public IActionResult Share([FromRoute] int planId, [FromBody] ICollection <UserDto> usersToShare)
{
var plan = _repo.GetPlan(planId);
if (plan == null)
{
return(NotFound("There is no plan with specified ID: " + planId));
}
var alreadyShared = _repo.GetShares(planId);
var usersToAdd = usersToShare.Where(us => !alreadyShared.Contains(us.Id)).Select(us => us.Id);
var usersToRemove = alreadyShared.Where(us => !usersToShare.Select(us => us.Id).Contains(us));
_repo.AddUsersToShare(plan, usersToAdd);
_repo.RemoveUsersFromShare(plan, usersToRemove);
return(Ok());
}