Pruning Japanese Rhododendron Azalea ??

I have a four year old Japanese Azalea which, since I planted it, has grudgingly given a few little blooms around March/April. This year, nothing!!! Looking at it (photos attached, it looks a bit sparse at the base though you can see it's got foliage at the tips but no flowers.

I am wondering if I should do something drastic like cut it right back and see if it will grow thicker stems for next year etc. Incidentally, I feed it all my coffee grounds etc as I understand this helps the soil balance.

Any advice much appreciated.

Barry