[API] Allow removing issues (#18879)

Add new feature to delete issues and pulls via API

Co-authored-by: fnetx <git@fralix.ovh>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Gusted <williamzijl7@hotmail.com>
Co-authored-by: 6543 <6543@obermui.de>

3 files changed, 167 insertions, 3 deletions

diff --git a/models/issue.go b/models/issue.go
index 91d4df32d1..625374faaf 100644
--- a/models/issue.go
+++ b/models/issue.go
@@ -13,6 +13,7 @@ import (
 	"strconv"
 	"strings"
 
+	admin_model "code.gitea.io/gitea/models/admin"
 	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/issues"
 	"code.gitea.io/gitea/models/perm"
@@ -24,6 +25,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/references"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/storage"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
@@ -1990,6 +1992,118 @@ func UpdateIssueDeadline(issue *Issue, deadlineUnix timeutil.TimeStamp, doer *us
 	return committer.Commit()
 }
 
+// DeleteIssue deletes the issue
+func DeleteIssue(issue *Issue) error {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+
+	if err := deleteIssue(ctx, issue); err != nil {
+		return err
+	}
+
+	return committer.Commit()
+}
+
+func deleteInIssue(e db.Engine, issueID int64, beans ...interface{}) error {
+	for _, bean := range beans {
+		if _, err := e.In("issue_id", issueID).Delete(bean); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func deleteIssue(ctx context.Context, issue *Issue) error {
+	e := db.GetEngine(ctx)
+	if _, err := e.ID(issue.ID).NoAutoCondition().Delete(issue); err != nil {
+		return err
+	}
+
+	if issue.IsPull {
+		if _, err := e.ID(issue.RepoID).Decr("num_pulls").Update(new(repo_model.Repository)); err != nil {
+			return err
+		}
+		if issue.IsClosed {
+			if _, err := e.ID(issue.RepoID).Decr("num_closed_pulls").Update(new(repo_model.Repository)); err != nil {
+				return err
+			}
+		}
+	} else {
+		if _, err := e.ID(issue.RepoID).Decr("num_issues").Update(new(repo_model.Repository)); err != nil {
+			return err
+		}
+		if issue.IsClosed {
+			if _, err := e.ID(issue.RepoID).Decr("num_closed_issues").Update(new(repo_model.Repository)); err != nil {
+				return err
+			}
+		}
+	}
+
+	// delete actions assigned to this issue
+	var comments []int64
+	if err := e.Table(new(Comment)).In("issue_id", issue.ID).Cols("id").Find(&comments); err != nil {
+		return err
+	}
+	for i := range comments {
+		if _, err := e.Where("comment_id = ?", comments[i]).Delete(&Action{}); err != nil {
+			return err
+		}
+	}
+	if _, err := e.Table("action").Where("repo_id = ?", issue.RepoID).In("op_type", ActionCreateIssue, ActionCreatePullRequest).
+		Where("content LIKE ?", strconv.FormatInt(issue.ID, 10)+"|%").Delete(&Action{}); err != nil {
+		return err
+	}
+
+	// find attachments related to this issue and remove them
+	var attachments []*repo_model.Attachment
+	if err := e.In("issue_id", issue.ID).Find(&attachments); err != nil {
+		return err
+	}
+
+	for i := range attachments {
+		admin_model.RemoveStorageWithNotice(ctx, storage.Attachments, "Delete issue attachment", attachments[i].RelativePath())
+	}
+
+	// delete all database data still assigned to this issue
+	if err := deleteInIssue(e, issue.ID,
+		&issues.ContentHistory{},
+		&Comment{},
+		&IssueLabel{},
+		&IssueDependency{},
+		&IssueAssignees{},
+		&IssueUser{},
+		&Reaction{},
+		&IssueWatch{},
+		&Stopwatch{},
+		&TrackedTime{},
+		&ProjectIssue{},
+		&repo_model.Attachment{},
+		&PullRequest{},
+	); err != nil {
+		return err
+	}
+
+	// References to this issue in other issues
+	if _, err := e.In("ref_issue_id", issue.ID).Delete(&Comment{}); err != nil {
+		return err
+	}
+
+	// Delete dependencies for issues in other repositories
+	if _, err := e.In("dependency_id", issue.ID).Delete(&IssueDependency{}); err != nil {
+		return err
+	}
+
+	// delete from dependent issues
+	if _, err := e.In("dependent_issue_id", issue.ID).Delete(&Comment{}); 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"`
diff --git a/models/issue_comment.go b/models/issue_comment.go
index 31bd041ca7..0af45e80e8 100644
--- a/models/issue_comment.go
+++ b/models/issue_comment.go
@@ -1152,9 +1152,7 @@ func DeleteComment(comment *Comment) error {
 }
 
 func deleteComment(e db.Engine, comment *Comment) error {
-	if _, err := e.Delete(&Comment{
-		ID: comment.ID,
-	}); err != nil {
+	if _, err := e.ID(comment.ID).NoAutoCondition().Delete(comment); err != nil {
 		return err
 	}
 
diff --git a/models/issue_test.go b/models/issue_test.go
index 9344d385a7..7cc0aa61b0 100644
--- a/models/issue_test.go
+++ b/models/issue_test.go
@@ -397,6 +397,58 @@ func TestIssue_InsertIssue(t *testing.T) {
 	assert.NoError(t, err)
 }
 
+func TestIssue_DeleteIssue(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	issueIDs, err := GetIssueIDsByRepoID(1)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 5, len(issueIDs))
+
+	issue := &Issue{
+		RepoID: 1,
+		ID:     issueIDs[2],
+	}
+
+	err = DeleteIssue(issue)
+	assert.NoError(t, err)
+	issueIDs, err = GetIssueIDsByRepoID(1)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 4, len(issueIDs))
+
+	// check attachment removal
+	attachments, err := repo_model.GetAttachmentsByIssueID(4)
+	assert.NoError(t, err)
+	issue, err = GetIssueByID(4)
+	assert.NoError(t, err)
+	err = DeleteIssue(issue)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 2, len(attachments))
+	for i := range attachments {
+		attachment, err := repo_model.GetAttachmentByUUID(attachments[i].UUID)
+		assert.Error(t, err)
+		assert.True(t, repo_model.IsErrAttachmentNotExist(err))
+		assert.Nil(t, attachment)
+	}
+
+	// check issue dependencies
+	user, err := user_model.GetUserByID(1)
+	assert.NoError(t, err)
+	issue1, err := GetIssueByID(1)
+	assert.NoError(t, err)
+	issue2, err := GetIssueByID(2)
+	assert.NoError(t, err)
+	err = CreateIssueDependency(user, issue1, issue2)
+	assert.NoError(t, err)
+	left, err := IssueNoDependenciesLeft(issue1)
+	assert.NoError(t, err)
+	assert.False(t, left)
+	err = DeleteIssue(&Issue{ID: 2})
+	assert.NoError(t, err)
+	left, err = IssueNoDependenciesLeft(issue1)
+	assert.NoError(t, err)
+	assert.True(t, left)
+}
+
 func TestIssue_ResolveMentions(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())