Bracing for 3 bay mono-pitch barn

I've built a mono-pitch pole barn on wooden poles. Three 6m bays, each 8.5m deep. DIY rafters made from 400mm deep 11mm OSB sheeting sandwiching 4x4 top & bottom, screwed & glued. 9x3 timber purlins. Tin roof.

The components look & fell about right (he says hopefully) but I've less of a feel for wind bracing requirements, especially at resonance.

Candidates are

1. Y bracing from pole to the eaves strut/purlin
2. Knee bracing from pole to rafter
3. Diagonal bracing at rear wall (just one bay preferably)
4. Diagonal bracing of purlins, again just a single bay hopefully

Any suggestions on the best approach/combination/materials of the above? Sheltered location. I'm tempted to slap a bit of each but thought I'd run it past some of the experienced folk...
Thanks.