。
I wish I were as clever as you.
Literal
I [topic-は] you [degree-くらい] clever [conditional-と] good [explanatory-のだ] [but-が].
~といいのだが ('I wish...') expresses an unrealized wish — 'it would be good if..., but...' The trailing が ('but') implies 'but I'm not.' くらい sets the benchmark: 'to the degree of you.' 利口 (りこう, 'clever, smart'). A wistful, self-deprecating comparison.