Connect sign-up to Sendico Facts intake (#46)

backend/product/identity/service.go

@@ -0,0 +1,132 @@
+package identity
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	customer "git.sendico.io/tech/sxchnge/product/customers/model"
+	merrors "git.sendico.io/tech/sxchnge/shared/errors"
+	mlogger "git.sendico.io/tech/sxchnge/shared/logging"
+	"go.mongodb.org/mongo-driver/v2/bson"
+	"go.uber.org/zap"
+)
+
+type Provider interface {
+	Namespace() string
+	Register(context.Context, string) (string, error)
+	Submit(context.Context, string, string, Facts) (Receipt, error)
+}
+
+type Service struct {
+	Store    Store
+	Provider Provider
+	Logger   mlogger.Logger
+}
+
+func unavailable() error { return merrors.ServiceUnavailable("sign-up facts unavailable") }
+
+// Ensure completes only after a provider receipt has been persisted. Registration
+// has no idempotency contract, so its durable claim is never automatically expired.
+func (s *Service) Ensure(ctx context.Context, a *customer.Account) (result error) {
+	if a == nil || a.ID.IsZero() {
+		return merrors.InvalidArgument("customer required")
+	}
+	started := time.Now()
+	requestRef := ""
+	outcome := "unavailable"
+	defer func() {
+		requests.WithLabelValues(outcome).Inc()
+		duration.Observe(time.Since(started).Seconds())
+		fields := []zap.Field{zap.String("account_ref", a.ID.Hex()), zap.String("request_ref", requestRef), zap.String("outcome", outcome)}
+		if result != nil {
+			s.Logger.Warn("Sign-up facts handoff incomplete", fields...)
+		} else {
+			s.Logger.Info("Sign-up facts handoff completed", fields...)
+		}
+	}()
+	namespace := s.Provider.Namespace()
+	b, err := s.Store.Get(ctx, a.ID)
+	if errors.Is(err, merrors.ErrNoData) {
+		b = &Binding{Namespace: namespace, RegistrationRequest: bson.NewObjectID().Hex(), Facts: Facts{FullName: a.Name, Email: a.Login, CustomerRef: a.ID.Hex()}}
+		b.SetID(a.ID)
+		if err = s.Store.Create(ctx, b); err != nil {
+			if !errors.Is(err, merrors.ErrDataConflict) {
+				return merrors.OpaqueWrap(merrors.ErrServiceUnavailable, err, "persist sign-up facts")
+			}
+			b, err = s.Store.Get(ctx, a.ID)
+		}
+	}
+	if err != nil {
+		return merrors.OpaqueWrap(merrors.ErrServiceUnavailable, err, "load sign-up facts")
+	}
+	requestRef = b.RegistrationRequest
+	if b.Namespace != namespace {
+		outcome = "attention_required"
+		return merrors.FailedPrecondition("sign-up provider binding changed")
+	}
+	if b.Receipt != nil {
+		outcome = "replayed"
+		return nil
+	}
+	if b.SubjectRef == "" {
+		claimed, err := s.Store.Claim(ctx, a.ID, namespace)
+		if err != nil {
+			return merrors.OpaqueWrap(merrors.ErrServiceUnavailable, err, "claim individual registration")
+		}
+		if !claimed {
+			// Another request may have completed while this request was claiming.
+			b, err = s.Store.Get(ctx, a.ID)
+			if err != nil {
+				return merrors.OpaqueWrap(merrors.ErrServiceUnavailable, err, "reload sign-up facts")
+			}
+			if b.SubjectRef == "" {
+				if b.RegisteringAt.Add(30 * time.Second).After(time.Now()) {
+					return unavailable()
+				}
+				outcome = "attention_required"
+				return merrors.FailedPrecondition("individual registration requires reconciliation")
+			}
+		} else {
+			subject, err := s.Provider.Register(ctx, b.RegistrationRequest)
+			if err != nil {
+				outcome = "attention_required"
+				return merrors.OpaqueWrap(merrors.ErrFailedPrecondition, err, "individual registration requires reconciliation")
+			}
+			// Persist even if the browser left while Sendico accepted registration.
+			saveCtx, cancel := context.WithTimeout(context.WithoutCancel(ctx), 5*time.Second)
+			err = s.Store.Bind(saveCtx, a.ID, namespace, subject)
+			cancel()
+			if err != nil {
+				outcome = "attention_required"
+				s.Logger.Warn("Registered individual binding needs reconciliation", zap.String("account_ref", a.ID.Hex()), zap.String("subject_ref", subject))
+				return merrors.OpaqueWrap(merrors.ErrFailedPrecondition, err, "persist individual binding")
+			}
+			b.SubjectRef = subject
+		}
+	}
+	receipt, err := s.Provider.Submit(ctx, b.SubjectRef, sourceRef(a.ID), b.Facts)
+	if err != nil {
+		return merrors.OpaqueWrap(merrors.ErrServiceUnavailable, err, "submit sign-up facts")
+	}
+	if receipt.SubjectRef != b.SubjectRef || receipt.SubmissionRef == "" || receipt.AcceptedAt.IsZero() {
+		return unavailable()
+	}
+	if err = s.Store.Accept(ctx, a.ID, namespace, receipt); err != nil {
+		return merrors.OpaqueWrap(merrors.ErrServiceUnavailable, err, "persist facts receipt")
+	}
+	outcome = "accepted"
+	return nil
+}
+
+// Ready checks confirmed intake without external I/O inside activation transactions.
+func (s *Service) Ready(ctx context.Context, id bson.ObjectID) error {
+	b, err := s.Store.Get(ctx, id)
+	if err != nil {
+		return merrors.OpaqueWrap(merrors.ErrServiceUnavailable, err, "load facts receipt")
+	}
+	if b.Namespace != s.Provider.Namespace() || b.Receipt == nil {
+		return unavailable()
+	}
+	return nil
+}