diff --git a/models/issues/issue.go b/models/issues/issue.go
index df38e68519..8dc0381e02 100644
--- a/models/issues/issue.go
+++ b/models/issues/issue.go
@@ -9,27 +9,18 @@ import (
 	"fmt"
 	"regexp"
 	"sort"
-	"strings"
 
 	"code.gitea.io/gitea/models/db"
-	"code.gitea.io/gitea/models/organization"
-	"code.gitea.io/gitea/models/perm"
 	access_model "code.gitea.io/gitea/models/perm/access"
 	project_model "code.gitea.io/gitea/models/project"
 	repo_model "code.gitea.io/gitea/models/repo"
-	system_model "code.gitea.io/gitea/models/system"
-	"code.gitea.io/gitea/models/unit"
 	user_model "code.gitea.io/gitea/models/user"
-	"code.gitea.io/gitea/modules/base"
-	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
-	"code.gitea.io/gitea/modules/references"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
 
 	"xorm.io/builder"
-	"xorm.io/xorm"
 )
 
 // ErrIssueNotExist represents a "IssueNotExist" kind of error.
@@ -637,252 +628,6 @@ func ReplaceIssueLabels(issue *Issue, labels []*Label, doer *user_model.User) (e
 	return committer.Commit()
 }
 
-// UpdateIssueCols updates cols of issue
-func UpdateIssueCols(ctx context.Context, issue *Issue, cols ...string) error {
-	if _, err := db.GetEngine(ctx).ID(issue.ID).Cols(cols...).Update(issue); err != nil {
-		return err
-	}
-	return nil
-}
-
-func changeIssueStatus(ctx context.Context, issue *Issue, doer *user_model.User, isClosed, isMergePull bool) (*Comment, error) {
-	// Reload the issue
-	currentIssue, err := GetIssueByID(ctx, issue.ID)
-	if err != nil {
-		return nil, err
-	}
-
-	// Nothing should be performed if current status is same as target status
-	if currentIssue.IsClosed == isClosed {
-		if !issue.IsPull {
-			return nil, ErrIssueWasClosed{
-				ID: issue.ID,
-			}
-		}
-		return nil, ErrPullWasClosed{
-			ID: issue.ID,
-		}
-	}
-
-	issue.IsClosed = isClosed
-	return doChangeIssueStatus(ctx, issue, doer, isMergePull)
-}
-
-func doChangeIssueStatus(ctx context.Context, issue *Issue, doer *user_model.User, isMergePull bool) (*Comment, error) {
-	// Check for open dependencies
-	if issue.IsClosed && issue.Repo.IsDependenciesEnabled(ctx) {
-		// only check if dependencies are enabled and we're about to close an issue, otherwise reopening an issue would fail when there are unsatisfied dependencies
-		noDeps, err := IssueNoDependenciesLeft(ctx, issue)
-		if err != nil {
-			return nil, err
-		}
-
-		if !noDeps {
-			return nil, ErrDependenciesLeft{issue.ID}
-		}
-	}
-
-	if issue.IsClosed {
-		issue.ClosedUnix = timeutil.TimeStampNow()
-	} else {
-		issue.ClosedUnix = 0
-	}
-
-	if err := UpdateIssueCols(ctx, issue, "is_closed", "closed_unix"); err != nil {
-		return nil, err
-	}
-
-	// Update issue count of labels
-	if err := issue.getLabels(ctx); err != nil {
-		return nil, err
-	}
-	for idx := range issue.Labels {
-		if err := updateLabelCols(ctx, issue.Labels[idx], "num_issues", "num_closed_issue"); err != nil {
-			return nil, err
-		}
-	}
-
-	// Update issue count of milestone
-	if issue.MilestoneID > 0 {
-		if err := UpdateMilestoneCounters(ctx, issue.MilestoneID); err != nil {
-			return nil, err
-		}
-	}
-
-	// update repository's issue closed number
-	if err := repo_model.UpdateRepoIssueNumbers(ctx, issue.RepoID, issue.IsPull, true); err != nil {
-		return nil, err
-	}
-
-	// New action comment
-	cmtType := CommentTypeClose
-	if !issue.IsClosed {
-		cmtType = CommentTypeReopen
-	} else if isMergePull {
-		cmtType = CommentTypeMergePull
-	}
-
-	return CreateComment(ctx, &CreateCommentOptions{
-		Type:  cmtType,
-		Doer:  doer,
-		Repo:  issue.Repo,
-		Issue: issue,
-	})
-}
-
-// ChangeIssueStatus changes issue status to open or closed.
-func ChangeIssueStatus(ctx context.Context, issue *Issue, doer *user_model.User, isClosed bool) (*Comment, error) {
-	if err := issue.LoadRepo(ctx); err != nil {
-		return nil, err
-	}
-	if err := issue.LoadPoster(ctx); err != nil {
-		return nil, err
-	}
-
-	return changeIssueStatus(ctx, issue, doer, isClosed, false)
-}
-
-// ChangeIssueTitle changes the title of this issue, as the given user.
-func ChangeIssueTitle(ctx context.Context, issue *Issue, doer *user_model.User, oldTitle string) (err error) {
-	ctx, committer, err := db.TxContext(ctx)
-	if err != nil {
-		return err
-	}
-	defer committer.Close()
-
-	if err = UpdateIssueCols(ctx, issue, "name"); err != nil {
-		return fmt.Errorf("updateIssueCols: %w", err)
-	}
-
-	if err = issue.LoadRepo(ctx); err != nil {
-		return fmt.Errorf("loadRepo: %w", err)
-	}
-
-	opts := &CreateCommentOptions{
-		Type:     CommentTypeChangeTitle,
-		Doer:     doer,
-		Repo:     issue.Repo,
-		Issue:    issue,
-		OldTitle: oldTitle,
-		NewTitle: issue.Title,
-	}
-	if _, err = CreateComment(ctx, opts); err != nil {
-		return fmt.Errorf("createComment: %w", err)
-	}
-	if err = issue.AddCrossReferences(ctx, doer, true); err != nil {
-		return err
-	}
-
-	return committer.Commit()
-}
-
-// ChangeIssueRef changes the branch of this issue, as the given user.
-func ChangeIssueRef(issue *Issue, doer *user_model.User, oldRef string) (err error) {
-	ctx, committer, err := db.TxContext(db.DefaultContext)
-	if err != nil {
-		return err
-	}
-	defer committer.Close()
-
-	if err = UpdateIssueCols(ctx, issue, "ref"); err != nil {
-		return fmt.Errorf("updateIssueCols: %w", err)
-	}
-
-	if err = issue.LoadRepo(ctx); err != nil {
-		return fmt.Errorf("loadRepo: %w", err)
-	}
-	oldRefFriendly := strings.TrimPrefix(oldRef, git.BranchPrefix)
-	newRefFriendly := strings.TrimPrefix(issue.Ref, git.BranchPrefix)
-
-	opts := &CreateCommentOptions{
-		Type:   CommentTypeChangeIssueRef,
-		Doer:   doer,
-		Repo:   issue.Repo,
-		Issue:  issue,
-		OldRef: oldRefFriendly,
-		NewRef: newRefFriendly,
-	}
-	if _, err = CreateComment(ctx, opts); err != nil {
-		return fmt.Errorf("createComment: %w", err)
-	}
-
-	return committer.Commit()
-}
-
-// AddDeletePRBranchComment adds delete branch comment for pull request issue
-func AddDeletePRBranchComment(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, issueID int64, branchName string) error {
-	issue, err := GetIssueByID(ctx, issueID)
-	if err != nil {
-		return err
-	}
-	opts := &CreateCommentOptions{
-		Type:   CommentTypeDeleteBranch,
-		Doer:   doer,
-		Repo:   repo,
-		Issue:  issue,
-		OldRef: branchName,
-	}
-	_, err = CreateComment(ctx, opts)
-	return err
-}
-
-// UpdateIssueAttachments update attachments by UUIDs for the issue
-func UpdateIssueAttachments(issueID int64, uuids []string) (err error) {
-	ctx, committer, err := db.TxContext(db.DefaultContext)
-	if err != nil {
-		return err
-	}
-	defer committer.Close()
-	attachments, err := repo_model.GetAttachmentsByUUIDs(ctx, uuids)
-	if err != nil {
-		return fmt.Errorf("getAttachmentsByUUIDs [uuids: %v]: %w", uuids, err)
-	}
-	for i := 0; i < len(attachments); i++ {
-		attachments[i].IssueID = issueID
-		if err := repo_model.UpdateAttachment(ctx, attachments[i]); err != nil {
-			return fmt.Errorf("update attachment [id: %d]: %w", attachments[i].ID, err)
-		}
-	}
-	return committer.Commit()
-}
-
-// ChangeIssueContent changes issue content, as the given user.
-func ChangeIssueContent(issue *Issue, doer *user_model.User, content string) (err error) {
-	ctx, committer, err := db.TxContext(db.DefaultContext)
-	if err != nil {
-		return err
-	}
-	defer committer.Close()
-
-	hasContentHistory, err := HasIssueContentHistory(ctx, issue.ID, 0)
-	if err != nil {
-		return fmt.Errorf("HasIssueContentHistory: %w", err)
-	}
-	if !hasContentHistory {
-		if err = SaveIssueContentHistory(ctx, issue.PosterID, issue.ID, 0,
-			issue.CreatedUnix, issue.Content, true); err != nil {
-			return fmt.Errorf("SaveIssueContentHistory: %w", err)
-		}
-	}
-
-	issue.Content = content
-
-	if err = UpdateIssueCols(ctx, issue, "content"); err != nil {
-		return fmt.Errorf("UpdateIssueCols: %w", err)
-	}
-
-	if err = SaveIssueContentHistory(ctx, doer.ID, issue.ID, 0,
-		timeutil.TimeStampNow(), issue.Content, false); err != nil {
-		return fmt.Errorf("SaveIssueContentHistory: %w", err)
-	}
-
-	if err = issue.AddCrossReferences(ctx, doer, true); err != nil {
-		return fmt.Errorf("addCrossReferences: %w", err)
-	}
-
-	return committer.Commit()
-}
-
 // GetTasks returns the amount of tasks in the issues content
 func (issue *Issue) GetTasks() int {
 	return len(issueTasksPat.FindAllStringIndex(issue.Content, -1))
@@ -937,149 +682,6 @@ func (issue *Issue) GetLastEventLabelFake() string {
 	return "repo.issues.opened_by_fake"
 }
 
-// NewIssueOptions represents the options of a new issue.
-type NewIssueOptions struct {
-	Repo        *repo_model.Repository
-	Issue       *Issue
-	LabelIDs    []int64
-	Attachments []string // In UUID format.
-	IsPull      bool
-}
-
-// NewIssueWithIndex creates issue with given index
-func NewIssueWithIndex(ctx context.Context, doer *user_model.User, opts NewIssueOptions) (err error) {
-	e := db.GetEngine(ctx)
-	opts.Issue.Title = strings.TrimSpace(opts.Issue.Title)
-
-	if opts.Issue.MilestoneID > 0 {
-		milestone, err := GetMilestoneByRepoID(ctx, opts.Issue.RepoID, opts.Issue.MilestoneID)
-		if err != nil && !IsErrMilestoneNotExist(err) {
-			return fmt.Errorf("getMilestoneByID: %w", err)
-		}
-
-		// Assume milestone is invalid and drop silently.
-		opts.Issue.MilestoneID = 0
-		if milestone != nil {
-			opts.Issue.MilestoneID = milestone.ID
-			opts.Issue.Milestone = milestone
-		}
-	}
-
-	if opts.Issue.Index <= 0 {
-		return fmt.Errorf("no issue index provided")
-	}
-	if opts.Issue.ID > 0 {
-		return fmt.Errorf("issue exist")
-	}
-
-	if _, err := e.Insert(opts.Issue); err != nil {
-		return err
-	}
-
-	if opts.Issue.MilestoneID > 0 {
-		if err := UpdateMilestoneCounters(ctx, opts.Issue.MilestoneID); err != nil {
-			return err
-		}
-
-		opts := &CreateCommentOptions{
-			Type:           CommentTypeMilestone,
-			Doer:           doer,
-			Repo:           opts.Repo,
-			Issue:          opts.Issue,
-			OldMilestoneID: 0,
-			MilestoneID:    opts.Issue.MilestoneID,
-		}
-		if _, err = CreateComment(ctx, opts); err != nil {
-			return err
-		}
-	}
-
-	if err := repo_model.UpdateRepoIssueNumbers(ctx, opts.Issue.RepoID, opts.IsPull, false); err != nil {
-		return err
-	}
-
-	if len(opts.LabelIDs) > 0 {
-		// During the session, SQLite3 driver cannot handle retrieve objects after update something.
-		// So we have to get all needed labels first.
-		labels := make([]*Label, 0, len(opts.LabelIDs))
-		if err = e.In("id", opts.LabelIDs).Find(&labels); err != nil {
-			return fmt.Errorf("find all labels [label_ids: %v]: %w", opts.LabelIDs, err)
-		}
-
-		if err = opts.Issue.LoadPoster(ctx); err != nil {
-			return err
-		}
-
-		for _, label := range labels {
-			// Silently drop invalid labels.
-			if label.RepoID != opts.Repo.ID && label.OrgID != opts.Repo.OwnerID {
-				continue
-			}
-
-			if err = newIssueLabel(ctx, opts.Issue, label, opts.Issue.Poster); err != nil {
-				return fmt.Errorf("addLabel [id: %d]: %w", label.ID, err)
-			}
-		}
-	}
-
-	if err = NewIssueUsers(ctx, opts.Repo, opts.Issue); err != nil {
-		return err
-	}
-
-	if len(opts.Attachments) > 0 {
-		attachments, err := repo_model.GetAttachmentsByUUIDs(ctx, opts.Attachments)
-		if err != nil {
-			return fmt.Errorf("getAttachmentsByUUIDs [uuids: %v]: %w", opts.Attachments, err)
-		}
-
-		for i := 0; i < len(attachments); i++ {
-			attachments[i].IssueID = opts.Issue.ID
-			if _, err = e.ID(attachments[i].ID).Update(attachments[i]); err != nil {
-				return fmt.Errorf("update attachment [id: %d]: %w", attachments[i].ID, err)
-			}
-		}
-	}
-	if err = opts.Issue.LoadAttributes(ctx); err != nil {
-		return err
-	}
-
-	return opts.Issue.AddCrossReferences(ctx, doer, false)
-}
-
-// NewIssue creates new issue with labels for repository.
-func NewIssue(repo *repo_model.Repository, issue *Issue, labelIDs []int64, uuids []string) (err error) {
-	ctx, committer, err := db.TxContext(db.DefaultContext)
-	if err != nil {
-		return err
-	}
-	defer committer.Close()
-
-	idx, err := db.GetNextResourceIndex(ctx, "issue_index", repo.ID)
-	if err != nil {
-		return fmt.Errorf("generate issue index failed: %w", err)
-	}
-
-	issue.Index = idx
-
-	if err = NewIssueWithIndex(ctx, issue.Poster, NewIssueOptions{
-		Repo:        repo,
-		Issue:       issue,
-		LabelIDs:    labelIDs,
-		Attachments: uuids,
-	}); err != nil {
-		if repo_model.IsErrUserDoesNotHaveAccessToRepo(err) || IsErrNewIssueInsert(err) {
-			return err
-		}
-		return fmt.Errorf("newIssue: %w", err)
-	}
-
-	if err = committer.Commit(); err != nil {
-		return fmt.Errorf("Commit: %w", err)
-	}
-
-	return nil
-}
-
 // GetIssueByIndex returns raw issue without loading attributes by index in a repository.
 func GetIssueByIndex(repoID, index int64) (*Issue, error) {
 	if index < 1 {
@@ -1141,449 +743,6 @@ func GetIssueIDsByRepoID(ctx context.Context, repoID int64) ([]int64, error) {
 	return ids, err
 }
 
-// IssuesOptions represents options of an issue.
