Ford XL 150,smoking battery

I have an 1991 ford 150 XL.Just recently it started making a buzzing sound( like the door was open when you to leave).I turned off the car and it still was buzzing.I opened the hood and the battery was smoking and oil started to spray out.I went to disconnect the battery and one of the connectors(the possitive, I think)broke right off.was the battery the problem?do i have a short in the electrical area?What else could it be?and why did the oil start spraying out?I could use some help.Any hints or help would be great.