nip29: bring in helpers for managing groups to be used on the relay side.

nip29/group.go

@@ -16,11 +16,13 @@ type Group struct {
 	Closed  bool
 
 	LastMetadataUpdate nostr.Timestamp
+	LastAdminsUpdate   nostr.Timestamp
+	LastMembersUpdate  nostr.Timestamp
 }
 
 func (group Group) ToMetadataEvent() *nostr.Event {
 	evt := &nostr.Event{
-		Kind:      39000,
+		Kind:      nostr.KindSimpleGroupMetadata,
 		CreatedAt: group.LastMetadataUpdate,
 		Content:   group.About,
 		Tags: nostr.Tags{
@@ -52,6 +54,47 @@ func (group Group) ToMetadataEvent() *nostr.Event {
 	return evt
 }
 
+func (group Group) ToAdminsEvent() *nostr.Event {
+	evt := &nostr.Event{
+		Kind:      nostr.KindSimpleGroupAdmins,
+		CreatedAt: group.LastAdminsUpdate,
+		Tags:      make(nostr.Tags, 1, 1+len(group.Members)/3),
+	}
+	evt.Tags[0] = nostr.Tag{"d", group.ID}
+
+	for member, role := range group.Members {
+		if role != nil {
+			// is an admin
+			tag := make([]string, 0, 3+len(role.Permissions))
+			tag[0] = "p"
+			tag[1] = member
+			tag[2] = role.Name
+			for perm := range role.Permissions {
+				tag = append(tag, string(perm))
+			}
+			evt.Tags = append(evt.Tags, tag)
+		}
+	}
+
+	return evt
+}
+
+func (group Group) ToMembersEvent() *nostr.Event {
+	evt := &nostr.Event{
+		Kind:      nostr.KindSimpleGroupMembers,
+		CreatedAt: group.LastMembersUpdate,
+		Tags:      make(nostr.Tags, 1, 1+len(group.Members)),
+	}
+	evt.Tags[0] = nostr.Tag{"d", group.ID}
+
+	for member := range group.Members {
+		// include both admins and normal members
+		evt.Tags = append(evt.Tags, nostr.Tag{"p", member})
+	}
+
+	return evt
+}
+
 func (group *Group) MergeInMetadataEvent(evt *nostr.Event) error {
 	if evt.Kind != nostr.KindSimpleGroupMetadata {
 		return fmt.Errorf("expected kind %d, got %d", nostr.KindSimpleGroupMetadata, evt.Kind)
@@ -84,3 +127,53 @@ func (group *Group) MergeInMetadataEvent(evt *nostr.Event) error {
 
 	return nil
 }
+
+func (group *Group) MergeInAdminsEvent(evt *nostr.Event) error {
+	if evt.Kind != nostr.KindSimpleGroupAdmins {
+		return fmt.Errorf("expected kind %d, got %d", nostr.KindSimpleGroupAdmins, evt.Kind)
+	}
+
+	if evt.CreatedAt <= group.LastAdminsUpdate {
+		return fmt.Errorf("event is older than our last update (%d vs %d)", evt.CreatedAt, group.LastAdminsUpdate)
+	}
+
+	group.LastAdminsUpdate = evt.CreatedAt
+	for _, tag := range evt.Tags {
+		if len(tag) < 3 {
+			continue
+		}
+		if tag[0] != "p" {
+			continue
+		}
+		if !nostr.IsValidPublicKeyHex(tag[1]) {
+			continue
+		}
+	}
+
+	return nil
+}
+
+func (group *Group) MergeInMembersEvent(evt *nostr.Event) error {
+	if evt.Kind != nostr.KindSimpleGroupMembers {
+		return fmt.Errorf("expected kind %d, got %d", nostr.KindSimpleGroupMembers, evt.Kind)
+	}
+
+	if evt.CreatedAt <= group.LastMembersUpdate {
+		return fmt.Errorf("event is older than our last update (%d vs %d)", evt.CreatedAt, group.LastMembersUpdate)
+	}
+
+	group.LastMembersUpdate = evt.CreatedAt
+	for _, tag := range evt.Tags {
+		if len(tag) < 2 {
+			continue
+		}
+		if tag[0] != "p" {
+			continue
+		}
+		if !nostr.IsValidPublicKeyHex(tag[1]) {
+			continue
+		}
+	}
+
+	return nil
+}

nip29/nip29.go

@@ -2,6 +2,7 @@ package nip29
 
 import (
 	"github.com/nbd-wtf/go-nostr"
+	"golang.org/x/exp/maps"
 	"golang.org/x/exp/slices"
 )
 
