feat: allow limiting number of seats in plan

- seats limit can be configured via Behaviour Configuration
in products.
- 2 breaking changes are introduced
  - product credit amount is moved under config of product
  - to specify free credits awarded while subscribing to plan
    a new attribute on_start_credits is added
- products table has a breaking change in db to get rid of credit
amounts and replace it via config

Signed-off-by: Kush Sharma <[email protected]>

.github/workflows/lint.yml

@@ -13,11 +13,11 @@ jobs:
     steps:
       - uses: actions/setup-go@v4
         with:
-          go-version: '1.21.3'
+          go-version: '1.21.6'
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v3
         with:
-          version: v1.54.2
+          version: v1.55.2

.github/workflows/main.yml

@@ -15,7 +15,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version: "1.21.3"
+          go-version: "1.21.6"
       - name: Login to DockerHub
         uses: docker/login-action@v3
         with:

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version: "1.21.3"
+          go-version: "1.21.6"
       - name: Login to DockerHub
         uses: docker/login-action@v3
         with:
@@ -41,7 +41,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version: "1.21.3"
+          go-version: "1.21.6"
       - name: Login to DockerHub
         uses: docker/login-action@v1
         with:

.github/workflows/test.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version: '1.21.3'
+          go-version: '1.21.6'
       - name: install dependencies
         run: go mod tidy
       - name: run unit tests
@@ -42,7 +42,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version: '1.21.3'
+          go-version: '1.21.6'
       - name: install dependencies
         run: go mod tidy
       - name: install spicedb binary
@@ -65,7 +65,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version: '1.21.3'
+          go-version: '1.21.6'
       - name: install dependencies
         run: go mod tidy
       - name: run regression tests

.golangci.yml

@@ -17,6 +17,18 @@ linters:
     - gofmt
     - whitespace
     - misspell
+#    - gosimple
+#    - govet
+#    - ineffassign
+#    - bodyclose
+#    - gocritic
+#    - goconst
+#    - gosec
+#    - importas
+#    - perfsprint
+#    - prealloc
+#    - protogetter
+#    - wastedassign
 linters-settings:
   revive:
     ignore-generated-header: true

Makefile

@@ -4,7 +4,7 @@ TAG := $(shell git rev-list --tags --max-count=1)
 VERSION := $(shell git describe --tags ${TAG})
 .PHONY: build check fmt lint test test-race vet test-cover-html help install proto ui
 .DEFAULT_GOAL := build
-PROTON_COMMIT := "70c01935bc75115a794eedcad102c77e57d4cbf9"
+PROTON_COMMIT := "c09248ad02032c76dc030db192420a4f354a186a"
 
 ui:
 	@echo " > generating ui build"

billing/checkout/service.go

@@ -12,8 +12,6 @@ import (
 
 	"github.com/robfig/cron/v3"
 
-	"github.com/raystack/frontier/pkg/utils"
-
 	"github.com/raystack/frontier/billing/credit"
 
 	"github.com/google/uuid"
@@ -177,11 +175,22 @@ func (s *Service) Create(ctx context.Context, ch Checkout) (Checkout, error) {
 		var subsItems []*stripe.CheckoutSessionLineItemParams
 
 		for _, planFeature := range plan.Products {
-			// if it's credit, skip, they are handled separately
+			// if it's credit, skip
 			if planFeature.Behavior == product.CreditBehavior {
 				continue
 			}
 
+			// if per seat, check if there is a limit of seats, if it breaches limit, fail
+			if planFeature.Behavior == product.PerSeatBehavior {
+				count, err := s.orgService.MemberCount(ctx, billingCustomer.OrgID)
+				if err != nil {
+					return Checkout{}, fmt.Errorf("failed to get member count: %w", err)
+				}
+				if planFeature.Config.SeatLimit > 0 && count > planFeature.Config.SeatLimit {
+					return Checkout{}, fmt.Errorf("member count exceeds allowed limit of the plan: %w", product.ErrPerSeatLimitReached)
+				}
+			}
+
 			for _, productPrice := range planFeature.Prices {
 				// only work with plan interval prices
 				if productPrice.Interval != plan.Interval {
@@ -194,7 +203,7 @@ func (s *Service) Create(ctx context.Context, ch Checkout) (Checkout, error) {
 				if productPrice.UsageType == product.PriceUsageTypeLicensed {
 					itemParams.Quantity = stripe.Int64(1)
 