-type IssuesOptions struct { //nolint
-	db.ListOptions
-	RepoID             int64 // overwrites RepoCond if not 0
-	RepoCond           builder.Cond
-	AssigneeID         int64
-	PosterID           int64
-	MentionedID        int64
-	ReviewRequestedID  int64
-	ReviewedID         int64
-	SubscriberID       int64
-	MilestoneIDs       []int64
-	ProjectID          int64
-	ProjectBoardID     int64
-	IsClosed           util.OptionalBool
-	IsPull             util.OptionalBool
-	LabelIDs           []int64
-	IncludedLabelNames []string
-	ExcludedLabelNames []string
-	IncludeMilestones  []string
-	SortType           string
-	IssueIDs           []int64
-	UpdatedAfterUnix   int64
-	UpdatedBeforeUnix  int64
-	// prioritize issues from this repo
-	PriorityRepoID int64
-	IsArchived     util.OptionalBool
-	Org            *organization.Organization // issues permission scope
-	Team           *organization.Team         // issues permission scope
-	User           *user_model.User           // issues permission scope
-}
-
-// sortIssuesSession sort an issues-related session based on the provided
-// sortType string
-func sortIssuesSession(sess *xorm.Session, sortType string, priorityRepoID int64) {
-	switch sortType {
-	case "oldest":
-		sess.Asc("issue.created_unix").Asc("issue.id")
-	case "recentupdate":
-		sess.Desc("issue.updated_unix").Desc("issue.created_unix").Desc("issue.id")
-	case "leastupdate":
-		sess.Asc("issue.updated_unix").Asc("issue.created_unix").Asc("issue.id")
-	case "mostcomment":
-		sess.Desc("issue.num_comments").Desc("issue.created_unix").Desc("issue.id")
-	case "leastcomment":
-		sess.Asc("issue.num_comments").Desc("issue.created_unix").Desc("issue.id")
-	case "priority":
-		sess.Desc("issue.priority").Desc("issue.created_unix").Desc("issue.id")
-	case "nearduedate":
-		// 253370764800 is 01/01/9999 @ 12:00am (UTC)
-		sess.Join("LEFT", "milestone", "issue.milestone_id = milestone.id").
-			OrderBy("CASE " +
-				"WHEN issue.deadline_unix = 0 AND (milestone.deadline_unix = 0 OR milestone.deadline_unix IS NULL) THEN 253370764800 " +
-				"WHEN milestone.deadline_unix = 0 OR milestone.deadline_unix IS NULL THEN issue.deadline_unix " +
-				"WHEN milestone.deadline_unix < issue.deadline_unix OR issue.deadline_unix = 0 THEN milestone.deadline_unix " +
-				"ELSE issue.deadline_unix END ASC").
-			Desc("issue.created_unix").
-			Desc("issue.id")
-	case "farduedate":
-		sess.Join("LEFT", "milestone", "issue.milestone_id = milestone.id").
-			OrderBy("CASE " +
-				"WHEN milestone.deadline_unix IS NULL THEN issue.deadline_unix " +
-				"WHEN milestone.deadline_unix < issue.deadline_unix OR issue.deadline_unix = 0 THEN milestone.deadline_unix " +
-				"ELSE issue.deadline_unix END DESC").
-			Desc("issue.created_unix").
-			Desc("issue.id")
-	case "priorityrepo":
-		sess.OrderBy("CASE "+
-			"WHEN issue.repo_id = ? THEN 1 "+
-			"ELSE 2 END ASC", priorityRepoID).
-			Desc("issue.created_unix").
-			Desc("issue.id")
-	case "project-column-sorting":
-		sess.Asc("project_issue.sorting").Desc("issue.created_unix").Desc("issue.id")
-	default:
-		sess.Desc("issue.created_unix").Desc("issue.id")
-	}
-}
-
-func (opts *IssuesOptions) setupSessionWithLimit(sess *xorm.Session) {
-	if opts.Page >= 0 && opts.PageSize > 0 {
-		var start int
-		if opts.Page == 0 {
-			start = 0
-		} else {
-			start = (opts.Page - 1) * opts.PageSize
-		}
-		sess.Limit(opts.PageSize, start)
-	}
-	opts.setupSessionNoLimit(sess)
-}
-
-func (opts *IssuesOptions) setupSessionNoLimit(sess *xorm.Session) {
-	if len(opts.IssueIDs) > 0 {
-		sess.In("issue.id", opts.IssueIDs)
-	}
-
-	if opts.RepoID != 0 {
-		opts.RepoCond = builder.Eq{"issue.repo_id": opts.RepoID}
-	}
-	if opts.RepoCond != nil {
-		sess.And(opts.RepoCond)
-	}
-
-	if !opts.IsClosed.IsNone() {
-		sess.And("issue.is_closed=?", opts.IsClosed.IsTrue())
-	}
-
-	if opts.AssigneeID > 0 {
-		applyAssigneeCondition(sess, opts.AssigneeID)
-	} else if opts.AssigneeID == db.NoConditionID {
-		sess.Where("issue.id NOT IN (SELECT issue_id FROM issue_assignees)")
-	}
-
-	if opts.PosterID > 0 {
-		applyPosterCondition(sess, opts.PosterID)
-	}
-
-	if opts.MentionedID > 0 {
-		applyMentionedCondition(sess, opts.MentionedID)
-	}
-
-	if opts.ReviewRequestedID > 0 {
-		applyReviewRequestedCondition(sess, opts.ReviewRequestedID)
-	}
-
-	if opts.ReviewedID > 0 {
-		applyReviewedCondition(sess, opts.ReviewedID)
-	}
-
-	if opts.SubscriberID > 0 {
-		applySubscribedCondition(sess, opts.SubscriberID)
-	}
-
-	if len(opts.MilestoneIDs) == 1 && opts.MilestoneIDs[0] == db.NoConditionID {
-		sess.And("issue.milestone_id = 0")
-	} else if len(opts.MilestoneIDs) > 0 {
-		sess.In("issue.milestone_id", opts.MilestoneIDs)
-	}
-
-	if opts.UpdatedAfterUnix != 0 {
-		sess.And(builder.Gte{"issue.updated_unix": opts.UpdatedAfterUnix})
-	}
-	if opts.UpdatedBeforeUnix != 0 {
-		sess.And(builder.Lte{"issue.updated_unix": opts.UpdatedBeforeUnix})
-	}
-
-	if opts.ProjectID > 0 {
-		sess.Join("INNER", "project_issue", "issue.id = project_issue.issue_id").
-			And("project_issue.project_id=?", opts.ProjectID)
-	} else if opts.ProjectID == db.NoConditionID { // show those that are in no project
-		sess.And(builder.NotIn("issue.id", builder.Select("issue_id").From("project_issue")))
-	}
-
-	if opts.ProjectBoardID != 0 {
-		if opts.ProjectBoardID > 0 {
-			sess.In("issue.id", builder.Select("issue_id").From("project_issue").Where(builder.Eq{"project_board_id": opts.ProjectBoardID}))
-		} else {
-			sess.In("issue.id", builder.Select("issue_id").From("project_issue").Where(builder.Eq{"project_board_id": 0}))
-		}
-	}
-
-	switch opts.IsPull {
-	case util.OptionalBoolTrue:
-		sess.And("issue.is_pull=?", true)
-	case util.OptionalBoolFalse:
-		sess.And("issue.is_pull=?", false)
-	}
-
-	if opts.IsArchived != util.OptionalBoolNone {
-		sess.And(builder.Eq{"repository.is_archived": opts.IsArchived.IsTrue()})
-	}
-
-	if len(opts.LabelIDs) > 0 {
-		if opts.LabelIDs[0] == 0 {
-			sess.Where("issue.id NOT IN (SELECT issue_id FROM issue_label)")
-		} else {
-			for i, labelID := range opts.LabelIDs {
-				if labelID > 0 {
-					sess.Join("INNER", fmt.Sprintf("issue_label il%d", i),
-						fmt.Sprintf("issue.id = il%[1]d.issue_id AND il%[1]d.label_id = %[2]d", i, labelID))
-				} else if labelID < 0 { // 0 is not supported here, so just ignore it
-					sess.Where("issue.id not in (select issue_id from issue_label where label_id = ?)", -labelID)
-				}
-			}
-		}
-	}
-
-	if len(opts.IncludedLabelNames) > 0 {
-		sess.In("issue.id", BuildLabelNamesIssueIDsCondition(opts.IncludedLabelNames))
-	}
-
-	if len(opts.ExcludedLabelNames) > 0 {
-		sess.And(builder.NotIn("issue.id", BuildLabelNamesIssueIDsCondition(opts.ExcludedLabelNames)))
-	}
-
-	if len(opts.IncludeMilestones) > 0 {
-		sess.In("issue.milestone_id",
-			builder.Select("id").
-				From("milestone").
-				Where(builder.In("name", opts.IncludeMilestones)))
-	}
-
-	if opts.User != nil {
-		sess.And(issuePullAccessibleRepoCond("issue.repo_id", opts.User.ID, opts.Org, opts.Team, opts.IsPull.IsTrue()))
-	}
-}
-
-// teamUnitsRepoCond returns query condition for those repo id in the special org team with special units access
-func teamUnitsRepoCond(id string, userID, orgID, teamID int64, units ...unit.Type) builder.Cond {
-	return builder.In(id,
-		builder.Select("repo_id").From("team_repo").Where(
-			builder.Eq{
-				"team_id": teamID,
-			}.And(
-				builder.Or(
-					// Check if the user is member of the team.
-					builder.In(
-						"team_id", builder.Select("team_id").From("team_user").Where(
-							builder.Eq{
-								"uid": userID,
-							},
-						),
-					),
-					// Check if the user is in the owner team of the organisation.
-					builder.Exists(builder.Select("team_id").From("team_user").
-						Where(builder.Eq{
-							"org_id": orgID,
-							"team_id": builder.Select("id").From("team").Where(
-								builder.Eq{
-									"org_id":     orgID,
-									"lower_name": strings.ToLower(organization.OwnerTeamName),
-								}),
-							"uid": userID,
-						}),
-					),
-				)).And(
-				builder.In(
-					"team_id", builder.Select("team_id").From("team_unit").Where(
-						builder.Eq{
-							"`team_unit`.org_id": orgID,
-						}.And(
-							builder.In("`team_unit`.type", units),
-						),
-					),
-				),
-			),
-		))
-}
-
-// issuePullAccessibleRepoCond userID must not be zero, this condition require join repository table
-func issuePullAccessibleRepoCond(repoIDstr string, userID int64, org *organization.Organization, team *organization.Team, isPull bool) builder.Cond {
-	cond := builder.NewCond()
-	unitType := unit.TypeIssues
-	if isPull {
-		unitType = unit.TypePullRequests
-	}
-	if org != nil {
-		if team != nil {
-			cond = cond.And(teamUnitsRepoCond(repoIDstr, userID, org.ID, team.ID, unitType)) // special team member repos
-		} else {
-			cond = cond.And(
-				builder.Or(
-					repo_model.UserOrgUnitRepoCond(repoIDstr, userID, org.ID, unitType), // team member repos
-					repo_model.UserOrgPublicUnitRepoCond(userID, org.ID),                // user org public non-member repos, TODO: check repo has issues
-				),
-			)
-		}
-	} else {
-		cond = cond.And(
-			builder.Or(
-				repo_model.UserOwnedRepoCond(userID),                          // owned repos
-				repo_model.UserAccessRepoCond(repoIDstr, userID),              // user can access repo in a unit independent way
-				repo_model.UserAssignedRepoCond(repoIDstr, userID),            // user has been assigned accessible public repos
-				repo_model.UserMentionedRepoCond(repoIDstr, userID),           // user has been mentioned accessible public repos
-				repo_model.UserCreateIssueRepoCond(repoIDstr, userID, isPull), // user has created issue/pr accessible public repos
-			),
-		)
-	}
-	return cond
-}
-
-func applyAssigneeCondition(sess *xorm.Session, assigneeID int64) *xorm.Session {
-	return sess.Join("INNER", "issue_assignees", "issue.id = issue_assignees.issue_id").
-		And("issue_assignees.assignee_id = ?", assigneeID)
-}
-
-func applyPosterCondition(sess *xorm.Session, posterID int64) *xorm.Session {
-	return sess.And("issue.poster_id=?", posterID)
-}
-
-func applyMentionedCondition(sess *xorm.Session, mentionedID int64) *xorm.Session {
-	return sess.Join("INNER", "issue_user", "issue.id = issue_user.issue_id").
-		And("issue_user.is_mentioned = ?", true).
-		And("issue_user.uid = ?", mentionedID)
-}
-
-func applyReviewRequestedCondition(sess *xorm.Session, reviewRequestedID int64) *xorm.Session {
-	return sess.Join("INNER", []string{"review", "r"}, "issue.id = r.issue_id").
-		And("issue.poster_id <> ?", reviewRequestedID).
-		And("r.type = ?", ReviewTypeRequest).
-		And("r.reviewer_id = ? and r.id in (select max(id) from review where issue_id = r.issue_id and reviewer_id = r.reviewer_id and type in (?, ?, ?))"+
-			" or r.reviewer_team_id in (select team_id from team_user where uid = ?)",
-			reviewRequestedID, ReviewTypeApprove, ReviewTypeReject, ReviewTypeRequest, reviewRequestedID)
-}
-
-func applyReviewedCondition(sess *xorm.Session, reviewedID int64) *xorm.Session {
-	// Query for pull requests where you are a reviewer or commenter, excluding
-	// any pull requests already returned by the the review requested filter.
-	notPoster := builder.Neq{"issue.poster_id": reviewedID}
-	reviewed := builder.In("issue.id", builder.
-		Select("issue_id").
-		From("review").
-		Where(builder.And(
-			builder.Neq{"type": ReviewTypeRequest},
-			builder.Or(
-				builder.Eq{"reviewer_id": reviewedID},
-				builder.In("reviewer_team_id", builder.
-					Select("team_id").
-					From("team_user").
-					Where(builder.Eq{"uid": reviewedID}),
-				),
-			),
-		)),
-	)
-	commented := builder.In("issue.id", builder.
-		Select("issue_id").
-		From("comment").
-		Where(builder.And(
-			builder.Eq{"poster_id": reviewedID},
-			builder.In("type", CommentTypeComment, CommentTypeCode, CommentTypeReview),
-		)),
-	)
-	return sess.And(notPoster, builder.Or(reviewed, commented))
-}
-
-func applySubscribedCondition(sess *xorm.Session, subscriberID int64) *xorm.Session {
-	return sess.And(
-		builder.
-			NotIn("issue.id",
-				builder.Select("issue_id").
-					From("issue_watch").
-					Where(builder.Eq{"is_watching": false, "user_id": subscriberID}),
-			),
-	).And(
-		builder.Or(
-			builder.In("issue.id", builder.
-				Select("issue_id").
-				From("issue_watch").
-				Where(builder.Eq{"is_watching": true, "user_id": subscriberID}),
-			),
-			builder.In("issue.id", builder.
-				Select("issue_id").
-				From("comment").
-				Where(builder.Eq{"poster_id": subscriberID}),
-			),
-			builder.Eq{"issue.poster_id": subscriberID},
-			builder.In("issue.repo_id", builder.
-				Select("id").
-				From("watch").