@@ -10,7 +11,7 @@ type Role struct {
 	Permissions map[Permission]struct{}
 }
 
-type Permission = string
+type Permission string
 
 const (
 	PermAddUser          Permission = "add-user"
@@ -24,15 +25,7 @@ const (
 
 type KindRange []int
 
-var ModerationEventKinds = KindRange{
+var ModerationEventKinds = KindRange(maps.Keys(moderationActionFactories))
-	nostr.KindSimpleGroupAddUser,
-	nostr.KindSimpleGroupRemoveUser,
-	nostr.KindSimpleGroupEditMetadata,
-	nostr.KindSimpleGroupAddPermission,
-	nostr.KindSimpleGroupRemovePermission,
-	nostr.KindSimpleGroupDeleteEvent,
-	nostr.KindSimpleGroupEditGroupStatus,
-}
 
 var MetadataEventKinds = KindRange{
 	nostr.KindSimpleGroupMetadata,

nip29/relay.go

@@ -0,0 +1,308 @@
+package nip29
+
+import (
+	"fmt"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+var (
+	// used for the default role, the actual relay, hidden otherwise
+	MasterRole *Role = &Role{
+		Name: "master",
+		Permissions: map[Permission]struct{}{
+			PermAddUser:          {},
+			PermEditMetadata:     {},
+			PermDeleteEvent:      {},
+			PermRemoveUser:       {},
+			PermAddPermission:    {},
+			PermRemovePermission: {},
+			PermEditGroupStatus:  {},
+		},
+	}
+
+	// used for normal members without admin powers, not displayed
+	EmptyRole *Role = nil
+
+	PermissionsMap = map[Permission]struct{}{
+		PermAddUser:          {},
+		PermEditMetadata:     {},
+		PermDeleteEvent:      {},
+		PermRemoveUser:       {},
+		PermAddPermission:    {},
+		PermRemovePermission: {},
+		PermEditGroupStatus:  {},
+	}
+)
+
+type Action interface {
+	Apply(group *Group)
+	PermissionName() Permission
+}
+
+func GetModerationAction(evt *nostr.Event) (Action, error) {
+	factory, ok := moderationActionFactories[evt.Kind]
+	if !ok {
+		return nil, fmt.Errorf("event kind %d is not a supported moderation action", evt.Kind)
+	}
+	return factory(evt)
+}
+
+var moderationActionFactories = map[int]func(*nostr.Event) (Action, error){
+	nostr.KindSimpleGroupAddUser: func(evt *nostr.Event) (Action, error) {
+		targets := make([]string, 0, len(evt.Tags))
+		for _, tag := range evt.Tags.GetAll([]string{"p", ""}) {
+			if !nostr.IsValidPublicKeyHex(tag[1]) {
+				return nil, fmt.Errorf("")
+			}
+			targets = append(targets, tag[1])
+		}
+		if len(targets) > 0 {
+			return &AddUser{Targets: targets}, nil
+		}
+		return nil, fmt.Errorf("missing 'p' tags")
+	},
+	nostr.KindSimpleGroupRemoveUser: func(evt *nostr.Event) (Action, error) {
+		targets := make([]string, 0, len(evt.Tags))
+		for _, tag := range evt.Tags.GetAll([]string{"p", ""}) {
+			if !nostr.IsValidPublicKeyHex(tag[1]) {
+				return nil, fmt.Errorf("invalid public key hex")
+			}
+			targets = append(targets, tag[1])
+		}
+		if len(targets) > 0 {
+			return &RemoveUser{Targets: targets}, nil
+		}
+		return nil, fmt.Errorf("missing 'p' tags")
+	},
+	nostr.KindSimpleGroupEditMetadata: func(evt *nostr.Event) (Action, error) {
+		ok := false
+		edit := EditMetadata{When: evt.CreatedAt}
+		if t := evt.Tags.GetFirst([]string{"name", ""}); t != nil {
