feat: add subscriptions api (#73)

* feat: add subscriptions api

* test: add subscription api tests

* refactor: remove redundant code

* refactor: replace if/else with switch-case & remove redundant boolean flag

* fix: avoid merging of alerts having common alertname

Author: Abhishek Sah

api/handlers/v1/grpc_subscription.go

@@ -0,0 +1,166 @@
+package v1
+
+import (
+	"context"
+	sirenv1beta1 "github.com/odpf/siren/api/proto/odpf/siren/v1beta1"
+	"github.com/odpf/siren/domain"
+	"go.uber.org/zap"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/types/known/emptypb"
+	"google.golang.org/protobuf/types/known/timestamppb"
+	"strings"
+)
+
+func (s *GRPCServer) ListSubscriptions(_ context.Context, _ *emptypb.Empty) (*sirenv1beta1.ListSubscriptionsResponse, error) {
+	subscriptions, err := s.container.SubscriptionService.ListSubscriptions()
+	if err != nil {
+		s.logger.Error("handler", zap.Error(err))
+		return nil, status.Errorf(codes.Internal, err.Error())
+	}
+
+	res := &sirenv1beta1.ListSubscriptionsResponse{
+		Subscriptions: make([]*sirenv1beta1.Subscription, 0),
+	}
+	for _, subscription := range subscriptions {
+		item := &sirenv1beta1.Subscription{
+			Id:        subscription.Id,
+			Urn:       subscription.Urn,
+			Namespace: subscription.Namespace,
+			Match:     subscription.Match,
+			Receivers: getReceiverMetadataListFromDomainObject(subscription.Receivers),
+			CreatedAt: timestamppb.New(subscription.CreatedAt),
+			UpdatedAt: timestamppb.New(subscription.UpdatedAt),
+		}
+		res.Subscriptions = append(res.Subscriptions, item)
+	}
+	return res, nil
+}
+
+func (s *GRPCServer) CreateSubscription(_ context.Context, req *sirenv1beta1.CreateSubscriptionRequest) (*sirenv1beta1.Subscription, error) {
+	subscription, err := s.container.SubscriptionService.CreateSubscription(&domain.Subscription{
+		Namespace: req.GetNamespace(),
+		Urn:       req.GetUrn(),
+		Receivers: getReceiverMetadataListInDomainObject(req.GetReceivers()),
+		Match:     req.GetMatch(),
+	})
+	if err != nil {
+		s.logger.Error("handler", zap.Error(err))
+		return nil, status.Errorf(codes.Internal, err.Error())
+	}
+
+	receivers := make([]*sirenv1beta1.ReceiverMetadata, 0)
+	for _, receiverMetadataItem := range subscription.Receivers {
+		item := getReceiverMetadataFromDomainObject(&receiverMetadataItem)
+		receivers = append(receivers, &item)
+	}
+	return &sirenv1beta1.Subscription{
+		Id:        subscription.Id,
+		Urn:       subscription.Urn,
+		Namespace: subscription.Namespace,
+		Match:     subscription.Match,
+		Receivers: receivers,
+		CreatedAt: timestamppb.New(subscription.CreatedAt),
+		UpdatedAt: timestamppb.New(subscription.UpdatedAt),
+	}, nil
+}
+
+func (s *GRPCServer) GetSubscription(_ context.Context, req *sirenv1beta1.GetSubscriptionRequest) (*sirenv1beta1.Subscription, error) {
+	subscription, err := s.container.SubscriptionService.GetSubscription(req.GetId())
+	if err != nil {
+		s.logger.Error("handler", zap.Error(err))
+		return nil, status.Errorf(codes.Internal, err.Error())
+	}
+	if subscription == nil {
+		return nil, status.Errorf(codes.NotFound, "subscription not found")
+	}
+
+	receivers := make([]*sirenv1beta1.ReceiverMetadata, 0)
+	for _, receiverMetadataItem := range subscription.Receivers {