-				Where(builder.And(builder.Eq{"user_id": subscriberID},
-					builder.In("mode", repo_model.WatchModeNormal, repo_model.WatchModeAuto))),
-			),
-		),
-	)
-}
-
-// CountIssuesByRepo map from repoID to number of issues matching the options
-func CountIssuesByRepo(ctx context.Context, opts *IssuesOptions) (map[int64]int64, error) {
-	sess := db.GetEngine(ctx).
-		Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
-
-	opts.setupSessionNoLimit(sess)
-
-	countsSlice := make([]*struct {
-		RepoID int64
-		Count  int64
-	}, 0, 10)
-	if err := sess.GroupBy("issue.repo_id").
-		Select("issue.repo_id AS repo_id, COUNT(*) AS count").
-		Table("issue").
-		Find(&countsSlice); err != nil {
-		return nil, fmt.Errorf("unable to CountIssuesByRepo: %w", err)
-	}
-
-	countMap := make(map[int64]int64, len(countsSlice))
-	for _, c := range countsSlice {
-		countMap[c.RepoID] = c.Count
-	}
-	return countMap, nil
-}
-
-// GetRepoIDsForIssuesOptions find all repo ids for the given options
-func GetRepoIDsForIssuesOptions(opts *IssuesOptions, user *user_model.User) ([]int64, error) {
-	repoIDs := make([]int64, 0, 5)
-	e := db.GetEngine(db.DefaultContext)
-
-	sess := e.Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
-
-	opts.setupSessionNoLimit(sess)
-
-	accessCond := repo_model.AccessibleRepositoryCondition(user, unit.TypeInvalid)
-	if err := sess.Where(accessCond).
-		Distinct("issue.repo_id").
-		Table("issue").
-		Find(&repoIDs); err != nil {
-		return nil, fmt.Errorf("unable to GetRepoIDsForIssuesOptions: %w", err)
-	}
-
-	return repoIDs, nil
-}
-
-// Issues returns a list of issues by given conditions.
-func Issues(ctx context.Context, opts *IssuesOptions) ([]*Issue, error) {
-	sess := db.GetEngine(ctx).
-		Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
-	opts.setupSessionWithLimit(sess)
-
-	sortIssuesSession(sess, opts.SortType, opts.PriorityRepoID)
-
-	issues := make([]*Issue, 0, opts.ListOptions.PageSize)
-	if err := sess.Find(&issues); err != nil {
-		return nil, fmt.Errorf("unable to query Issues: %w", err)
-	}
-
-	if err := IssueList(issues).LoadAttributes(); err != nil {
-		return nil, fmt.Errorf("unable to LoadAttributes for Issues: %w", err)
-	}
-
-	return issues, nil
-}
-
-// CountIssues number return of issues by given conditions.
-func CountIssues(ctx context.Context, opts *IssuesOptions) (int64, error) {
-	sess := db.GetEngine(ctx).
-		Select("COUNT(issue.id) AS count").
-		Table("issue").
-		Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
-	opts.setupSessionNoLimit(sess)
-
-	return sess.Count()
-}
-
 // GetParticipantsIDsByIssueID returns the IDs of all users who participated in comments of an issue,
 // but skips joining with `user` for performance reasons.
 // User permissions must be verified elsewhere if required.
@@ -1608,515 +767,6 @@ func IsUserParticipantsOfIssue(user *user_model.User, issue *Issue) bool {
 	return util.SliceContains(userIDs, user.ID)
 }
 
-// UpdateIssueMentions updates issue-user relations for mentioned users.
-func UpdateIssueMentions(ctx context.Context, issueID int64, mentions []*user_model.User) error {
-	if len(mentions) == 0 {
-		return nil
-	}
-	ids := make([]int64, len(mentions))
-	for i, u := range mentions {
-		ids[i] = u.ID
-	}
-	if err := UpdateIssueUsersByMentions(ctx, issueID, ids); err != nil {
-		return fmt.Errorf("UpdateIssueUsersByMentions: %w", err)
-	}
-	return nil
-}
-
-// IssueStats represents issue statistic information.
-type IssueStats struct {
-	OpenCount, ClosedCount int64
-	YourRepositoriesCount  int64
-	AssignCount            int64
-	CreateCount            int64
-	MentionCount           int64
-	ReviewRequestedCount   int64
-	ReviewedCount          int64
-}
-
-// Filter modes.
-const (
-	FilterModeAll = iota
-	FilterModeAssign
-	FilterModeCreate
-	FilterModeMention
-	FilterModeReviewRequested
-	FilterModeReviewed
-	FilterModeYourRepositories
-)
-
-// IssueStatsOptions contains parameters accepted by GetIssueStats.
-type IssueStatsOptions struct {
-	RepoID            int64
-	Labels            string
-	MilestoneID       int64
-	ProjectID         int64
-	AssigneeID        int64
-	MentionedID       int64
-	PosterID          int64
-	ReviewRequestedID int64
-	ReviewedID        int64
-	IsPull            util.OptionalBool
-	IssueIDs          []int64
-}
-
-const (
-	// MaxQueryParameters represents the max query parameters
-	// When queries are broken down in parts because of the number
-	// of parameters, attempt to break by this amount
-	MaxQueryParameters = 300
-)
-
-// GetIssueStats returns issue statistic information by given conditions.
-func GetIssueStats(opts *IssueStatsOptions) (*IssueStats, error) {
-	if len(opts.IssueIDs) <= MaxQueryParameters {
-		return getIssueStatsChunk(opts, opts.IssueIDs)
-	}
-
-	// If too long a list of IDs is provided, we get the statistics in
-	// smaller chunks and get accumulates. Note: this could potentially
-	// get us invalid results. The alternative is to insert the list of
-	// ids in a temporary table and join from them.
-	accum := &IssueStats{}
-	for i := 0; i < len(opts.IssueIDs); {
-		chunk := i + MaxQueryParameters
-		if chunk > len(opts.IssueIDs) {
-			chunk = len(opts.IssueIDs)
-		}
-		stats, err := getIssueStatsChunk(opts, opts.IssueIDs[i:chunk])
-		if err != nil {
-			return nil, err
-		}
-		accum.OpenCount += stats.OpenCount
-		accum.ClosedCount += stats.ClosedCount
-		accum.YourRepositoriesCount += stats.YourRepositoriesCount
-		accum.AssignCount += stats.AssignCount
-		accum.CreateCount += stats.CreateCount
-		accum.OpenCount += stats.MentionCount
-		accum.ReviewRequestedCount += stats.ReviewRequestedCount
-		accum.ReviewedCount += stats.ReviewedCount
-		i = chunk
-	}
-	return accum, nil
-}
-
-func getIssueStatsChunk(opts *IssueStatsOptions, issueIDs []int64) (*IssueStats, error) {
-	stats := &IssueStats{}
-
-	countSession := func(opts *IssueStatsOptions, issueIDs []int64) *xorm.Session {
-		sess := db.GetEngine(db.DefaultContext).
-			Where("issue.repo_id = ?", opts.RepoID)
-
-		if len(issueIDs) > 0 {
-			sess.In("issue.id", issueIDs)
-		}
-
-		if len(opts.Labels) > 0 {
-			labelIDs, err := base.StringsToInt64s(strings.Split(opts.Labels, ","))
-			if err != nil {
-				log.Warn("Malformed Labels argument: %s", opts.Labels)
-			} else {
-				if labelIDs[0] == 0 {
-					sess.Where("issue.id NOT IN (SELECT issue_id FROM issue_label)")
-				} else {
-					for i, labelID := range labelIDs {
-						if labelID > 0 {
-							sess.Join("INNER", fmt.Sprintf("issue_label il%d", i),
-								fmt.Sprintf("issue.id = il%[1]d.issue_id AND il%[1]d.label_id = %[2]d", i, labelID))
-						} else if labelID < 0 { // 0 is not supported here, so just ignore it
-							sess.Where("issue.id NOT IN (SELECT issue_id FROM issue_label WHERE label_id = ?)", -labelID)
-						}
-					}
-				}
-			}
-		}
-
-		if opts.MilestoneID > 0 {
-			sess.And("issue.milestone_id = ?", opts.MilestoneID)
-		} else if opts.MilestoneID == db.NoConditionID {
-			sess.And("issue.milestone_id = 0")
-		}
-
-		if opts.ProjectID > 0 {
-			sess.Join("INNER", "project_issue", "issue.id = project_issue.issue_id").
-				And("project_issue.project_id=?", opts.ProjectID)
-		}
-
-		if opts.AssigneeID > 0 {
-			applyAssigneeCondition(sess, opts.AssigneeID)
-		} else if opts.AssigneeID == db.NoConditionID {
-			sess.Where("id NOT IN (SELECT issue_id FROM issue_assignees)")
-		}
-
-		if opts.PosterID > 0 {
-			applyPosterCondition(sess, opts.PosterID)
-		}
-
-		if opts.MentionedID > 0 {
-			applyMentionedCondition(sess, opts.MentionedID)
-		}
-
-		if opts.ReviewRequestedID > 0 {
-			applyReviewRequestedCondition(sess, opts.ReviewRequestedID)
-		}
-
-		if opts.ReviewedID > 0 {
-			applyReviewedCondition(sess, opts.ReviewedID)
-		}
-
-		switch opts.IsPull {
-		case util.OptionalBoolTrue:
-			sess.And("issue.is_pull=?", true)
-		case util.OptionalBoolFalse:
-			sess.And("issue.is_pull=?", false)
-		}
-
-		return sess
-	}
-
-	var err error
-	stats.OpenCount, err = countSession(opts, issueIDs).
-		And("issue.is_closed = ?", false).
-		Count(new(Issue))
-	if err != nil {
-		return stats, err
-	}
-	stats.ClosedCount, err = countSession(opts, issueIDs).
-		And("issue.is_closed = ?", true).
-		Count(new(Issue))
-	return stats, err
-}
-
-// UserIssueStatsOptions contains parameters accepted by GetUserIssueStats.
-type UserIssueStatsOptions struct {
-	UserID     int64
-	RepoIDs    []int64
-	FilterMode int
-	IsPull     bool
-	IsClosed   bool
-	IssueIDs   []int64
-	IsArchived util.OptionalBool
-	LabelIDs   []int64
-	RepoCond   builder.Cond
-	Org        *organization.Organization
-	Team       *organization.Team
-}
-
-// GetUserIssueStats returns issue statistic information for dashboard by given conditions.
-func GetUserIssueStats(opts UserIssueStatsOptions) (*IssueStats, error) {
-	var err error
-	stats := &IssueStats{}
-
-	cond := builder.NewCond()
-	cond = cond.And(builder.Eq{"issue.is_pull": opts.IsPull})
-	if len(opts.RepoIDs) > 0 {
-		cond = cond.And(builder.In("issue.repo_id", opts.RepoIDs))
-	}
-	if len(opts.IssueIDs) > 0 {
-		cond = cond.And(builder.In("issue.id", opts.IssueIDs))
-	}
-	if opts.RepoCond != nil {
-		cond = cond.And(opts.RepoCond)
-	}
-
-	if opts.UserID > 0 {
-		cond = cond.And(issuePullAccessibleRepoCond("issue.repo_id", opts.UserID, opts.Org, opts.Team, opts.IsPull))
-	}
-
-	sess := func(cond builder.Cond) *xorm.Session {
-		s := db.GetEngine(db.DefaultContext).Where(cond)
-		if len(opts.LabelIDs) > 0 {
-			s.Join("INNER", "issue_label", "issue_label.issue_id = issue.id").
-				In("issue_label.label_id", opts.LabelIDs)
-		}
-		if opts.UserID > 0 || opts.IsArchived != util.OptionalBoolNone {
-			s.Join("INNER", "repository", "issue.repo_id = repository.id")
-			if opts.IsArchived != util.OptionalBoolNone {
-				s.And(builder.Eq{"repository.is_archived": opts.IsArchived.IsTrue()})
-			}
-		}
-		return s
-	}
-
-	switch opts.FilterMode {
-	case FilterModeAll, FilterModeYourRepositories:
-		stats.OpenCount, err = sess(cond).
-			And("issue.is_closed = ?", false).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-		stats.ClosedCount, err = sess(cond).
-			And("issue.is_closed = ?", true).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-	case FilterModeAssign:
-		stats.OpenCount, err = applyAssigneeCondition(sess(cond), opts.UserID).
-			And("issue.is_closed = ?", false).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-		stats.ClosedCount, err = applyAssigneeCondition(sess(cond), opts.UserID).
-			And("issue.is_closed = ?", true).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-	case FilterModeCreate:
-		stats.OpenCount, err = applyPosterCondition(sess(cond), opts.UserID).
-			And("issue.is_closed = ?", false).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-		stats.ClosedCount, err = applyPosterCondition(sess(cond), opts.UserID).
-			And("issue.is_closed = ?", true).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-	case FilterModeMention:
-		stats.OpenCount, err = applyMentionedCondition(sess(cond), opts.UserID).
-			And("issue.is_closed = ?", false).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-		stats.ClosedCount, err = applyMentionedCondition(sess(cond), opts.UserID).
-			And("issue.is_closed = ?", true).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-	case FilterModeReviewRequested:
-		stats.OpenCount, err = applyReviewRequestedCondition(sess(cond), opts.UserID).
-			And("issue.is_closed = ?", false).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-		stats.ClosedCount, err = applyReviewRequestedCondition(sess(cond), opts.UserID).
-			And("issue.is_closed = ?", true).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-	case FilterModeReviewed:
-		stats.OpenCount, err = applyReviewedCondition(sess(cond), opts.UserID).
-			And("issue.is_closed = ?", false).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-		stats.ClosedCount, err = applyReviewedCondition(sess(cond), opts.UserID).
-			And("issue.is_closed = ?", true).
-			Count(new(Issue))
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	cond = cond.And(builder.Eq{"issue.is_closed": opts.IsClosed})
-	stats.AssignCount, err = applyAssigneeCondition(sess(cond), opts.UserID).Count(new(Issue))
-	if err != nil {
-		return nil, err
-	}
-
-	stats.CreateCount, err = applyPosterCondition(sess(cond), opts.UserID).Count(new(Issue))
-	if err != nil {
-		return nil, err
-	}
-
-	stats.MentionCount, err = applyMentionedCondition(sess(cond), opts.UserID).Count(new(Issue))
-	if err != nil {
-		return nil, err
-	}
-
-	stats.YourRepositoriesCount, err = sess(cond).Count(new(Issue))
-	if err != nil {
-		return nil, err
-	}
-
-	stats.ReviewRequestedCount, err = applyReviewRequestedCondition(sess(cond), opts.UserID).Count(new(Issue))
-	if err != nil {
-		return nil, err
-	}
-
-	stats.ReviewedCount, err = applyReviewedCondition(sess(cond), opts.UserID).Count(new(Issue))
-	if err != nil {
-		return nil, err
-	}
-
-	return stats, nil
-}
-
-// GetRepoIssueStats returns number of open and closed repository issues by given filter mode.
-func GetRepoIssueStats(repoID, uid int64, filterMode int, isPull bool) (numOpen, numClosed int64) {
-	countSession := func(isClosed, isPull bool, repoID int64) *xorm.Session {
-		sess := db.GetEngine(db.DefaultContext).
-			Where("is_closed = ?", isClosed).
-			And("is_pull = ?", isPull).
