The pilot reported that on landing the airplane touched down hard and began to porpoise, striking the runway twice during the accident sequence. The pilot reported a loss of nose wheel and rudder control responsiveness and was unable to maintain directional control when the airplane departed the runway to the right, traveled down an embankment and subsequently rolled over, coming to rest inverted. The airplane sustained substantial damage to right wing, vertical stabilizer and fuselage. The pilot reported no preimpact mechanical failures or malfunctions that would have precluded normal operation of the airplane.