Reversing the direction of current in an inductor
Remember the defining equation for an inductor:

$$V = L \frac{di}{dt}$$

"Instantly" reversing the direction of current implies \$\frac{di}{dt} = \infty\$ and therefore

$$V=\infty$$

Infinite voltage is non-trivial to deal with.

You should carefully think through your proposed method for instantly reversing current through an inductor. You will find that it is very difficult to accomplish (in the non-ideal world of real life, impossible would be the appropriate term).