Not sure what your asking here but with a dual master cylinder you should have some brakes.
It will be a very low pedal but something.
If you have NO brakes, there was also an undetected problem with your rear brakes.
The front brake hose could have failed, a relatively easy fix, or the piston came out of the caliper, due to extreme wear of the brake pads.
Look at both sides of the rotor. If one side feels like sand paper, you need caliper, rotor and brake pads. You should also do both fronts.
Did the "Brake" light come on ?