ShieldPlayerModule.java

package tc.oc.pgm.shield;

import java.util.logging.Logger;

import org.bukkit.Sound;
import org.bukkit.entity.Player;
import org.bukkit.event.entity.EntityDamageEvent;
import org.bukkit.event.entity.PotionEffectRemoveEvent;
import org.bukkit.potion.PotionEffectType;
import tc.oc.commons.core.logging.ClassLogger;
import tc.oc.commons.core.util.TimeUtils;
import tc.oc.pgm.match.Match;
import tc.oc.pgm.match.MatchPlayer;

public class ShieldPlayerModule {

    private final ShieldMatchModule smm;
    private final Logger logger;
    private final MatchPlayer player;
    private final Player bukkit;
    private final ShieldParameters parameters;

    // Current shield strength, which may be less than the player's absorption
    // if they are getting some from a potion effect.
    private double shieldHealth;

    // Ticks until next shield recharge.
    private long rechargeTicks;

    public ShieldPlayerModule(ShieldMatchModule smm, MatchPlayer player, ShieldParameters parameters) {
        this.smm = smm;
        this.logger = ClassLogger.get(smm.getLogger(), getClass(), player.getName());
        this.player = player;
        this.bukkit = player.getBukkit();
        this.parameters = parameters;
        this.shieldHealth = parameters.maxHealth;
    }

    double getAbsorption() {
        return bukkit.getAbsorption();
    }

    void setAbsorption(double absorption) {
        bukkit.setAbsorption((float) absorption);
    }

    void addAbsorption(double delta) {
        if(delta != 0d) setAbsorption(getAbsorption() + delta);
    }

    public void apply() {
        addAbsorption(shieldHealth);
    }

    public void remove() {
        addAbsorption(-shieldHealth);
    }

    /**
     * Recharge the shield to its maximum health. If the player has more
     * absorption than the current shield strength, the excess is preserved.
     */
    void recharge() {
        if(shieldHealth < parameters.maxHealth) {
            double delta = parameters.maxHealth - shieldHealth;
            logger.fine("Recharging shield: shield=" + shieldHealth + " delta=" + delta);
            shieldHealth = parameters.maxHealth;
            addAbsorption(delta);
            bukkit.playSound(bukkit.getLocation(), Sound.ENTITY_EXPERIENCE_ORB_PICKUP, 1, 2);
        }
    }

    void damage() {
        rechargeTicks = TimeUtils.toTicks(parameters.rechargeDelay);
    }

    public void tick(Match match) {
        if(rechargeTicks > 0) {
            if(--rechargeTicks == 0) {
                recharge();
            }
        } else {
            // Detect shield damage, in case it somehow happens without firing an event.
            double absorption = getAbsorption();
            if(shieldHealth > absorption) {
                logger.fine("Detected unexpected shield damage: shield=" + shieldHealth + " absorption=" + absorption);
                shieldHealth = absorption;
                damage();
            }
        }
    }

    void onEvent(EntityDamageEvent event) {
        if(event.getFinalDamage() > 0) {
            // Absorbed damage is applied to the shield before any potion effect
            double shieldDamage = -event.getDamage(EntityDamageEvent.DamageModifier.ABSORPTION);
            logger.fine("Absorbing damage with shield: shield=" + shieldHealth + " shieldDamage=" + shieldDamage);
            shieldHealth = Math.max(0, shieldHealth - shieldDamage);

            damage();
        }
    }

    void onEvent(PotionEffectRemoveEvent event) {
        // The NMS code assumes that a potion effect is the only way to get
        // absorption hearts, so when the effect is removed, it simply removes
        // the same amount of absorption that it added initially. If any of that
        // eats into the shield, we refund the difference.
        if(PotionEffectType.ABSORPTION.equals(event.getEffect().getType())) {
            double newAbsorption = Math.max(0, getAbsorption() - 4 * (1 + event.getEffect().getAmplifier()));
            if(newAbsorption < shieldHealth) {
                logger.fine("Compensating for removal of absorption " + event.getEffect().getAmplifier() +
                            " effect, which will reduce absorption hearts to " + newAbsorption +
                            ", which is below shield health of " + shieldHealth);
                addAbsorption(shieldHealth - newAbsorption);
            }
        }
    }
}