+		item := getReceiverMetadataFromDomainObject(&receiverMetadataItem)
+		receivers = append(receivers, &item)
+	}
+	
+	return &sirenv1beta1.Subscription{
+		Id:        subscription.Id,
+		Urn:       subscription.Urn,
+		Namespace: subscription.Namespace,
+		Match:     subscription.Match,
+		Receivers: receivers,
+		CreatedAt: timestamppb.New(subscription.CreatedAt),
+		UpdatedAt: timestamppb.New(subscription.UpdatedAt),
+	}, nil
+}
+
+func (s *GRPCServer) UpdateSubscription(_ context.Context, req *sirenv1beta1.UpdateSubscriptionRequest) (*sirenv1beta1.Subscription, error) {
+	subscription, err := s.container.SubscriptionService.UpdateSubscription(&domain.Subscription{
+		Id:        req.GetId(),
+		Namespace: req.GetNamespace(),
+		Urn:       req.GetUrn(),
+		Receivers: getReceiverMetadataListInDomainObject(req.GetReceivers()),
+		Match:     req.GetMatch(),
+	})
+	if err != nil {
+		if strings.Contains(err.Error(), `violates unique constraint "urn_provider_id_unique"`) {
+			return nil, status.Errorf(codes.InvalidArgument, "urn and provider pair already exist")
+		}
+		s.logger.Error("handler", zap.Error(err))
+		return nil, status.Errorf(codes.Internal, err.Error())
+	}
+
+	receivers := make([]*sirenv1beta1.ReceiverMetadata, 0)
+	for _, receiverMetadataItem := range subscription.Receivers {
+		item := getReceiverMetadataFromDomainObject(&receiverMetadataItem)
+		receivers = append(receivers, &item)
+	}
+
+	return &sirenv1beta1.Subscription{
+		Id:        subscription.Id,
+		Urn:       subscription.Urn,
+		Namespace: subscription.Namespace,
+		Match:     subscription.Match,
+		Receivers: receivers,
+		CreatedAt: timestamppb.New(subscription.CreatedAt),
+		UpdatedAt: timestamppb.New(subscription.UpdatedAt),
+	}, nil
+}
+
+func (s *GRPCServer) DeleteSubscription(_ context.Context, req *sirenv1beta1.DeleteSubscriptionRequest) (*emptypb.Empty, error) {
+	err := s.container.SubscriptionService.DeleteSubscription(req.GetId())
+	if err != nil {
+		s.logger.Error("handler", zap.Error(err))
+		return nil, status.Errorf(codes.Internal, err.Error())
+	}
+	return &emptypb.Empty{}, nil
+}
+
+func getReceiverMetadataFromDomainObject(item *domain.ReceiverMetadata) sirenv1beta1.ReceiverMetadata {
+	return sirenv1beta1.ReceiverMetadata{
+		Id:            item.Id,
+		Configuration: item.Configuration,
+	}
+}
+
+func getReceiverMetadataInDomainObject(item *sirenv1beta1.ReceiverMetadata) domain.ReceiverMetadata {
+	return domain.ReceiverMetadata{
+		Id:            item.Id,
+		Configuration: item.Configuration,
+	}
+}
+
+func getReceiverMetadataListInDomainObject(domainReceivers []*sirenv1beta1.ReceiverMetadata) []domain.ReceiverMetadata {
+	receivers := make([]domain.ReceiverMetadata, 0)
+	for _, receiverMetadataItem := range domainReceivers {
+		receivers = append(receivers, getReceiverMetadataInDomainObject(receiverMetadataItem))
+	}
+	return receivers
+}
+
+func getReceiverMetadataListFromDomainObject(domainReceivers []domain.ReceiverMetadata) []*sirenv1beta1.ReceiverMetadata {
+	receivers := make([]*sirenv1beta1.ReceiverMetadata, 0)
+	for _, receiverMetadataItem := range domainReceivers {
+		item := getReceiverMetadataFromDomainObject(&receiverMetadataItem)
+		receivers = append(receivers, &item)
+	}
+	return receivers
+}