I think we’re talking cross purposes here.
Your energy monitor is only taking two INPUTS current and volts, and is OUTPUTTING current, energy, power, voltage, frequency and the power factor. To do this it will be doing some level of waveform analysis on the AC and some internal calculations and transfer functions to derive those outputs from the inputs. This is documented with this sensor:
This ‘measure module’ is the logic/math I’m interested in replicating inside ESPHome/HomeAssistant, perhaps this is simple in your eyes but I was hoping for a bit more guidance as the Wiki articles are not at a level I can understand. I don’t think it truly is that ‘simple’ as you’re making out, but if it is, could you perhaps write it as pseudo code that I can turn into Python?