feat: activity log producers

internal/domain/audit/auditChanges.go

@@ -0,0 +1,30 @@
+package audit
+
+import (
+	"RenewCMS/internal/domain/article"
+	"strconv"
+	"unicode/utf8"
+)
+
+func TextChange(field string, before string, after string) Change {
+	return Change{Field: field, Kind: ChangeText, Before: &before, After: &after}
+}
+
+func BodyChange(before string, after string) Change {
+	delta := utf8.RuneCountInString(after) - utf8.RuneCountInString(before)
+	return Change{Field: FieldBody, Kind: ChangeBody, Delta: &delta}
+}
+
+func ArticleChanges(before article.Article, after article.Article) []Change {
+	changes := []Change{}
+	if before.Title != after.Title {
+		changes = append(changes, TextChange(FieldTitle, before.Title, after.Title))
+	}
+	if before.IsOnline != after.IsOnline {
+		changes = append(changes, TextChange(FieldOnline, strconv.FormatBool(before.IsOnline), strconv.FormatBool(after.IsOnline)))
+	}
+	if before.Body != after.Body {
+		changes = append(changes, BodyChange(before.Body, after.Body))
+	}
+	return changes
+}

internal/domain/audit/auditDomain.go

@@ -66,11 +66,36 @@ const (
 	ActionAPIKeyRevoke         = "api_key.revoke"
 	ActionRetentionChanged     = "system.activity_retention_changed"
 	ActionCleanup              = "system.activity_cleanup"
+	ActionArticleCreate        = "article.create"
+	ActionArticleEdit          = "article.edit"
+	ActionArticlePublish       = "article.publish"
+	ActionArticleUnpublish     = "article.unpublish"
+	ActionArticleDelete        = "article.delete"
+	ActionMediaUpload          = "media.upload"
+	ActionMediaRename          = "media.rename"
+	ActionMediaDelete          = "media.delete"
+	ActionMediaMerge           = "media.merge"
+	ActionMediaPurge           = "media.purge"
+	ActionUserRegister         = "user.register"
+	ActionUserVerify           = "user.verify"
+	ActionUserUpdateProfile    = "user.update_profile"
+	ActionInviteCreate         = "invite.create"
+	ActionInviteCancel         = "invite.cancel"
+	ActionInviteRenew          = "invite.renew"
+	ActionInviteAccept         = "invite.accept"
+	ActionMediaPurgeScheduled  = "system.media_purge"
+	ActionUpdateChecked        = "system.update_checked"
+	ActionUpdateDownloaded     = "system.update_downloaded"
+	ActionRestartRequested     = "system.restart_requested"
 )
 
 const (
-	TargetAPIKey = "api_key"
-	TargetUser   = "user"
+	TargetAPIKey  = "api_key"
+	TargetUser    = "user"
+	TargetArticle = "article"
+	TargetImage   = "image"
+	TargetInvite  = "invite"
+	TargetRelease = "release"
 )
 
 const (
@@ -80,6 +105,17 @@ const (
 	ParamRemoved         = "removed"
 	ParamFrom            = "from"
 	ParamTo              = "to"
+	ParamMerged          = "merged"
+	ParamArticlesUpdated = "articles_updated"
+	ParamFailedGroups    = "failed_groups"
+	ParamUpdateAvailable = "update_available"
+	ParamKind            = "kind"
+	ParamTag             = "tag"
+	FieldTitle           = "title"
+	FieldOnline          = "online"
+	FieldBody            = "body"
+	FieldFilename        = "filename"
+	FieldDisplayName     = "display_name"
 	maxNameLength        = 255
 	maxActionLength      = 64
 	maxFailureReasonSize = 255

internal/domain/audit/auditTargets.go

@@ -0,0 +1,11 @@
+package audit
+
+import "strconv"
+
+func NewTarget(targetType string, id uint32, name string) Target {
+	return Target{Type: targetType, ID: strconv.FormatUint(uint64(id), 10), Name: name}
+}
+
+func ReleaseTarget(tag string) Target {
+	return Target{Type: TargetRelease, ID: tag, Name: tag}
+}

internal/domain/user/userDomain.go

@@ -15,6 +15,7 @@ var ErrInvalidPasswordResetCode = errors.New("invalid password reset code")
 var ErrPasswordResetCodeExpired = errors.New("password reset code expired")
 var ErrInvalidDisplayName = errors.New("invalid display name")
 var ErrUsernameTaken = errors.New("username taken")
+var ErrVerificationEmailNotSent = errors.New("verification email not sent")
 
 type Role string
 

internal/infrastructure/useCases/AcceptInvite.go

@@ -1,9 +1,11 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/hash"
 	"RenewCMS/internal/domain/invite"
 	"RenewCMS/internal/domain/user"
+	"context"
 	"errors"
 	"strings"
 	"time"
@@ -13,6 +15,7 @@ type AcceptInviteUseCase struct {
 	userRepository   user.Repository
 	inviteRepository invite.Repository
 	hasher           hash.Hasher
+	recorder         audit.Recorder
 }
 
 type AcceptInviteCommand struct {
@@ -21,18 +24,37 @@ type AcceptInviteCommand struct {
 	Password string
 }
 
-func NewAcceptInviteUseCase(userRepository user.Repository, inviteRepository invite.Repository, hasher hash.Hasher) *AcceptInviteUseCase {
-	return &AcceptInviteUseCase{userRepository, inviteRepository, hasher}
+func NewAcceptInviteUseCase(userRepository user.Repository, inviteRepository invite.Repository, hasher hash.Hasher, recorder audit.Recorder) *AcceptInviteUseCase {
+	return &AcceptInviteUseCase{userRepository, inviteRepository, hasher, recorder}
 }
 
-func (a *AcceptInviteUseCase) AcceptInvite(command AcceptInviteCommand) (user.User, error) {
+func (a *AcceptInviteUseCase) AcceptInvite(ctx context.Context, command AcceptInviteCommand) (user.User, error) {
+	event := audit.NewEvent(audit.ActionInviteAccept, audit.CategoryUsers)
 	now := time.Now()
 
 	pending, err := findUsableInvite(a.inviteRepository, a.hasher, command.Code, now)
 	if err != nil {
+		a.recordRefusal(ctx, event, command, err)
 		return user.User{}, err
 	}
+	event.Target = inviteTarget(pending)
 
+	created, err := a.accept(command, pending, now)
+	if err != nil {
+		a.recordRefusal(ctx, event, command, err)
+		return user.User{}, err
+	}
+	event.Actor = audit.UserActor(created)
+	a.recorder.Record(ctx, event)
+	return created, nil
+}
+
+func (a *AcceptInviteUseCase) recordRefusal(ctx context.Context, event audit.Event, command AcceptInviteCommand, cause error) {
+	event.Actor = audit.AnonymousActor(command.Username)
+	recordFailure(ctx, a.recorder, event, cause)
+}
+
+func (a *AcceptInviteUseCase) accept(command AcceptInviteCommand, pending invite.Invite, now time.Time) (user.User, error) {
 	if a.emailHasAccount(pending.Email) {
 		if _, err := findUsableInvite(a.inviteRepository, a.hasher, command.Code, now); err != nil {
 			return user.User{}, err

internal/infrastructure/useCases/CancelInvite.go

@@ -1,18 +1,36 @@
 package useCases
 
-import "RenewCMS/internal/domain/invite"
+import (
+	"RenewCMS/internal/domain/audit"
+	"RenewCMS/internal/domain/invite"
+	"context"
+)
 
 type CancelInviteUseCase struct {
 	inviteRepository invite.Repository
+	recorder         audit.Recorder
 }
 
