FireListener

import java.util.HashMap;
import org.bukkit.Bukkit;
import org.bukkit.entity.Entity;
import org.bukkit.entity.LivingEntity;
import org.bukkit.entity.Player;
import org.bukkit.entity.SmallFireball;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.entity.EntityDamageByEntityEvent;
import org.bukkit.event.entity.EntityDeathEvent;
import org.bukkit.event.player.PlayerQuitEvent;
import org.bukkit.scheduler.BukkitScheduler;

import static org.bukkit.entity.EntityType.SMALL_FIREBALL;
import static org.bukkit.event.entity.EntityDamageEvent.DamageCause.FIRE_TICK;
import static org.bukkit.event.EventPriority.MONITOR;

import com.herocraftonline.heroes.Heroes;
import com.herocraftonline.heroes.characters.Hero;
import com.herocraftonline.heroes.characters.classes.HeroClass.ExperienceType;

/** Should give exp to players kill entities with fireballs
 *  It looks like it turned out well for being written in under
 *  an hour. Note it is untested
 *
 *  I, Roadkill909, the author of this class allow anyone to use, modify, distribute,
 * or relicense this source file or this file in compiled form without restriction
 *  @author Roadkill909 */
public class FireListener implements Listener{
    private static HashMap<LivingEntity,BurningEntityInfo> onFireEntities =
            new HashMap<LivingEntity,BurningEntityInfo>();
    private final Heroes heroes;

    private FireListener(Heroes heroes) {
        this.heroes = heroes;
    }

    /** checks if a fireball casted by a hero hits
     * an entity and adds this info to the collection of onFireEntities.
     * If the collection already contains that entity, the hero and removal task are reset */
    @EventHandler(ignoreCancelled=true, priority=MONITOR)
    public void onEntityDamageByEntity(EntityDamageByEntityEvent event){
        final Entity victim = event.getEntity();
        if(!(victim instanceof LivingEntity))return;

        //check if fireball
        final Entity damager = event.getDamager();
        final SmallFireball projectile;
        if(damager.getType()==SMALL_FIREBALL)
            projectile=(SmallFireball) damager;
        else return;

        //check if hero is caster
        final LivingEntity caster = projectile.getShooter();
        final Hero heroicCaster;
        if(caster!=null&&caster instanceof Player){
            heroicCaster =heroes.getCharacterManager().getHero((Player) caster);
            final BurningEntityInfo info = onFireEntities.get(victim);
            if(info==null){
                new BurningEntityInfo((LivingEntity) victim,heroicCaster);
            }else{
                info.reset(heroicCaster);//used if the entity is already on fire and in the collection of onFireEntities
            }
        }
    }

    /** attempts to remove the entity, if removed, gives the Hero Exp */
    @EventHandler(ignoreCancelled=true, priority=MONITOR)
    public void onEntityDeath(EntityDeathEvent event){
        final LivingEntity entity = event.getEntity();
        final BurningEntityInfo info = onFireEntities.remove(entity);
        if(entity.getLastDamageCause().getCause()!=FIRE_TICK&&info!=null){
            info.caster.gainExp(
                    heroes.getCharacterManager().getMonster(entity).getExperience(),
                    ExperienceType.KILLING,
                    entity.getLocation()
                );
        }
    }

    /** attempts to remove the entity if it's a player that logs out */
    @EventHandler(priority=MONITOR)
    public void onPlayerQuit(PlayerQuitEvent event){
        onFireEntities.remove(event.getPlayer());
    }

    /** I was going to make this two different classes stored in two different maps,
     * but seemed safer to combine this.
     *
     * This task when run removes the entity from the onFireEntities
     * can be reset if another/same hero hits the same entity agains
     */
    private final class BurningEntityInfo implements Runnable{
        private final LivingEntity victim;
        private Hero caster;
        private int taskId;

        private BurningEntityInfo(LivingEntity victim, Hero caster) {
            this.victim=victim;
            this.caster=caster;
            taskId= Bukkit.getScheduler().scheduleSyncDelayedTask(heroes,this,victim.getFireTicks());
            onFireEntities.put(victim,this);
        }

        /** removes the burning entity when run*/
        public void run() {
            onFireEntities.remove(victim);
        }

        /** Used if the entity is hit again by a fireball
         * it reschedules the task and restores the hero object
         * in case it is a different hero (Two mages hitting the same target */
        private void reset(Hero caster){
            this.caster=caster;
            BukkitScheduler schedule = Bukkit.getScheduler();
            schedule.cancelTask(taskId);
            taskId=schedule.scheduleSyncDelayedTask(heroes, this, victim.getFireTicks());
        }
    }
}