comey to testify infront of senate publicly doesnt make sence heres why

if comey says yes trump asked me to end an investigation if Flynn and If he stayed quite this whole time he's hurting he's own creditability and if he says no it never happen then he's vindicating trump which the deep state cant allow it I don't think he can say it was part of the investigation which would mean he was undercover in the Whitehouse lol doesn't make sense can someone plz help me make sense of it thanks guys