implement paywall (#161)

* implement core foundation

* inject deps

* fix incorrect migration

* tail migration

* use transaction for migration

* fix: inject deps for tests

* cleanup billing management for admin

* upgrade stripe sdk to v85

* set price env variables

* cleanup billing management

* allow multiple dev windows

* fix: settings scroll

* feat: show nice video thumbnail in listview

* feat: implement freemium restrictions

* remove unnecessary comments

* refactor

* docs

* format

* tweak network settings better hierarchy

go/internal/network/models.go

@@ -3,11 +3,11 @@ package network
 import "time"
 
 type Network struct {
-	ID                    string
-	Name                  string
-	AdminHumanId          string
-	MemberHumanIds        []string
-	CreatedAt             time.Time
+	ID             string
+	Name           string
+	AdminHumanId   string
+	MemberHumanIds []string
+	CreatedAt      time.Time
 }
 
 type Invitation struct {

go/internal/network/repository.go

@@ -5,10 +5,20 @@ import (
 	"errors"
 
 	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgconn"
 	"github.com/jackc/pgx/v5/pgxpool"
 	"go.jetify.com/typeid"
 )
 
+// dbtx is the subset of pgx's query API shared by *pgxpool.Pool and pgx.Tx.
+// Used by repository helpers that the service layer may run either standalone
+// (against the pool) or inside a transaction.
+type dbtx interface {
+	Exec(ctx context.Context, sql string, args ...any) (pgconn.CommandTag, error)
+	Query(ctx context.Context, sql string, args ...any) (pgx.Rows, error)
+	QueryRow(ctx context.Context, sql string, args ...any) pgx.Row
+}
+
 var errNotFound = errors.New("not found")
 
 type networkIDPrefix struct{}
@@ -30,9 +40,10 @@ type repository interface {
 	getByID(ctx context.Context, id string) (*Network, error)
 	updateName(ctx context.Context, id, name string) error
 	delete(ctx context.Context, id string) error
-	addMember(ctx context.Context, networkID, humanId string) error
-	removeMember(ctx context.Context, networkID, humanId string) error
+	addMember(ctx context.Context, db dbtx, networkID, humanId string) error
+	removeMember(ctx context.Context, db dbtx, networkID, humanId string) error
 	getMemberHumanIds(ctx context.Context, networkID string) ([]string, error)
+	countSeats(ctx context.Context, db dbtx, networkID string) (int, error)
 	getNetworksForHuman(ctx context.Context, humanId string) ([]*Network, error)
 	isMember(ctx context.Context, networkID, humanId string) (bool, error)
 	listAll(ctx context.Context) ([]*Network, error)
@@ -41,7 +52,15 @@ type repository interface {
 	createInvitation(ctx context.Context, networkID, email string) error
 	getInvitationsByEmail(ctx context.Context, email string) ([]*Invitation, error)
 	getInvitationsByNetwork(ctx context.Context, networkID string) ([]*Invitation, error)
-	deleteInvitation(ctx context.Context, networkID, email string) error
+	deleteInvitation(ctx context.Context, db dbtx, networkID, email string) error
+}
+
+// networkColumns lists every column selected when hydrating a Network.
+// Centralized to keep SELECTs and Scan() calls in sync.
+const networkColumns = `id, name, admin_human_id, created_at`
+
+func scanNetwork(row pgx.Row, n *Network) error {
+	return row.Scan(&n.ID, &n.Name, &n.AdminHumanId, &n.CreatedAt)
 }
 
 type repositoryImpl struct {
@@ -59,12 +78,12 @@ func (r *repositoryImpl) create(ctx context.Context, name, adminHumanId string)
 	}
 
 	var n Network
-	err = r.pool.QueryRow(ctx,
+	row := r.pool.QueryRow(ctx,
 		`INSERT INTO networks (id, name, admin_human_id) VALUES ($1, $2, $3)
-		 RETURNING id, name, admin_human_id, created_at`,
+		 RETURNING `+networkColumns,
 		id.String(), name, adminHumanId,
-	).Scan(&n.ID, &n.Name, &n.AdminHumanId, &n.CreatedAt)
-	if err != nil {
+	)
+	if err := scanNetwork(row, &n); err != nil {
 		return nil, err
 	}
 
