How to revive this wisteria?

This wisteria is a right shrubby mess, if someone can recommend what I should do to get it flowering and looking nice again I would be most appreciative

 

Heehee....here we go again! First off, get some really heavy duty support on that fence! Old electric or phone cable is better/stronger than wire. Ideally, space the horizontals 18" apart.
Then decide on the framework you want. An espalier-type would work well. Tie in the strongest stems to the wires (even if they're a bit curvy, that won't show as they age and thicken up). So, say you've got three horizontals, you'll have six stems tied in, three either side.
Cut out everything else at ground level.
Then it's just a case of cutting any growth coming off these main stems back to two buds, at least twice a year. That'll make the plant form flower buds. It'll be a thing of beauty and a joy forever....
ETA...If you want to go for the minimalist look, just train two stems, one in either direction, and cut back the rest.