comment status API

internal/api/controller/pullreq/comment_create.go

@@ -169,11 +169,14 @@ func (c *Controller) CommentCreate(
 
 	_, err = c.pullreqStore.UpdateOptLock(ctx, pr, func(pr *types.PullReq) error {
 		pr.CommentCount++
+		if act.IsBlocking() {
+			pr.UnresolvedCount++
+		}
 		return nil
 	})
 	if err != nil {
 		// non-critical error
-		log.Ctx(ctx).Err(err).Msgf("failed to increment pull request comment counter")
+		log.Ctx(ctx).Err(err).Msgf("failed to increment pull request comment counters")
 	}
 
 	return act, nil
@@ -226,7 +229,10 @@ func (c *Controller) writeActivity(ctx context.Context, pr *types.PullReq, act *
 // sets the correct Order and SubOrder values and writes the activity to the database.
 // Even if the writing fails, the updating of the sequence number can succeed.
 func (c *Controller) writeReplyActivity(ctx context.Context, parent, act *types.PullReqActivity) error {
-	parentUpd, err := c.activityStore.UpdateReplySeq(ctx, parent)
+	parentUpd, err := c.activityStore.UpdateOptLock(ctx, parent, func(act *types.PullReqActivity) error {
+		act.ReplySeq++
+		return nil
+	})
 	if err != nil {
 		return fmt.Errorf("failed to get pull request activity number: %w", err)
 	}

internal/api/controller/pullreq/comment_delete.go

@@ -10,7 +10,10 @@ import (
 	"time"
 
 	"github.com/harness/gitness/internal/auth"
+	"github.com/harness/gitness/types"
 	"github.com/harness/gitness/types/enum"
+
+	"github.com/rs/zerolog/log"
 )
 
 // CommentDelete deletes a pull request comment.
@@ -40,13 +43,28 @@ func (c *Controller) CommentDelete(
 		return nil
 	}
 
+	isBlocking := act.IsBlocking()
+
+	_, err = c.activityStore.UpdateOptLock(ctx, act, func(act *types.PullReqActivity) error {
 		now := time.Now().UnixMilli()
 		act.Deleted = &now
-
-	err = c.activityStore.Update(ctx, act)
+		return nil
+	})
 	if err != nil {
 		return fmt.Errorf("failed to mark comment as deleted: %w", err)
 	}
 
+	_, err = c.pullreqStore.UpdateOptLock(ctx, pr, func(pr *types.PullReq) error {
+		pr.CommentCount--
+		if isBlocking {
+			pr.UnresolvedCount--
+		}
+		return nil
+	})
+	if err != nil {
+		// non-critical error
+		log.Ctx(ctx).Err(err).Msgf("failed to decrement pull request comment counters")
+	}
+
 	return nil
 }