@@ -74,21 +93,22 @@ func (r *repositoryImpl) create(ctx context.Context, name, adminHumanId string)
 
 func (r *repositoryImpl) getByID(ctx context.Context, id string) (*Network, error) {
 	var n Network
-	err := r.pool.QueryRow(ctx,
-		`SELECT id, name, admin_human_id, created_at FROM networks WHERE id = $1`,
+	row := r.pool.QueryRow(ctx,
+		`SELECT `+networkColumns+` FROM networks WHERE id = $1`,
 		id,
-	).Scan(&n.ID, &n.Name, &n.AdminHumanId, &n.CreatedAt)
-	if err != nil {
+	)
+	if err := scanNetwork(row, &n); err != nil {
 		if errors.Is(err, pgx.ErrNoRows) {
 			return nil, errNotFound
 		}
 		return nil, err
 	}
 
-	n.MemberHumanIds, err = r.getMemberHumanIds(ctx, id)
+	memberIds, err := r.getMemberHumanIds(ctx, id)
 	if err != nil {
 		return nil, err
 	}
+	n.MemberHumanIds = memberIds
 
 	return &n, nil
 }
@@ -118,8 +138,8 @@ func (r *repositoryImpl) delete(ctx context.Context, id string) error {
 	return nil
 }
 
-func (r *repositoryImpl) addMember(ctx context.Context, networkID, humanId string) error {
-	_, err := r.pool.Exec(ctx,
+func (r *repositoryImpl) addMember(ctx context.Context, db dbtx, networkID, humanId string) error {
+	_, err := db.Exec(ctx,
 		`INSERT INTO network_members (network_id, human_id) VALUES ($1, $2)
 		 ON CONFLICT (network_id, human_id) DO NOTHING`,
 		networkID, humanId,
@@ -127,14 +147,23 @@ func (r *repositoryImpl) addMember(ctx context.Context, networkID, humanId strin
 	return err
 }
 
-func (r *repositoryImpl) removeMember(ctx context.Context, networkID, humanId string) error {
-	_, err := r.pool.Exec(ctx,
+func (r *repositoryImpl) removeMember(ctx context.Context, db dbtx, networkID, humanId string) error {
+	_, err := db.Exec(ctx,
 		`DELETE FROM network_members WHERE network_id = $1 AND human_id = $2`,
 		networkID, humanId,
 	)
 	return err
 }
 
+func (r *repositoryImpl) countSeats(ctx context.Context, db dbtx, networkID string) (int, error) {
+	var count int
+	err := db.QueryRow(ctx,
+		`SELECT COUNT(*) FROM network_members WHERE network_id = $1`,
+		networkID,
+	).Scan(&count)
+	return count, err
+}
+
 func (r *repositoryImpl) getMemberHumanIds(ctx context.Context, networkID string) ([]string, error) {
 	rows, err := r.pool.Query(ctx,
 		`SELECT human_id FROM network_members WHERE network_id = $1`,
@@ -158,10 +187,10 @@ func (r *repositoryImpl) getMemberHumanIds(ctx context.Context, networkID string
 
 func (r *repositoryImpl) getNetworksForHuman(ctx context.Context, humanId string) ([]*Network, error) {
 	rows, err := r.pool.Query(ctx,
-		`SELECT n.id, n.name, n.admin_human_id, n.created_at
-		 FROM networks n
-		 WHERE n.admin_human_id = $1
-		 OR EXISTS (SELECT 1 FROM network_members nm WHERE nm.network_id = n.id AND nm.human_id = $1)`,
+		`SELECT `+networkColumns+`
+		 FROM networks
+		 WHERE admin_human_id = $1
+		 OR EXISTS (SELECT 1 FROM network_members nm WHERE nm.network_id = id AND nm.human_id = $1)`,
 		humanId,
 	)
 	if err != nil {
@@ -172,7 +201,7 @@ func (r *repositoryImpl) getNetworksForHuman(ctx context.Context, humanId string
 	var networks []*Network
 	for rows.Next() {
 		var n Network
-		if err := rows.Scan(&n.ID, &n.Name, &n.AdminHumanId, &n.CreatedAt); err != nil {
+		if err := scanNetwork(rows, &n); err != nil {
 			return nil, err
 		}
 		networks = append(networks, &n)
@@ -205,7 +234,7 @@ func (r *repositoryImpl) isMember(ctx context.Context, networkID, humanId string
 
