PotionDamageResolver.java

package tc.oc.pgm.tracker.resolvers;

import javax.annotation.Nullable;

import org.bukkit.entity.Entity;
import org.bukkit.event.entity.EntityDamageEvent;
import org.bukkit.potion.PotionEffectType;
import tc.oc.pgm.tracker.damage.GenericPotionInfo;
import tc.oc.pgm.tracker.damage.PhysicalInfo;
import tc.oc.pgm.tracker.damage.PotionInfo;
import tc.oc.pgm.tracker.damage.ProjectileInfo;

public class PotionDamageResolver implements DamageResolver {

    @Override
    public @Nullable PotionInfo resolveDamage(EntityDamageEvent.DamageCause damageType, Entity victim, @Nullable PhysicalInfo damager) {
        // If potion is already resolved (i.e. as a splash potion), leave it alone
        if(damager instanceof PotionInfo ||
           damager instanceof ProjectileInfo && ((ProjectileInfo) damager).getProjectile() instanceof PotionInfo) {
            return null;
        }

        final PotionEffectType effect;
        switch(damageType) {
            case POISON: effect = PotionEffectType.POISON; break;
            case WITHER: effect = PotionEffectType.WITHER; break;
            case MAGIC: effect = PotionEffectType.HARM; break;
            default: return null;
        }

        return new GenericPotionInfo(effect);
    }
}