internal/api/controller/pullreq/comment_status.go

@@ -0,0 +1,117 @@
+// Copyright 2022 Harness Inc. All rights reserved.
+// Use of this source code is governed by the Polyform Free Trial License
+// that can be found in the LICENSE.md file for this repository.
+
+package pullreq
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/harness/gitness/internal/api/controller"
+	"github.com/harness/gitness/internal/api/usererror"
+	"github.com/harness/gitness/internal/auth"
+	"github.com/harness/gitness/types"
+	"github.com/harness/gitness/types/enum"
+)
+
+type CommentStatusInput struct {
+	Status enum.PullReqCommentStatus `json:"status"`
+}
+
+func (in *CommentStatusInput) Validate() error {
+	_, ok := in.Status.Sanitize()
+	if !ok {
+		return usererror.BadRequest("Invalid value provided for comment status")
+	}
+
+	return nil
+}
+
+func (in *CommentStatusInput) hasChanges(act *types.PullReqActivity, userID int64) bool {
+	// clearing resolved
+	if in.Status == enum.PullReqCommentStatusActive {
+		return act.Resolved != nil
+	}
+	// setting resolved
+	return act.Resolved == nil || act.ResolvedBy == nil || *act.ResolvedBy != userID
+}
+
+// CommentStatus updates a pull request comment status.
+func (c *Controller) CommentStatus(
+	ctx context.Context,
+	session *auth.Session,
+	repoRef string,
+	prNum int64,
+	commentID int64,
+	in *CommentStatusInput,
+) (*types.PullReqActivity, error) {
+	repo, err := c.getRepoCheckAccess(ctx, session, repoRef, enum.PermissionRepoView)
+	if err != nil {
+		return nil, fmt.Errorf("failed to acquire access to repo: %w", err)
+	}
+
+	var act *types.PullReqActivity
+
+	err = controller.TxOptLock(ctx, c.db, func(ctx context.Context) error {
+		pr, err := c.pullreqStore.FindByNumber(ctx, repo.ID, prNum)
+		if err != nil {
+			return fmt.Errorf("failed to find pull request by number: %w", err)
+		}
+
+		if errValidate := in.Validate(); errValidate != nil {
+			return errValidate
+		}
+
+		act, err = c.getCommentCheckChangeStatusAccess(ctx, session, pr, commentID)
+		if err != nil {
+			return fmt.Errorf("failed to get comment: %w", err)
+		}
+
+		if !in.hasChanges(act, session.Principal.ID) {
+			return nil
+		}
+
+		now := time.Now().UnixMilli()
+		act.Edited = now
+
+		act.Resolved = nil
+		act.ResolvedBy = nil
+
+		if in.Status != enum.PullReqCommentStatusActive {
+			// In the future if we add more comment resolved statuses
+			// we'll add the ResolvedReason field and put the reason there.
+			// For now, the nullable timestamp field/db-column "Resolved" tells the status (active/resolved).
+			act.Resolved = &now
+			act.ResolvedBy = &session.Principal.ID
+		}
+
+		err = c.activityStore.Update(ctx, act)
+		if err != nil {
+			return fmt.Errorf("failed to update status of pull request activity: %w", err)
+		}
+
+		// Here we deliberately use the transaction and counting the unresolved comments,
+		// rather than optimistic locking and incrementing/decrementing the counter.
+		// The idea is that if the counter ever goes out of sync, this would be the place where we get it back in sync.
+		unresolvedCount, err := c.activityStore.CountUnresolved(ctx, pr.ID)
+		if err != nil {
+			return fmt.Errorf("failed to count unresolved comments: %w", err)
+		}
+
+		pr.UnresolvedCount = unresolvedCount
+
+		err = c.pullreqStore.Update(ctx, pr)
+		if err != nil {
+			return fmt.Errorf("failed to update pull request's unresolved comment count: %w", err)
+		}
+
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return act, nil
+}

internal/api/controller/pullreq/comment_update.go

@@ -18,6 +18,11 @@ type CommentUpdateInput struct {
 	Text string `json:"text"`
 }
 
+func (in *CommentUpdateInput) Validate() error {
+	// TODO: Check Text length
+	return nil
+}
+
 func (in *CommentUpdateInput) hasChanges(act *types.PullReqActivity) bool {
 	return in.Text != act.Text
 }
@@ -41,6 +46,10 @@ func (c *Controller) CommentUpdate(
 		return nil, fmt.Errorf("failed to find pull request by number: %w", err)
 	}
 
+	if errValidate := in.Validate(); errValidate != nil {
+		return nil, errValidate
+	}
+
 	act, err := c.getCommentCheckEditAccess(ctx, session, pr, commentID)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get comment: %w", err)
@@ -50,12 +59,12 @@ func (c *Controller) CommentUpdate(
 		return act, nil
 	}
 
+	act, err = c.activityStore.UpdateOptLock(ctx, act, func(act *types.PullReqActivity) error {
 		now := time.Now().UnixMilli()
 		act.Edited = now
-
 		act.Text = in.Text
-
-	err = c.activityStore.Update(ctx, act)
+		return nil
+	})
 	if err != nil {
 		return nil, fmt.Errorf("failed to update comment: %w", err)
 	}

internal/api/controller/pullreq/controller.go

@@ -121,7 +121,7 @@ func (c *Controller) getRepoCheckAccess(ctx context.Context,
 	return repo, nil
 }
 
-func (c *Controller) getCommentCheckEditAccess(ctx context.Context,
+func (c *Controller) getCommentCheckModifyAccess(ctx context.Context,
 	session *auth.Session, pr *types.PullReq, commentID int64,
 ) (*types.PullReqActivity, error) {
 	if commentID <= 0 {
@@ -133,7 +133,7 @@ func (c *Controller) getCommentCheckEditAccess(ctx context.Context,
 		return nil, fmt.Errorf("failed to find comment by ID: %w", err)
 	}
 
