嘥心機,挨眼瞓 (saai1 sam1 gei1 ngaai4 ngaan5 fan3) — to rack one's brain for nothing; all for naught in Cantonese
saaiˉ¹嘥samˉ¹心geiˉ¹機,ngaaiˎ₄挨ngaanˏ₅眼fan˗₃瞓简 嘥心机,挨眼瞓
Mandarin Pinyin: sai1 xin1 ji1 , ai1 yan3 fen4
Meaning of 嘥心機,挨眼瞓
nounto rack one's brain for nothing; all for naught