Arakne / Araknemu

 * This file is part of Araknemu.

 *

 * Araknemu is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Lesser General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * Araknemu is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with Araknemu.  If not, see <https://www.gnu.org/licenses/>.

 *

 * Copyright (c) 2017-2022 Vincent Quatrevieux

 */

package fr.quatrevieux.araknemu.game.fight.castable.effect.handler.misc;

import fr.quatrevieux.araknemu.game.fight.Fight;

import fr.quatrevieux.araknemu.game.fight.castable.CastScope;

import fr.quatrevieux.araknemu.game.fight.castable.FightCastScope;

import fr.quatrevieux.araknemu.game.fight.castable.Castable;

import fr.quatrevieux.araknemu.game.fight.castable.effect.EffectsUtils;

import fr.quatrevieux.araknemu.game.fight.castable.effect.buff.Buff;

import fr.quatrevieux.araknemu.game.fight.castable.effect.buff.BuffHook;

import fr.quatrevieux.araknemu.game.fight.castable.effect.handler.EffectHandler;

import fr.quatrevieux.araknemu.game.fight.fighter.Fighter;

import fr.quatrevieux.araknemu.game.fight.fighter.FighterData;

import fr.quatrevieux.araknemu.game.spell.effect.SpellEffect;

import fr.quatrevieux.araknemu.network.game.out.fight.CellShown;

/**

 * Handle invisibility effect

 *

 * This effect only works has buff : direct effect is not supported

 * The hidden flag will be changed on buff start and termination

 *

 * When the fighter cast a spell or close combat attack, he will lose its invisibility if he performs direct damage.

 * For other spells (or close combat) effects, the cast cell (i.e. current cell of the caster) will be shown to all fighters.

 *

 * Note: If two (or more) invisibility buffs are effective on a fighter, the invisibility state will be terminated

 * with the last (i.e. longest) buff.

 *

 * @see FighterData#hidden() Check the hidden state

 * @see Fighter#setHidden(FighterData, boolean) Called by the handler for change hidden state

 */

public final class InvisibilityHandler implements EffectHandler, BuffHook {

    private final Fight fight;

    public InvisibilityHandler(Fight fight) {

        this.fight = fight;

    }

    @Override

    public void handle(FightCastScope cast, FightCastScope.EffectScope effect) {

        throw new UnsupportedOperationException("Invisibility effect must be used as a buff");

    }

    @Override

    public void buff(FightCastScope cast, FightCastScope.EffectScope effect) {

        final SpellEffect spellEffect = effect.effect();

        final Fighter caster = cast.caster();

        final Castable action = cast.action();

        for (Fighter target : effect.targets()) {

            target.buffs().add(new Buff(spellEffect, action, caster, target, this));

        }

    }

    @Override

    public void onBuffStarted(Buff buff) {

        buff.target().setHidden(buff.caster(), true);

    }

    }

    @Override

    public void onCast(Buff buff, FightCastScope cast) {

        final Fighter target = buff.target();

        if (!target.hidden()) {

            return;

        }

        // The fighter cast a damage effect : he loses its invisibility

        if (hasDirectDamageEffect(cast)) {

            target.setHidden(target, false);

            return;

        }

        // Show cell only on the first buff

        if (isFirstInvisibilityBuff(target, buff)) {

            fight.send(new CellShown(target, target.cell().id()));

        }

    }

    /**

     * Check if another active invisibility buff is present

     */

    private boolean hasOtherInvisibilityBuff(FighterData fighter) {

        for (Buff activeBuff : fighter.buffs()) {

            // Another invisibility buff exists : do not set target visible

            if (activeBuff.valid() && activeBuff.hook() == this) {

                return true;

            }

        }

        return false;

    }

    /**

     * Does the given cast will perform direct damage or not

     */

    private boolean hasDirectDamageEffect(FightCastScope cast) {

        for (CastScope.EffectScope<Fighter> effect : cast.effects()) {

            final SpellEffect spellEffect = effect.effect();

            if (spellEffect.duration() == 0 && EffectsUtils.isDamageEffect(spellEffect.effect())) {

                return true;

            }

        }

        return false;

    }

    /**

     * Check if the given buff is the first of the buff list

     */

    private boolean isFirstInvisibilityBuff(FighterData fighter, Buff currentBuff) {

        for (Buff otherBuff : fighter.buffs()) {

            if (otherBuff.hook() == this) {

                // Current buff is not the first active invisibility buff

                return otherBuff == currentBuff;

            }

        }

        // Should not occur

        return true;

    }

}