-	if comment == nil || comment.Type != enum.PullReqActivityTypeComment {
+	if comment == nil {
 		return nil, usererror.ErrNotFound
 	}
 
@@ -145,6 +145,21 @@ func (c *Controller) getCommentCheckEditAccess(ctx context.Context,
 		return nil, usererror.BadRequest("Can't update a comment created by the system.")
 	}
 
+	if comment.Type != enum.PullReqActivityTypeComment && comment.Type != enum.PullReqActivityTypeCodeComment {
+		return nil, usererror.BadRequest("Only comments and code comments can be edited.")
+	}
+
+	return comment, nil
+}
+
+func (c *Controller) getCommentCheckEditAccess(ctx context.Context,
+	session *auth.Session, pr *types.PullReq, commentID int64,
+) (*types.PullReqActivity, error) {
+	comment, err := c.getCommentCheckModifyAccess(ctx, session, pr, commentID)
+	if err != nil {
+		return nil, err
+	}
+
 	if comment.CreatedBy != session.Principal.ID {
 		return nil, usererror.BadRequest("Only own comments may be updated.")
 	}
@@ -152,6 +167,21 @@ func (c *Controller) getCommentCheckEditAccess(ctx context.Context,
 	return comment, nil
 }
 
+func (c *Controller) getCommentCheckChangeStatusAccess(ctx context.Context,
+	session *auth.Session, pr *types.PullReq, commentID int64,
+) (*types.PullReqActivity, error) {
+	comment, err := c.getCommentCheckModifyAccess(ctx, session, pr, commentID)
+	if err != nil {
+		return nil, err
+	}
+
+	if comment.SubOrder != 0 {
+		return nil, usererror.BadRequest("Can't change status of replies.")
+	}
+
+	return comment, nil
+}
+
 func (c *Controller) checkIfAlreadyExists(ctx context.Context,
 	targetRepoID, sourceRepoID int64, targetBranch, sourceBranch string,
 ) error {

internal/api/controller/tx.go

@@ -0,0 +1,36 @@
+// Copyright 2022 Harness Inc. All rights reserved.
+// Use of this source code is governed by the Polyform Free Trial License
+// that can be found in the LICENSE.md file for this repository.
+
+package controller
+
+import (
+	"context"
+	"errors"
+	"github.com/harness/gitness/internal/store"
+	"github.com/harness/gitness/internal/store/database/dbtx"
+	"github.com/jmoiron/sqlx"
+)
+
+type TxOptionRetryCount int
+
+// TxOptLock runs the provided function inside a database transaction. If optimistic lock error occurs
+// during the operation, the function will retry the whole transaction again (to the maximum of 5 times,
+// but this can be overridden by providing an additional TxOptionRetryCount option)
+func TxOptLock(ctx context.Context, db *sqlx.DB, txFn func(ctx context.Context) error, opts ...interface{}) (err error) {
+	tries := 5
+	for _, opt := range opts {
+		if n, ok := opt.(TxOptionRetryCount); ok {
+			tries = int(n)
+		}
+	}
+
+	for try := 0; try < tries; try++ {
+		err = dbtx.New(db).WithTx(ctx, txFn, opts...)
+		if !errors.Is(err, store.ErrVersionConflict) {
+			break
+		}
+	}
+
+	return
+}

internal/api/handler/pullreq/comment_status.go

@@ -0,0 +1,55 @@
+// Copyright 2022 Harness Inc. All rights reserved.
+// Use of this source code is governed by the Polyform Free Trial License
+// that can be found in the LICENSE.md file for this repository.
+
+package pullreq
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/harness/gitness/internal/api/controller/pullreq"
+	"github.com/harness/gitness/internal/api/render"
+	"github.com/harness/gitness/internal/api/request"
+)
+
+// HandleCommentStatus is an HTTP handler for updating a pull request comment status.
+func HandleCommentStatus(pullreqCtrl *pullreq.Controller) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		ctx := r.Context()
+		session, _ := request.AuthSessionFrom(ctx)
+
+		repoRef, err := request.GetRepoRefFromPath(r)
+		if err != nil {
+			render.TranslatedUserError(w, err)
+			return
+		}
+
+		pullreqNumber, err := request.GetPullReqNumberFromPath(r)
+		if err != nil {
+			render.TranslatedUserError(w, err)
+			return
+		}
+
+		commentID, err := request.GetPullReqCommentIDPath(r)
+		if err != nil {
+			render.TranslatedUserError(w, err)
+			return
+		}
+
+		in := new(pullreq.CommentStatusInput)
+		err = json.NewDecoder(r.Body).Decode(in)
+		if err != nil {
+			render.BadRequestf(w, "Invalid Request Body: %s.", err)
+			return
+		}
+
+		comment, err := pullreqCtrl.CommentStatus(ctx, session, repoRef, pullreqNumber, commentID, in)
+		if err != nil {
+			render.TranslatedUserError(w, err)
+			return
+		}
+
+		render.JSON(w, http.StatusOK, comment)
+	}
+}