-			And("repo_id = ?", repoID)
-
-		return sess
-	}
-
-	openCountSession := countSession(false, isPull, repoID)
-	closedCountSession := countSession(true, isPull, repoID)
-
-	switch filterMode {
-	case FilterModeAssign:
-		applyAssigneeCondition(openCountSession, uid)
-		applyAssigneeCondition(closedCountSession, uid)
-	case FilterModeCreate:
-		applyPosterCondition(openCountSession, uid)
-		applyPosterCondition(closedCountSession, uid)
-	}
-
-	openResult, _ := openCountSession.Count(new(Issue))
-	closedResult, _ := closedCountSession.Count(new(Issue))
-
-	return openResult, closedResult
-}
-
-// SearchIssueIDsByKeyword search issues on database
-func SearchIssueIDsByKeyword(ctx context.Context, kw string, repoIDs []int64, limit, start int) (int64, []int64, error) {
-	repoCond := builder.In("repo_id", repoIDs)
-	subQuery := builder.Select("id").From("issue").Where(repoCond)
-	cond := builder.And(
-		repoCond,
-		builder.Or(
-			db.BuildCaseInsensitiveLike("name", kw),
-			db.BuildCaseInsensitiveLike("content", kw),
-			builder.In("id", builder.Select("issue_id").
-				From("comment").
-				Where(builder.And(
-					builder.Eq{"type": CommentTypeComment},
-					builder.In("issue_id", subQuery),
-					db.BuildCaseInsensitiveLike("content", kw),
-				)),
-			),
-		),
-	)
-
-	ids := make([]int64, 0, limit)
-	res := make([]struct {
-		ID          int64
-		UpdatedUnix int64
-	}, 0, limit)
-	err := db.GetEngine(ctx).Distinct("id", "updated_unix").Table("issue").Where(cond).
-		OrderBy("`updated_unix` DESC").Limit(limit, start).
-		Find(&res)
-	if err != nil {
-		return 0, nil, err
-	}
-	for _, r := range res {
-		ids = append(ids, r.ID)
-	}
-
-	total, err := db.GetEngine(ctx).Distinct("id").Table("issue").Where(cond).Count()
-	if err != nil {
-		return 0, nil, err
-	}
-
-	return total, ids, nil
-}
-
-// UpdateIssueByAPI updates all allowed fields of given issue.
-// If the issue status is changed a statusChangeComment is returned
-// similarly if the title is changed the titleChanged bool is set to true
-func UpdateIssueByAPI(issue *Issue, doer *user_model.User) (statusChangeComment *Comment, titleChanged bool, err error) {
-	ctx, committer, err := db.TxContext(db.DefaultContext)
-	if err != nil {
-		return nil, false, err
-	}
-	defer committer.Close()
-
-	if err := issue.LoadRepo(ctx); err != nil {
-		return nil, false, fmt.Errorf("loadRepo: %w", err)
-	}
-
-	// Reload the issue
-	currentIssue, err := GetIssueByID(ctx, issue.ID)
-	if err != nil {
-		return nil, false, err
-	}
-
-	if _, err := db.GetEngine(ctx).ID(issue.ID).Cols(
-		"name", "content", "milestone_id", "priority",
-		"deadline_unix", "updated_unix", "is_locked").
-		Update(issue); err != nil {
-		return nil, false, err
-	}
-
-	titleChanged = currentIssue.Title != issue.Title
-	if titleChanged {
-		opts := &CreateCommentOptions{
-			Type:     CommentTypeChangeTitle,
-			Doer:     doer,
-			Repo:     issue.Repo,
-			Issue:    issue,
-			OldTitle: currentIssue.Title,
-			NewTitle: issue.Title,
-		}
-		_, err := CreateComment(ctx, opts)
-		if err != nil {
-			return nil, false, fmt.Errorf("createComment: %w", err)
-		}
-	}
-
-	if currentIssue.IsClosed != issue.IsClosed {
-		statusChangeComment, err = doChangeIssueStatus(ctx, issue, doer, false)
-		if err != nil {
-			return nil, false, err
-		}
-	}
-
-	if err := issue.AddCrossReferences(ctx, doer, true); err != nil {
-		return nil, false, err
-	}
-	return statusChangeComment, titleChanged, committer.Commit()
-}
-
-// UpdateIssueDeadline updates an issue deadline and adds comments. Setting a deadline to 0 means deleting it.
-func UpdateIssueDeadline(issue *Issue, deadlineUnix timeutil.TimeStamp, doer *user_model.User) (err error) {
-	// if the deadline hasn't changed do nothing
-	if issue.DeadlineUnix == deadlineUnix {
-		return nil
-	}
-	ctx, committer, err := db.TxContext(db.DefaultContext)
-	if err != nil {
-		return err
-	}
-	defer committer.Close()
-
-	// Update the deadline
-	if err = UpdateIssueCols(ctx, &Issue{ID: issue.ID, DeadlineUnix: deadlineUnix}, "deadline_unix"); err != nil {
-		return err
-	}
-
-	// Make the comment
-	if _, err = createDeadlineComment(ctx, doer, issue, deadlineUnix); err != nil {
-		return fmt.Errorf("createRemovedDueDateComment: %w", err)
-	}
-
-	return committer.Commit()
-}
-
-// DeleteInIssue delete records in beans with external key issue_id = ?
-func DeleteInIssue(ctx context.Context, issueID int64, beans ...interface{}) error {
-	e := db.GetEngine(ctx)
-	for _, bean := range beans {
-		if _, err := e.In("issue_id", issueID).Delete(bean); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
 // DependencyInfo represents high level information about an issue which is a dependency of another issue.
 type DependencyInfo struct {
 	Issue                 `xorm:"extends"`
@@ -2184,166 +834,6 @@ func (issue *Issue) BlockingDependencies(ctx context.Context) (issueDeps []*Depe
 	return issueDeps, err
 }
 
-// FindAndUpdateIssueMentions finds users mentioned in the given content string, and saves them in the database.
-func FindAndUpdateIssueMentions(ctx context.Context, issue *Issue, doer *user_model.User, content string) (mentions []*user_model.User, err error) {
-	rawMentions := references.FindAllMentionsMarkdown(content)
-	mentions, err = ResolveIssueMentionsByVisibility(ctx, issue, doer, rawMentions)
-	if err != nil {
-		return nil, fmt.Errorf("UpdateIssueMentions [%d]: %w", issue.ID, err)
-	}
-	if err = UpdateIssueMentions(ctx, issue.ID, mentions); err != nil {
-		return nil, fmt.Errorf("UpdateIssueMentions [%d]: %w", issue.ID, err)
-	}
-	return mentions, err
-}
-
-// ResolveIssueMentionsByVisibility returns the users mentioned in an issue, removing those that
-// don't have access to reading it. Teams are expanded into their users, but organizations are ignored.
-func ResolveIssueMentionsByVisibility(ctx context.Context, issue *Issue, doer *user_model.User, mentions []string) (users []*user_model.User, err error) {
-	if len(mentions) == 0 {
-		return
-	}
-	if err = issue.LoadRepo(ctx); err != nil {
-		return
-	}
-
-	resolved := make(map[string]bool, 10)
-	var mentionTeams []string
-
-	if err := issue.Repo.LoadOwner(ctx); err != nil {
-		return nil, err
-	}
-
-	repoOwnerIsOrg := issue.Repo.Owner.IsOrganization()
-	if repoOwnerIsOrg {
-		mentionTeams = make([]string, 0, 5)
-	}
-
-	resolved[doer.LowerName] = true
-	for _, name := range mentions {
-		name := strings.ToLower(name)
-		if _, ok := resolved[name]; ok {
-			continue
-		}
-		if repoOwnerIsOrg && strings.Contains(name, "/") {
-			names := strings.Split(name, "/")
-			if len(names) < 2 || names[0] != issue.Repo.Owner.LowerName {
-				continue
-			}
-			mentionTeams = append(mentionTeams, names[1])
-			resolved[name] = true
-		} else {
-			resolved[name] = false
-		}
-	}
-
-	if issue.Repo.Owner.IsOrganization() && len(mentionTeams) > 0 {
-		teams := make([]*organization.Team, 0, len(mentionTeams))
-		if err := db.GetEngine(ctx).
-			Join("INNER", "team_repo", "team_repo.team_id = team.id").
-			Where("team_repo.repo_id=?", issue.Repo.ID).
-			In("team.lower_name", mentionTeams).
-			Find(&teams); err != nil {
-			return nil, fmt.Errorf("find mentioned teams: %w", err)
-		}
-		if len(teams) != 0 {
-			checked := make([]int64, 0, len(teams))
-			unittype := unit.TypeIssues
-			if issue.IsPull {
-				unittype = unit.TypePullRequests
-			}
-			for _, team := range teams {
-				if team.AccessMode >= perm.AccessModeAdmin {
-					checked = append(checked, team.ID)
-					resolved[issue.Repo.Owner.LowerName+"/"+team.LowerName] = true
-					continue
-				}
-				has, err := db.GetEngine(ctx).Get(&organization.TeamUnit{OrgID: issue.Repo.Owner.ID, TeamID: team.ID, Type: unittype})
-				if err != nil {
-					return nil, fmt.Errorf("get team units (%d): %w", team.ID, err)
-				}
-				if has {
-					checked = append(checked, team.ID)
-					resolved[issue.Repo.Owner.LowerName+"/"+team.LowerName] = true
-				}
-			}
-			if len(checked) != 0 {
-				teamusers := make([]*user_model.User, 0, 20)
-				if err := db.GetEngine(ctx).
-					Join("INNER", "team_user", "team_user.uid = `user`.id").
-					In("`team_user`.team_id", checked).
-					And("`user`.is_active = ?", true).
-					And("`user`.prohibit_login = ?", false).
-					Find(&teamusers); err != nil {
-					return nil, fmt.Errorf("get teams users: %w", err)
-				}
-				if len(teamusers) > 0 {
-					users = make([]*user_model.User, 0, len(teamusers))
-					for _, user := range teamusers {
-						if already, ok := resolved[user.LowerName]; !ok || !already {
-							users = append(users, user)
-							resolved[user.LowerName] = true
-						}
-					}
-				}
-			}
-		}
-	}
-
-	// Remove names already in the list to avoid querying the database if pending names remain
-	mentionUsers := make([]string, 0, len(resolved))
-	for name, already := range resolved {
-		if !already {
-			mentionUsers = append(mentionUsers, name)
-		}
-	}
-	if len(mentionUsers) == 0 {
-		return
-	}
-
-	if users == nil {
-		users = make([]*user_model.User, 0, len(mentionUsers))
-	}
-
-	unchecked := make([]*user_model.User, 0, len(mentionUsers))
-	if err := db.GetEngine(ctx).
-		Where("`user`.is_active = ?", true).
-		And("`user`.prohibit_login = ?", false).
-		In("`user`.lower_name", mentionUsers).
-		Find(&unchecked); err != nil {
-		return nil, fmt.Errorf("find mentioned users: %w", err)
-	}
-	for _, user := range unchecked {
-		if already := resolved[user.LowerName]; already || user.IsOrganization() {
-			continue
-		}
-		// Normal users must have read access to the referencing issue
-		perm, err := access_model.GetUserRepoPermission(ctx, issue.Repo, user)
-		if err != nil {
-			return nil, fmt.Errorf("GetUserRepoPermission [%d]: %w", user.ID, err)
-		}
-		if !perm.CanReadIssuesOrPulls(issue.IsPull) {
-			continue
-		}
-		users = append(users, user)
-	}
-
-	return users, err
-}
-
-// UpdateIssuesMigrationsByType updates all migrated repositories' issues from gitServiceType to replace originalAuthorID to posterID
-func UpdateIssuesMigrationsByType(gitServiceType api.GitServiceType, originalAuthorID string, posterID int64) error {
-	_, err := db.GetEngine(db.DefaultContext).Table("issue").
-		Where("repo_id IN (SELECT id FROM repository WHERE original_service_type = ?)", gitServiceType).
-		And("original_author_id = ?", originalAuthorID).
-		Update(map[string]interface{}{
-			"poster_id":          posterID,
-			"original_author":    "",
-			"original_author_id": 0,
-		})
-	return err
-}
-
 func migratedIssueCond(tp api.GitServiceType) builder.Cond {
 	return builder.In("issue_id",
 		builder.Select("issue.id").
@@ -2355,105 +845,6 @@ func migratedIssueCond(tp api.GitServiceType) builder.Cond {
 	)
 }
 
-// UpdateReactionsMigrationsByType updates all migrated repositories' reactions from gitServiceType to replace originalAuthorID to posterID
-func UpdateReactionsMigrationsByType(gitServiceType api.GitServiceType, originalAuthorID string, userID int64) error {
-	_, err := db.GetEngine(db.DefaultContext).Table("reaction").
-		Where("original_author_id = ?", originalAuthorID).
-		And(migratedIssueCond(gitServiceType)).
-		Update(map[string]interface{}{
-			"user_id":            userID,
-			"original_author":    "",
-			"original_author_id": 0,
-		})
-	return err
-}
-
-// DeleteIssuesByRepoID deletes issues by repositories id
-func DeleteIssuesByRepoID(ctx context.Context, repoID int64) (attachmentPaths []string, err error) {
-	deleteCond := builder.Select("id").From("issue").Where(builder.Eq{"issue.repo_id": repoID})
-
-	sess := db.GetEngine(ctx)
-	// Delete content histories
-	if _, err = sess.In("issue_id", deleteCond).
-		Delete(&ContentHistory{}); err != nil {
-		return
-	}
-
-	// Delete comments and attachments
-	if _, err = sess.In("issue_id", deleteCond).
-		Delete(&Comment{}); err != nil {
-		return
-	}
-
-	// Dependencies for issues in this repository
-	if _, err = sess.In("issue_id", deleteCond).
-		Delete(&IssueDependency{}); err != nil {
-		return
-	}
-
-	// Delete dependencies for issues in other repositories
-	if _, err = sess.In("dependency_id", deleteCond).
-		Delete(&IssueDependency{}); err != nil {
-		return
-	}
-
-	if _, err = sess.In("issue_id", deleteCond).
-		Delete(&IssueUser{}); err != nil {
-		return
-	}
-
-	if _, err = sess.In("issue_id", deleteCond).
-		Delete(&Reaction{}); err != nil {
-		return
-	}
-
-	if _, err = sess.In("issue_id", deleteCond).
-		Delete(&IssueWatch{}); err != nil {
-		return
-	}
-
-	if _, err = sess.In("issue_id", deleteCond).
-		Delete(&Stopwatch{}); err != nil {
-		return
-	}
-
-	if _, err = sess.In("issue_id", deleteCond).
-		Delete(&TrackedTime{}); err != nil {
-		return
-	}
-
-	if _, err = sess.In("issue_id", deleteCond).
-		Delete(&project_model.ProjectIssue{}); err != nil {
-		return
-	}
-
-	if _, err = sess.In("dependent_issue_id", deleteCond).
-		Delete(&Comment{}); err != nil {
-		return
-	}
-
-	var attachments []*repo_model.Attachment
-	if err = sess.In("issue_id", deleteCond).
-		Find(&attachments); err != nil {
-		return
-	}
-
-	for j := range attachments {
-		attachmentPaths = append(attachmentPaths, attachments[j].RelativePath())
-	}
-
-	if _, err = sess.In("issue_id", deleteCond).
-		Delete(&repo_model.Attachment{}); err != nil {
-		return
-	}
-
-	if _, err = db.DeleteByBean(ctx, &Issue{RepoID: repoID}); err != nil {
-		return
-	}
-
-	return attachmentPaths, err
-}
-
 // RemapExternalUser ExternalUserRemappable interface
 func (issue *Issue) RemapExternalUser(externalName string, externalID, userID int64) error {
 	issue.OriginalAuthor = externalName
@@ -2481,40 +872,6 @@ func CountOrphanedIssues(ctx context.Context) (int64, error) {
 		Count()
 }
 
-// DeleteOrphanedIssues delete issues without a repo
-func DeleteOrphanedIssues(ctx context.Context) error {
-	var attachmentPaths []string
-	err := db.WithTx(ctx, func(ctx context.Context) error {
-		var ids []int64
-
-		if err := db.GetEngine(ctx).Table("issue").Distinct("issue.repo_id").
