(a) It shall be unlawful for any person to discharge a firearm while:

(1) Under the influence of alcohol or any drug or any combination of alcohol and any drug to the extent that it is unsafe for the person to discharge such firearm except in the defense of life, health, and property;

(2) The person's alcohol concentration is 0.08 grams or more at any time while discharging such firearm or within three hours after such discharge of such firearm from alcohol consumed before such discharge ended; or

(3) Subject to the provisions of subsection (b) of this Code section, there is any amount of marijuana or a controlled substance, as defined in Code Section 16-13-21, present in the person's blood or urine, or both, including the metabolites and derivatives of each or both without regard to whether or not any alcohol is present in the person's breath or blood.

(b) The fact that any person charged with violating this Code section is or has been legally entitled to use a drug shall not constitute a defense against any charge of violating this Code section; provided, however, that such person shall not be in violation of this Code section unless such person is rendered incapable of possessing or discharging a firearm safely as a result of using a drug other than alcohol which such person is legally entitled to use.

(c) Any person convicted of violating subsection (a) of this Code section shall be guilty of a misdemeanor of a high and aggravated nature.