-func NewCancelInviteUseCase(inviteRepository invite.Repository) *CancelInviteUseCase {
-	return &CancelInviteUseCase{inviteRepository}
+func NewCancelInviteUseCase(inviteRepository invite.Repository, recorder audit.Recorder) *CancelInviteUseCase {
+	return &CancelInviteUseCase{inviteRepository, recorder}
 }
 
-func (c *CancelInviteUseCase) CancelInvite(id uint32) error {
-	if _, err := findManageableInvite(c.inviteRepository, id); err != nil {
+func (c *CancelInviteUseCase) CancelInvite(ctx context.Context, id uint32) error {
+	event := audit.NewEvent(audit.ActionInviteCancel, audit.CategoryUsers)
+	pending, err := findManageableInvite(c.inviteRepository, id)
+	if err != nil {
+		recordFailure(ctx, c.recorder, event, err)
 		return err
 	}
-	return c.inviteRepository.Delete(id)
+	event.Target = inviteTarget(pending)
+	if err := c.inviteRepository.Delete(id); err != nil {
+		recordFailure(ctx, c.recorder, event, err)
+		return err
+	}
+	c.recorder.Record(ctx, event)
+	return nil
+}
+
+func inviteTarget(i invite.Invite) audit.Target {
+	return audit.NewTarget(audit.TargetInvite, i.ID, i.Email)
 }

internal/infrastructure/useCases/CheckForUpdate.go

@@ -1,7 +1,9 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/update"
+	"context"
 	"time"
 )
 
@@ -10,13 +12,27 @@ type CheckForUpdateUseCase struct {
 	store          update.StatusStore
 	currentVersion string
 	now            func() time.Time
+	recorder       audit.Recorder
 }
 
-func NewCheckForUpdateUseCase(feed update.ReleaseFeed, store update.StatusStore, currentVersion string, now func() time.Time) *CheckForUpdateUseCase {
-	return &CheckForUpdateUseCase{feed: feed, store: store, currentVersion: currentVersion, now: now}
+func NewCheckForUpdateUseCase(feed update.ReleaseFeed, store update.StatusStore, currentVersion string, now func() time.Time, recorder audit.Recorder) *CheckForUpdateUseCase {
+	return &CheckForUpdateUseCase{feed: feed, store: store, currentVersion: currentVersion, now: now, recorder: recorder}
 }
 
-func (c *CheckForUpdateUseCase) Check() (update.UpdateStatus, error) {
+func (c *CheckForUpdateUseCase) Check(ctx context.Context) (update.UpdateStatus, error) {
+	event := audit.NewEvent(audit.ActionUpdateChecked, audit.CategorySystem)
+	status, err := c.check()
+	if err != nil {
+		recordFailure(ctx, c.recorder, event, err)
+		return update.UpdateStatus{}, err
+	}
+	event.Target = audit.ReleaseTarget(status.Latest)
+	event.Params = map[string]any{audit.ParamUpdateAvailable: status.Available}
+	c.recorder.Record(ctx, event)
+	return status, nil
+}
+
+func (c *CheckForUpdateUseCase) check() (update.UpdateStatus, error) {
 	release, err := c.feed.Latest()
 	if err != nil {
 		return update.UpdateStatus{}, err

internal/infrastructure/useCases/CreateArticle.go

@@ -2,11 +2,14 @@ package useCases
 
 import (
 	"RenewCMS/internal/domain/article"
+	"RenewCMS/internal/domain/audit"
+	"context"
 )
 
 type CreateArticleUseCase struct {
 	articleRepository article.Repository
 	bodyRenderer      article.BodyRenderer
+	recorder          audit.Recorder
 }
 
 type CreateArticleCommand struct {
@@ -15,12 +18,14 @@ type CreateArticleCommand struct {
 	Format article.BodyFormat
 }
 
-func NewCreateArticleUseCase(articleRepository article.Repository, bodyRenderer article.BodyRenderer) *CreateArticleUseCase {
-	return &CreateArticleUseCase{articleRepository, bodyRenderer}
+func NewCreateArticleUseCase(articleRepository article.Repository, bodyRenderer article.BodyRenderer, recorder audit.Recorder) *CreateArticleUseCase {
+	return &CreateArticleUseCase{articleRepository, bodyRenderer, recorder}
 }
 
-func (g *CreateArticleUseCase) CreateArticle(createArticle CreateArticleCommand) (article.Article, error) {
+func (g *CreateArticleUseCase) CreateArticle(ctx context.Context, createArticle CreateArticleCommand) (article.Article, error) {
+	event := audit.NewEvent(audit.ActionArticleCreate, audit.CategoryArticles)
 	if err := article.ValidateTitle(createArticle.Title); err != nil {
+		recordFailure(ctx, g.recorder, event, err)
 		return article.Article{}, err
 	}
 
@@ -30,7 +35,15 @@ func (g *CreateArticleUseCase) CreateArticle(createArticle CreateArticleCommand)
 		IsOnline: false,
 	})
 	if err != nil {
+		recordFailure(ctx, g.recorder, event, err)
 		return article.Article{}, err
 	}
+
+	event.Target = articleTarget(created)
+	g.recorder.Record(ctx, event)
 	return renderArticle(g.bodyRenderer, created, createArticle.Format)
 }
+
+func articleTarget(a article.Article) audit.Target {
+	return audit.NewTarget(audit.TargetArticle, a.ID, a.Title)
+}

internal/infrastructure/useCases/CreateImage.go

@@ -1,13 +1,16 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/image"
 	"bytes"
+	"context"
 	"crypto/sha256"
 	"encoding/hex"
 	"encoding/xml"
 	stdimage "image"
 	"io"
+	"strings"
 
 	_ "golang.org/x/image/webp"
 	_ "image/jpeg"
@@ -25,13 +28,38 @@ var rasterFormats = map[string]string{
 type CreateImageUseCase struct {
 	imageRepository image.Repository
 	storage         image.Storage
+	recorder        audit.Recorder
 }
 
-func NewCreateImageUseCase(imageRepository image.Repository, storage image.Storage) *CreateImageUseCase {
-	return &CreateImageUseCase{imageRepository, storage}
+func NewCreateImageUseCase(imageRepository image.Repository, storage image.Storage, recorder audit.Recorder) *CreateImageUseCase {
+	return &CreateImageUseCase{imageRepository, storage, recorder}
 }
 