internal/api/openapi/pullreq.go

@@ -71,7 +71,11 @@ type commentUpdatePullReqRequest struct {
 
 type commentDeletePullReqRequest struct {
 	pullReqCommentRequest
-	pullreq.CommentUpdateInput
+}
+
+type commentStatusPullReqRequest struct {
+	pullReqCommentRequest
+	pullreq.CommentStatusInput
 }
 
 type reviewerListPullReqRequest struct {
@@ -364,6 +368,18 @@ func pullReqOperations(reflector *openapi3.Reflector) {
 	_ = reflector.Spec.AddOperation(http.MethodDelete,
 		"/repos/{repo_ref}/pullreq/{pullreq_number}/comments/{pullreq_comment_id}", commentDeletePullReq)
 
+	commentStatusPullReq := openapi3.Operation{}
+	commentStatusPullReq.WithTags("pullreq")
+	commentStatusPullReq.WithMapOfAnything(map[string]interface{}{"operationId": "commentStatusPullReq"})
+	_ = reflector.SetRequest(&commentStatusPullReq, new(commentStatusPullReqRequest), http.MethodPut)
+	_ = reflector.SetJSONResponse(&commentStatusPullReq, new(types.PullReqActivity), http.StatusOK)
+	_ = reflector.SetJSONResponse(&commentStatusPullReq, new(usererror.Error), http.StatusBadRequest)
+	_ = reflector.SetJSONResponse(&commentStatusPullReq, new(usererror.Error), http.StatusInternalServerError)
+	_ = reflector.SetJSONResponse(&commentStatusPullReq, new(usererror.Error), http.StatusUnauthorized)
+	_ = reflector.SetJSONResponse(&commentStatusPullReq, new(usererror.Error), http.StatusForbidden)
+	_ = reflector.Spec.AddOperation(http.MethodPut,
+		"/repos/{repo_ref}/pullreq/{pullreq_number}/comments/{pullreq_comment_id}/status", commentStatusPullReq)
+
 	reviewerAdd := openapi3.Operation{}
 	reviewerAdd.WithTags("pullreq")
 	reviewerAdd.WithMapOfAnything(map[string]interface{}{"operationId": "reviewerAddPullReq"})

internal/router/api.go

@@ -266,6 +266,7 @@ func SetupPullReq(r chi.Router, pullreqCtrl *pullreq.Controller) {
 				r.Route(fmt.Sprintf("/{%s}", request.PathParamPullReqCommentID), func(r chi.Router) {
 					r.Patch("/", handlerpullreq.HandleCommentUpdate(pullreqCtrl))
 					r.Delete("/", handlerpullreq.HandleCommentDelete(pullreqCtrl))
+					r.Put("/status", handlerpullreq.HandleCommentStatus(pullreqCtrl))
 				})
 			})
 			r.Route("/reviewers", func(r chi.Router) {

internal/store/database.go

@@ -256,7 +256,7 @@ type (
 		Create(ctx context.Context, pullreq *types.PullReq) error
 
 		// Update the pull request. It will set new values to the Version and Updated fields.
-		Update(ctx context.Context, repo *types.PullReq) error
+		Update(ctx context.Context, pr *types.PullReq) error
 
 		// UpdateOptLock the pull request details using the optimistic locking mechanism.
 		UpdateOptLock(ctx context.Context, pr *types.PullReq,
@@ -281,7 +281,7 @@ type (
 		Find(ctx context.Context, id int64) (*types.PullReqActivity, error)
 