-					if planFeature.Behavior == product.UserCountBehavior {
+					if planFeature.Behavior == product.PerSeatBehavior {
 						count, err := s.orgService.MemberCount(ctx, billingCustomer.OrgID)
 						if err != nil {
 							return Checkout{}, fmt.Errorf("failed to get member count: %w", err)
@@ -262,16 +271,16 @@ func (s *Service) Create(ctx context.Context, ch Checkout) (Checkout, error) {
 	}
 
 	if ch.ProductID != "" {
-		chFeature, err := s.productService.GetByID(ctx, ch.ProductID)
+		chProduct, err := s.productService.GetByID(ctx, ch.ProductID)
 		if err != nil {
 			return Checkout{}, fmt.Errorf("failed to get product: %w", err)
 		}
-		if len(chFeature.Prices) == 0 {
+		if len(chProduct.Prices) == 0 {
 			return Checkout{}, fmt.Errorf("invalid product, no prices found")
 		}
 
 		var subsItems []*stripe.CheckoutSessionLineItemParams
-		for _, productPrice := range chFeature.Prices {
+		for _, productPrice := range chProduct.Prices {
 			itemParams := &stripe.CheckoutSessionLineItemParams{
 				Price: stripe.String(productPrice.ProviderID),
 			}
@@ -295,8 +304,8 @@ func (s *Service) Create(ctx context.Context, ch Checkout) (Checkout, error) {
 			Mode:      stripe.String(string(stripe.CheckoutSessionModePayment)),
 			Metadata: map[string]string{
 				"org_id":        billingCustomer.OrgID,
-				"product_name":  chFeature.Name,
-				"credit_amount": fmt.Sprintf("%d", chFeature.CreditAmount),
+				"product_name":  chProduct.Name,
+				"credit_amount": fmt.Sprintf("%d", chProduct.Config.CreditAmount),
 				"checkout_id":   checkoutID,
 				"managed_by":    "frontier",
 			},
@@ -312,14 +321,14 @@ func (s *Service) Create(ctx context.Context, ch Checkout) (Checkout, error) {
 			ID:            checkoutID,
 			ProviderID:    stripeCheckout.ID,
 			CustomerID:    billingCustomer.ID,
-			ProductID:     chFeature.ID,
+			ProductID:     chProduct.ID,
 			CancelUrl:     ch.CancelUrl,
 			SuccessUrl:    ch.SuccessUrl,
 			CheckoutUrl:   stripeCheckout.URL,
 			State:         string(stripeCheckout.Status),
 			PaymentStatus: string(stripeCheckout.PaymentStatus),
 			Metadata: map[string]any{
-				"product_name": chFeature.Name,
+				"product_name": chProduct.Name,
 			},
 			ExpireAt: time.Unix(stripeCheckout.ExpiresAt, 0),
 		})
@@ -430,8 +439,8 @@ func (s *Service) SyncWithProvider(ctx context.Context, customerID string) error
 				}
 			} else if ch.ProductID != "" {
 				// if the checkout was created for product
-				if err := s.ensureCreditsForFeature(ctx, ch); err != nil {
-					return fmt.Errorf("ensureCreditsForFeature: %w", err)
+				if err := s.ensureCreditsForProduct(ctx, ch); err != nil {
+					return fmt.Errorf("ensureCreditsForProduct: %w", err)
 				}
 			}
 		}
@@ -440,21 +449,21 @@ func (s *Service) SyncWithProvider(ctx context.Context, customerID string) error
 	return nil
 }
 
-func (s *Service) ensureCreditsForFeature(ctx context.Context, ch Checkout) error {
-	chFeature, err := s.productService.GetByID(ctx, ch.ProductID)
+func (s *Service) ensureCreditsForProduct(ctx context.Context, ch Checkout) error {
+	chProduct, err := s.productService.GetByID(ctx, ch.ProductID)
 	if err != nil {
 		return err
 	}
-	description := fmt.Sprintf("addition of %d credits for %s", chFeature.CreditAmount, chFeature.Title)
+	description := fmt.Sprintf("addition of %d credits for %s", chProduct.Config.CreditAmount, chProduct.Title)
 	if price, pok := ch.Metadata[AmountSubscriptionMetadataKey].(int64); pok {
 		if currency, cok := ch.Metadata[CurrencySubscriptionMetadataKey].(string); cok {
-			description = fmt.Sprintf("addition of %d credits for %s at %d[%s]", chFeature.CreditAmount, chFeature.Title, price, currency)
+			description = fmt.Sprintf("addition of %d credits for %s at %d[%s]", chProduct.Config.CreditAmount, chProduct.Title, price, currency)
 		}
 	}
 	if err := s.creditService.Add(ctx, credit.Credit{
 		ID:          ch.ID,
 		AccountID:   ch.CustomerID,
-		Amount:      chFeature.CreditAmount,
+		Amount:      chProduct.Config.CreditAmount,
 		Metadata:    ch.Metadata,
 		Description: description,
 	}); err != nil && !errors.Is(err, credit.ErrAlreadyApplied) {
@@ -469,26 +478,20 @@ func (s *Service) ensureCreditsForPlan(ctx context.Context, ch Checkout) error {
 		return err
 	}
 
-	// find product with credits
-	creditFeatures := utils.Filter(chPlan.Products, func(f product.Product) bool {
-		return f.CreditAmount > 0
-	})
-	if len(creditFeatures) == 0 {
+	if chPlan.OnStartCredits == 0 {
 		// no such product
 		return nil
 	}
 
