add subscription tiers

backend/internal/models/user.go

@@ -19,14 +19,14 @@ func NewUserModel(pool *pgxpool.Pool) *UserModel {
 
 const userColumns = `id, firebase_uid, email, display_name,
 	stripe_customer_id, stripe_subscription_id, subscription_status,
-	subscription_created_at, created_at, updated_at`
+	subscription_tier, subscription_created_at, created_at, updated_at`
 
 func scanUser(row pgx.Row) (*domain.User, error) {
 	var u domain.User
 	err := row.Scan(
 		&u.ID, &u.FirebaseUID, &u.Email, &u.DisplayName,
 		&u.StripeCustomerID, &u.StripeSubscriptionID, &u.SubscriptionStatus,
-		&u.SubscriptionCreatedAt, &u.CreatedAt, &u.UpdatedAt,
+		&u.SubscriptionTier, &u.SubscriptionCreatedAt, &u.CreatedAt, &u.UpdatedAt,
 	)
 	if err != nil {
 		if errors.Is(err, pgx.ErrNoRows) {
@@ -66,15 +66,37 @@ func (m *UserModel) UpdateStripeCustomer(ctx context.Context, userID, stripeCust
 	return err
 }
 
-func (m *UserModel) ActivateSubscription(ctx context.Context, stripeCustomerID, subscriptionID, status string) error {
+func (m *UserModel) ActivateSubscription(ctx context.Context, stripeCustomerID, subscriptionID, status string, tier domain.SubscriptionTier) error {
 	_, err := m.pool.Exec(ctx,
 		`UPDATE users
 		 SET stripe_subscription_id = $2,
 		     subscription_status = $3,
+		     subscription_tier = $4,
 		     subscription_created_at = COALESCE(subscription_created_at, NOW()),
 		     updated_at = NOW()
 		 WHERE stripe_customer_id = $1`,
-		stripeCustomerID, subscriptionID, status,
+		stripeCustomerID, subscriptionID, status, string(tier),
+	)
+	return err
+}
+
+func (m *UserModel) UpdateSubscriptionTier(ctx context.Context, userID string, tier domain.SubscriptionTier) error {
+	_, err := m.pool.Exec(ctx,
+		`UPDATE users SET subscription_tier = $2, updated_at = NOW() WHERE id = $1`,
+		userID, string(tier),
+	)
+	return err
+}
+
+func (m *UserModel) ActivateFreeTier(ctx context.Context, userID string) error {
+	_, err := m.pool.Exec(ctx,
+		`UPDATE users
+		 SET subscription_status = 'active',
+		     subscription_tier = 'free',
+		     subscription_created_at = COALESCE(subscription_created_at, NOW()),
+		     updated_at = NOW()
+		 WHERE id = $1`,
+		userID,
 	)
 	return err
 }