func extraUserForEvent(event types.Event) *types.UserId {
if event.GetEventType() == matrixTypes.EventTypeMembership {
membership := event.GetContent().(*matrixTypes.MembershipEventContent).Membership
isInvited := membership == matrixTypes.MembershipInvited
isKnocking := membership == matrixTypes.MembershipKnocking
isBanned := membership == matrixTypes.MembershipBanned
if isInvited || isKnocking || isBanned {
state, ok := event.(*matrixTypes.State)
if !ok {
log.Println("membership event was not a state event:", event)
return nil
}
user, err := types.ParseUserId(state.StateKey)
if err != nil {
log.Println("failed to parse user id state key:", state.StateKey)
return nil
}
return &user
}
}
return nil
}
