I'm sure everyone else will come up with the sensible solutions, but if there's water dripping, you have to think how much it's leaked to soak through that much. It'll be a replace job i reckon.

much the same thing happened to my partner's rental place years ago. flat leaking roof over the bathroom, i suspected a leak but could only watch as it got worse, then xmas eve, it rained Inside the house !!! it was hilarious. we wanted to move anyway. I called her up and couldn't stop laughing as I explained her house was leaking over my tree !!! still makes me giggle.