt(meter meter.Meter) *time.Time {
+	return meter.DeletedAt
+}
+
+func getLastMeters(meters []meter.Meter) map[string]meter.Meter {
+	return getLastEntity(meters, meterAccessor{})
+}

openmeter/billing/service/featuremeter_test.go

@@ -0,0 +1,63 @@
+package billingservice
+
+import (
+	"testing"
+	"time"
+
+	"github.com/samber/lo"
+	"github.com/stretchr/testify/require"
+
+	"github.com/openmeterio/openmeter/openmeter/productcatalog/feature"
+)
+
+func TestGetLastFeatures(t *testing.T) {
+	tcs := []struct {
+		name     string
+		features []feature.Feature
+		expected map[string]string
+	}{
+		{
+			name: "single-active",
+			features: []feature.Feature{
+				{ID: "id-active", ArchivedAt: nil, Key: "feature-1-active"},
+			},
+			expected: map[string]string{"feature-1-active": "id-active"},
+		},
+		{
+			name: "single-archived",
+			features: []feature.Feature{
+				{ID: "id-archived", ArchivedAt: lo.ToPtr(time.Now()), Key: "feature-1-archived"},
+			},
+			expected: map[string]string{"feature-1-archived": "id-archived"},
+		},
+		{
+			name: "multi-archived",
+			features: []feature.Feature{
+				{ID: "id-archived", ArchivedAt: lo.ToPtr(time.Now()), Key: "feature-1"},
+				{ID: "id-active", ArchivedAt: nil, Key: "feature-1"},
+			},
+			expected: map[string]string{"feature-1": "id-active"},
+		},
+		{
+			name: "archived-ordering",
+			features: []feature.Feature{
+				{ID: "id-archived-1", ArchivedAt: lo.ToPtr(time.Now()), Key: "feature-1"},
+				{ID: "id-archived-2", ArchivedAt: lo.ToPtr(time.Now().Add(5 * time.Second)), Key: "feature-1"},
+			},
+			expected: map[string]string{"feature-1": "id-archived-2"},
+		},
+	}
+
+	for _, tc := range tcs {
+		t.Run(tc.name, func(t *testing.T) {
+			out := getLastFeatures(tc.features)
+
+			featureKeyToID := map[string]string{}
+			for key, feature := range out {
+				featureKeyToID[key] = feature.ID
+			}
+
+			require.Equal(t, tc.expected, featureKeyToID)
+		})
+	}
+}