MM-52600: [Shared Channels] Shared channels do not sync channel membership (#30976)

server/channels/store/sqlstore/channel_store.go

@@ -2070,22 +2070,34 @@ func (s SqlChannelStore) PatchMultipleMembersNotifyProps(members []*model.Channe
 	return updated, nil
 }
 
-func (s SqlChannelStore) GetMembers(channelID string, offset, limit int) (model.ChannelMembers, error) {
-	sql, args, err := s.channelMembersForTeamWithSchemeSelectQuery.
+func (s SqlChannelStore) GetMembers(opts model.ChannelMembersGetOptions) (model.ChannelMembers, error) {
+	query := s.channelMembersForTeamWithSchemeSelectQuery.
 		Where(sq.Eq{
-			"ChannelId": channelID,
-		}).
-		Limit(uint64(limit)).
-		Offset(uint64(offset)).
-		ToSql()
+			"ChannelId": opts.ChannelID,
+		})
+
+	if opts.UpdatedAfter > 0 {
+		query = query.Where(sq.Gt{"ChannelMembers.LastUpdateAt": opts.UpdatedAfter})
+		query = query.OrderBy("ChannelMembers.LastUpdateAt")
+	}
+
+	if opts.Limit > 0 {
+		query = query.Limit(uint64(opts.Limit))
+	}
+
+	if opts.Offset > 0 {
+		query = query.Offset(uint64(opts.Offset))
+	}
+
+	sql, args, err := query.ToSql()
 	if err != nil {
-		return nil, errors.Wrapf(err, "GetMember_ToSql ChannelID=%s", channelID)
+		return nil, errors.Wrapf(err, "GetMember_ToSql ChannelID=%s", opts.ChannelID)
 	}
 
 	dbMembers := channelMemberWithSchemeRolesList{}
 	err = s.GetReplica().Select(&dbMembers, sql, args...)
 	if err != nil {
-		return nil, errors.Wrapf(err, "failed to get ChannelMembers with channelId=%s", channelID)
+		return nil, errors.Wrapf(err, "failed to get ChannelMembers with channelId=%s", opts.ChannelID)
 	}
 
 	return dbMembers.ToModel(), nil

server/channels/store/sqlstore/shared_channel_store.go

@@ -417,6 +417,7 @@ func sharedChannelRemoteFields(prefix string) []string {
 		"COALESCE(" + prefix + "LastPostCreateID,'') AS LastPostCreateID",
 		prefix + "LastPostUpdateAt",
 		"COALESCE(" + prefix + "LastPostId,'') AS LastPostUpdateID",
+		prefix + "LastMembersSyncAt",
 	}
 }
 
@@ -708,6 +709,7 @@ func sharedChannelUserFields(prefix string) []string {
 		prefix + "RemoteId",
 		prefix + "CreateAt",
 		prefix + "LastSyncAt",
+		prefix + "LastMembershipSyncAt",
 	}
 }
 
@@ -720,7 +722,7 @@ func (s SqlSharedChannelStore) SaveUser(scUser *model.SharedChannelUser) (*model
 
 	query, args, err := s.getQueryBuilder().Insert("SharedChannelUsers").
 		Columns(sharedChannelUserFields("")...).
-		Values(scUser.Id, scUser.UserId, scUser.ChannelId, scUser.RemoteId, scUser.CreateAt, scUser.LastSyncAt).
+		Values(scUser.Id, scUser.UserId, scUser.ChannelId, scUser.RemoteId, scUser.CreateAt, scUser.LastSyncAt, scUser.LastMembershipSyncAt).
 		ToSql()
 	if err != nil {
 		return nil, errors.Wrapf(err, "savesharedchanneluser_tosql")
@@ -853,6 +855,25 @@ func (s SqlSharedChannelStore) UpdateUserLastSyncAt(userID string, channelID str
 	return nil
 }
 
+// UpdateUserLastMembershipSyncAt updates the LastMembershipSyncAt timestamp for the specified SharedChannelUser using the provided sync time.
+func (s SqlSharedChannelStore) UpdateUserLastMembershipSyncAt(userID string, channelID string, remoteID string, syncTime int64) error {
+	query := s.getQueryBuilder().
+		Update("SharedChannelUsers AS scu").
+		Set("LastMembershipSyncAt", sq.Expr("GREATEST(scu.LastMembershipSyncAt, ?)", syncTime)).
+		Where(sq.Eq{
+			"scu.UserId":    userID,
+			"scu.ChannelId": channelID,
+			"scu.RemoteId":  remoteID,
+		})
+
+	_, err := s.GetMaster().ExecBuilder(query)
+	if err != nil {
+		return fmt.Errorf("failed to update LastMembershipSyncAt for SharedChannelUser with userId=%s, channelId=%s, remoteId=%s: %w",
+			userID, channelID, remoteID, err)
+	}
+	return nil
+}
+
 func sharedChannelAttachementFields(prefix string) []string {
 	if prefix != "" && !strings.HasSuffix(prefix, ".") {
 		prefix = prefix + "."

server/channels/store/sqlstore/shared_channel_store_membership.go

@@ -0,0 +1,66 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package sqlstore
+
+import (
+	"database/sql"
+	"fmt"
+
+	"github.com/mattermost/mattermost/server/public/model"
+	sq "github.com/mattermost/squirrel"
+	"github.com/pkg/errors"
+)
+
+// UpdateRemoteMembershipCursor updates the LastMembersSyncAt timestamp for the specified SharedChannelRemote,
+// but only if the new timestamp is greater than the current value.
+func (s SqlSharedChannelStore) UpdateRemoteMembershipCursor(id string, syncTime int64) error {
+	query := s.getQueryBuilder().
+		Update("SharedChannelRemotes")
+
+	query = query.Set("LastMembersSyncAt", sq.Expr("GREATEST(LastMembersSyncAt, ?)", syncTime))
+
+	query = query.Where(sq.Eq{"Id": id})
+
+	result, err := s.GetMaster().ExecBuilder(query)
+	if err != nil {
+		return errors.Wrap(err, "failed to update membership cursor for SharedChannelRemote")
+	}
+
+	count, err := result.RowsAffected()
+	if err != nil {
+		return errors.Wrap(err, "failed to determine rows affected")
+	}
+
+	if count == 0 {
+		return fmt.Errorf("id not found: %s", id)
+	}
+
+	return nil
+}
+
+// GetUserChanges gets all SharedChannelUser changes for a given user, channel after a specific time.
+// This is used to detect if there are conflicting membership changes.
+func (s SqlSharedChannelStore) GetUserChanges(userID string, channelID string, afterTime int64) ([]*model.SharedChannelUser, error) {
+	squery, args, err := s.getQueryBuilder().
+		Select(sharedChannelUserFields("")...).
+		From("SharedChannelUsers").
+		Where(sq.Eq{"SharedChannelUsers.UserId": userID}).
+		Where(sq.Eq{"SharedChannelUsers.ChannelId": channelID}).
+		Where(sq.Gt{"SharedChannelUsers.LastSyncAt": afterTime}).
+		ToSql()
+
+	if err != nil {
+		return nil, errors.Wrapf(err, "getsharedchanneluserchanges_tosql")
+	}
+
+	users := []*model.SharedChannelUser{}
+	if err := s.GetReplica().Select(&users, squery, args...); err != nil {
+		if err == sql.ErrNoRows {
+			return make([]*model.SharedChannelUser, 0), nil
+		}
+		return nil, errors.Wrapf(err, "failed to find shared channel user changes with UserId=%s, ChannelId=%s, afterTime=%d",
+			userID, channelID, afterTime)
+	}
+	return users, nil
+}