-func (g *CreateImageUseCase) CreateImage(input image.ImageInput) (image.Image, error) {
+func (g *CreateImageUseCase) CreateImage(ctx context.Context, input image.ImageInput) (image.Image, error) {
+	created, err := g.create(input)
+	event := audit.NewEvent(audit.ActionMediaUpload, audit.CategoryMedia)
+	if err != nil {
+		event.Target = attemptedUploadTarget(input)
+		recordFailure(ctx, g.recorder, event, err)
+		return image.Image{}, err
+	}
+	event.Target = imageTarget(created)
+	g.recorder.Record(ctx, event)
+	return created, nil
+}
+
+func imageTarget(img image.Image) audit.Target {
+	return audit.NewTarget(audit.TargetImage, img.ID, img.Filename)
+}
+
+func attemptedUploadTarget(input image.ImageInput) audit.Target {
+	if strings.TrimSpace(input.Filename) == "" {
+		return audit.Target{}
+	}
+	return audit.Target{Type: audit.TargetImage, Name: image.NormalizeUploadFilename(input.Filename, input.ContentType)}
+}
+
+func (g *CreateImageUseCase) create(input image.ImageInput) (image.Image, error) {
 	if !image.IsAllowedContentType(input.ContentType) {
 		return image.Image{}, image.ErrImageTypeNotAllowed
 	}

internal/infrastructure/useCases/CreateInvite.go

@@ -1,10 +1,12 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/hash"
 	"RenewCMS/internal/domain/invite"
 	"RenewCMS/internal/domain/mail"
 	"RenewCMS/internal/domain/user"
+	"context"
 	"errors"
 	"strings"
 	"time"
@@ -15,6 +17,7 @@ type CreateInviteUseCase struct {
 	inviteRepository invite.Repository
 	hasher           hash.Hasher
 	mailer           inviteMailer
+	recorder         audit.Recorder
 }
 
 type CreateInviteCommand struct {
@@ -22,11 +25,23 @@ type CreateInviteCommand struct {
 	InvitedBy uint32
 }
 
-func NewCreateInviteUseCase(userRepository user.Repository, inviteRepository invite.Repository, hasher hash.Hasher, mailRepository mail.Repository, publicURL string) *CreateInviteUseCase {
-	return &CreateInviteUseCase{userRepository, inviteRepository, hasher, inviteMailer{mailRepository, publicURL}}
+func NewCreateInviteUseCase(userRepository user.Repository, inviteRepository invite.Repository, hasher hash.Hasher, mailRepository mail.Repository, publicURL string, recorder audit.Recorder) *CreateInviteUseCase {
+	return &CreateInviteUseCase{userRepository, inviteRepository, hasher, inviteMailer{mailRepository, publicURL}, recorder}
 }
 
-func (g *CreateInviteUseCase) CreateInvite(command CreateInviteCommand) (invite.Invite, error) {
+func (g *CreateInviteUseCase) CreateInvite(ctx context.Context, command CreateInviteCommand) (invite.Invite, error) {
+	event := audit.NewEvent(audit.ActionInviteCreate, audit.CategoryUsers)
+	created, err := g.create(command)
+	if err != nil {
+		recordFailure(ctx, g.recorder, event, err)
+		return invite.Invite{}, err
+	}
+	event.Target = inviteTarget(created)
+	g.recorder.Record(ctx, event)
+	return created, nil
+}
+
+func (g *CreateInviteUseCase) create(command CreateInviteCommand) (invite.Invite, error) {
 	email := strings.ToLower(command.Email)
 	now := time.Now()
 

internal/infrastructure/useCases/CreateUser.go

@@ -1,9 +1,11 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/hash"
 	"RenewCMS/internal/domain/mail"
 	"RenewCMS/internal/domain/user"
+	"context"
 	"errors"
 	"fmt"
 	"time"
@@ -16,6 +18,7 @@ type CreateUserUseCase struct {
 	hasher         hash.Hasher
 	mailRepository mail.Repository
 	publicURL      string
+	recorder       audit.Recorder
 }
 
 type CreateUserCommand struct {
@@ -29,11 +32,25 @@ type MailValidationData struct {
 	VerificationCode string
 }
 
-func NewCreateUserUseCase(userRepository user.Repository, hasher hash.Hasher, mailRepository mail.Repository, publicURL string) *CreateUserUseCase {
-	return &CreateUserUseCase{userRepository, hasher, mailRepository, publicURL}
+func NewCreateUserUseCase(userRepository user.Repository, hasher hash.Hasher, mailRepository mail.Repository, publicURL string, recorder audit.Recorder) *CreateUserUseCase {
+	return &CreateUserUseCase{userRepository, hasher, mailRepository, publicURL, recorder}
 }
 
-func (g *CreateUserUseCase) CreateUser(createUser CreateUserCommand) (user.User, error) {
+func (g *CreateUserUseCase) CreateUser(ctx context.Context, createUser CreateUserCommand) (user.User, error) {
+	event := audit.NewEvent(audit.ActionUserRegister, audit.CategoryUsers)
+	created, err := g.create(createUser)
+	if err != nil {
+		event.Actor = audit.AnonymousActor(createUser.Username)
+		recordFailure(ctx, g.recorder, event, err)
+		return user.User{}, err
+	}
+	event.Actor = audit.UserActor(created)
+	event.Target = audit.NewTarget(audit.TargetUser, created.ID, created.Username)
+	g.recorder.Record(ctx, event)
+	return created, nil
+}
+
+func (g *CreateUserUseCase) create(createUser CreateUserCommand) (user.User, error) {
 	if g.registrationClosed() {
 		return user.User{}, user.ErrRegistrationClosed
 	}
@@ -70,7 +87,7 @@ func (g *CreateUserUseCase) CreateUser(createUser CreateUserCommand) (user.User,
 		Host:             g.publicURL,
 		VerificationCode: rawUuid,
 	}); err != nil {
-		sendErr := fmt.Errorf("failed to send verification email: %w", err)
+		sendErr := fmt.Errorf("%w: %w", user.ErrVerificationEmailNotSent, err)
 		if deleteErr := g.userRepository.Delete(createdUser.ID); deleteErr != nil {
 			return user.User{}, errors.Join(sendErr, deleteErr)
 		}

internal/infrastructure/useCases/DeleteArticle.go

@@ -1,15 +1,32 @@
 package useCases
 
-import "RenewCMS/internal/domain/article"
+import (
+	"RenewCMS/internal/domain/article"
+	"RenewCMS/internal/domain/audit"
+	"context"
+)
 
 type DeleteArticleUseCase struct {
 	articleRepository article.Repository
+	recorder          audit.Recorder
 }
 
-func NewDeleteArticleUseCase(articleRepository article.Repository) *DeleteArticleUseCase {
-	return &DeleteArticleUseCase{articleRepository}
+func NewDeleteArticleUseCase(articleRepository article.Repository, recorder audit.Recorder) *DeleteArticleUseCase {
+	return &DeleteArticleUseCase{articleRepository, recorder}
 }
 