+			edit.NameValue = (*t)[1]
+			ok = true
+		}
+		if t := evt.Tags.GetFirst([]string{"picture", ""}); t != nil {
+			edit.PictureValue = (*t)[1]
+			ok = true
+		}
+		if t := evt.Tags.GetFirst([]string{"about", ""}); t != nil {
+			edit.AboutValue = (*t)[1]
+			ok = true
+		}
+		if ok {
+			return &edit, nil
+		}
+		return nil, fmt.Errorf("missing metadata tags")
+	},
+	nostr.KindSimpleGroupAddPermission: func(evt *nostr.Event) (Action, error) {
+		nTags := len(evt.Tags)
+
+		permissions := make([]Permission, 0, nTags-1)
+		for _, tag := range evt.Tags.GetAll([]string{"permission", ""}) {
+			perm := Permission(tag[1])
+			if _, ok := PermissionsMap[perm]; !ok {
+				return nil, fmt.Errorf("unknown permission '%s'", tag[1])
+			}
+			permissions = append(permissions, perm)
+		}
+
+		targets := make([]string, 0, nTags-1)
+		for _, tag := range evt.Tags.GetAll([]string{"p", ""}) {
+			if !nostr.IsValidPublicKeyHex(tag[1]) {
+				return nil, fmt.Errorf("invalid public key hex")
+			}
+			targets = append(targets, tag[1])
+		}
+
+		if len(permissions) > 0 && len(targets) > 0 {
+			return &AddPermission{Targets: targets, Permissions: permissions}, nil
+		}
+
+		return nil, fmt.Errorf("")
+	},
+	nostr.KindSimpleGroupRemovePermission: func(evt *nostr.Event) (Action, error) {
+		nTags := len(evt.Tags)
+
+		permissions := make([]Permission, 0, nTags-1)
+		for _, tag := range evt.Tags.GetAll([]string{"permission", ""}) {
+			perm := Permission(tag[1])
+			if _, ok := PermissionsMap[perm]; !ok {
+				return nil, fmt.Errorf("unknown permission '%s'", tag[1])
+			}
+			permissions = append(permissions, perm)
+		}
+
+		targets := make([]string, 0, nTags-1)
+		for _, tag := range evt.Tags.GetAll([]string{"p", ""}) {
+			if !nostr.IsValidPublicKeyHex(tag[1]) {
+				return nil, fmt.Errorf("invalid public key hex")
+			}
+			targets = append(targets, tag[1])
+		}
+
+		if len(permissions) > 0 && len(targets) > 0 {
+			return &RemovePermission{Targets: targets, Permissions: permissions}, nil
+		}
+
+		return nil, fmt.Errorf("")
+	},
+	nostr.KindSimpleGroupDeleteEvent: func(evt *nostr.Event) (Action, error) {
+		tags := evt.Tags.GetAll([]string{"e", ""})
+		if len(tags) == 0 {
+			return nil, fmt.Errorf("missing 'e' tag")
+		}
+
+		targets := make([]string, len(tags))
+		for i, tag := range tags {
+			if nostr.IsValidPublicKeyHex(tag[1]) {
+				targets[i] = tag[1]
+			} else {
+				return nil, fmt.Errorf("invalid event id hex")
+			}
+		}
+
+		return &DeleteEvent{Targets: targets}, nil
+	},
+	nostr.KindSimpleGroupEditGroupStatus: func(evt *nostr.Event) (Action, error) {
+		egs := EditGroupStatus{When: evt.CreatedAt}
+
+		egs.Public = evt.Tags.GetFirst([]string{"public"}) != nil
+		egs.Private = evt.Tags.GetFirst([]string{"private"}) != nil
+		egs.Open = evt.Tags.GetFirst([]string{"open"}) != nil
+		egs.Closed = evt.Tags.GetFirst([]string{"closed"}) != nil
+
+		// disallow contradictions
+		if egs.Public && egs.Private {
+			return nil, fmt.Errorf("contradiction")
+		}
+		if egs.Open && egs.Closed {
+			return nil, fmt.Errorf("contradiction")