 func (r *repositoryImpl) listAll(ctx context.Context) ([]*Network, error) {
 	rows, err := r.pool.Query(ctx,
-		`SELECT id, name, admin_human_id, created_at FROM networks`,
+		`SELECT `+networkColumns+` FROM networks`,
 	)
 	if err != nil {
 		return nil, err
@@ -215,7 +244,7 @@ func (r *repositoryImpl) listAll(ctx context.Context) ([]*Network, error) {
 	var networks []*Network
 	for rows.Next() {
 		var n Network
-		if err := rows.Scan(&n.ID, &n.Name, &n.AdminHumanId, &n.CreatedAt); err != nil {
+		if err := scanNetwork(rows, &n); err != nil {
 			return nil, err
 		}
 		networks = append(networks, &n)
@@ -293,8 +322,8 @@ func (r *repositoryImpl) getInvitationsByNetwork(ctx context.Context, networkID
 	return invitations, rows.Err()
 }
 
-func (r *repositoryImpl) deleteInvitation(ctx context.Context, networkID, email string) error {
-	_, err := r.pool.Exec(ctx,
+func (r *repositoryImpl) deleteInvitation(ctx context.Context, db dbtx, networkID, email string) error {
+	_, err := db.Exec(ctx,
 		`DELETE FROM network_invitations WHERE network_id = $1 AND email = $2`,
 		networkID, email,
 	)

go/internal/network/service.go

@@ -9,8 +9,11 @@ import (
 	"strings"
 
 	pbaero "github.com/flowy-live/llink/genproto/aero"
+	"github.com/flowy-live/llink/internal/billing"
 	"github.com/flowy-live/llink/internal/utils"
+	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgxpool"
+	"slices"
 )
 
 var ErrNotFound = errors.New("network not found")
@@ -25,8 +28,11 @@ type Service interface {
 	GetByID(ctx context.Context, id string) (*Network, error)
 	// SetName returns ErrNotFound or ErrInvalidName.
 	SetName(ctx context.Context, id, name string) error
+	// AddMembers inserts members and syncs the new seat count to billing
+	// atomically; a Stripe failure rolls the insert back.
 	AddMembers(ctx context.Context, networkID string, humanIds []string) error
 	RemoveMember(ctx context.Context, networkID, humanId string) error
+	CountSeats(ctx context.Context, networkID string) (int, error)
 	ListForHuman(ctx context.Context, humanId string) ([]*Network, error)
 	IsMember(ctx context.Context, networkID, humanId string) (bool, error)
 	// ListAll returns all networks with their members
@@ -41,12 +47,19 @@ type Service interface {
 }
 
 type serviceImpl struct {
-	repo    repository
-	aeroSvc pbaero.PrimaryClient
+	pool       *pgxpool.Pool
+	repo       repository
+	aeroSvc    pbaero.PrimaryClient
+	billingSvc billing.Service
 }
 
-func NewService(pool *pgxpool.Pool, aeroSvc pbaero.PrimaryClient) Service {
-	return &serviceImpl{repo: newRepository(pool), aeroSvc: aeroSvc}
+func NewService(pool *pgxpool.Pool, aeroSvc pbaero.PrimaryClient, billingSvc billing.Service) Service {
+	return &serviceImpl{
+		pool:       pool,
+		repo:       newRepository(pool),
+		aeroSvc:    aeroSvc,
+		billingSvc: billingSvc,
+	}
 }
 
 func (s *serviceImpl) Create(ctx context.Context, name, adminHumanId string) (*Network, error) {
@@ -60,8 +73,7 @@ func (s *serviceImpl) Create(ctx context.Context, name, adminHumanId string) (*N
 		return nil, err
 	}
 
-	err = s.AddMembers(ctx, network.ID, []string{adminHumanId})
-	if err != nil {
+	if err := s.AddMembers(ctx, network.ID, []string{adminHumanId}); err != nil {
 		return nil, err
 	}
 