-func (g *DeleteArticleUseCase) DeleteArticle(id uint32) error {
-	return g.articleRepository.Delete(id)
+func (g *DeleteArticleUseCase) DeleteArticle(ctx context.Context, id uint32) error {
+	target, err := g.articleRepository.Get(id)
+	if err != nil {
+		return err
+	}
+
+	event := audit.NewEvent(audit.ActionArticleDelete, audit.CategoryArticles)
+	event.Target = articleTarget(target)
+	if err := g.articleRepository.Delete(id); err != nil {
+		recordFailure(ctx, g.recorder, event, err)
+		return err
+	}
+	g.recorder.Record(ctx, event)
+	return nil
 }

internal/infrastructure/useCases/DeleteMedia.go

@@ -1,20 +1,33 @@
 package useCases
 
-import "RenewCMS/internal/domain/image"
+import (
+	"RenewCMS/internal/domain/audit"
+	"RenewCMS/internal/domain/image"
+	"context"
+)
 
 type DeleteMediaUseCase struct {
 	imageRepository image.Repository
 	remover         mediaRemover
+	recorder        audit.Recorder
 }
 
-func NewDeleteMediaUseCase(imageRepository image.Repository, storage image.Storage) *DeleteMediaUseCase {
-	return &DeleteMediaUseCase{imageRepository, mediaRemover{imageRepository, storage}}
+func NewDeleteMediaUseCase(imageRepository image.Repository, storage image.Storage, recorder audit.Recorder) *DeleteMediaUseCase {
+	return &DeleteMediaUseCase{imageRepository, mediaRemover{imageRepository, storage}, recorder}
 }
 
-func (u *DeleteMediaUseCase) Delete(id uint32) error {
+func (u *DeleteMediaUseCase) Delete(ctx context.Context, id uint32) error {
 	img, err := u.imageRepository.Get(id)
 	if err != nil {
 		return err
 	}
-	return u.remover.remove(img)
+
+	event := audit.NewEvent(audit.ActionMediaDelete, audit.CategoryMedia)
+	event.Target = imageTarget(img)
+	if err := u.remover.remove(img); err != nil {
+		recordFailure(ctx, u.recorder, event, err)
+		return err
+	}
+	u.recorder.Record(ctx, event)
+	return nil
 }

internal/infrastructure/useCases/ListActivity.go

@@ -11,11 +11,6 @@ import (
 	"time"
 )
 
-const (
-	targetArticle = "article"
-	targetImage   = "image"
-)
-
 type ListActivityUseCase struct {
 	events   audit.Repository
 	users    user.Repository
@@ -118,7 +113,7 @@ func (l *ListActivityUseCase) targetExists(target audit.Target) (bool, error) {
 		return true, nil
 	}
 	switch target.Type {
-	case targetArticle:
+	case audit.TargetArticle:
 		_, err = l.articles.Get(uint32(id))
 		return existsUnless(err, article.ErrArticleNotFound)
 	case audit.TargetUser:
@@ -127,7 +122,7 @@ func (l *ListActivityUseCase) targetExists(target audit.Target) (bool, error) {
 	case audit.TargetAPIKey:
 		_, err = l.apiKeys.Get(uint32(id))
 		return existsUnless(err, apikey.ErrAPIKeyNotFound)
-	case targetImage:
+	case audit.TargetImage:
 		_, err = l.images.Get(uint32(id))
 		return existsUnless(err, image.ErrImageNotFound)
 	default:

internal/infrastructure/useCases/MergeMedia.go

@@ -2,8 +2,10 @@ package useCases
 
 import (
 	"RenewCMS/internal/domain/article"
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/image"
 	"cmp"
+	"context"
 	"errors"
 	"slices"
 	"strings"
@@ -19,10 +21,11 @@ type MergeMediaUseCase struct {
 	imageRepository   image.Repository
 	articleRepository article.Repository
 	remover           mediaRemover
+	recorder          audit.Recorder
 }
 
-func NewMergeMediaUseCase(imageRepository image.Repository, articleRepository article.Repository, storage image.Storage) *MergeMediaUseCase {
-	return &MergeMediaUseCase{imageRepository, articleRepository, mediaRemover{imageRepository, storage}}
+func NewMergeMediaUseCase(imageRepository image.Repository, articleRepository article.Repository, storage image.Storage, recorder audit.Recorder) *MergeMediaUseCase {
+	return &MergeMediaUseCase{imageRepository, articleRepository, mediaRemover{imageRepository, storage}, recorder}
 }
 
 type bodyRewrite struct {
@@ -31,7 +34,30 @@ type bodyRewrite struct {
 	rewritten string
 }
 
-func (u *MergeMediaUseCase) Merge(keepId uint32, mergeIds []uint32) (MergeMediaResult, error) {
+func (u *MergeMediaUseCase) Merge(ctx context.Context, keepId uint32, mergeIds []uint32) (MergeMediaResult, error) {
+	result, err := u.merge(keepId, mergeIds)
+	event := audit.NewEvent(audit.ActionMediaMerge, audit.CategoryMedia)
+	if kept, found := u.keptImage(keepId); found {
+		event.Target = imageTarget(kept)
+	}
+	if err != nil {
+		recordFailure(ctx, u.recorder, event, err)
+		return MergeMediaResult{}, err
+	}
+	event.Params = map[string]any{audit.ParamMerged: result.Merged, audit.ParamArticlesUpdated: result.ArticlesUpdated}
+	u.recorder.Record(ctx, event)
+	return result, nil
+}
+
+func (u *MergeMediaUseCase) keptImage(keepId uint32) (image.Image, bool) {
+	if keepId == 0 {
+		return image.Image{}, false
+	}
+	kept, err := u.imageRepository.Get(keepId)
+	return kept, err == nil
+}
+
+func (u *MergeMediaUseCase) merge(keepId uint32, mergeIds []uint32) (MergeMediaResult, error) {
 	if err := validateMergeRequest(keepId, mergeIds); err != nil {
 		return MergeMediaResult{}, err
 	}

internal/infrastructure/useCases/PurgeScheduler.go

@@ -1,21 +1,25 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/purge"
+	"context"
+	"errors"
 	"time"
 )
 
 type PurgeRunner interface {
-	Run(fingerprint *string) (purge.RunResult, error)
+	Execute(fingerprint *string) (purge.RunResult, error)
 }
 
 type PurgeSchedulerUseCase struct {
 	repository purge.Repository
 	runner     PurgeRunner
+	recorder   audit.Recorder
 }
 
-func NewPurgeSchedulerUseCase(repository purge.Repository, runner PurgeRunner) *PurgeSchedulerUseCase {
-	return &PurgeSchedulerUseCase{repository, runner}
+func NewPurgeSchedulerUseCase(repository purge.Repository, runner PurgeRunner, recorder audit.Recorder) *PurgeSchedulerUseCase {
+	return &PurgeSchedulerUseCase{repository, runner, recorder}
 }
 
 func (u *PurgeSchedulerUseCase) Tick(now time.Time) (purge.RunResult, bool, error) {
@@ -27,9 +31,29 @@ func (u *PurgeSchedulerUseCase) Tick(now time.Time) (purge.RunResult, bool, erro
 	if next == nil || now.Before(*next) {
 		return purge.RunResult{}, false, nil
 	}
-	result, err := u.runner.Run(nil)
+	result, err := u.runner.Execute(nil)
 	if err != nil {
+		u.recordFailedRun(err)
 		return purge.RunResult{}, false, err
 	}
+	if result.GroupsTotal > 0 {
+		event := systemPurgeEvent()
+		event.Params = purgeParams(result)
+		u.recorder.Record(context.Background(), event)
+	}
 	return result, true, nil
 }
+
+func (u *PurgeSchedulerUseCase) recordFailedRun(err error) {
+	if errors.Is(err, purge.ErrPurgeBusy) {
+		return
+	}
+	failFrom(context.Background(), u.recorder, systemPurgeEvent(), reasonFor(err))
+}
+
+func systemPurgeEvent() audit.Event {
+	event := audit.NewEvent(audit.ActionMediaPurgeScheduled, audit.CategorySystem)
+	event.Actor = audit.SystemActor()
+	event.Source = audit.SourceSystem
+	return event
+}

internal/infrastructure/useCases/RenameMedia.go

@@ -1,25 +1,43 @@
 package useCases
 
-import "RenewCMS/internal/domain/image"
+import (
+	"RenewCMS/internal/domain/audit"
+	"RenewCMS/internal/domain/image"
+	"context"
+)
 
 type RenameMediaUseCase struct {
 	imageRepository image.Repository
+	recorder        audit.Recorder
 }
 