+		}
+
+		// TODO remove this once we start supporting private groups
+		if egs.Private {
+			return nil, fmt.Errorf("private groups not yet supported")
+		}
+
+		return egs, nil
+	},
+}
+
+type DeleteEvent struct {
+	Targets []string
+}
+
+func (DeleteEvent) PermissionName() Permission { return PermDeleteEvent }
+func (a DeleteEvent) Apply(group *Group)       {}
+
+type AddUser struct {
+	Targets []string
+}
+
+func (AddUser) PermissionName() Permission { return PermAddUser }
+func (a AddUser) Apply(group *Group) {
+	for _, target := range a.Targets {
+		group.Members[target] = EmptyRole
+	}
+}
+
+type RemoveUser struct {
+	Targets []string
+}
+
+func (RemoveUser) PermissionName() Permission { return PermRemoveUser }
+func (a RemoveUser) Apply(group *Group) {
+	for _, target := range a.Targets {
+		delete(group.Members, target)
+	}
+}
+
+type EditMetadata struct {
+	NameValue    string
+	PictureValue string
+	AboutValue   string
+	When         nostr.Timestamp
+}
+
+func (EditMetadata) PermissionName() Permission { return PermEditMetadata }
+func (a EditMetadata) Apply(group *Group) {
+	group.Name = a.NameValue
+	group.Picture = a.PictureValue
+	group.About = a.AboutValue
+	group.LastMetadataUpdate = a.When
+}
+
+type AddPermission struct {
+	Targets     []string
+	Permissions []Permission
+}
+
+func (AddPermission) PermissionName() Permission { return PermAddPermission }
+func (a AddPermission) Apply(group *Group) {
+	for _, target := range a.Targets {
+		role, ok := group.Members[target]
+
+		// if it's a normal user, create a new permissions object thing for this user
+		// instead of modifying the global EmptyRole
+		if !ok || role == EmptyRole {
+			role = &Role{Permissions: make(map[Permission]struct{})}
+			group.Members[target] = role
+		}
+
+		// add all permissions listed
+		for _, perm := range a.Permissions {
+			role.Permissions[perm] = struct{}{}
+		}
+	}
+}
+
+type RemovePermission struct {
+	Targets     []string
+	Permissions []Permission
+}
+
+func (RemovePermission) PermissionName() Permission { return PermRemovePermission }
+func (a RemovePermission) Apply(group *Group) {
+	for _, target := range a.Targets {
+		role, ok := group.Members[target]
+		if !ok || role == EmptyRole {
+			continue
+		}
+
+		// remove all permissions listed
+		for _, perm := range a.Permissions {
+			delete(role.Permissions, perm)
+		}
+
+		// if no more permissions are available, change this guy to be a normal user
+		if role.Name == "" && len(role.Permissions) == 0 {
+			group.Members[target] = EmptyRole
+		}
+	}
+}
+
+type EditGroupStatus struct {
+	Public  bool
+	Private bool
+	Open    bool
+	Closed  bool
+	When    nostr.Timestamp
+}
+
+func (EditGroupStatus) PermissionName() Permission { return PermEditGroupStatus }
+func (a EditGroupStatus) Apply(group *Group) {
+	if a.Public {
+		group.Private = false
+	} else if a.Private {
+		group.Private = true
+	}
+
+	if a.Open {
+		group.Closed = false
+	} else if a.Closed {
+		group.Closed = true
+	}
+
+	group.LastMetadataUpdate = a.When
+}