Arakne / Araknemu

public final class DamageApplier {

    private final Element element;

    private final Fight fight;

    public DamageApplier(Element element, Fight fight) {

        this.element = element;

        this.fight = fight;

    }

    /**

     * Apply a direct damage effect to a fighter

     *

     * Note: do not use this method for a buff, it will call the invalid buff hook

     *

     * @param caster The spell caster

     * @param effect The effect to apply

     * @param target The target

     *

     * @return The real damage value

     *

     * @see DamageApplier#apply(Buff) For apply a buff damage (i.e. poison)

     * @see fr.quatrevieux.araknemu.game.fight.castable.effect.buff.Buffs#onDirectDamage(ActiveFighter, Damage) The called buff hook

     */

    public int apply(ActiveFighter caster, SpellEffect effect, PassiveFighter target) {

        final Damage damage = computeDamage(caster, effect, target);

        return applyDirectDamage(caster, damage, target);

    }

    /**

     * Apply a fixed (i.e. precomputed) amount of damage on the target

     *

     * Like {@link DamageApplier#apply(ActiveFighter, SpellEffect, PassiveFighter)} :

     * - resistance are applied

     * - direct damage buff are called

     * - returned damage are applied

     *

     * @param caster The spell caster

     * @param value The damage value. Must be positive. Can be 0 for no damage.

     * @param target The cast target

     *

     * @return The applied damage value. Negative for damage, or positive for heal.

     *

     * @see DamageApplier#applyFixed(Buff, int) For apply a precomputed damage buff

     * @see fr.quatrevieux.araknemu.game.fight.castable.effect.buff.Buffs#onDirectDamage(ActiveFighter, Damage) The called buff hook

     */

    public int applyFixed(ActiveFighter caster, int value, PassiveFighter target) {

        final Damage damage = createDamage(caster, target, value);

        return applyDirectDamage(caster, damage, target);

    }

    /**

     * Apply a damage buff effect

     *

     * @param buff Buff to apply

     *

     * @return The real damage value

     *

     * @see fr.quatrevieux.araknemu.game.fight.castable.effect.buff.Buffs#onBuffDamage(Buff, Damage) The called buff hook

     */

    public int apply(Buff buff) {

        final PassiveFighter target = buff.target();

        final ActiveFighter caster = buff.caster();

        final Damage damage = computeDamage(caster, buff.effect(), target);

        return applyBuffDamage(buff, damage, target);

    }

    /**

     * Apply a fixed (i.e. precomputed) amount of damage on the target from a buff

     *

     * Like {@link DamageApplier#apply(Buff)} :

     * - resistance are applied

     * - buff damage buff are called

     *

     * @param buff Buff to apply

     * @param value The damage value. Must be positive. Can be 0 for no damage.

     *

     * @return The applied damage value. Negative for damage, or positive for heal.

     *

     * @see fr.quatrevieux.araknemu.game.fight.castable.effect.buff.Buffs#onBuffDamage(Buff, Damage) The called buff hook

     */

    public int applyFixed(Buff buff, int value) {

        final PassiveFighter target = buff.target();

        final Damage damage = createDamage(buff.caster(), target, value);

        return applyBuffDamage(buff, damage, target);

    }

    /**

     * Create the damage object

     */

    private Damage computeDamage(ActiveFighter caster, SpellEffect effect, PassiveFighter target) {

        final EffectValue value = EffectValue.create(effect, caster, target)

            .percent(caster.characteristics().get(element.boost()))

            .percent(caster.characteristics().get(Characteristic.PERCENT_DAMAGE))

            .fixed(caster.characteristics().get(Characteristic.FIXED_DAMAGE))

        ;

        return createDamage(caster, target, value.value());

    }

    /**

     * Apply damage to the target for direct damage

     *

     * This method will call direct damage buff and apply returned damage

     *

     * @return The life change value. Negative for damage, positive for heal.

     */

    private int applyDirectDamage(ActiveFighter caster, Damage damage, PassiveFighter target) {

        target.buffs().onDirectDamage(caster, damage);

        if (!caster.equals(target)) {

            damage.reflect(target.characteristics().get(Characteristic.COUNTER_DAMAGE));

        }

        return applyDamage(caster, damage, target);

    }

    /**

     * Apply damage to the target for buff damage

     *

     * This method will call buff damage buff

     *

     * @return The life change value. Negative for damage, positive for heal.

     */

    private int applyBuffDamage(Buff buff, Damage damage, PassiveFighter target) {

        target.buffs().onBuffDamage(buff, damage);

        return applyDamage(buff.caster(), damage, target);

    }

    /**

     * Apply the damage object to the target

     *

     * @return The life change value. Negative for damage, positive for heal.

     */

    private int applyDamage(ActiveFighter caster, Damage damage, PassiveFighter target) {

        if (damage.reducedDamage() > 0) {

            fight.send(ActionEffect.reducedDamage(target, damage.reducedDamage()));

        }

        final int lifeChange = target.life().alter(caster, -damage.value());

        if (lifeChange < 0 && !target.equals(caster) && damage.reflectedDamage() > 0) {

            applyReflectedDamage(target, caster, damage);

        }

        return lifeChange;

    }

    /**

     * Apply returned damage on the original caster

     *

     * Notes:

     * - do not handle target change chain

     * - use resistance on returned damage ?

     *

     * @param caster The original spell caster

     * @param damage The applied damage

     */

    private void applyReflectedDamage(PassiveFighter castTarget, ActiveFighter caster, Damage damage) {

        final ReflectedDamage returnedDamage = new ReflectedDamage(damage, caster);

        caster.buffs().onReflectedDamage(returnedDamage);

        if (returnedDamage.baseValue() > 0) {

            fight.send(ActionEffect.reflectedDamage(castTarget, returnedDamage.baseValue()));

            returnedDamage.target().life().alter(castTarget, -returnedDamage.value());

        }

    }

    /**

     * Create the damage object, and call {@link fr.quatrevieux.araknemu.game.fight.castable.effect.buff.Buffs#onCastDamage(Damage, PassiveFighter)}

     *

     * @param caster The spell caster

     * @param target The effect target

     * @param value Raw damage value

     *

     * @return The damage object to apply

     */

    private Damage createDamage(ActiveFighter caster, PassiveFighter target, int value) {

        final Damage damage = new Damage(value, element)

            .percent(target.characteristics().get(element.percentResistance()))

            .fixed(target.characteristics().get(element.fixedResistance()))

        ;

        caster.buffs().onCastDamage(damage, target);

        return damage;