-func NewRenameMediaUseCase(imageRepository image.Repository) *RenameMediaUseCase {
-	return &RenameMediaUseCase{imageRepository}
+func NewRenameMediaUseCase(imageRepository image.Repository, recorder audit.Recorder) *RenameMediaUseCase {
+	return &RenameMediaUseCase{imageRepository, recorder}
 }
 
-func (u *RenameMediaUseCase) Rename(id uint32, stem string) (image.Image, error) {
-	validStem, err := image.ValidateFilenameStem(stem)
-	if err != nil {
-		return image.Image{}, err
-	}
-
+func (u *RenameMediaUseCase) Rename(ctx context.Context, id uint32, stem string) (image.Image, error) {
 	current, err := u.imageRepository.Get(id)
 	if err != nil {
 		return image.Image{}, err
 	}
 
-	return u.imageRepository.Rename(id, validStem+image.ExtensionOf(current.Filename))
+	event := audit.NewEvent(audit.ActionMediaRename, audit.CategoryMedia)
+	event.Target = imageTarget(current)
+	validStem, err := image.ValidateFilenameStem(stem)
+	if err != nil {
+		recordFailure(ctx, u.recorder, event, err)
+		return image.Image{}, err
+	}
+
+	renamed, err := u.imageRepository.Rename(id, validStem+image.ExtensionOf(current.Filename))
+	if err != nil {
+		recordFailure(ctx, u.recorder, event, err)
+		return image.Image{}, err
+	}
+	if renamed.Filename != current.Filename {
+		event.Target = imageTarget(renamed)
+		event.Changes = []audit.Change{audit.TextChange(audit.FieldFilename, current.Filename, renamed.Filename)}
+		u.recorder.Record(ctx, event)
+	}
+	return renamed, nil
 }

internal/infrastructure/useCases/RenewInvite.go

@@ -1,10 +1,12 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/hash"
 	"RenewCMS/internal/domain/invite"
 	"RenewCMS/internal/domain/mail"
 	"RenewCMS/internal/domain/user"
+	"context"
 	"errors"
 	"time"
 )
@@ -14,6 +16,7 @@ type RenewInviteUseCase struct {
 	inviteRepository invite.Repository
 	hasher           hash.Hasher
 	mailer           inviteMailer
+	recorder         audit.Recorder
 }
 
 type RenewInviteCommand struct {
@@ -21,11 +24,23 @@ type RenewInviteCommand struct {
 	RenewedBy uint32
 }
 
-func NewRenewInviteUseCase(userRepository user.Repository, inviteRepository invite.Repository, hasher hash.Hasher, mailRepository mail.Repository, publicURL string) *RenewInviteUseCase {
-	return &RenewInviteUseCase{userRepository, inviteRepository, hasher, inviteMailer{mailRepository, publicURL}}
+func NewRenewInviteUseCase(userRepository user.Repository, inviteRepository invite.Repository, hasher hash.Hasher, mailRepository mail.Repository, publicURL string, recorder audit.Recorder) *RenewInviteUseCase {
+	return &RenewInviteUseCase{userRepository, inviteRepository, hasher, inviteMailer{mailRepository, publicURL}, recorder}
 }
 
-func (u *RenewInviteUseCase) RenewInvite(command RenewInviteCommand) (invite.Invite, error) {
+func (u *RenewInviteUseCase) RenewInvite(ctx context.Context, command RenewInviteCommand) (invite.Invite, error) {
+	event := audit.NewEvent(audit.ActionInviteRenew, audit.CategoryUsers)
+	renewed, err := u.renew(command)
+	if err != nil {
+		recordFailure(ctx, u.recorder, event, err)
+		return invite.Invite{}, err
+	}
+	event.Target = inviteTarget(renewed)
+	u.recorder.Record(ctx, event)
+	return renewed, nil
+}
+
+func (u *RenewInviteUseCase) renew(command RenewInviteCommand) (invite.Invite, error) {
 	now := time.Now()
 
 	renewer, err := u.userRepository.Get(command.RenewedBy)

internal/infrastructure/useCases/RequestRestart.go

@@ -1,7 +1,9 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/update"
+	"context"
 	"sync"
 	"time"
 )
@@ -13,10 +15,11 @@ type RequestRestartUseCase struct {
 	requests update.RestartRequestStore
 	status   updateStatusBuilder
 	now      func() time.Time
+	recorder audit.Recorder
 	mu       sync.Mutex
 }
 
-func NewRequestRestartUseCase(store update.StatusStore, jobs update.JobStore, helper update.HelperDetector, results update.ResultStore, requests update.RestartRequestStore, currentVersion string, now func() time.Time) *RequestRestartUseCase {
+func NewRequestRestartUseCase(store update.StatusStore, jobs update.JobStore, helper update.HelperDetector, results update.ResultStore, requests update.RestartRequestStore, currentVersion string, now func() time.Time, recorder audit.Recorder) *RequestRestartUseCase {
 	return &RequestRestartUseCase{
 		jobs:     jobs,
 		helper:   helper,
@@ -24,12 +27,33 @@ func NewRequestRestartUseCase(store update.StatusStore, jobs update.JobStore, he
 		requests: requests,
 		status:   updateStatusBuilder{store: store, jobs: jobs, results: results, requests: requests, currentVersion: currentVersion, now: now},
 		now:      now,
+		recorder: recorder,
 	}
 }
 