-			Join("LEFT", "repository", "issue.repo_id=repository.id").
-			Where(builder.IsNull{"repository.id"}).GroupBy("issue.repo_id").
-			Find(&ids); err != nil {
-			return err
-		}
-
-		for i := range ids {
-			paths, err := DeleteIssuesByRepoID(ctx, ids[i])
-			if err != nil {
-				return err
-			}
-			attachmentPaths = append(attachmentPaths, paths...)
-		}
-
-		return nil
-	})
-	if err != nil {
-		return err
-	}
-
-	// Remove issue attachment files.
-	for i := range attachmentPaths {
-		system_model.RemoveAllWithNotice(db.DefaultContext, "Delete issue attachment", attachmentPaths[i])
-	}
-	return nil
-}
-
 // HasOriginalAuthor returns if an issue was migrated and has an original author.
 func (issue *Issue) HasOriginalAuthor() bool {
 	return issue.OriginalAuthor != "" && issue.OriginalAuthorID != 0
diff --git a/models/issues/issue_search.go b/models/issues/issue_search.go
new file mode 100644
index 0000000000..e01070ecae
--- /dev/null
+++ b/models/issues/issue_search.go
@@ -0,0 +1,842 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package issues
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/organization"
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/models/unit"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/util"
+
+	"xorm.io/builder"
+	"xorm.io/xorm"
+)
+
+// IssuesOptions represents options of an issue.
+type IssuesOptions struct { //nolint
+	db.ListOptions
+	RepoID             int64 // overwrites RepoCond if not 0
+	RepoCond           builder.Cond
+	AssigneeID         int64
+	PosterID           int64
+	MentionedID        int64
+	ReviewRequestedID  int64
+	ReviewedID         int64
+	SubscriberID       int64
+	MilestoneIDs       []int64
+	ProjectID          int64
+	ProjectBoardID     int64
+	IsClosed           util.OptionalBool
+	IsPull             util.OptionalBool
+	LabelIDs           []int64
+	IncludedLabelNames []string
+	ExcludedLabelNames []string
+	IncludeMilestones  []string
+	SortType           string
+	IssueIDs           []int64
+	UpdatedAfterUnix   int64
+	UpdatedBeforeUnix  int64
+	// prioritize issues from this repo
+	PriorityRepoID int64
+	IsArchived     util.OptionalBool
+	Org            *organization.Organization // issues permission scope
+	Team           *organization.Team         // issues permission scope
+	User           *user_model.User           // issues permission scope
+}
+
+// applySorts sort an issues-related session based on the provided
+// sortType string
+func applySorts(sess *xorm.Session, sortType string, priorityRepoID int64) {
+	switch sortType {
+	case "oldest":
+		sess.Asc("issue.created_unix").Asc("issue.id")
+	case "recentupdate":
+		sess.Desc("issue.updated_unix").Desc("issue.created_unix").Desc("issue.id")
+	case "leastupdate":
+		sess.Asc("issue.updated_unix").Asc("issue.created_unix").Asc("issue.id")
+	case "mostcomment":
+		sess.Desc("issue.num_comments").Desc("issue.created_unix").Desc("issue.id")
+	case "leastcomment":
+		sess.Asc("issue.num_comments").Desc("issue.created_unix").Desc("issue.id")
+	case "priority":
+		sess.Desc("issue.priority").Desc("issue.created_unix").Desc("issue.id")
+	case "nearduedate":
+		// 253370764800 is 01/01/9999 @ 12:00am (UTC)
+		sess.Join("LEFT", "milestone", "issue.milestone_id = milestone.id").
+			OrderBy("CASE " +
+				"WHEN issue.deadline_unix = 0 AND (milestone.deadline_unix = 0 OR milestone.deadline_unix IS NULL) THEN 253370764800 " +
+				"WHEN milestone.deadline_unix = 0 OR milestone.deadline_unix IS NULL THEN issue.deadline_unix " +
+				"WHEN milestone.deadline_unix < issue.deadline_unix OR issue.deadline_unix = 0 THEN milestone.deadline_unix " +
+				"ELSE issue.deadline_unix END ASC").
+			Desc("issue.created_unix").
+			Desc("issue.id")
+	case "farduedate":
+		sess.Join("LEFT", "milestone", "issue.milestone_id = milestone.id").
+			OrderBy("CASE " +
+				"WHEN milestone.deadline_unix IS NULL THEN issue.deadline_unix " +
+				"WHEN milestone.deadline_unix < issue.deadline_unix OR issue.deadline_unix = 0 THEN milestone.deadline_unix " +
+				"ELSE issue.deadline_unix END DESC").
+			Desc("issue.created_unix").
+			Desc("issue.id")
+	case "priorityrepo":
+		sess.OrderBy("CASE "+
+			"WHEN issue.repo_id = ? THEN 1 "+
+			"ELSE 2 END ASC", priorityRepoID).
+			Desc("issue.created_unix").
+			Desc("issue.id")
+	case "project-column-sorting":
+		sess.Asc("project_issue.sorting").Desc("issue.created_unix").Desc("issue.id")
+	default:
+		sess.Desc("issue.created_unix").Desc("issue.id")
+	}
+}
+
+func applyLimit(sess *xorm.Session, opts *IssuesOptions) *xorm.Session {
+	if opts.Page >= 0 && opts.PageSize > 0 {
+		var start int
+		if opts.Page == 0 {
+			start = 0
+		} else {
+			start = (opts.Page - 1) * opts.PageSize
+		}
+		sess.Limit(opts.PageSize, start)
+	}
+	return sess
+}
+
+func applyLabelsCondition(sess *xorm.Session, opts *IssuesOptions) *xorm.Session {
+	if len(opts.LabelIDs) > 0 {
+		if opts.LabelIDs[0] == 0 {
+			sess.Where("issue.id NOT IN (SELECT issue_id FROM issue_label)")
+		} else {
+			for i, labelID := range opts.LabelIDs {
+				if labelID > 0 {
+					sess.Join("INNER", fmt.Sprintf("issue_label il%d", i),
+						fmt.Sprintf("issue.id = il%[1]d.issue_id AND il%[1]d.label_id = %[2]d", i, labelID))
+				} else if labelID < 0 { // 0 is not supported here, so just ignore it
+					sess.Where("issue.id not in (select issue_id from issue_label where label_id = ?)", -labelID)
+				}
+			}
+		}
+	}
+
+	if len(opts.IncludedLabelNames) > 0 {
+		sess.In("issue.id", BuildLabelNamesIssueIDsCondition(opts.IncludedLabelNames))
+	}
+
+	if len(opts.ExcludedLabelNames) > 0 {
+		sess.And(builder.NotIn("issue.id", BuildLabelNamesIssueIDsCondition(opts.ExcludedLabelNames)))
+	}
+
+	return sess
+}
+
+func applyMilestoneCondition(sess *xorm.Session, opts *IssuesOptions) *xorm.Session {
+	if len(opts.MilestoneIDs) == 1 && opts.MilestoneIDs[0] == db.NoConditionID {
+		sess.And("issue.milestone_id = 0")
+	} else if len(opts.MilestoneIDs) > 0 {
+		sess.In("issue.milestone_id", opts.MilestoneIDs)
+	}
+
+	if len(opts.IncludeMilestones) > 0 {
+		sess.In("issue.milestone_id",
+			builder.Select("id").
+				From("milestone").
+				Where(builder.In("name", opts.IncludeMilestones)))
+	}
+
+	return sess
+}
+
+func applyConditions(sess *xorm.Session, opts *IssuesOptions) *xorm.Session {
+	if len(opts.IssueIDs) > 0 {
+		sess.In("issue.id", opts.IssueIDs)
+	}
+
+	if opts.RepoID != 0 {
+		opts.RepoCond = builder.Eq{"issue.repo_id": opts.RepoID}
+	}
+	if opts.RepoCond != nil {
+		sess.And(opts.RepoCond)
+	}
+
+	if !opts.IsClosed.IsNone() {
+		sess.And("issue.is_closed=?", opts.IsClosed.IsTrue())
+	}
+
+	if opts.AssigneeID > 0 {
+		applyAssigneeCondition(sess, opts.AssigneeID)
+	} else if opts.AssigneeID == db.NoConditionID {
+		sess.Where("issue.id NOT IN (SELECT issue_id FROM issue_assignees)")
+	}
+
+	if opts.PosterID > 0 {
+		applyPosterCondition(sess, opts.PosterID)
+	}
+
+	if opts.MentionedID > 0 {
+		applyMentionedCondition(sess, opts.MentionedID)
+	}
+
+	if opts.ReviewRequestedID > 0 {
+		applyReviewRequestedCondition(sess, opts.ReviewRequestedID)
+	}
+
+	if opts.ReviewedID > 0 {
+		applyReviewedCondition(sess, opts.ReviewedID)
+	}
+
+	if opts.SubscriberID > 0 {
+		applySubscribedCondition(sess, opts.SubscriberID)
+	}
+
+	applyMilestoneCondition(sess, opts)
+
+	if opts.UpdatedAfterUnix != 0 {
+		sess.And(builder.Gte{"issue.updated_unix": opts.UpdatedAfterUnix})
+	}
+	if opts.UpdatedBeforeUnix != 0 {
+		sess.And(builder.Lte{"issue.updated_unix": opts.UpdatedBeforeUnix})
+	}
+
+	if opts.ProjectID > 0 {
+		sess.Join("INNER", "project_issue", "issue.id = project_issue.issue_id").
+			And("project_issue.project_id=?", opts.ProjectID)
+	} else if opts.ProjectID == db.NoConditionID { // show those that are in no project
+		sess.And(builder.NotIn("issue.id", builder.Select("issue_id").From("project_issue")))
+	}
+
+	if opts.ProjectBoardID != 0 {
+		if opts.ProjectBoardID > 0 {
+			sess.In("issue.id", builder.Select("issue_id").From("project_issue").Where(builder.Eq{"project_board_id": opts.ProjectBoardID}))
+		} else {
+			sess.In("issue.id", builder.Select("issue_id").From("project_issue").Where(builder.Eq{"project_board_id": 0}))
+		}
+	}
+
+	switch opts.IsPull {
+	case util.OptionalBoolTrue:
+		sess.And("issue.is_pull=?", true)
+	case util.OptionalBoolFalse:
+		sess.And("issue.is_pull=?", false)
+	}
+
+	if opts.IsArchived != util.OptionalBoolNone {
+		sess.And(builder.Eq{"repository.is_archived": opts.IsArchived.IsTrue()})
+	}
+
+	applyLabelsCondition(sess, opts)
+
+	if opts.User != nil {
+		sess.And(issuePullAccessibleRepoCond("issue.repo_id", opts.User.ID, opts.Org, opts.Team, opts.IsPull.IsTrue()))
+	}
+
+	return sess
+}
+
+// teamUnitsRepoCond returns query condition for those repo id in the special org team with special units access
+func teamUnitsRepoCond(id string, userID, orgID, teamID int64, units ...unit.Type) builder.Cond {
+	return builder.In(id,
+		builder.Select("repo_id").From("team_repo").Where(
+			builder.Eq{
+				"team_id": teamID,
+			}.And(
+				builder.Or(
+					// Check if the user is member of the team.
+					builder.In(
+						"team_id", builder.Select("team_id").From("team_user").Where(
+							builder.Eq{
+								"uid": userID,
+							},
+						),
+					),
+					// Check if the user is in the owner team of the organisation.
+					builder.Exists(builder.Select("team_id").From("team_user").
+						Where(builder.Eq{
+							"org_id": orgID,
+							"team_id": builder.Select("id").From("team").Where(
+								builder.Eq{
+									"org_id":     orgID,
+									"lower_name": strings.ToLower(organization.OwnerTeamName),
+								}),
+							"uid": userID,
+						}),
+					),
+				)).And(
+				builder.In(
+					"team_id", builder.Select("team_id").From("team_unit").Where(
+						builder.Eq{
+							"`team_unit`.org_id": orgID,
+						}.And(
+							builder.In("`team_unit`.type", units),
+						),
+					),
+				),
+			),
+		))
+}
+
+// issuePullAccessibleRepoCond userID must not be zero, this condition require join repository table
+func issuePullAccessibleRepoCond(repoIDstr string, userID int64, org *organization.Organization, team *organization.Team, isPull bool) builder.Cond {
+	cond := builder.NewCond()
+	unitType := unit.TypeIssues
+	if isPull {
+		unitType = unit.TypePullRequests
+	}
+	if org != nil {
+		if team != nil {
+			cond = cond.And(teamUnitsRepoCond(repoIDstr, userID, org.ID, team.ID, unitType)) // special team member repos
+		} else {
+			cond = cond.And(
+				builder.Or(
+					repo_model.UserOrgUnitRepoCond(repoIDstr, userID, org.ID, unitType), // team member repos
+					repo_model.UserOrgPublicUnitRepoCond(userID, org.ID),                // user org public non-member repos, TODO: check repo has issues
+				),
+			)
+		}
+	} else {
+		cond = cond.And(
+			builder.Or(
+				repo_model.UserOwnedRepoCond(userID),                          // owned repos
+				repo_model.UserAccessRepoCond(repoIDstr, userID),              // user can access repo in a unit independent way
+				repo_model.UserAssignedRepoCond(repoIDstr, userID),            // user has been assigned accessible public repos
+				repo_model.UserMentionedRepoCond(repoIDstr, userID),           // user has been mentioned accessible public repos
+				repo_model.UserCreateIssueRepoCond(repoIDstr, userID, isPull), // user has created issue/pr accessible public repos
+			),
+		)
+	}
+	return cond
+}
+
+func applyAssigneeCondition(sess *xorm.Session, assigneeID int64) *xorm.Session {
+	return sess.Join("INNER", "issue_assignees", "issue.id = issue_assignees.issue_id").
+		And("issue_assignees.assignee_id = ?", assigneeID)
+}
+
+func applyPosterCondition(sess *xorm.Session, posterID int64) *xorm.Session {
+	return sess.And("issue.poster_id=?", posterID)
+}
+
+func applyMentionedCondition(sess *xorm.Session, mentionedID int64) *xorm.Session {
+	return sess.Join("INNER", "issue_user", "issue.id = issue_user.issue_id").
+		And("issue_user.is_mentioned = ?", true).
+		And("issue_user.uid = ?", mentionedID)
+}
+
+func applyReviewRequestedCondition(sess *xorm.Session, reviewRequestedID int64) *xorm.Session {
+	return sess.Join("INNER", []string{"review", "r"}, "issue.id = r.issue_id").
+		And("issue.poster_id <> ?", reviewRequestedID).
+		And("r.type = ?", ReviewTypeRequest).
+		And("r.reviewer_id = ? and r.id in (select max(id) from review where issue_id = r.issue_id and reviewer_id = r.reviewer_id and type in (?, ?, ?))"+
+			" or r.reviewer_team_id in (select team_id from team_user where uid = ?)",
+			reviewRequestedID, ReviewTypeApprove, ReviewTypeReject, ReviewTypeRequest, reviewRequestedID)
+}
+
+func applyReviewedCondition(sess *xorm.Session, reviewedID int64) *xorm.Session {
+	// Query for pull requests where you are a reviewer or commenter, excluding
+	// any pull requests already returned by the the review requested filter.
+	notPoster := builder.Neq{"issue.poster_id": reviewedID}
+	reviewed := builder.In("issue.id", builder.
+		Select("issue_id").
+		From("review").
+		Where(builder.And(
+			builder.Neq{"type": ReviewTypeRequest},
+			builder.Or(
+				builder.Eq{"reviewer_id": reviewedID},
+				builder.In("reviewer_team_id", builder.
+					Select("team_id").
+					From("team_user").