-	for _, chFeature := range creditFeatures {
-		description := fmt.Sprintf("addition of %d credits for %s", chFeature.CreditAmount, chFeature.Title)
-		if err := s.creditService.Add(ctx, credit.Credit{
-			ID:          ch.ID,
-			AccountID:   ch.CustomerID,
-			Amount:      chFeature.CreditAmount,
-			Metadata:    ch.Metadata,
-			Description: description,
-		}); err != nil && !errors.Is(err, credit.ErrAlreadyApplied) {
-			return err
-		}
+	description := fmt.Sprintf("addition of %d credits for %s", chPlan.OnStartCredits, chPlan.Title)
+	if err := s.creditService.Add(ctx, credit.Credit{
+		ID:          ch.ID,
+		AccountID:   ch.CustomerID,
+		Amount:      chPlan.OnStartCredits,
+		Metadata:    ch.Metadata,
+		Description: description,
+	}); err != nil && !errors.Is(err, credit.ErrAlreadyApplied) {
+		return err
 	}
 	return nil
 }
@@ -647,7 +650,7 @@ func (s *Service) Apply(ctx context.Context, ch Checkout) (*subscription.Subscri
 				if productPrice.UsageType == product.PriceUsageTypeLicensed {
 					itemParams.Quantity = stripe.Int64(1)
 
-					if planFeature.Behavior == product.UserCountBehavior {
+					if planFeature.Behavior == product.PerSeatBehavior {
 						count, err := s.orgService.MemberCount(ctx, billingCustomer.OrgID)
 						if err != nil {
 							return nil, nil, fmt.Errorf("failed to get member count: %w", err)

billing/entitlement/error.go

@@ -0,0 +1,7 @@
+package entitlement
+
+import "fmt"
+
+var (
+	ErrPlanEntitlementFailed = fmt.Errorf("plan entitlement failed")
+)

billing/entitlement/check.go → billing/entitlement/service.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"errors"
 
+	"github.com/raystack/frontier/billing/plan"
+
 	"golang.org/x/exp/slices"
 
 	"github.com/raystack/frontier/billing/product"
@@ -20,16 +22,29 @@ type ProductService interface {
 	GetByID(ctx context.Context, id string) (product.Product, error)
 }
 
+type PlanService interface {
+	GetByID(ctx context.Context, id string) (plan.Plan, error)
+}
+
+type OrganizationService interface {
+	MemberCount(ctx context.Context, orgID string) (int64, error)
+}
+
 type Service struct {
 	subscriptionService SubscriptionService
 	productService      ProductService
+	planService         PlanService
+	organizationService OrganizationService
 }
 
 func NewEntitlementService(subscriptionService SubscriptionService,
-	featureService ProductService) *Service {
+	featureService ProductService, planService PlanService,
+	organizationService OrganizationService) *Service {
 	return &Service{
 		subscriptionService: subscriptionService,
 		productService:      featureService,
+		planService:         planService,
+		organizationService: organizationService,
 	}
 }
 
@@ -73,3 +88,37 @@ func (s *Service) Check(ctx context.Context, customerID, featureOrProductID stri
 	}
 	return false, nil
 }
+
+func (s *Service) CheckPlanEligibility(ctx context.Context, customerID string) error {
+	// get all subscriptions for the customer
+	subs, err := s.subscriptionService.List(ctx, subscription.Filter{
+		CustomerID: customerID,
+		State:      subscription.StateActive.String(),
+	})
+	if err != nil {
+		return err
+	}
+
+	for _, sub := range subs {
+		planOb, err := s.planService.GetByID(ctx, sub.PlanID)
+		if err != nil {
+			return err
+		}
+
+		// check if the product has seat based limits
+		for _, prod := range planOb.Products {
+			if prod.Behavior == product.PerSeatBehavior {
+				count, err := s.organizationService.MemberCount(ctx, customerID)
+				if err != nil {
+					return err
+				}
+				if prod.Config.SeatLimit > 0 && count > prod.Config.SeatLimit {
+					return product.ErrPerSeatLimitReached
+				}
+			}
+		}
+	}
+
+	// default to true
+	return nil
+}

billing/plan/plan.go

@@ -31,6 +31,9 @@ type Plan struct {
 	// e.g. day, week, month, year
 	Interval string `json:"interval" yaml:"interval"`
 
+	// OnStartCredits is the number of credits that are awarded when a subscription is started
+	OnStartCredits int64 `json:"on_start_credits" yaml:"on_start_credits"`
+
 	// Products for the plan, return only, should not be set when creating a plan
 	Products []product.Product `json:"products" yaml:"products"`
 
@@ -42,7 +45,7 @@ type Plan struct {
 
 func (p Plan) GetUserCountProduct() (product.Product, bool) {
 	for _, f := range p.Products {
-		if f.Behavior == product.UserCountBehavior {
+		if f.Behavior == product.PerSeatBehavior {
 			return f, true
 		}
 	}