-func (r *RequestRestartUseCase) Request(userId uint32, kind string) (update.UpdateStatus, error) {
+func (r *RequestRestartUseCase) Request(ctx context.Context, userId uint32, kind string) (update.UpdateStatus, error) {
+	event := audit.NewEvent(audit.ActionRestartRequested, audit.CategorySystem)
+	status, request, err := r.request(userId, kind)
+	if err != nil {
+		recordFailure(ctx, r.recorder, event, err, restartFailureReasons...)
+		return update.UpdateStatus{}, err
+	}
+	event.Params = restartParams(request)
+	r.recorder.Record(ctx, event)
+	return status, nil
+}
+
+func restartParams(request update.RestartRequest) map[string]any {
+	params := map[string]any{audit.ParamKind: request.Kind}
+	if request.Kind == update.RestartKindUpdate {
+		params[audit.ParamTag] = request.Tag
+	}
+	return params
+}
+
+func (r *RequestRestartUseCase) request(userId uint32, kind string) (update.UpdateStatus, update.RestartRequest, error) {
 	if !r.helper.Installed() {
-		return update.UpdateStatus{}, update.ErrNotPrepared
+		return update.UpdateStatus{}, update.RestartRequest{}, update.ErrNotPrepared
 	}
 
 	r.mu.Lock()
@@ -37,19 +61,19 @@ func (r *RequestRestartUseCase) Request(userId uint32, kind string) (update.Upda
 
 	current := r.status.build(true)
 	if err := refuseWhileBusy(current); err != nil {
-		return update.UpdateStatus{}, err
+		return update.UpdateStatus{}, update.RestartRequest{}, err
 	}
 	request, err := r.requestFor(kind, userId)
 	if err != nil {
-		return update.UpdateStatus{}, err
+		return update.UpdateStatus{}, update.RestartRequest{}, err
 	}
 	if err := r.results.Delete(); err != nil {
-		return update.UpdateStatus{}, err
+		return update.UpdateStatus{}, update.RestartRequest{}, err
 	}
 	if err := r.requests.Write(request); err != nil {
-		return update.UpdateStatus{}, err
+		return update.UpdateStatus{}, update.RestartRequest{}, err
 	}
-	return r.status.build(true), nil
+	return r.status.build(true), request, nil
 }
 
 func refuseWhileBusy(status update.UpdateStatus) error {

internal/infrastructure/useCases/RunPurge.go

@@ -2,8 +2,10 @@ package useCases
 
 import (
 	"RenewCMS/internal/domain/article"
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/image"
 	"RenewCMS/internal/domain/purge"
+	"context"
 	"log"
 	"slices"
 	"sync"
@@ -16,20 +18,42 @@ type RunPurgeUseCase struct {
 	repository purge.Repository
 	now        func() time.Time
 	logger     *log.Logger
+	recorder   audit.Recorder
 	guard      sync.Mutex
 }
 
-func NewRunPurgeUseCase(imageRepository image.Repository, articleRepository article.Repository, merge *MergeMediaUseCase, repository purge.Repository, now func() time.Time, logger *log.Logger) *RunPurgeUseCase {
+func NewRunPurgeUseCase(imageRepository image.Repository, articleRepository article.Repository, merge *MergeMediaUseCase, repository purge.Repository, now func() time.Time, logger *log.Logger, recorder audit.Recorder) *RunPurgeUseCase {
 	return &RunPurgeUseCase{
 		planner:    &purgePlanner{imageRepository, articleRepository},
 		merge:      merge,
 		repository: repository,
 		now:        now,
 		logger:     logger,
+		recorder:   recorder,
 	}
 }
 
-func (u *RunPurgeUseCase) Run(fingerprint *string) (purge.RunResult, error) {
+func (u *RunPurgeUseCase) Run(ctx context.Context, fingerprint *string) (purge.RunResult, error) {
+	result, err := u.Execute(fingerprint)
+	event := audit.NewEvent(audit.ActionMediaPurge, audit.CategoryMedia)
+	if err != nil {
+		recordFailure(ctx, u.recorder, event, err)
+		return purge.RunResult{}, err
+	}
+	event.Params = purgeParams(result)
+	u.recorder.Record(ctx, event)
+	return result, nil
+}
+
+func purgeParams(result purge.RunResult) map[string]any {
+	params := map[string]any{audit.ParamMerged: result.Merged, audit.ParamArticlesUpdated: result.ArticlesUpdated}
+	if result.FailedGroups > 0 {
+		params[audit.ParamFailedGroups] = result.FailedGroups
+	}
+	return params
+}
+
+func (u *RunPurgeUseCase) Execute(fingerprint *string) (purge.RunResult, error) {
 	if !u.guard.TryLock() {
 		return purge.RunResult{}, purge.ErrPurgeBusy
 	}
@@ -55,7 +79,7 @@ func (u *RunPurgeUseCase) mergeGroups(plan purgePlan) purge.RunResult {
 	result := purge.RunResult{GroupsTotal: len(plan.groups)}
 	updated := map[uint32]bool{}
 	for _, group := range plan.groups {
-		merged, err := u.merge.Merge(group.kept.ID, slices.Clone(group.mergedIds))
+		merged, err := u.merge.merge(group.kept.ID, slices.Clone(group.mergedIds))
 		if err != nil {
 			result.FailedGroups++
 			continue

internal/infrastructure/useCases/StartUpdateDownload.go

@@ -1,7 +1,9 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/update"
+	"context"
 	"errors"
 	"fmt"
 	"sync"
@@ -24,6 +26,7 @@ type StartUpdateDownloadUseCase struct {
 	platform       update.Platform
 	feedHost       string
 	now            func() time.Time
+	recorder       audit.Recorder
 	mu             sync.Mutex
 }
 
@@ -43,6 +46,7 @@ type StartUpdateDownloadDependencies struct {
 	Platform       update.Platform
 	FeedURL        string
 	Now            func() time.Time
+	Recorder       audit.Recorder
 }
 
 type jobFailure struct {
@@ -78,10 +82,19 @@ func NewStartUpdateDownloadUseCase(dependencies StartUpdateDownloadDependencies)
 		platform:       dependencies.Platform,
 		feedHost:       update.HostOf(dependencies.FeedURL),
 		now:            dependencies.Now,
+		recorder:       dependencies.Recorder,
 	}
 }
 
-func (s *StartUpdateDownloadUseCase) Start() (update.UpdateStatus, error) {
+func (s *StartUpdateDownloadUseCase) Start(ctx context.Context) (update.UpdateStatus, error) {
+	status, err := s.start(ctx)
+	if err != nil {
+		recordFailure(ctx, s.recorder, audit.NewEvent(audit.ActionUpdateDownloaded, audit.CategorySystem), err)
+	}
+	return status, err
+}
+
+func (s *StartUpdateDownloadUseCase) start(ctx context.Context) (update.UpdateStatus, error) {
 	if !s.helper.Installed() {
 		return update.UpdateStatus{}, update.ErrNotPrepared
 	}
@@ -118,7 +131,7 @@ func (s *StartUpdateDownloadUseCase) Start() (update.UpdateStatus, error) {
 		return update.UpdateStatus{}, err
 	}
 	status := s.status.build(true)
-	go s.run(job, binary, checksums, signature)
+	go s.run(context.WithoutCancel(ctx), job, binary, checksums, signature)
 
 	return status, nil
 }
@@ -139,15 +152,19 @@ func (s *StartUpdateDownloadUseCase) preflight(result update.CheckResult) (binar
 	return found[0], found[1], found[2], nil
 }
 