+					Where(builder.Eq{"uid": reviewedID}),
+				),
+			),
+		)),
+	)
+	commented := builder.In("issue.id", builder.
+		Select("issue_id").
+		From("comment").
+		Where(builder.And(
+			builder.Eq{"poster_id": reviewedID},
+			builder.In("type", CommentTypeComment, CommentTypeCode, CommentTypeReview),
+		)),
+	)
+	return sess.And(notPoster, builder.Or(reviewed, commented))
+}
+
+func applySubscribedCondition(sess *xorm.Session, subscriberID int64) *xorm.Session {
+	return sess.And(
+		builder.
+			NotIn("issue.id",
+				builder.Select("issue_id").
+					From("issue_watch").
+					Where(builder.Eq{"is_watching": false, "user_id": subscriberID}),
+			),
+	).And(
+		builder.Or(
+			builder.In("issue.id", builder.
+				Select("issue_id").
+				From("issue_watch").
+				Where(builder.Eq{"is_watching": true, "user_id": subscriberID}),
+			),
+			builder.In("issue.id", builder.
+				Select("issue_id").
+				From("comment").
+				Where(builder.Eq{"poster_id": subscriberID}),
+			),
+			builder.Eq{"issue.poster_id": subscriberID},
+			builder.In("issue.repo_id", builder.
+				Select("id").
+				From("watch").
+				Where(builder.And(builder.Eq{"user_id": subscriberID},
+					builder.In("mode", repo_model.WatchModeNormal, repo_model.WatchModeAuto))),
+			),
+		),
+	)
+}
+
+// CountIssuesByRepo map from repoID to number of issues matching the options
+func CountIssuesByRepo(ctx context.Context, opts *IssuesOptions) (map[int64]int64, error) {
+	sess := db.GetEngine(ctx).
+		Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
+
+	applyConditions(sess, opts)
+
+	countsSlice := make([]*struct {
+		RepoID int64
+		Count  int64
+	}, 0, 10)
+	if err := sess.GroupBy("issue.repo_id").
+		Select("issue.repo_id AS repo_id, COUNT(*) AS count").
+		Table("issue").
+		Find(&countsSlice); err != nil {
+		return nil, fmt.Errorf("unable to CountIssuesByRepo: %w", err)
+	}
+
+	countMap := make(map[int64]int64, len(countsSlice))
+	for _, c := range countsSlice {
+		countMap[c.RepoID] = c.Count
+	}
+	return countMap, nil
+}
+
+// GetRepoIDsForIssuesOptions find all repo ids for the given options
+func GetRepoIDsForIssuesOptions(opts *IssuesOptions, user *user_model.User) ([]int64, error) {
+	repoIDs := make([]int64, 0, 5)
+	e := db.GetEngine(db.DefaultContext)
+
+	sess := e.Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
+
+	applyConditions(sess, opts)
+
+	accessCond := repo_model.AccessibleRepositoryCondition(user, unit.TypeInvalid)
+	if err := sess.Where(accessCond).
+		Distinct("issue.repo_id").
+		Table("issue").
+		Find(&repoIDs); err != nil {
+		return nil, fmt.Errorf("unable to GetRepoIDsForIssuesOptions: %w", err)
+	}
+
+	return repoIDs, nil
+}
+
+// Issues returns a list of issues by given conditions.
+func Issues(ctx context.Context, opts *IssuesOptions) ([]*Issue, error) {
+	sess := db.GetEngine(ctx).
+		Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
+	applyLimit(sess, opts)
+	applyConditions(sess, opts)
+	applySorts(sess, opts.SortType, opts.PriorityRepoID)
+
+	issues := make([]*Issue, 0, opts.ListOptions.PageSize)
+	if err := sess.Find(&issues); err != nil {
+		return nil, fmt.Errorf("unable to query Issues: %w", err)
+	}
+
+	if err := IssueList(issues).LoadAttributes(); err != nil {
+		return nil, fmt.Errorf("unable to LoadAttributes for Issues: %w", err)
+	}
+
+	return issues, nil
+}
+
+// CountIssues number return of issues by given conditions.
+func CountIssues(ctx context.Context, opts *IssuesOptions) (int64, error) {
+	sess := db.GetEngine(ctx).
+		Select("COUNT(issue.id) AS count").
+		Table("issue").
+		Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
+	applyConditions(sess, opts)
+
+	return sess.Count()
+}
+
+// IssueStats represents issue statistic information.
+type IssueStats struct {
+	OpenCount, ClosedCount int64
+	YourRepositoriesCount  int64
+	AssignCount            int64
+	CreateCount            int64
+	MentionCount           int64
+	ReviewRequestedCount   int64
+	ReviewedCount          int64
+}
+
+// Filter modes.
+const (
+	FilterModeAll = iota
+	FilterModeAssign
+	FilterModeCreate
+	FilterModeMention
+	FilterModeReviewRequested
+	FilterModeReviewed
+	FilterModeYourRepositories
+)
+
+const (
+	// MaxQueryParameters represents the max query parameters
+	// When queries are broken down in parts because of the number
+	// of parameters, attempt to break by this amount
+	MaxQueryParameters = 300
+)
+
+// GetIssueStats returns issue statistic information by given conditions.
+func GetIssueStats(opts *IssuesOptions) (*IssueStats, error) {
+	if len(opts.IssueIDs) <= MaxQueryParameters {
+		return getIssueStatsChunk(opts, opts.IssueIDs)
+	}
+
+	// If too long a list of IDs is provided, we get the statistics in
+	// smaller chunks and get accumulates. Note: this could potentially
+	// get us invalid results. The alternative is to insert the list of
+	// ids in a temporary table and join from them.
+	accum := &IssueStats{}
+	for i := 0; i < len(opts.IssueIDs); {
+		chunk := i + MaxQueryParameters
+		if chunk > len(opts.IssueIDs) {
+			chunk = len(opts.IssueIDs)
+		}
+		stats, err := getIssueStatsChunk(opts, opts.IssueIDs[i:chunk])
+		if err != nil {
+			return nil, err
+		}
+		accum.OpenCount += stats.OpenCount
+		accum.ClosedCount += stats.ClosedCount
+		accum.YourRepositoriesCount += stats.YourRepositoriesCount
+		accum.AssignCount += stats.AssignCount
+		accum.CreateCount += stats.CreateCount
+		accum.OpenCount += stats.MentionCount
+		accum.ReviewRequestedCount += stats.ReviewRequestedCount
+		accum.ReviewedCount += stats.ReviewedCount
+		i = chunk
+	}
+	return accum, nil
+}
+
+func getIssueStatsChunk(opts *IssuesOptions, issueIDs []int64) (*IssueStats, error) {
+	stats := &IssueStats{}
+
+	countSession := func(opts *IssuesOptions, issueIDs []int64) *xorm.Session {
+		sess := db.GetEngine(db.DefaultContext).
+			Where("issue.repo_id = ?", opts.RepoID)
+
+		if len(issueIDs) > 0 {
+			sess.In("issue.id", issueIDs)
+		}
+
+		applyLabelsCondition(sess, opts)
+
+		applyMilestoneCondition(sess, opts)
+
+		if opts.ProjectID > 0 {
+			sess.Join("INNER", "project_issue", "issue.id = project_issue.issue_id").
+				And("project_issue.project_id=?", opts.ProjectID)
+		}
+
+		if opts.AssigneeID > 0 {
+			applyAssigneeCondition(sess, opts.AssigneeID)
+		} else if opts.AssigneeID == db.NoConditionID {
+			sess.Where("id NOT IN (SELECT issue_id FROM issue_assignees)")
+		}
+
+		if opts.PosterID > 0 {
+			applyPosterCondition(sess, opts.PosterID)
+		}
+
+		if opts.MentionedID > 0 {
+			applyMentionedCondition(sess, opts.MentionedID)
+		}
+
+		if opts.ReviewRequestedID > 0 {
+			applyReviewRequestedCondition(sess, opts.ReviewRequestedID)
+		}
+
+		if opts.ReviewedID > 0 {
+			applyReviewedCondition(sess, opts.ReviewedID)
+		}
+
+		switch opts.IsPull {
+		case util.OptionalBoolTrue:
+			sess.And("issue.is_pull=?", true)
+		case util.OptionalBoolFalse:
+			sess.And("issue.is_pull=?", false)
+		}
+
+		return sess
+	}
+
+	var err error
+	stats.OpenCount, err = countSession(opts, issueIDs).
+		And("issue.is_closed = ?", false).
+		Count(new(Issue))
+	if err != nil {
+		return stats, err
+	}
+	stats.ClosedCount, err = countSession(opts, issueIDs).
+		And("issue.is_closed = ?", true).
+		Count(new(Issue))
+	return stats, err
+}
+
+// UserIssueStatsOptions contains parameters accepted by GetUserIssueStats.
+type UserIssueStatsOptions struct {
+	UserID     int64
+	RepoIDs    []int64
+	FilterMode int
+	IsPull     bool
+	IsClosed   bool
+	IssueIDs   []int64
+	IsArchived util.OptionalBool
+	LabelIDs   []int64
+	RepoCond   builder.Cond
+	Org        *organization.Organization
+	Team       *organization.Team
+}
+
+// GetUserIssueStats returns issue statistic information for dashboard by given conditions.
+func GetUserIssueStats(opts UserIssueStatsOptions) (*IssueStats, error) {
+	var err error
+	stats := &IssueStats{}
+
+	cond := builder.NewCond()
+	cond = cond.And(builder.Eq{"issue.is_pull": opts.IsPull})
+	if len(opts.RepoIDs) > 0 {
+		cond = cond.And(builder.In("issue.repo_id", opts.RepoIDs))
+	}
+	if len(opts.IssueIDs) > 0 {
+		cond = cond.And(builder.In("issue.id", opts.IssueIDs))
+	}
+	if opts.RepoCond != nil {
+		cond = cond.And(opts.RepoCond)
+	}
+
+	if opts.UserID > 0 {
+		cond = cond.And(issuePullAccessibleRepoCond("issue.repo_id", opts.UserID, opts.Org, opts.Team, opts.IsPull))
+	}
+
+	sess := func(cond builder.Cond) *xorm.Session {
+		s := db.GetEngine(db.DefaultContext).Where(cond)
+		if len(opts.LabelIDs) > 0 {
+			s.Join("INNER", "issue_label", "issue_label.issue_id = issue.id").
+				In("issue_label.label_id", opts.LabelIDs)
+		}
+		if opts.UserID > 0 || opts.IsArchived != util.OptionalBoolNone {
+			s.Join("INNER", "repository", "issue.repo_id = repository.id")
+			if opts.IsArchived != util.OptionalBoolNone {
+				s.And(builder.Eq{"repository.is_archived": opts.IsArchived.IsTrue()})
+			}
+		}
+		return s
+	}
+
+	switch opts.FilterMode {
+	case FilterModeAll, FilterModeYourRepositories:
+		stats.OpenCount, err = sess(cond).
+			And("issue.is_closed = ?", false).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+		stats.ClosedCount, err = sess(cond).
+			And("issue.is_closed = ?", true).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+	case FilterModeAssign:
+		stats.OpenCount, err = applyAssigneeCondition(sess(cond), opts.UserID).
+			And("issue.is_closed = ?", false).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+		stats.ClosedCount, err = applyAssigneeCondition(sess(cond), opts.UserID).
+			And("issue.is_closed = ?", true).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+	case FilterModeCreate:
+		stats.OpenCount, err = applyPosterCondition(sess(cond), opts.UserID).
+			And("issue.is_closed = ?", false).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+		stats.ClosedCount, err = applyPosterCondition(sess(cond), opts.UserID).
+			And("issue.is_closed = ?", true).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+	case FilterModeMention:
+		stats.OpenCount, err = applyMentionedCondition(sess(cond), opts.UserID).
+			And("issue.is_closed = ?", false).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+		stats.ClosedCount, err = applyMentionedCondition(sess(cond), opts.UserID).
+			And("issue.is_closed = ?", true).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+	case FilterModeReviewRequested:
+		stats.OpenCount, err = applyReviewRequestedCondition(sess(cond), opts.UserID).
+			And("issue.is_closed = ?", false).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+		stats.ClosedCount, err = applyReviewRequestedCondition(sess(cond), opts.UserID).
+			And("issue.is_closed = ?", true).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+	case FilterModeReviewed:
+		stats.OpenCount, err = applyReviewedCondition(sess(cond), opts.UserID).
+			And("issue.is_closed = ?", false).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+		stats.ClosedCount, err = applyReviewedCondition(sess(cond), opts.UserID).
+			And("issue.is_closed = ?", true).
+			Count(new(Issue))
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	cond = cond.And(builder.Eq{"issue.is_closed": opts.IsClosed})
+	stats.AssignCount, err = applyAssigneeCondition(sess(cond), opts.UserID).Count(new(Issue))
+	if err != nil {
+		return nil, err
+	}
+
+	stats.CreateCount, err = applyPosterCondition(sess(cond), opts.UserID).Count(new(Issue))
+	if err != nil {
+		return nil, err
+	}
+
+	stats.MentionCount, err = applyMentionedCondition(sess(cond), opts.UserID).Count(new(Issue))
+	if err != nil {
+		return nil, err
+	}
+
+	stats.YourRepositoriesCount, err = sess(cond).Count(new(Issue))
+	if err != nil {
+		return nil, err
+	}
+
+	stats.ReviewRequestedCount, err = applyReviewRequestedCondition(sess(cond), opts.UserID).Count(new(Issue))
+	if err != nil {
+		return nil, err
+	}
+
+	stats.ReviewedCount, err = applyReviewedCondition(sess(cond), opts.UserID).Count(new(Issue))
+	if err != nil {
+		return nil, err
+	}
+
+	return stats, nil
+}
+
+// GetRepoIssueStats returns number of open and closed repository issues by given filter mode.
+func GetRepoIssueStats(repoID, uid int64, filterMode int, isPull bool) (numOpen, numClosed int64) {
+	countSession := func(isClosed, isPull bool, repoID int64) *xorm.Session {
+		sess := db.GetEngine(db.DefaultContext).
+			Where("is_closed = ?", isClosed).
+			And("is_pull = ?", isPull).
+			And("repo_id = ?", repoID)
+
+		return sess
+	}
+
+	openCountSession := countSession(false, isPull, repoID)
+	closedCountSession := countSession(true, isPull, repoID)
+
+	switch filterMode {
+	case FilterModeAssign:
+		applyAssigneeCondition(openCountSession, uid)
+		applyAssigneeCondition(closedCountSession, uid)
+	case FilterModeCreate:
+		applyPosterCondition(openCountSession, uid)
+		applyPosterCondition(closedCountSession, uid)
+	}
+
+	openResult, _ := openCountSession.Count(new(Issue))
+	closedResult, _ := closedCountSession.Count(new(Issue))
+
+	return openResult, closedResult
+}
+
+// SearchIssueIDsByKeyword search issues on database
+func SearchIssueIDsByKeyword(ctx context.Context, kw string, repoIDs []int64, limit, start int) (int64, []int64, error) {
+	repoCond := builder.In("repo_id", repoIDs)
+	subQuery := builder.Select("id").From("issue").Where(repoCond)
+	cond := builder.And(
+		repoCond,
+		builder.Or(
+			db.BuildCaseInsensitiveLike("name", kw),
+			db.BuildCaseInsensitiveLike("content", kw),
+			builder.In("id", builder.Select("issue_id").
+				From("comment").
+				Where(builder.And(
+					builder.Eq{"type": CommentTypeComment},
+					builder.In("issue_id", subQuery),
+					db.BuildCaseInsensitiveLike("content", kw),
+				)),
+			),
+		),
+	)
+
+	ids := make([]int64, 0, limit)
+	res := make([]struct {
+		ID          int64
+		UpdatedUnix int64
+	}, 0, limit)
+	err := db.GetEngine(ctx).Distinct("id", "updated_unix").Table("issue").Where(cond).
