Who wrote the preface to the long pavilion?

There seems to be no Preface to the Long Pavilion.

A Farewell to the West Chamber and the Pavilion was written by Wang Shifu, a poet in the Yuan Dynasty.

"Farewell to the West Pavilion" tells the parting scene of Zhang Sheng in Cui Yingying Shili Pavilion in the form of Yuan Zaju, while Zhang Sheng and Cui Yingying, lovers who broke through the secular love, are about to experience long-term parting lovesickness after a short pleasure.

reflects the sharp contradiction between free love and feudal ethics, and shows the accusation that feudal ethics severely bound and suppressed human nature.