merged from gramsrv upstream

internal/app/welcomemessages/service.go

@@ -0,0 +1,121 @@
+package welcomemessages
+
+import (
+	"context"
+	"time"
+
+	"telesrv/internal/domain"
+	"telesrv/internal/store"
+)
+
+type ChannelAccess interface {
+	ResolveChannel(ctx context.Context, userID, channelID int64) (domain.ChannelView, error)
+}
+
+type Option func(*Service)
+
+func WithClock(now func() time.Time) Option {
+	return func(s *Service) {
+		if now != nil {
+			s.now = now
+		}
+	}
+}
+
+type Service struct {
+	messages store.WelcomeMessageStore
+	channels ChannelAccess
+	now      func() time.Time
+}
+
+func NewService(messages store.WelcomeMessageStore, channels ChannelAccess, options ...Option) *Service {
+	s := &Service{messages: messages, channels: channels, now: time.Now}
+	for _, option := range options {
+		if option != nil {
+			option(s)
+		}
+	}
+	return s
+}
+
+// Authorize is the cheap gate RPC uses before resolving upload/media/rich
+// content. Mutations call authorize again immediately before the store write so
+// a concurrent demotion cannot turn this preflight into a stale capability.
+func (s *Service) Authorize(ctx context.Context, userID int64, peer domain.Peer) error {
+	return s.authorize(ctx, userID, peer)
+}
+
+func (s *Service) Create(ctx context.Context, userID int64, peer domain.Peer, randomID int64, content domain.WelcomeMessageContent) (domain.WelcomeMessage, bool, error) {
+	if err := s.authorize(ctx, userID, peer); err != nil {
+		return domain.WelcomeMessage{}, false, err
+	}
+	if err := content.Validate(); err != nil {
+		return domain.WelcomeMessage{}, false, err
+	}
+	fingerprint, err := domain.WelcomeCreateFingerprint(peer, userID, randomID, content)
+	if err != nil {
+		return domain.WelcomeMessage{}, false, domain.ErrWelcomeMessageInvalid
+	}
+	return s.messages.CreateWelcomeMessage(ctx, domain.CreateWelcomeMessageRequest{
+		Peer: peer, CreatorUserID: userID, Date: int(s.now().Unix()), RandomID: randomID,
+		Content: content, CreateFingerprint: fingerprint,
+	})
+}
+
+func (s *Service) Edit(ctx context.Context, userID int64, peer domain.Peer, id int, fields domain.WelcomeMessageEditFields) (domain.WelcomeMessage, error) {
+	if err := s.authorize(ctx, userID, peer); err != nil {
+		return domain.WelcomeMessage{}, err
+	}
+	return s.messages.EditWelcomeMessage(ctx, domain.EditWelcomeMessageRequest{
+		Peer: peer, ID: id, EditDate: int(s.now().Unix()), Fields: fields,
+	})
+}
+
+func (s *Service) List(ctx context.Context, userID int64, peer domain.Peer, hash int64) (domain.WelcomeMessageList, error) {
+	if err := s.authorize(ctx, userID, peer); err != nil {
+		return domain.WelcomeMessageList{}, err
+	}
+	return s.messages.ListWelcomeMessages(ctx, peer, hash)
+}
+
+func (s *Service) Delete(ctx context.Context, userID int64, peer domain.Peer, id int) (bool, error) {
+	if err := s.authorize(ctx, userID, peer); err != nil {
+		return false, err
+	}
+	return s.messages.DeleteWelcomeMessage(ctx, peer, id)
+}
+
+func (s *Service) DeleteAll(ctx context.Context, userID int64, peer domain.Peer) (bool, error) {
+	if err := s.authorize(ctx, userID, peer); err != nil {
+		return false, err
+	}
+	return s.messages.DeleteAllWelcomeMessages(ctx, peer)
+}
+
+// HasAny is used only after the ordinary full-chat access check has succeeded.
+// It deliberately does not require manage_welcome_messages so non-admin members
+// receive the same has_welcome_messages projection as official clients.
+func (s *Service) HasAny(ctx context.Context, peer domain.Peer) (bool, error) {
+	if s == nil || s.messages == nil || peer.Type != domain.PeerTypeChannel || peer.ID <= 0 {
+		return false, domain.ErrWelcomeMessageInvalid
+	}
+	return s.messages.HasWelcomeMessages(ctx, peer)
+}
+
+func (s *Service) authorize(ctx context.Context, userID int64, peer domain.Peer) error {
+	if s == nil || s.messages == nil || s.channels == nil || userID <= 0 ||
+		peer.Type != domain.PeerTypeChannel || peer.ID <= 0 {
+		return domain.ErrWelcomeMessageInvalid
+	}
+	view, err := s.channels.ResolveChannel(ctx, userID, peer.ID)
+	if err != nil {
+		return err
+	}
+	if view.Channel.Monoforum {
+		return domain.ErrWelcomeMessagePeerInvalid
+	}
+	if !view.Self.CanManageWelcomeMessages() {
+		return domain.ErrWelcomeMessageForbidden
+	}
+	return nil
+}