+		OrderBy("`updated_unix` DESC").Limit(limit, start).
+		Find(&res)
+	if err != nil {
+		return 0, nil, err
+	}
+	for _, r := range res {
+		ids = append(ids, r.ID)
+	}
+
+	total, err := db.GetEngine(ctx).Distinct("id").Table("issue").Where(cond).Count()
+	if err != nil {
+		return 0, nil, err
+	}
+
+	return total, ids, nil
+}
diff --git a/models/issues/issue_test.go b/models/issues/issue_test.go
index 3a83d8d2b7..5bf2f819be 100644
--- a/models/issues/issue_test.go
+++ b/models/issues/issue_test.go
@@ -494,7 +494,7 @@ func TestCorrectIssueStats(t *testing.T) {
 
 	// Now we will call the GetIssueStats with these IDs and if working,
 	// get the correct stats back.
-	issueStats, err := issues_model.GetIssueStats(&issues_model.IssueStatsOptions{
+	issueStats, err := issues_model.GetIssueStats(&issues_model.IssuesOptions{
 		RepoID:   1,
 		IssueIDs: ids,
 	})
diff --git a/models/issues/issue_update.go b/models/issues/issue_update.go
new file mode 100644
index 0000000000..bebd5f4cd6
--- /dev/null
+++ b/models/issues/issue_update.go
@@ -0,0 +1,815 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package issues
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/organization"
+	"code.gitea.io/gitea/models/perm"
+	access_model "code.gitea.io/gitea/models/perm/access"
+	project_model "code.gitea.io/gitea/models/project"
+	repo_model "code.gitea.io/gitea/models/repo"
+	system_model "code.gitea.io/gitea/models/system"
+	"code.gitea.io/gitea/models/unit"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/references"
+	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"xorm.io/builder"
+)
+
+// UpdateIssueCols updates cols of issue
+func UpdateIssueCols(ctx context.Context, issue *Issue, cols ...string) error {
+	if _, err := db.GetEngine(ctx).ID(issue.ID).Cols(cols...).Update(issue); err != nil {
+		return err
+	}
+	return nil
+}
+
+func changeIssueStatus(ctx context.Context, issue *Issue, doer *user_model.User, isClosed, isMergePull bool) (*Comment, error) {
+	// Reload the issue
+	currentIssue, err := GetIssueByID(ctx, issue.ID)
+	if err != nil {
+		return nil, err
+	}
+
+	// Nothing should be performed if current status is same as target status
+	if currentIssue.IsClosed == isClosed {
+		if !issue.IsPull {
+			return nil, ErrIssueWasClosed{
+				ID: issue.ID,
+			}
+		}
+		return nil, ErrPullWasClosed{
+			ID: issue.ID,
+		}
+	}
+
+	issue.IsClosed = isClosed
+	return doChangeIssueStatus(ctx, issue, doer, isMergePull)
+}
+
+func doChangeIssueStatus(ctx context.Context, issue *Issue, doer *user_model.User, isMergePull bool) (*Comment, error) {
+	// Check for open dependencies
+	if issue.IsClosed && issue.Repo.IsDependenciesEnabled(ctx) {
+		// only check if dependencies are enabled and we're about to close an issue, otherwise reopening an issue would fail when there are unsatisfied dependencies
+		noDeps, err := IssueNoDependenciesLeft(ctx, issue)
+		if err != nil {
+			return nil, err
+		}
+
+		if !noDeps {
+			return nil, ErrDependenciesLeft{issue.ID}
+		}
+	}
+
+	if issue.IsClosed {
+		issue.ClosedUnix = timeutil.TimeStampNow()
+	} else {
+		issue.ClosedUnix = 0
+	}
+
+	if err := UpdateIssueCols(ctx, issue, "is_closed", "closed_unix"); err != nil {
+		return nil, err
+	}
+
+	// Update issue count of labels
+	if err := issue.getLabels(ctx); err != nil {
+		return nil, err
+	}
+	for idx := range issue.Labels {
+		if err := updateLabelCols(ctx, issue.Labels[idx], "num_issues", "num_closed_issue"); err != nil {
+			return nil, err
+		}
+	}
+
+	// Update issue count of milestone
+	if issue.MilestoneID > 0 {
+		if err := UpdateMilestoneCounters(ctx, issue.MilestoneID); err != nil {
+			return nil, err
+		}
+	}
+
+	// update repository's issue closed number
+	if err := repo_model.UpdateRepoIssueNumbers(ctx, issue.RepoID, issue.IsPull, true); err != nil {
+		return nil, err
+	}
+
+	// New action comment
+	cmtType := CommentTypeClose
+	if !issue.IsClosed {
+		cmtType = CommentTypeReopen
+	} else if isMergePull {
+		cmtType = CommentTypeMergePull
+	}
+
+	return CreateComment(ctx, &CreateCommentOptions{
+		Type:  cmtType,
+		Doer:  doer,
+		Repo:  issue.Repo,
+		Issue: issue,
+	})
+}
+
+// ChangeIssueStatus changes issue status to open or closed.
+func ChangeIssueStatus(ctx context.Context, issue *Issue, doer *user_model.User, isClosed bool) (*Comment, error) {
+	if err := issue.LoadRepo(ctx); err != nil {
+		return nil, err
+	}
+	if err := issue.LoadPoster(ctx); err != nil {
+		return nil, err
+	}
+
+	return changeIssueStatus(ctx, issue, doer, isClosed, false)
+}
+
+// ChangeIssueTitle changes the title of this issue, as the given user.
+func ChangeIssueTitle(ctx context.Context, issue *Issue, doer *user_model.User, oldTitle string) (err error) {
+	ctx, committer, err := db.TxContext(ctx)
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+
+	if err = UpdateIssueCols(ctx, issue, "name"); err != nil {
+		return fmt.Errorf("updateIssueCols: %w", err)
+	}
+
+	if err = issue.LoadRepo(ctx); err != nil {
+		return fmt.Errorf("loadRepo: %w", err)
+	}
+
+	opts := &CreateCommentOptions{
+		Type:     CommentTypeChangeTitle,
+		Doer:     doer,
+		Repo:     issue.Repo,
+		Issue:    issue,
+		OldTitle: oldTitle,
+		NewTitle: issue.Title,
+	}
+	if _, err = CreateComment(ctx, opts); err != nil {
+		return fmt.Errorf("createComment: %w", err)
+	}
+	if err = issue.AddCrossReferences(ctx, doer, true); err != nil {
+		return err
+	}
+
+	return committer.Commit()
+}
+
+// ChangeIssueRef changes the branch of this issue, as the given user.
+func ChangeIssueRef(issue *Issue, doer *user_model.User, oldRef string) (err error) {
+	ctx, committer, err := db.TxContext(db.DefaultContext)
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+
+	if err = UpdateIssueCols(ctx, issue, "ref"); err != nil {
+		return fmt.Errorf("updateIssueCols: %w", err)
+	}
+
+	if err = issue.LoadRepo(ctx); err != nil {
+		return fmt.Errorf("loadRepo: %w", err)
+	}
+	oldRefFriendly := strings.TrimPrefix(oldRef, git.BranchPrefix)
+	newRefFriendly := strings.TrimPrefix(issue.Ref, git.BranchPrefix)
+
+	opts := &CreateCommentOptions{
+		Type:   CommentTypeChangeIssueRef,
+		Doer:   doer,
+		Repo:   issue.Repo,
+		Issue:  issue,
+		OldRef: oldRefFriendly,
+		NewRef: newRefFriendly,
+	}
+	if _, err = CreateComment(ctx, opts); err != nil {
+		return fmt.Errorf("createComment: %w", err)
+	}
+
+	return committer.Commit()
+}
+
+// AddDeletePRBranchComment adds delete branch comment for pull request issue
+func AddDeletePRBranchComment(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, issueID int64, branchName string) error {
+	issue, err := GetIssueByID(ctx, issueID)
+	if err != nil {
+		return err
+	}
+	opts := &CreateCommentOptions{
+		Type:   CommentTypeDeleteBranch,
+		Doer:   doer,
+		Repo:   repo,
+		Issue:  issue,
+		OldRef: branchName,
+	}
+	_, err = CreateComment(ctx, opts)
+	return err
+}
+
+// UpdateIssueAttachments update attachments by UUIDs for the issue
+func UpdateIssueAttachments(issueID int64, uuids []string) (err error) {
+	ctx, committer, err := db.TxContext(db.DefaultContext)
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+	attachments, err := repo_model.GetAttachmentsByUUIDs(ctx, uuids)
+	if err != nil {
+		return fmt.Errorf("getAttachmentsByUUIDs [uuids: %v]: %w", uuids, err)
+	}
+	for i := 0; i < len(attachments); i++ {
+		attachments[i].IssueID = issueID
+		if err := repo_model.UpdateAttachment(ctx, attachments[i]); err != nil {
+			return fmt.Errorf("update attachment [id: %d]: %w", attachments[i].ID, err)
+		}
+	}
+	return committer.Commit()
+}
+
+// ChangeIssueContent changes issue content, as the given user.
+func ChangeIssueContent(issue *Issue, doer *user_model.User, content string) (err error) {
+	ctx, committer, err := db.TxContext(db.DefaultContext)
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+
+	hasContentHistory, err := HasIssueContentHistory(ctx, issue.ID, 0)
+	if err != nil {
+		return fmt.Errorf("HasIssueContentHistory: %w", err)
+	}
+	if !hasContentHistory {
+		if err = SaveIssueContentHistory(ctx, issue.PosterID, issue.ID, 0,
+			issue.CreatedUnix, issue.Content, true); err != nil {
+			return fmt.Errorf("SaveIssueContentHistory: %w", err)
+		}
+	}
+
+	issue.Content = content
+
+	if err = UpdateIssueCols(ctx, issue, "content"); err != nil {
+		return fmt.Errorf("UpdateIssueCols: %w", err)
+	}
+
+	if err = SaveIssueContentHistory(ctx, doer.ID, issue.ID, 0,
+		timeutil.TimeStampNow(), issue.Content, false); err != nil {
+		return fmt.Errorf("SaveIssueContentHistory: %w", err)
+	}
+
+	if err = issue.AddCrossReferences(ctx, doer, true); err != nil {
+		return fmt.Errorf("addCrossReferences: %w", err)
+	}
+
+	return committer.Commit()
+}
+
+// NewIssueOptions represents the options of a new issue.
+type NewIssueOptions struct {
+	Repo        *repo_model.Repository
+	Issue       *Issue
+	LabelIDs    []int64
+	Attachments []string // In UUID format.
+	IsPull      bool
+}
+
+// NewIssueWithIndex creates issue with given index
+func NewIssueWithIndex(ctx context.Context, doer *user_model.User, opts NewIssueOptions) (err error) {
+	e := db.GetEngine(ctx)
+	opts.Issue.Title = strings.TrimSpace(opts.Issue.Title)
+
+	if opts.Issue.MilestoneID > 0 {
+		milestone, err := GetMilestoneByRepoID(ctx, opts.Issue.RepoID, opts.Issue.MilestoneID)
+		if err != nil && !IsErrMilestoneNotExist(err) {
+			return fmt.Errorf("getMilestoneByID: %w", err)
+		}
+
+		// Assume milestone is invalid and drop silently.
+		opts.Issue.MilestoneID = 0
+		if milestone != nil {
+			opts.Issue.MilestoneID = milestone.ID
+			opts.Issue.Milestone = milestone
+		}
+	}
+
+	if opts.Issue.Index <= 0 {
+		return fmt.Errorf("no issue index provided")
+	}
+	if opts.Issue.ID > 0 {
+		return fmt.Errorf("issue exist")
+	}
+
+	if _, err := e.Insert(opts.Issue); err != nil {
+		return err
+	}
+
+	if opts.Issue.MilestoneID > 0 {
+		if err := UpdateMilestoneCounters(ctx, opts.Issue.MilestoneID); err != nil {
+			return err
+		}
+
+		opts := &CreateCommentOptions{
+			Type:           CommentTypeMilestone,
+			Doer:           doer,
+			Repo:           opts.Repo,
+			Issue:          opts.Issue,
+			OldMilestoneID: 0,
+			MilestoneID:    opts.Issue.MilestoneID,
+		}
+		if _, err = CreateComment(ctx, opts); err != nil {
+			return err
+		}
+	}
+
+	if err := repo_model.UpdateRepoIssueNumbers(ctx, opts.Issue.RepoID, opts.IsPull, false); err != nil {
+		return err
+	}
+
+	if len(opts.LabelIDs) > 0 {
+		// During the session, SQLite3 driver cannot handle retrieve objects after update something.
+		// So we have to get all needed labels first.
+		labels := make([]*Label, 0, len(opts.LabelIDs))
+		if err = e.In("id", opts.LabelIDs).Find(&labels); err != nil {
+			return fmt.Errorf("find all labels [label_ids: %v]: %w", opts.LabelIDs, err)
+		}
+
+		if err = opts.Issue.LoadPoster(ctx); err != nil {
+			return err
+		}
+
+		for _, label := range labels {
+			// Silently drop invalid labels.
+			if label.RepoID != opts.Repo.ID && label.OrgID != opts.Repo.OwnerID {
+				continue
+			}
+
+			if err = newIssueLabel(ctx, opts.Issue, label, opts.Issue.Poster); err != nil {
+				return fmt.Errorf("addLabel [id: %d]: %w", label.ID, err)
+			}
+		}
+	}
+
+	if err = NewIssueUsers(ctx, opts.Repo, opts.Issue); err != nil {
+		return err
+	}
+
+	if len(opts.Attachments) > 0 {
+		attachments, err := repo_model.GetAttachmentsByUUIDs(ctx, opts.Attachments)
+		if err != nil {
+			return fmt.Errorf("getAttachmentsByUUIDs [uuids: %v]: %w", opts.Attachments, err)
+		}
+
+		for i := 0; i < len(attachments); i++ {
+			attachments[i].IssueID = opts.Issue.ID
+			if _, err = e.ID(attachments[i].ID).Update(attachments[i]); err != nil {
+				return fmt.Errorf("update attachment [id: %d]: %w", attachments[i].ID, err)
+			}
+		}
+	}
+	if err = opts.Issue.LoadAttributes(ctx); err != nil {
+		return err
+	}
+
+	return opts.Issue.AddCrossReferences(ctx, doer, false)
+}
+
+// NewIssue creates new issue with labels for repository.
+func NewIssue(repo *repo_model.Repository, issue *Issue, labelIDs []int64, uuids []string) (err error) {
+	ctx, committer, err := db.TxContext(db.DefaultContext)
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+
+	idx, err := db.GetNextResourceIndex(ctx, "issue_index", repo.ID)
+	if err != nil {
+		return fmt.Errorf("generate issue index failed: %w", err)
+	}
+
+	issue.Index = idx
+
+	if err = NewIssueWithIndex(ctx, issue.Poster, NewIssueOptions{
+		Repo:        repo,
+		Issue:       issue,
+		LabelIDs:    labelIDs,
+		Attachments: uuids,
+	}); err != nil {
+		if repo_model.IsErrUserDoesNotHaveAccessToRepo(err) || IsErrNewIssueInsert(err) {
+			return err
+		}
+		return fmt.Errorf("newIssue: %w", err)
+	}
+
+	if err = committer.Commit(); err != nil {
+		return fmt.Errorf("Commit: %w", err)
+	}
+
+	return nil
+}
+
+// UpdateIssueMentions updates issue-user relations for mentioned users.