@@ -90,22 +102,58 @@ func (s *serviceImpl) SetName(ctx context.Context, id, name string) error {
 }
 
 func (s *serviceImpl) AddMembers(ctx context.Context, networkID string, humanIds []string) error {
-	for _, humanId := range humanIds {
-		if humanId == "" {
-			return fmt.Errorf("invalid humanId")
-		}
-		if err := s.repo.addMember(ctx, networkID, humanId); err != nil {
-			return err
-		}
+	if slices.Contains(humanIds, "") {
+		return fmt.Errorf("invalid humanId")
 	}
-	return nil
+	return s.mutateMembers(ctx, networkID, func(tx pgx.Tx) error {
+		for _, humanId := range humanIds {
+			if err := s.repo.addMember(ctx, tx, networkID, humanId); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
 }
 
 func (s *serviceImpl) RemoveMember(ctx context.Context, networkID, humanId string) error {
 	if humanId == "" {
 		return fmt.Errorf("invalid humanId")
 	}
-	return s.repo.removeMember(ctx, networkID, humanId)
+	return s.mutateMembers(ctx, networkID, func(tx pgx.Tx) error {
+		return s.repo.removeMember(ctx, tx, networkID, humanId)
+	})
+}
+
+// mutateMembers runs fn in a tx, recounts seats, calls billing.SyncSeats,
+// and commits. Any error rolls the membership change back.
+func (s *serviceImpl) mutateMembers(ctx context.Context, networkID string, fn func(pgx.Tx) error) error {
+	tx, err := s.pool.Begin(ctx)
+	if err != nil {
+		return fmt.Errorf("begin tx: %w", err)
+	}
+	defer tx.Rollback(ctx)
+
+	if err := fn(tx); err != nil {
+		return err
+	}
+
+	seats, err := s.repo.countSeats(ctx, tx, networkID)
+	if err != nil {
+		return fmt.Errorf("count seats: %w", err)
+	}
+
+	if err := s.billingSvc.SyncSeats(ctx, networkID, seats); err != nil {
+		return fmt.Errorf("sync billing seats: %w", err)
+	}
+
+	if err := tx.Commit(ctx); err != nil {
+		return fmt.Errorf("commit tx: %w", err)
+	}
+	return nil
+}
+
+func (s *serviceImpl) CountSeats(ctx context.Context, networkID string) (int, error) {
+	return s.repo.countSeats(ctx, s.pool, networkID)
 }
 
 func (s *serviceImpl) ListForHuman(ctx context.Context, humanId string) ([]*Network, error) {
@@ -126,8 +174,6 @@ func (s *serviceImpl) ListAll(ctx context.Context) ([]*Network, error) {
 	return s.repo.listAll(ctx)
 }
 
-// Invitation methods
-
 func (s *serviceImpl) InviteByEmail(ctx context.Context, networkID string, emails []string) error {
 	network, err := s.repo.getByID(ctx, networkID)
 	if err != nil {
@@ -180,10 +226,13 @@ func (s *serviceImpl) AcceptInvitation(ctx context.Context, networkID, email, hu
 		return fmt.Errorf("invalid humanId")
 	}
 
-	if err := s.repo.deleteInvitation(ctx, networkID, normalized); err != nil {
-		return err
-	}
-	return s.repo.addMember(ctx, networkID, humanId)
+	return s.mutateMembers(ctx, networkID, func(tx pgx.Tx) error {
+		err := s.repo.deleteInvitation(ctx, tx, networkID, normalized)
+		if err != nil {
+			return err
+		}
+		return s.repo.addMember(ctx, tx, networkID, humanId)
+	})
 }
 
 func (s *serviceImpl) RevokeInvitation(ctx context.Context, networkID, email string) error {
@@ -191,7 +240,7 @@ func (s *serviceImpl) RevokeInvitation(ctx context.Context, networkID, email str
 	if err != nil {
 		return fmt.Errorf("invalid email: %w", err)
 	}
-	return s.repo.deleteInvitation(ctx, networkID, normalized)
+	return s.repo.deleteInvitation(ctx, s.pool, networkID, normalized)
 }
 
 func buildInvitationHTML(networkName string) string {

go/internal/network/service_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 
 	pbaero "github.com/flowy-live/llink/genproto/aero"
+	"github.com/flowy-live/llink/internal/billing"
 	"github.com/flowy-live/llink/internal/network"
 	"github.com/flowy-live/llink/internal/network/mocks"
 	"github.com/flowy-live/llink/internal/testhelper"
@@ -31,7 +32,7 @@ func newTestService(t *testing.T) network.Service {
 		ShootEmail(gomock.Any(), gomock.Any()).
 		Return(&pbaero.ShootEmailResponse{}, nil).
 		AnyTimes()
-	return network.NewService(dbPool, mockAero)
+	return network.NewService(dbPool, mockAero, billing.Noop())
 }
 
 func TestNetworkService(t *testing.T) {