use master 
go
create or alter function dbo.fn_hadr_group_is_primary (@agname sysname) returns bit as 
begin
	if exists (select name from sys.availability_groups) begin
		declare @primaryreplica sysname

		select
		@primaryreplica = hags.primary_replica
		from sys.dm_hadr_availability_group_states hags
		inner join sys.availability_groups ag on ag.group_id = hags.group_id
		where ag.name = @agname

		if upper(@primaryreplica) = upper(@@servername) return 1 -- primary
		else return 0 -- secondary
	end 
	return 1 -- not AG server
end
go