feat: [CODE-3450]: add pullreq count API (#3624)

* add pullreq count API

app/api/controller/space/pr_count.go

@@ -0,0 +1,45 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package space
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/harness/gitness/app/auth"
+	"github.com/harness/gitness/types"
+	"github.com/harness/gitness/types/enum"
+)
+
+// CountPullReqs returns the number of pull requests from the provided space that matches the criteria.
+func (c *Controller) CountPullReqs(
+	ctx context.Context,
+	session *auth.Session,
+	spaceRef string,
+	includeSubspaces bool,
+	filter *types.PullReqFilter,
+) (int64, error) {
+	space, err := c.getSpaceCheckAuth(ctx, session, spaceRef, enum.PermissionSpaceView)
+	if err != nil {
+		return 0, fmt.Errorf("failed to acquire access to space: %w", err)
+	}
+
+	count, err := c.prListService.CountForSpace(ctx, space, includeSubspaces, filter)
+	if err != nil {
+		return 0, fmt.Errorf("failed to fetch pull requests from space: %w", err)
+	}
+
+	return count, nil
+}

app/api/handler/space/pr_count.go

@@ -0,0 +1,55 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package space
+
+import (
+	"net/http"
+
+	"github.com/harness/gitness/app/api/controller/space"
+	"github.com/harness/gitness/app/api/render"
+	"github.com/harness/gitness/app/api/request"
+)
+
+func HandleCountPullReqs(spaceCtrl *space.Controller) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		ctx := r.Context()
+		session, _ := request.AuthSessionFrom(ctx)
+		spaceRef, err := request.GetSpaceRefFromPath(r)
+		if err != nil {
+			render.TranslatedUserError(ctx, w, err)
+			return
+		}
+
+		includeSubspaces, err := request.GetIncludeSubspacesFromQuery(r)
+		if err != nil {
+			render.TranslatedUserError(ctx, w, err)
+			return
+		}
+
+		pullReqFilter, err := request.ParsePullReqFilter(r)
+		if err != nil {
+			render.TranslatedUserError(ctx, w, err)
+			return
+		}
+
+		count, err := spaceCtrl.CountPullReqs(ctx, session, spaceRef, includeSubspaces, pullReqFilter)
+		if err != nil {
+			render.TranslatedUserError(ctx, w, err)
+			return
+		}
+
+		render.JSON(w, http.StatusOK, count)
+	}
+}

app/api/openapi/space.go

@@ -679,6 +679,26 @@ func spaceOperations(reflector *openapi3.Reflector) {
 	_ = reflector.Spec.AddOperation(http.MethodPatch,
 		"/spaces/{space_ref}/labels/{key}/values/{value}", opUpdateLabelValue)
 
+	countPullReq := openapi3.Operation{}
+	countPullReq.WithTags("space")
+	countPullReq.WithMapOfAnything(map[string]interface{}{"operationId": "countSpacePullReq"})
+	countPullReq.WithParameters(
+		queryParameterStatePullRequest, queryParameterSourceRepoRefPullRequest,
+		queryParameterSourceBranchPullRequest, queryParameterTargetBranchPullRequest,
+		queryParameterQueryPullRequest, queryParameterCreatedByPullRequest,
+		queryParameterCreatedLt, queryParameterCreatedGt, queryParameterUpdatedLt,
+		queryParameterIncludeSubspaces,
+		QueryParameterLabelID, QueryParameterValueID,
+		queryParameterAuthorID, queryParameterCommenterID, queryParameterMentionedID,
+		queryParameterReviewerID, queryParameterReviewDecision)
+	_ = reflector.SetRequest(&countPullReq, new(spaceRequest), http.MethodGet)
+	_ = reflector.SetJSONResponse(&countPullReq, new([]types.PullReqRepo), http.StatusOK)
+	_ = reflector.SetJSONResponse(&countPullReq, new(usererror.Error), http.StatusBadRequest)
+	_ = reflector.SetJSONResponse(&countPullReq, new(usererror.Error), http.StatusInternalServerError)
+	_ = reflector.SetJSONResponse(&countPullReq, new(usererror.Error), http.StatusUnauthorized)
+	_ = reflector.SetJSONResponse(&countPullReq, new(usererror.Error), http.StatusForbidden)
+	_ = reflector.Spec.AddOperation(http.MethodGet, "/spaces/{space_ref}/pullreq/count", countPullReq)
+
 	listPullReq := openapi3.Operation{}
 	listPullReq.WithTags("space")
 	listPullReq.WithMapOfAnything(map[string]interface{}{"operationId": "listSpacePullReq"})

app/router/api.go

@@ -277,6 +277,7 @@ func setupSpaces(
 			r.Get("/export-progress", handlerspace.HandleExportProgress(spaceCtrl))
 			r.Post("/public-access", handlerspace.HandleUpdatePublicAccess(spaceCtrl))
 			r.Get("/pullreq", handlerspace.HandleListPullReqs(spaceCtrl))
+			r.Get("/pullreq/count", handlerspace.HandleCountPullReqs(spaceCtrl))
 
 			r.Route("/members", func(r chi.Router) {
 				r.Get("/", handlerspace.HandleMembershipList(spaceCtrl))

app/services/pullreq/service_list.go

@@ -72,6 +72,36 @@ func NewListService(
 	}
 }
 
+// CountForSpace returns number of pull requests in a specific space (and optionally in subspaces).
+// The API doesn't do a permission check for repositories.
+func (c *ListService) CountForSpace(
+	ctx context.Context,
+	space *types.SpaceCore,
+	includeSubspaces bool,
+	filter *types.PullReqFilter,
+) (int64, error) {
+	if includeSubspaces {
+		subspaces, err := c.spaceStore.GetDescendantsData(ctx, space.ID)
+		if err != nil {
+			return 0, fmt.Errorf("failed to get space descendant data: %w", err)
+		}
+
+		filter.SpaceIDs = make([]int64, 0, len(subspaces))
+		for i := range subspaces {
+			filter.SpaceIDs = append(filter.SpaceIDs, subspaces[i].ID)
+		}
+	} else {
+		filter.SpaceIDs = []int64{space.ID}
+	}
+
+	count, err := c.pullreqStore.Count(ctx, filter)
+	if err != nil {
+		return 0, fmt.Errorf("failed to count pull requests: %w", err)
+	}
+
+	return count, nil
+}
+
 // ListForSpace returns a list of pull requests and their respective repositories for a specific space.
 //
 //nolint:gocognit