Merge pull request #1080 from openmeterio/feat/automatic-grant-issuing

Feat/automatic grant issuing

api/openapi.yaml

@@ -1837,13 +1837,20 @@ components:
             - $ref: "#/components/schemas/ExpirationPeriod"
         maxRolloverAmount:
           description: |
-            The maximum amount of the grant that can be rolled over. Defaults to 0.
+            Grants are rolled over at reset, after which they can have a different balance compared to what they had before the reset.
 
-            - maxAmount = {original_amount} -> rollover original amount
-            - maxAmount = 0 -> no rollover
-            - maxAmount = 90 -> rollover 90 max
+            Balance after the reset is calculated as:
+            Balance_After_Reset = MIN(MaxRolloverAmount, MAX(Balance_Before_Reset, MinRolloverAmount))
+          type: number
+          format: double
+          default: 0
+          example: 100
+        minRolloverAmount:
+          description: |
+            Grants are rolled over at reset, after which they can have a different balance compared to what they had before the reset.
 
-            If it's larger than 0 then the grant's balance will be the MAX(maxRollover, balance) + amount.
+            Balance after the reset is calculated as:
+            Balance_After_Reset = MIN(MaxRolloverAmount, MAX(Balance_Before_Reset, MinRolloverAmount))
           type: number
           format: double
           default: 0

e2e/e2e_test.go

@@ -560,6 +560,7 @@ func TestCredit(t *testing.T) {
 
 		priority := 1
 		maxRolloverAmount := 100.0
+		minRolloverAmount := 0.0
 
 		// Create grant
 		resp, err := client.CreateGrantWithResponse(context.Background(), subject, *entitlementId, api.EntitlementGrantCreateInput{
@@ -571,6 +572,7 @@ func TestCredit(t *testing.T) {
 			},
 			Priority:          &priority,
 			MaxRolloverAmount: &maxRolloverAmount,
+			MinRolloverAmount: &minRolloverAmount,
 			Recurrence: &api.RecurringPeriodCreateInput{
 				Anchor:   convert.ToPointer(time.Date(2024, time.January, 1, 0, 0, 0, 0, time.UTC)),
 				Interval: "YEAR",
@@ -591,6 +593,7 @@ func TestCredit(t *testing.T) {
 			Priority:          &priority,
 			EffectiveAt:       effectiveAt.UTC(),
 			MaxRolloverAmount: &maxRolloverAmount,
+			MinRolloverAmount: &minRolloverAmount,
 			Expiration: api.ExpirationPeriod{
 				Duration: "MONTH",
 				Count:    1,

internal/credit/grant.go

@@ -22,6 +22,10 @@ func (n NamespacedGrantOwner) NamespacedID() models.NamespacedID {
 	}
 }
 
+const (
+	GrantPriorityDefault uint8 = 1
+)
+
 // Grant is an immutable definition used to increase balance.
 type Grant struct {
 	models.ManagedModel
@@ -57,8 +61,13 @@ type Grant struct {
 	VoidedAt *time.Time `json:"voidedAt,omitempty"`
 
 	// How much of the grant can be rolled over after a reset operation.
+	// Balance after a reset will be between ResetMinRollover and ResetMaxRollover.
 	ResetMaxRollover float64 `json:"resetMaxRollover"`
 
+	// How much balance the grant must have after a reset.
+	// Balance after a reset will be between ResetMinRollover and ResetMaxRollover.
+	ResetMinRollover float64 `json:"resetMinRollover"`
+
 	// Recurrence config for the grant. If nil the grant doesn't recur.
 	Recurrence *recurrence.Recurrence `json:"recurrence,omitempty"`
 }
@@ -95,8 +104,9 @@ func (g Grant) RecurrenceBalance(currentBalance float64) float64 {
 
 // Calculates the new balance after a rollover from the current balance
 func (g Grant) RolloverBalance(currentBalance float64) float64 {
-	// At a rollover the maximum balance that can remain is the ResetMaxRollover
-	return math.Min(g.ResetMaxRollover, currentBalance)
+	// At a rollover the maximum balance that can remain is the ResetMaxRollover,
+	// while the minimum that has to be granted is ResetMinRollover.
+	return math.Min(g.ResetMaxRollover, math.Max(g.ResetMinRollover, currentBalance))
 }
 
 func (g Grant) GetNamespacedID() models.NamespacedID {

internal/credit/grant_connector.go

@@ -17,6 +17,7 @@ type CreateGrantInput struct {
 	Expiration       ExpirationPeriod
 	Metadata         map[string]string
 	ResetMaxRollover float64
+	ResetMinRollover float64
 	Recurrence       *recurrence.Recurrence
 }
 
@@ -57,6 +58,7 @@ type GrantRepoCreateGrantInput struct {
 	ExpiresAt        time.Time
 	Metadata         map[string]string
 	ResetMaxRollover float64
+	ResetMinRollover float64
 	Recurrence       *recurrence.Recurrence
 }
 
@@ -133,6 +135,7 @@ func (m *grantConnector) CreateGrant(ctx context.Context, owner NamespacedGrantO
 			ExpiresAt:        input.Expiration.GetExpiration(input.EffectiveAt),
 			Metadata:         input.Metadata,
 			ResetMaxRollover: input.ResetMaxRollover,
+			ResetMinRollover: input.ResetMinRollover,
 			Recurrence:       input.Recurrence,
 		})