How to use Raspberry / Arduino to monitor voltage and power surges in the mains?

Question

Arduino

Actually, you need to implement the following:
Through raspberry or arduino, monitor jumps, voltage in the mains.
Please, describe how to do this, or better links, where you can read about it in detail.

Answer 1

Diode bridge.
Measuring/resistive bridge .
Probably something like that.
Well, or look for voltmeters with an I2C connector, but I think they will still be low-voltage and for direct current.

Answer 2

Find (make?) a sensor that will receive this information and will support USB\COM\RS485 or any other interface through which you can receive this data from it. Then anything - you throw an SMS or cut down the power there ...