 		// Create a new pull request activity. Value of the Order field should be fetched with UpdateActivitySeq.
-		// Value of the SubOrder field (for replies) should be fetched with UpdateReplySeq (non-replies have 0).
+		// Value of the SubOrder field (for replies) should be the incremented ReplySeq field (non-replies have 0).
 		Create(ctx context.Context, act *types.PullReqActivity) error
 
 		// CreateWithPayload create a new system activity from the provided payload.
@@ -291,13 +291,18 @@ type (
 		// Update the pull request activity. It will set new values to the Version and Updated fields.
 		Update(ctx context.Context, act *types.PullReqActivity) error
 
-		// UpdateReplySeq the pull request activity's reply sequence number.
-		// It will set new values to the ReplySeq, Version and Updated fields.
-		UpdateReplySeq(ctx context.Context, act *types.PullReqActivity) (*types.PullReqActivity, error)
+		// UpdateOptLock updates the pull request activity using the optimistic locking mechanism.
+		UpdateOptLock(ctx context.Context,
+			act *types.PullReqActivity,
+			mutateFn func(act *types.PullReqActivity) error,
+		) (*types.PullReqActivity, error)
 
 		// Count returns number of pull request activities in a pull request.
 		Count(ctx context.Context, prID int64, opts *types.PullReqActivityFilter) (int64, error)
 
+		// CountUnresolved returns number of unresolved comments.
+		CountUnresolved(ctx context.Context, prID int64) (int, error)
+
 		// List returns a list of pull request activities in a pull request (a timeline).
 		List(ctx context.Context, prID int64, opts *types.PullReqActivityFilter) ([]*types.PullReqActivity, error)
 	}

internal/store/database/migrate/postgres/0016_alter_pullreq_add_unresolved.down.sql

@@ -0,0 +1 @@
+ALTER TABLE pullreqs DROP COLUMN pullreq_unresolved_count;

internal/store/database/migrate/postgres/0016_alter_pullreq_add_unresolved.up.sql

@@ -0,0 +1,18 @@
+ALTER TABLE pullreqs ADD COLUMN pullreq_unresolved_count INTEGER NOT NULL DEFAULT 0;
+
+WITH unresolved_counts AS (
+    SELECT
+        pullreq_activity_pullreq_id AS "unresolved_pullreq_id",
+        COUNT(*) AS "unresolved_count"
+    FROM pullreq_activities
+    WHERE
+        pullreq_activity_sub_order = 0 AND
+        pullreq_activity_resolved IS NULL AND
+        pullreq_activity_deleted IS NULL AND
+        pullreq_activity_kind <> 'system'
+    GROUP BY pullreq_activity_pullreq_id
+)
+UPDATE pullreqs
+SET pullreq_unresolved_count = unresolved_counts.unresolved_count
+FROM unresolved_counts
+WHERE pullreq_id = unresolved_pullreq_id;

internal/store/database/migrate/sqlite/0016_alter_pullreq_add_unresolved.down.sql

@@ -0,0 +1 @@
+ALTER TABLE pullreqs DROP COLUMN pullreq_unresolved_count;

internal/store/database/migrate/sqlite/0016_alter_pullreq_add_unresolved.up.sql

@@ -0,0 +1,18 @@
+ALTER TABLE pullreqs ADD COLUMN pullreq_unresolved_count INTEGER NOT NULL DEFAULT 0;
+
+WITH unresolved_counts AS (
+    SELECT
+        pullreq_activity_pullreq_id AS "unresolved_pullreq_id",
+        COUNT(*) AS "unresolved_count"
+    FROM pullreq_activities
+    WHERE
+        pullreq_activity_sub_order = 0 AND
+        pullreq_activity_resolved IS NULL AND
+        pullreq_activity_deleted IS NULL AND
+        pullreq_activity_kind <> 'system'
+    GROUP BY pullreq_activity_pullreq_id
+)
+UPDATE pullreqs
+SET pullreq_unresolved_count = unresolved_counts.unresolved_count
+FROM unresolved_counts
+WHERE pullreq_id = unresolved_pullreq_id;

internal/store/database/pullreq.go

@@ -55,6 +55,7 @@ type pullReq struct {
 	IsDraft bool              `db:"pullreq_is_draft"`
 
 	CommentCount    int `db:"pullreq_comment_count"`
+	UnresolvedCount int `db:"pullreq_unresolved_count"`
 
