feat: combine review requests comments

- Combine review requests comments similairy how labels comments are
combined. If review requests comments were made within 60 seconds of
each other they will be grouped.
- Integration and unit test added.
- Resolves #2774

routers/web/repo/issue.go

@@ -1825,6 +1825,7 @@ func ViewIssue(ctx *context.Context) {
 
 	// Combine multiple label assignments into a single comment
 	combineLabelComments(issue)
+	combineRequestReviewComments(issue)
 
 	getBranchData(ctx, issue)
 	if issue.IsPull {
@@ -3665,6 +3666,127 @@ func attachmentsHTML(ctx *context.Context, attachments []*repo_model.Attachment,
 	return attachHTML
 }
 
+type RequestReviewTarget struct {
+	user *user_model.User
+	team *organization.Team
+}
+
+func (t *RequestReviewTarget) ID() int64 {
+	if t.user != nil {
+		return t.user.ID
+	}
+	return t.team.ID
+}
+
+func (t *RequestReviewTarget) Name() string {
+	if t.user != nil {
+		return t.user.GetDisplayName()
+	}
+	return t.team.Name
+}
+
+func (t *RequestReviewTarget) Type() string {
+	if t.user != nil {
+		return "user"
+	}
+	return "team"
+}
+
+// combineRequestReviewComments combine the nearby request review comments as one.
+func combineRequestReviewComments(issue *issues_model.Issue) {
+	var prev, cur *issues_model.Comment
+	for i := 0; i < len(issue.Comments); i++ {
+		cur = issue.Comments[i]
+		if i > 0 {
+			prev = issue.Comments[i-1]
+		}
+		if i == 0 || cur.Type != issues_model.CommentTypeReviewRequest ||
+			(prev != nil && prev.PosterID != cur.PosterID) ||
+			(prev != nil && cur.CreatedUnix-prev.CreatedUnix >= 60) {
+			if cur.Type == issues_model.CommentTypeReviewRequest && (cur.Assignee != nil || cur.AssigneeTeam != nil) {
+				if cur.RemovedAssignee {
+					if cur.AssigneeTeam != nil {
+						cur.RemovedRequestReview = append(cur.RemovedRequestReview, &RequestReviewTarget{team: cur.AssigneeTeam})
+					} else {
+						cur.RemovedRequestReview = append(cur.RemovedRequestReview, &RequestReviewTarget{user: cur.Assignee})
+					}
+				} else {
+					if cur.AssigneeTeam != nil {
+						cur.AddedRequestReview = append(cur.AddedRequestReview, &RequestReviewTarget{team: cur.AssigneeTeam})
+					} else {
+						cur.AddedRequestReview = append(cur.AddedRequestReview, &RequestReviewTarget{user: cur.Assignee})
+					}
+				}
+			}
+			continue
+		}
+
+		// Previous comment is not a review request, so cannot group. Start a new group.
+		if prev.Type != issues_model.CommentTypeReviewRequest {
+			if cur.RemovedAssignee {
+				if cur.AssigneeTeam != nil {
+					cur.RemovedRequestReview = append(cur.RemovedRequestReview, &RequestReviewTarget{team: cur.AssigneeTeam})
+				} else {
+					cur.RemovedRequestReview = append(cur.RemovedRequestReview, &RequestReviewTarget{user: cur.Assignee})
+				}
+			} else {
+				if cur.AssigneeTeam != nil {
+					cur.AddedRequestReview = append(cur.AddedRequestReview, &RequestReviewTarget{team: cur.AssigneeTeam})
+				} else {
+					cur.AddedRequestReview = append(cur.AddedRequestReview, &RequestReviewTarget{user: cur.Assignee})
+				}
+			}
+			continue
+		}
+
+		// Start grouping.
+		if cur.RemovedAssignee {
+			addedIndex := slices.IndexFunc(prev.AddedRequestReview, func(t issues_model.RequestReviewTarget) bool {
+				if cur.AssigneeTeam != nil {
+					return cur.AssigneeTeam.ID == t.ID() && t.Type() == "team"
+				}
+				return cur.Assignee.ID == t.ID() && t.Type() == "user"
+			})
+
+			// If for this target a AddedRequestReview, then we remove that entry. If it's not found, then add it to the RemovedRequestReview.
+			if addedIndex == -1 {
+				if cur.AssigneeTeam != nil {
+					prev.RemovedRequestReview = append(prev.RemovedRequestReview, &RequestReviewTarget{team: cur.AssigneeTeam})
+				} else {
+					prev.RemovedRequestReview = append(prev.RemovedRequestReview, &RequestReviewTarget{user: cur.Assignee})
+				}
+			} else {
+				prev.AddedRequestReview = slices.Delete(prev.AddedRequestReview, addedIndex, addedIndex+1)
+			}
+		} else {
+			removedIndex := slices.IndexFunc(prev.RemovedRequestReview, func(t issues_model.RequestReviewTarget) bool {
+				if cur.AssigneeTeam != nil {
+					return cur.AssigneeTeam.ID == t.ID() && t.Type() == "team"
+				}
+				return cur.Assignee.ID == t.ID() && t.Type() == "user"
+			})
+
+			// If for this target a RemovedRequestReview, then we remove that entry. If it's not found, then add it to the AddedRequestReview.
+			if removedIndex == -1 {
+				if cur.AssigneeTeam != nil {
+					prev.AddedRequestReview = append(prev.AddedRequestReview, &RequestReviewTarget{team: cur.AssigneeTeam})
+				} else {
+					prev.AddedRequestReview = append(prev.AddedRequestReview, &RequestReviewTarget{user: cur.Assignee})
+				}
+			} else {
+				prev.RemovedRequestReview = slices.Delete(prev.RemovedRequestReview, removedIndex, removedIndex+1)
+			}
+		}
+
+		// Propoagate creation time.
+		prev.CreatedUnix = cur.CreatedUnix
+
+		// Remove the current comment since it has been combined to prev comment
+		issue.Comments = append(issue.Comments[:i], issue.Comments[i+1:]...)
+		i--
+	}
+}
+
 // combineLabelComments combine the nearby label comments as one.
 func combineLabelComments(issue *issues_model.Issue) {
 	var prev, cur *issues_model.Comment