-func (s *StartUpdateDownloadUseCase) run(job update.Job, binary, checksums, signature update.Asset) {
+func (s *StartUpdateDownloadUseCase) run(ctx context.Context, job update.Job, binary, checksums, signature update.Asset) {
 	defer func() {
 		if recovered := recover(); recovered != nil {
-			s.fail(job, downloadFailure(fmt.Errorf("panic: %v", recovered)))
+			s.fail(ctx, job, downloadFailure(fmt.Errorf("panic: %v", recovered)))
 		}
 	}()
 	if err := s.execute(&job, binary, checksums, signature); err != nil {
-		s.fail(job, err)
+		s.fail(ctx, job, err)
+		return
 	}
+	event := audit.NewEvent(audit.ActionUpdateDownloaded, audit.CategorySystem)
+	event.Target = audit.ReleaseTarget(job.Tag)
+	s.recorder.Record(ctx, event)
 }
 
 func (s *StartUpdateDownloadUseCase) execute(job *update.Job, binary, checksums, signature update.Asset) error {
@@ -263,7 +280,7 @@ func downloadFailure(err error) error {
 	return jobFailure{kind: update.ErrorKindDownload, reason: err}
 }
 
-func (s *StartUpdateDownloadUseCase) fail(job update.Job, err error) {
+func (s *StartUpdateDownloadUseCase) fail(ctx context.Context, job update.Job, err error) {
 	kind := update.ErrorKindDownload
 	var failure jobFailure
 	if errors.As(err, &failure) {
@@ -279,4 +296,7 @@ func (s *StartUpdateDownloadUseCase) fail(job update.Job, err error) {
 	if saveErr := s.jobs.Save(job); saveErr != nil {
 		s.logger.Printf("update job record could not be saved: %v", saveErr)
 	}
+	event := audit.NewEvent(audit.ActionUpdateDownloaded, audit.CategorySystem)
+	event.Target = audit.ReleaseTarget(job.Tag)
+	failFrom(ctx, s.recorder, event, downloadFailureReasons[kind])
 }

internal/infrastructure/useCases/UpdateArticle.go

@@ -1,28 +1,69 @@
 package useCases
 
-import "RenewCMS/internal/domain/article"
+import (
+	"RenewCMS/internal/domain/article"
+	"RenewCMS/internal/domain/audit"
+	"context"
+)
 
 type UpdateArticleUseCase struct {
 	articleRepository article.Repository
 	bodyRenderer      article.BodyRenderer
+	recorder          audit.Recorder
 }
 
-func NewUpdateArticleUseCase(articleRepository article.Repository, bodyRenderer article.BodyRenderer) *UpdateArticleUseCase {
-	return &UpdateArticleUseCase{articleRepository, bodyRenderer}
+func NewUpdateArticleUseCase(articleRepository article.Repository, bodyRenderer article.BodyRenderer, recorder audit.Recorder) *UpdateArticleUseCase {
+	return &UpdateArticleUseCase{articleRepository, bodyRenderer, recorder}
 }
 
-func (g *UpdateArticleUseCase) UpdateBody(id uint32, body string, format article.BodyFormat) (article.Article, error) {
+func (g *UpdateArticleUseCase) UpdateBody(ctx context.Context, id uint32, body string, format article.BodyFormat) (article.Article, error) {
+	before, err := g.articleRepository.Get(id)
+	if err != nil {
+		return article.Article{}, err
+	}
 	updated, err := g.articleRepository.UpdateBody(id, body)
 	if err != nil {
+		g.recordFailure(ctx, audit.ActionArticleEdit, before, err)
 		return article.Article{}, err
 	}
+	g.recordChange(ctx, audit.ActionArticleEdit, before, updated)
 	return renderArticle(g.bodyRenderer, updated, format)
 }
 
-func (g *UpdateArticleUseCase) UpdateIsOnline(id uint32, isOnline bool, format article.BodyFormat) (article.Article, error) {
-	updated, err := g.articleRepository.UpdateIsOnline(id, isOnline)
+func (g *UpdateArticleUseCase) UpdateIsOnline(ctx context.Context, id uint32, isOnline bool, format article.BodyFormat) (article.Article, error) {
+	before, err := g.articleRepository.Get(id)
 	if err != nil {
 		return article.Article{}, err
 	}
+	updated, err := g.articleRepository.UpdateIsOnline(id, isOnline)
+	if err != nil {
+		g.recordFailure(ctx, publishAction(isOnline), before, err)
+		return article.Article{}, err
+	}
+	g.recordChange(ctx, publishAction(isOnline), before, updated)
 	return renderArticle(g.bodyRenderer, updated, format)
 }
+
+func publishAction(isOnline bool) string {
+	if isOnline {
+		return audit.ActionArticlePublish
+	}
+	return audit.ActionArticleUnpublish
+}
+
+func (g *UpdateArticleUseCase) recordChange(ctx context.Context, action string, before article.Article, after article.Article) {
+	changes := audit.ArticleChanges(before, after)
+	if len(changes) == 0 {
+		return
+	}
+	event := audit.NewEvent(action, audit.CategoryArticles)
+	event.Target = articleTarget(after)
+	event.Changes = changes
+	g.recorder.Record(ctx, event)
+}
+
+func (g *UpdateArticleUseCase) recordFailure(ctx context.Context, action string, before article.Article, cause error) {
+	event := audit.NewEvent(action, audit.CategoryArticles)
+	event.Target = articleTarget(before)
+	recordFailure(ctx, g.recorder, event, cause)
+}

internal/infrastructure/useCases/UpdateUserProfile.go

@@ -1,7 +1,9 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/user"
+	"context"
 	"strings"
 	"unicode/utf8"
 )
@@ -10,16 +12,40 @@ const maxDisplayNameRunes = 60
 
 type UpdateUserProfileUseCase struct {
 	userRepository user.Repository
+	recorder       audit.Recorder
 }
 
-func NewUpdateUserProfileUseCase(userRepository user.Repository) *UpdateUserProfileUseCase {
-	return &UpdateUserProfileUseCase{userRepository}
+func NewUpdateUserProfileUseCase(userRepository user.Repository, recorder audit.Recorder) *UpdateUserProfileUseCase {
+	return &UpdateUserProfileUseCase{userRepository, recorder}
 }
 
-func (u *UpdateUserProfileUseCase) UpdateDisplayName(userId uint32, displayName string) (user.User, error) {
+func (u *UpdateUserProfileUseCase) UpdateDisplayName(ctx context.Context, userId uint32, displayName string) (user.User, error) {
+	before, err := u.userRepository.Get(userId)
+	if err != nil {
+		return user.User{}, err
+	}
+
+	event := audit.NewEvent(audit.ActionUserUpdateProfile, audit.CategoryUsers)
+	event.Target = userTarget(before)
 	trimmed := strings.TrimSpace(displayName)
 	if utf8.RuneCountInString(trimmed) > maxDisplayNameRunes {
+		recordFailure(ctx, u.recorder, event, user.ErrInvalidDisplayName)
 		return user.User{}, user.ErrInvalidDisplayName
 	}
-	return u.userRepository.UpdateDisplayName(userId, trimmed)
+
+	updated, err := u.userRepository.UpdateDisplayName(userId, trimmed)
+	if err != nil {
+		recordFailure(ctx, u.recorder, event, err)
+		return user.User{}, err
+	}
+	if updated.DisplayName != before.DisplayName {
+		event.Target = userTarget(updated)
+		event.Changes = []audit.Change{audit.TextChange(audit.FieldDisplayName, before.DisplayName, updated.DisplayName)}
+		u.recorder.Record(ctx, event)
+	}
+	return updated, nil
+}
+
+func userTarget(u user.User) audit.Target {
+	return audit.NewTarget(audit.TargetUser, u.ID, audit.UserActor(u).Name)
 }

internal/infrastructure/useCases/VerifyUser.go

@@ -1,26 +1,42 @@
 package useCases
 
 import (
+	"RenewCMS/internal/domain/audit"
 	"RenewCMS/internal/domain/hash"
 	"RenewCMS/internal/domain/user"
+	"context"
 	"time"
 )
 
 type VerifyUserUseCase struct {
 	userRepository user.Repository
 	hasher         hash.Hasher
+	recorder       audit.Recorder
 }
 
