AC Dimmer Detection Circuit

I want to detect the state of a standard, off-the-shelf AC phase-control dimmer switch using a microcontroller. The dimmer switch will have access to mains, neutral, 3.3v, 5v, and a microcontroller. The dimmer switch will not be connected to an external load. Ideally this circuit will work with any mains voltage (100V~240V) and be configurable strictly using the microcontroller. The Microcontroller is 3.3v but there is a 5v rail that can be used as well. You do not need to design the microcontroller part – only to define whatever I/O lines you will need (ADC, DAC, GPIO, etc) and voltage rails to operate the detection circuit. Just need a schematic and specs, not a PCB. A photo or video of a proof-of-concept prototype on a breadboard or other rapid prototyping hardware helpful but not required. Please see the attached PDF for more detailed requirements.