 	Title       string `db:"pullreq_title"`
 	Description string `db:"pullreq_description"`
@@ -90,6 +91,7 @@ const (
 		,pullreq_state
 		,pullreq_is_draft
 		,pullreq_comment_count
+		,pullreq_unresolved_count
 		,pullreq_title
 		,pullreq_description
 		,pullreq_source_repo_id
@@ -178,6 +180,7 @@ func (s *PullReqStore) Create(ctx context.Context, pr *types.PullReq) error {
 		,pullreq_state
 		,pullreq_is_draft
 		,pullreq_comment_count
+		,pullreq_unresolved_count
 		,pullreq_title
 		,pullreq_description
 		,pullreq_source_repo_id
@@ -204,6 +207,7 @@ func (s *PullReqStore) Create(ctx context.Context, pr *types.PullReq) error {
 		,:pullreq_state
 		,:pullreq_is_draft
 		,:pullreq_comment_count
+		,:pullreq_unresolved_count
 		,:pullreq_title
 		,:pullreq_description
 		,:pullreq_source_repo_id
@@ -247,6 +251,7 @@ func (s *PullReqStore) Update(ctx context.Context, pr *types.PullReq) error {
 		,pullreq_state = :pullreq_state
 		,pullreq_is_draft = :pullreq_is_draft
 		,pullreq_comment_count = :pullreq_comment_count
+		,pullreq_unresolved_count = :pullreq_unresolved_count
 		,pullreq_title = :pullreq_title
 		,pullreq_description = :pullreq_description
 		,pullreq_activity_seq = :pullreq_activity_seq
@@ -288,8 +293,7 @@ func (s *PullReqStore) Update(ctx context.Context, pr *types.PullReq) error {
 		return store.ErrVersionConflict
 	}
 
-	pr.Version = dbPR.Version
-	pr.Updated = dbPR.Updated
+	*pr = *s.mapPullReq(ctx, dbPR)
 
 	return nil
 }
@@ -468,6 +472,7 @@ func mapPullReq(pr *pullReq) *types.PullReq {
 		State:            pr.State,
 		IsDraft:          pr.IsDraft,
 		CommentCount:     pr.CommentCount,
+		UnresolvedCount:  pr.UnresolvedCount,
 		Title:            pr.Title,
 		Description:      pr.Description,
 		SourceRepoID:     pr.SourceRepoID,
@@ -488,6 +493,7 @@ func mapPullReq(pr *pullReq) *types.PullReq {
 		Merger:           nil,
 		Stats: types.PullReqStats{
 			Conversations:   pr.CommentCount,
+			UnresolvedCount: pr.UnresolvedCount,
 			DiffStats: types.DiffStats{
 				Commits:      0,
 				FilesChanged: 0,
@@ -508,6 +514,7 @@ func mapInternalPullReq(pr *types.PullReq) *pullReq {
 		State:            pr.State,
 		IsDraft:          pr.IsDraft,
 		CommentCount:     pr.CommentCount,
+		UnresolvedCount:  pr.UnresolvedCount,
 		Title:            pr.Title,
 		Description:      pr.Description,
 		SourceRepoID:     pr.SourceRepoID,

internal/store/database/pullreq_activity.go

@@ -287,20 +287,25 @@ func (s *PullReqActivityStore) Update(ctx context.Context, act *types.PullReqAct
 		return store.ErrVersionConflict
 	}
 
-	act.Version = dbAct.Version
-	act.Updated = dbAct.Updated
+	*act = *s.mapPullReqActivity(ctx, dbAct)
 
 	return nil
 }
 
-// UpdateReplySeq updates the pull request activity's reply sequence.
-func (s *PullReqActivityStore) UpdateReplySeq(ctx context.Context,
-	act *types.PullReqActivity) (*types.PullReqActivity, error) {
+// UpdateOptLock updates the pull request using the optimistic locking mechanism.
+func (s *PullReqActivityStore) UpdateOptLock(ctx context.Context,
+	act *types.PullReqActivity,
+	mutateFn func(act *types.PullReqActivity) error,
+) (*types.PullReqActivity, error) {
 	for {
 		dup := *act
 
-		dup.ReplySeq++
-		err := s.Update(ctx, &dup)
+		err := mutateFn(&dup)
+		if err != nil {
+			return nil, err
+		}
+
+		err = s.Update(ctx, &dup)
 		if err == nil {
 			return &dup, nil
 		}
@@ -414,6 +419,32 @@ func (s *PullReqActivityStore) List(ctx context.Context, prID int64,
 	return result, nil
 }
 