-func NewVerifyUserUseCase(userRepository user.Repository, hasher hash.Hasher) *VerifyUserUseCase {
-	return &VerifyUserUseCase{userRepository, hasher}
+func NewVerifyUserUseCase(userRepository user.Repository, hasher hash.Hasher, recorder audit.Recorder) *VerifyUserUseCase {
+	return &VerifyUserUseCase{userRepository, hasher, recorder}
 }
 
-func (v *VerifyUserUseCase) Verify(userId uint32, code string) (user.User, error) {
+func (v *VerifyUserUseCase) Verify(ctx context.Context, userId uint32, code string) (user.User, error) {
 	dbUser, err := v.userRepository.Get(userId)
 	if err != nil {
 		return user.User{}, err
 	}
 
+	event := audit.NewEvent(audit.ActionUserVerify, audit.CategoryUsers)
+	event.Actor = audit.UserActor(dbUser)
+	event.Target = audit.NewTarget(audit.TargetUser, dbUser.ID, dbUser.Username)
+	verified, err := v.verify(dbUser, code)
+	if err != nil {
+		recordFailure(ctx, v.recorder, event, err)
+		return user.User{}, err
+	}
+	v.recorder.Record(ctx, event)
+	return verified, nil
+}
+
+func (v *VerifyUserUseCase) verify(dbUser user.User, code string) (user.User, error) {
 	if dbUser.VerificationCode == "" || v.hasher.Compare(dbUser.VerificationCode, code) != nil {
 		return user.User{}, user.ErrInvalidVerificationCode
 	}
@@ -29,5 +45,5 @@ func (v *VerifyUserUseCase) Verify(userId uint32, code string) (user.User, error
 		return user.User{}, user.ErrVerificationCodeExpired
 	}
 
-	return v.userRepository.ClearVerificationCode(userId)
+	return v.userRepository.ClearVerificationCode(dbUser.ID)
 }

internal/infrastructure/useCases/auditFailures.go

@@ -0,0 +1,101 @@
+package useCases
+
+import (
+	"RenewCMS/internal/domain/article"
+	"RenewCMS/internal/domain/audit"
+	"RenewCMS/internal/domain/image"
+	"RenewCMS/internal/domain/invite"
+	"RenewCMS/internal/domain/purge"
+	"RenewCMS/internal/domain/update"
+	"RenewCMS/internal/domain/user"
+	"context"
+	"errors"
+	"slices"
+)
+
+const GenericFailureReason = "Something went wrong on our side. Please try again."
+
+type failureReason struct {
+	cause  error
+	reason string
+}
+
+var failureReasons = []failureReason{
+	{article.ErrInvalidTitle, "The title must be between 3 and 200 characters."},
+	{image.ErrImageTypeNotAllowed, "The file must be a PNG, JPEG, WEBP or SVG image."},
+	{image.ErrImageTooLarge, "The file is too large to upload."},
+	{image.ErrImageUnreadable, "The image could not be read."},
+	{image.ErrInvalidFilename, "That file name is not valid."},
+	{image.ErrInvalidMergeRequest, "The merge request is not valid."},
+	{image.ErrMergeCopyMissing, "One of the copies no longer exists."},
+	{image.ErrMergeHashMismatch, "The images are not identical copies."},
+	{purge.ErrPurgeConflict, "The library changed since the preview. Review it again."},
+	{purge.ErrPurgeBusy, "A purge is already running."},
+	{user.ErrRegistrationClosed, "Registration is closed on this site."},
+	{user.ErrVerificationEmailNotSent, "The verification email could not be sent."},
+	{user.ErrInvalidVerificationCode, "The verification code is not valid."},
+	{user.ErrVerificationCodeExpired, "The verification code has expired."},
+	{user.ErrInvalidDisplayName, "That display name is too long."},
+	{user.ErrUsernameTaken, "That username is already taken."},
+	{invite.ErrEmailHasAccount, "That email already has an account."},
+	{invite.ErrPendingInvite, "An invitation is already pending for that email."},
+	{invite.ErrInviteEmailNotSent, "The invitation email could not be sent."},
+	{invite.ErrInviteAlreadyAccepted, "That invitation was already accepted."},
+	{invite.ErrInviteInvalid, "That invitation is not valid."},
+	{invite.ErrInviteExpired, "That invitation has expired."},
+	{update.ErrFeedUnavailable, "The release feed could not be reached."},
+	{update.ErrNoRelease, "No release was found."},
+	{update.ErrNotPrepared, "This server cannot apply updates."},
+	{update.ErrJobInProgress, "An update is already being downloaded."},
+	{update.ErrRestartPending, "A restart is already pending."},
+	{update.ErrNothingToUpdate, "There is nothing to update."},
+	{update.ErrPreflightRefused, "The update cannot be downloaded."},
+	{update.ErrRestartKindMismatch, "The requested restart does not match the server state."},
+}
+
+var restartFailureReasons = []failureReason{
+	{update.ErrJobInProgress, "An update is still being downloaded."},
+}
+
+var downloadFailureReasons = map[string]string{
+	update.ErrorKindDownload:     "The update could not be downloaded.",
+	update.ErrorKindVerification: "The downloaded update failed its integrity check.",
+}
+
+var notFoundCauses = []error{
+	article.ErrArticleNotFound,
+	image.ErrImageNotFound,
+	invite.ErrInviteNotFound,
+	user.ErrUserNotFound,
+}
+
+func reasonFor(err error, overrides ...failureReason) string {
+	for _, candidate := range slices.Concat(overrides, failureReasons) {
+		if errors.Is(err, candidate.cause) {
+			return candidate.reason
+		}
+	}
+	return GenericFailureReason
+}
+
+func isNotFound(err error) bool {
+	for _, cause := range notFoundCauses {
+		if errors.Is(err, cause) {
+			return true
+		}
+	}
+	return false
+}
+
+func recordFailure(ctx context.Context, recorder audit.Recorder, event audit.Event, err error, overrides ...failureReason) {
+	if isNotFound(err) {
+		return
+	}
+	failFrom(ctx, recorder, event, reasonFor(err, overrides...))
+}
+
+func failFrom(ctx context.Context, recorder audit.Recorder, event audit.Event, reason string) {
+	event.Outcome = audit.OutcomeFailed
+	event.FailureReason = &reason
+	recorder.Record(ctx, event)
+}