A light fixture with 2 white, 2 black wires, 1 copper. How do I connect this light fixture to a ceiling junction box? (See drawn diagram)
The easy answer is "Hook it up just like the previous light was hooked up", but I'm assuming that you didn't keep track of the original configuration.

To make it work again, connect both of the lamp white wires to the white wire coming from the circuit breaker panel.

Then connect the black wire from the panel to the black wire leading to the switch.

Then connect the white wire from the switch to both black wires of the lamp.

Then, make sure you mark both ends of that white wire with black (tape, pen, paint, etc) to show that it's a switched hot so someone doesn't confuse it with a neutral some day.