+func UpdateIssueMentions(ctx context.Context, issueID int64, mentions []*user_model.User) error {
+	if len(mentions) == 0 {
+		return nil
+	}
+	ids := make([]int64, len(mentions))
+	for i, u := range mentions {
+		ids[i] = u.ID
+	}
+	if err := UpdateIssueUsersByMentions(ctx, issueID, ids); err != nil {
+		return fmt.Errorf("UpdateIssueUsersByMentions: %w", err)
+	}
+	return nil
+}
+
+// UpdateIssueByAPI updates all allowed fields of given issue.
+// If the issue status is changed a statusChangeComment is returned
+// similarly if the title is changed the titleChanged bool is set to true
+func UpdateIssueByAPI(issue *Issue, doer *user_model.User) (statusChangeComment *Comment, titleChanged bool, err error) {
+	ctx, committer, err := db.TxContext(db.DefaultContext)
+	if err != nil {
+		return nil, false, err
+	}
+	defer committer.Close()
+
+	if err := issue.LoadRepo(ctx); err != nil {
+		return nil, false, fmt.Errorf("loadRepo: %w", err)
+	}
+
+	// Reload the issue
+	currentIssue, err := GetIssueByID(ctx, issue.ID)
+	if err != nil {
+		return nil, false, err
+	}
+
+	if _, err := db.GetEngine(ctx).ID(issue.ID).Cols(
+		"name", "content", "milestone_id", "priority",
+		"deadline_unix", "updated_unix", "is_locked").
+		Update(issue); err != nil {
+		return nil, false, err
+	}
+
+	titleChanged = currentIssue.Title != issue.Title
+	if titleChanged {
+		opts := &CreateCommentOptions{
+			Type:     CommentTypeChangeTitle,
+			Doer:     doer,
+			Repo:     issue.Repo,
+			Issue:    issue,
+			OldTitle: currentIssue.Title,
+			NewTitle: issue.Title,
+		}
+		_, err := CreateComment(ctx, opts)
+		if err != nil {
+			return nil, false, fmt.Errorf("createComment: %w", err)
+		}
+	}
+
+	if currentIssue.IsClosed != issue.IsClosed {
+		statusChangeComment, err = doChangeIssueStatus(ctx, issue, doer, false)
+		if err != nil {
+			return nil, false, err
+		}
+	}
+
+	if err := issue.AddCrossReferences(ctx, doer, true); err != nil {
+		return nil, false, err
+	}
+	return statusChangeComment, titleChanged, committer.Commit()
+}
+
+// UpdateIssueDeadline updates an issue deadline and adds comments. Setting a deadline to 0 means deleting it.
+func UpdateIssueDeadline(issue *Issue, deadlineUnix timeutil.TimeStamp, doer *user_model.User) (err error) {
+	// if the deadline hasn't changed do nothing
+	if issue.DeadlineUnix == deadlineUnix {
+		return nil
+	}
+	ctx, committer, err := db.TxContext(db.DefaultContext)
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+
+	// Update the deadline
+	if err = UpdateIssueCols(ctx, &Issue{ID: issue.ID, DeadlineUnix: deadlineUnix}, "deadline_unix"); err != nil {
+		return err
+	}
+
+	// Make the comment
+	if _, err = createDeadlineComment(ctx, doer, issue, deadlineUnix); err != nil {
+		return fmt.Errorf("createRemovedDueDateComment: %w", err)
+	}
+
+	return committer.Commit()
+}
+
+// DeleteInIssue delete records in beans with external key issue_id = ?
+func DeleteInIssue(ctx context.Context, issueID int64, beans ...interface{}) error {
+	e := db.GetEngine(ctx)
+	for _, bean := range beans {
+		if _, err := e.In("issue_id", issueID).Delete(bean); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// FindAndUpdateIssueMentions finds users mentioned in the given content string, and saves them in the database.
+func FindAndUpdateIssueMentions(ctx context.Context, issue *Issue, doer *user_model.User, content string) (mentions []*user_model.User, err error) {
+	rawMentions := references.FindAllMentionsMarkdown(content)
+	mentions, err = ResolveIssueMentionsByVisibility(ctx, issue, doer, rawMentions)
+	if err != nil {
+		return nil, fmt.Errorf("UpdateIssueMentions [%d]: %w", issue.ID, err)
+	}
+	if err = UpdateIssueMentions(ctx, issue.ID, mentions); err != nil {
+		return nil, fmt.Errorf("UpdateIssueMentions [%d]: %w", issue.ID, err)
+	}
+	return mentions, err
+}
+
+// ResolveIssueMentionsByVisibility returns the users mentioned in an issue, removing those that
+// don't have access to reading it. Teams are expanded into their users, but organizations are ignored.
+func ResolveIssueMentionsByVisibility(ctx context.Context, issue *Issue, doer *user_model.User, mentions []string) (users []*user_model.User, err error) {
+	if len(mentions) == 0 {
+		return
+	}
+	if err = issue.LoadRepo(ctx); err != nil {
+		return
+	}
+
+	resolved := make(map[string]bool, 10)
+	var mentionTeams []string
+
+	if err := issue.Repo.LoadOwner(ctx); err != nil {
+		return nil, err
+	}
+
+	repoOwnerIsOrg := issue.Repo.Owner.IsOrganization()
+	if repoOwnerIsOrg {
+		mentionTeams = make([]string, 0, 5)
+	}
+
+	resolved[doer.LowerName] = true
+	for _, name := range mentions {
+		name := strings.ToLower(name)
+		if _, ok := resolved[name]; ok {
+			continue
+		}
+		if repoOwnerIsOrg && strings.Contains(name, "/") {
+			names := strings.Split(name, "/")
+			if len(names) < 2 || names[0] != issue.Repo.Owner.LowerName {
+				continue
+			}
+			mentionTeams = append(mentionTeams, names[1])
+			resolved[name] = true
+		} else {
+			resolved[name] = false
+		}
+	}
+
+	if issue.Repo.Owner.IsOrganization() && len(mentionTeams) > 0 {
+		teams := make([]*organization.Team, 0, len(mentionTeams))
+		if err := db.GetEngine(ctx).
+			Join("INNER", "team_repo", "team_repo.team_id = team.id").
+			Where("team_repo.repo_id=?", issue.Repo.ID).
+			In("team.lower_name", mentionTeams).
+			Find(&teams); err != nil {
+			return nil, fmt.Errorf("find mentioned teams: %w", err)
+		}
+		if len(teams) != 0 {
+			checked := make([]int64, 0, len(teams))
+			unittype := unit.TypeIssues
+			if issue.IsPull {
+				unittype = unit.TypePullRequests
+			}
+			for _, team := range teams {
+				if team.AccessMode >= perm.AccessModeAdmin {
+					checked = append(checked, team.ID)
+					resolved[issue.Repo.Owner.LowerName+"/"+team.LowerName] = true
+					continue
+				}
+				has, err := db.GetEngine(ctx).Get(&organization.TeamUnit{OrgID: issue.Repo.Owner.ID, TeamID: team.ID, Type: unittype})
+				if err != nil {
+					return nil, fmt.Errorf("get team units (%d): %w", team.ID, err)
+				}
+				if has {
+					checked = append(checked, team.ID)
+					resolved[issue.Repo.Owner.LowerName+"/"+team.LowerName] = true
+				}
+			}
+			if len(checked) != 0 {
+				teamusers := make([]*user_model.User, 0, 20)
+				if err := db.GetEngine(ctx).
+					Join("INNER", "team_user", "team_user.uid = `user`.id").
+					In("`team_user`.team_id", checked).
+					And("`user`.is_active = ?", true).
+					And("`user`.prohibit_login = ?", false).
+					Find(&teamusers); err != nil {
+					return nil, fmt.Errorf("get teams users: %w", err)
+				}
+				if len(teamusers) > 0 {
+					users = make([]*user_model.User, 0, len(teamusers))
+					for _, user := range teamusers {
+						if already, ok := resolved[user.LowerName]; !ok || !already {
+							users = append(users, user)
+							resolved[user.LowerName] = true
+						}
+					}
+				}
+			}
+		}
+	}
+
+	// Remove names already in the list to avoid querying the database if pending names remain
+	mentionUsers := make([]string, 0, len(resolved))
+	for name, already := range resolved {
+		if !already {
+			mentionUsers = append(mentionUsers, name)
+		}
+	}
+	if len(mentionUsers) == 0 {
+		return
+	}
+
+	if users == nil {
+		users = make([]*user_model.User, 0, len(mentionUsers))
+	}
+
+	unchecked := make([]*user_model.User, 0, len(mentionUsers))
+	if err := db.GetEngine(ctx).
+		Where("`user`.is_active = ?", true).
+		And("`user`.prohibit_login = ?", false).
+		In("`user`.lower_name", mentionUsers).
+		Find(&unchecked); err != nil {
+		return nil, fmt.Errorf("find mentioned users: %w", err)
+	}
+	for _, user := range unchecked {
+		if already := resolved[user.LowerName]; already || user.IsOrganization() {
+			continue
+		}
+		// Normal users must have read access to the referencing issue
+		perm, err := access_model.GetUserRepoPermission(ctx, issue.Repo, user)
+		if err != nil {
+			return nil, fmt.Errorf("GetUserRepoPermission [%d]: %w", user.ID, err)
+		}
+		if !perm.CanReadIssuesOrPulls(issue.IsPull) {
+			continue
+		}
+		users = append(users, user)
+	}
+
+	return users, err
+}
+
+// UpdateIssuesMigrationsByType updates all migrated repositories' issues from gitServiceType to replace originalAuthorID to posterID
+func UpdateIssuesMigrationsByType(gitServiceType api.GitServiceType, originalAuthorID string, posterID int64) error {
+	_, err := db.GetEngine(db.DefaultContext).Table("issue").
+		Where("repo_id IN (SELECT id FROM repository WHERE original_service_type = ?)", gitServiceType).
+		And("original_author_id = ?", originalAuthorID).
+		Update(map[string]interface{}{
+			"poster_id":          posterID,
+			"original_author":    "",
+			"original_author_id": 0,
+		})
+	return err
+}
+
+// UpdateReactionsMigrationsByType updates all migrated repositories' reactions from gitServiceType to replace originalAuthorID to posterID
+func UpdateReactionsMigrationsByType(gitServiceType api.GitServiceType, originalAuthorID string, userID int64) error {
+	_, err := db.GetEngine(db.DefaultContext).Table("reaction").
+		Where("original_author_id = ?", originalAuthorID).
+		And(migratedIssueCond(gitServiceType)).
+		Update(map[string]interface{}{
+			"user_id":            userID,
+			"original_author":    "",
+			"original_author_id": 0,
+		})
+	return err
+}
+
+// DeleteIssuesByRepoID deletes issues by repositories id
+func DeleteIssuesByRepoID(ctx context.Context, repoID int64) (attachmentPaths []string, err error) {
+	deleteCond := builder.Select("id").From("issue").Where(builder.Eq{"issue.repo_id": repoID})
+
+	sess := db.GetEngine(ctx)
+	// Delete content histories
+	if _, err = sess.In("issue_id", deleteCond).
+		Delete(&ContentHistory{}); err != nil {
+		return
+	}
+
+	// Delete comments and attachments
+	if _, err = sess.In("issue_id", deleteCond).
+		Delete(&Comment{}); err != nil {
+		return
+	}
+
+	// Dependencies for issues in this repository
+	if _, err = sess.In("issue_id", deleteCond).
+		Delete(&IssueDependency{}); err != nil {
+		return
+	}
+
+	// Delete dependencies for issues in other repositories
+	if _, err = sess.In("dependency_id", deleteCond).
+		Delete(&IssueDependency{}); err != nil {
+		return
+	}
+
+	if _, err = sess.In("issue_id", deleteCond).
+		Delete(&IssueUser{}); err != nil {
+		return
+	}
+
+	if _, err = sess.In("issue_id", deleteCond).
+		Delete(&Reaction{}); err != nil {
+		return
+	}
+
+	if _, err = sess.In("issue_id", deleteCond).
+		Delete(&IssueWatch{}); err != nil {
+		return
+	}
+
+	if _, err = sess.In("issue_id", deleteCond).
+		Delete(&Stopwatch{}); err != nil {
+		return
+	}
+
+	if _, err = sess.In("issue_id", deleteCond).
+		Delete(&TrackedTime{}); err != nil {
+		return
+	}
+
+	if _, err = sess.In("issue_id", deleteCond).
+		Delete(&project_model.ProjectIssue{}); err != nil {
+		return
+	}
+
+	if _, err = sess.In("dependent_issue_id", deleteCond).
+		Delete(&Comment{}); err != nil {
+		return
+	}
+
+	var attachments []*repo_model.Attachment
+	if err = sess.In("issue_id", deleteCond).
+		Find(&attachments); err != nil {
+		return
+	}
+
+	for j := range attachments {
+		attachmentPaths = append(attachmentPaths, attachments[j].RelativePath())
+	}
+
+	if _, err = sess.In("issue_id", deleteCond).
+		Delete(&repo_model.Attachment{}); err != nil {
+		return
+	}
+
+	if _, err = db.DeleteByBean(ctx, &Issue{RepoID: repoID}); err != nil {
+		return
+	}
+
+	return attachmentPaths, err
+}
+
+// DeleteOrphanedIssues delete issues without a repo
+func DeleteOrphanedIssues(ctx context.Context) error {
+	var attachmentPaths []string
+	err := db.WithTx(ctx, func(ctx context.Context) error {
+		var ids []int64
+
+		if err := db.GetEngine(ctx).Table("issue").Distinct("issue.repo_id").
+			Join("LEFT", "repository", "issue.repo_id=repository.id").
+			Where(builder.IsNull{"repository.id"}).GroupBy("issue.repo_id").
+			Find(&ids); err != nil {
+			return err
+		}
+
+		for i := range ids {
+			paths, err := DeleteIssuesByRepoID(ctx, ids[i])
+			if err != nil {
+				return err
+			}
+			attachmentPaths = append(attachmentPaths, paths...)
+		}
+
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	// Remove issue attachment files.
+	for i := range attachmentPaths {
+		system_model.RemoveAllWithNotice(db.DefaultContext, "Delete issue attachment", attachmentPaths[i])
+	}
+	return nil
+}
diff --git a/models/issues/pull_list.go b/models/issues/pull_list.go
index f2adac0701..c443928344 100644
--- a/models/issues/pull_list.go
+++ b/models/issues/pull_list.go
@@ -141,7 +141,7 @@ func PullRequests(baseRepoID int64, opts *PullRequestsOptions) ([]*PullRequest,
 	}
 
 	findSession, err := listPullRequestStatement(baseRepoID, opts)
-	sortIssuesSession(findSession, opts.SortType, 0)
+	applySorts(findSession, opts.SortType, 0)
 	if err != nil {
 		log.Error("listPullRequestStatement: %v", err)
 		return nil, maxResults, err
diff --git a/routers/web/repo/issue.go b/routers/web/repo/issue.go
index 66a4986139..cb0aaa3db5 100644
--- a/routers/web/repo/issue.go
+++ b/routers/web/repo/issue.go
@@ -206,10 +206,10 @@ func issues(ctx *context.Context, milestoneID, projectID int64, isPullOption uti
 	if forceEmpty {
 		issueStats = &issues_model.IssueStats{}
 	} else {
-		issueStats, err = issues_model.GetIssueStats(&issues_model.IssueStatsOptions{
+		issueStats, err = issues_model.GetIssueStats(&issues_model.IssuesOptions{
 			RepoID:            repo.ID,
-			Labels:            selectLabels,
-			MilestoneID:       milestoneID,
+			LabelIDs:          labelIDs,
+			MilestoneIDs:      []int64{milestoneID},
 			ProjectID:         projectID,
 			AssigneeID:        assigneeID,
 			MentionedID:       mentionedID,