+func (s *PullReqActivityStore) CountUnresolved(ctx context.Context, prID int64) (int, error) {
+	stmt := builder.
+		Select("count(*)").
+		From("pullreq_activities").
+		Where("pullreq_activity_pullreq_id = ?", prID).
+		Where("pullreq_activity_sub_order = 0").
+		Where("pullreq_activity_resolved IS NULL").
+		Where("pullreq_activity_deleted IS NULL").
+		Where("pullreq_activity_kind <> ?", enum.PullReqActivityKindSystem)
+
+	sql, args, err := stmt.ToSql()
+	if err != nil {
+		return 0, errors.Wrap(err, "Failed to convert query to sql")
+	}
+
+	db := dbtx.GetAccessor(ctx, s.db)
+
+	var count int
+	err = db.QueryRowContext(ctx, sql, args...).Scan(&count)
+	if err != nil {
+		return 0, processSQLErrorf(err, "Failed executing count unresolved query")
+	}
+
+	return count, nil
+}
+
 func mapPullReqActivity(act *pullReqActivity) *types.PullReqActivity {
 	m := &types.PullReqActivity{
 		ID:         act.ID,

types/enum/pullreq.go

@@ -111,6 +111,30 @@ var pullReqActivityKinds = sortEnum([]PullReqActivityKind{
 	PullReqActivityKindChangeComment,
 })
 
+// PullReqCommentStatus defines status of a pull request comment.
+type PullReqCommentStatus string
+
+func (PullReqCommentStatus) Enum() []interface{} { return toInterfaceSlice(pullReqCommentStatuses) }
+
+func (s PullReqCommentStatus) Sanitize() (PullReqCommentStatus, bool) {
+	return Sanitize(s, GetAllPullReqCommentStatuses)
+}
+
+func GetAllPullReqCommentStatuses() ([]PullReqCommentStatus, PullReqCommentStatus) {
+	return pullReqCommentStatuses, "" // No default value
+}
+
+// PullReqCommentStatus enumeration.
+const (
+	PullReqCommentStatusActive   PullReqCommentStatus = "active"
+	PullReqCommentStatusResolved PullReqCommentStatus = "resolved"
+)
+
+var pullReqCommentStatuses = sortEnum([]PullReqCommentStatus{
+	PullReqCommentStatusActive,
+	PullReqCommentStatusResolved,
+})
+
 // PullReqReviewDecision defines state of a pull request review.
 type PullReqReviewDecision string
 

types/pullreq.go

@@ -23,6 +23,7 @@ type PullReq struct {
 	IsDraft bool              `json:"is_draft"`
 
 	CommentCount    int `json:"-"` // returned as "conversations" in the Stats
+	UnresolvedCount int `json:"-"` // returned as "unresolved_count" in the Stats
 
 	Title       string `json:"title"`
 	Description string `json:"description"`
@@ -52,14 +53,15 @@ type PullReq struct {
 
 // DiffStats shows total number of commits and modified files.
 type DiffStats struct {
-	Commits      int `json:"commits"`
-	FilesChanged int `json:"files_changed"`
+	Commits      int `json:"commits,omitempty"`
+	FilesChanged int `json:"files_changed,omitempty"`
 }
 
 // PullReqStats shows Diff statistics and number of conversations.
 type PullReqStats struct {
 	DiffStats
 	Conversations   int `json:"conversations,omitempty"`
+	UnresolvedCount int `json:"unresolved_count,omitempty"`
 }
 
 // PullReqFilter stores pull request query parameters.

types/pullreq_activity.go

@@ -92,6 +92,11 @@ func (a *PullReqActivity) IsReply() bool {
 	return a.SubOrder > 0
 }
 
+// IsBlocking returns true if the pull request activity (comment/code-comment) is blocking the pull request merge.
+func (a *PullReqActivity) IsBlocking() bool {
+	return a.SubOrder == 0 && a.Resolved == nil && a.Deleted == nil && a.Kind != enum.PullReqActivityKindSystem
+}
+
 // SetPayload sets the payload and verifies it's of correct type for the activity.
 func (a *PullReqActivity) SetPayload(payload PullReqActivityPayload) error {
 	if payload == nil {