zMobFighter addon - Fireball

package fr.maxlego08.fireball ;

import java.util.ArrayList ;
import java.util.List ;
import java.util.Random ;
import org.bukkit.entity.Entity ;
import org.bukkit.entity.Fireball ;
import org.bukkit.entity.LivingEntity ;
import org.bukkit.event.EventHandler ;
import org.bukkit.event.Listener ;
import org.bukkit.event.entity.EntityExplodeEvent ;
import org.bukkit.potion.PotionEffect ;
import org.bukkit.potion.PotionEffectType ;
import org.bukkit.util.Vector ;
import fr.maxlego08.mobfighter.api.Arena ;
import fr.maxlego08.mobfighter.api.Duel ;
import fr.maxlego08.mobfighter.api.Fighter ;
import fr.maxlego08.mobfighter.api.addons.JavaAddon ;
public class FireBallAddon extends JavaAddon implements Listener {
    private long lastAttackSend = 0 ;
    private List <Fireball > fireBalls = new ArrayList <Fireball > ( ) ;
    @Override
    public void onEnable ( ) {
        System. out. println ( "Enable !" ) ;
        this. registerListener ( this ) ;
    }
    @Override
    public void onDisable ( ) {
        System. out. println ( "Disable !" ) ;
    }
    @Override
    public void duelStart (Duel duel, Arena arena, Fighter first, Fighter second ) {
        // TODO Auto-generated method stub
    }
    @Override
    public void duelStop (Duel duel, Arena arena, Fighter first, Fighter second ) {
        // TODO Auto-generated method stub
    }
    @Override
    public void duelWin (Duel duel, Arena arena, Fighter first, Fighter second ) {
        // TODO Auto-generated method stub
    }
    @Override
    public void duelTick (Duel duel, Arena arena, Fighter first, Fighter second ) {
        if ( System. currentTimeMillis ( ) > lastAttackSend && first. getLocation ( ). distance (second. getLocation ( ) ) > 5 ) {
            Random random = new Random ( ) ;
            Fighter fighter = random. nextBoolean ( ) ? first : second ;
                   
            LivingEntity entity = fighter. getEntity ( ) ;
           
            entity. addPotionEffect ( new PotionEffect (PotionEffectType. SLOW, 20, 150 ) ) ;
           
            Fireball fireball = entity. launchProjectile (Fireball. class ) ;      
           
            Vector vector = fireball. getVelocity ( ) ;
            fireball. setVelocity (vector ) ;
           
            fireBalls. add (fireball ) ;
            lastAttackSend = System. currentTimeMillis ( ) + ( 1000 * (random. nextInt ( 2 ) + 1 ) ) ;
        }
    }
    @EventHandler
    public void onEntityExplode (EntityExplodeEvent event ) {
        Entity entity = event. getEntity ( ) ;
        if ( this. fireBalls. contains (entity ) ) {
            event. setCancelled ( true ) ;          
            this. fireBalls. remove (entity ) ;
        }
    }
}