No latch to speak of but need one.

So my daughter bought this bungalow that has an ancient patio door that has been jerry-rigged; no latch, just a pull and a lame knob. The catch has been bent upwards for some reason so it all needs replaced. She can't afford a new door as of yet but her cat has learned to claw the screen to the side so he can escape so a latch is imperative at this time. I think we are starting from scratch here so tell me if you need any other info. If it matters at all the black pull measures 3" to the center of each screw.

Thanks in advance.