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) 2017-2021 Vincent Quatrevieux

 */

package fr.quatrevieux.araknemu.game.fight.ai.action;

import fr.quatrevieux.araknemu.game.fight.ai.AI;

import fr.quatrevieux.araknemu.game.fight.ai.simulation.CastSimulation;

import fr.quatrevieux.araknemu.game.fight.ai.simulation.Simulator;

import fr.quatrevieux.araknemu.game.fight.turn.action.Action;

import java.util.Optional;

/**

 * Try to attack enemies

 *

 * Select spells causing damage on enemies

 * All cells are tested for select the most effective target for each spells

 */

public final class Attack implements ActionGenerator, CastSpell.SimulationSelector {

    private final CastSpell generator;

    private final SuicideStrategy suicideStrategy;

    private double averageEnemyLifePoints = 0;

    private int enemiesCount = 0;

    public Attack(Simulator simulator) {

        this(simulator, SuicideStrategy.IF_KILL_ENEMY);

    }

    public Attack(Simulator simulator, SuicideStrategy suicideStrategy) {

        this.generator = new CastSpell(simulator, this);

        this.suicideStrategy = suicideStrategy;

    }

    @Override

    public void initialize(AI ai) {

        generator.initialize(ai);

        averageEnemyLifePoints = ai.helper().enemies().stream().mapToInt(fighter -> fighter.life().max()).average().orElse(0);

        enemiesCount = ai.helper().enemies().count();

    }

    @Override

    public Optional<Action> generate(AI ai) {

        return generator.generate(ai);

    }

    @Override

    public boolean valid(CastSimulation simulation) {

        if (simulation.enemiesLife() >= 0) {

            return false;

        }

        // Kill all enemies

        if (simulation.killedEnemies() >= enemiesCount) {

            return true;

        }

        if (!suicideStrategy.allow(simulation)) {

            return false;

        }

        // Kill more allies than enemies

        if (simulation.killedAllies() > simulation.killedEnemies()) {

            return false;

        }

        // At least one enemy will be killed

        if (simulation.killedEnemies() >= 0.99) {

            return true;

        }

        // Cause more damage on enemies than allies

        return simulation.enemiesLife() < simulation.alliesLife() + simulation.selfLife();

    }

    @Override

    public boolean compare(CastSimulation a, CastSimulation b) {

        return score(a) > score(b);

    }

    /**

     * Compute the score for the given simulation

     *

     * @param simulation The simulation result

     *

     * @return The score of the simulation. 0 is null

     */

    public double score(CastSimulation simulation) {

        final double score = damageScore(simulation) + killScore(simulation) + boostScore(simulation);

        return score / simulation.spell().apCost();

    }

    private double damageScore(CastSimulation simulation) {

        return - simulation.enemiesLife() + simulation.alliesLife() + simulation.selfLife() * 2;

    }

    private double killScore(CastSimulation simulation) {

        final double killRatio = simulation.killedEnemies()

            - 1.5 * simulation.killedAllies()

            - 2 * simulation.suicideProbability()

        ;

        return averageEnemyLifePoints * killRatio;

    }

    /**

     * Filter the cast by the suicide probability

     *

     * @see CastSimulation#suicideProbability()

     */

    enum SuicideStrategy {

        /**

         * Always allow suicide

         * Should be used on The Sacrificial Doll AI

         */

        ALLOW {

            @Override

            public boolean allow(CastSimulation simulation) {

                return true;

            }

        },

        /**

         * Suicide is never accepted

         */

        DENY {

            @Override

            public boolean allow(CastSimulation simulation) {

                return simulation.suicideProbability() <= 0;

            }

        },

        /**

         * Suicide is accepted only if there is more chance (or number) to kill an enemy

         */

        IF_KILL_ENEMY {

            @Override

            public boolean allow(CastSimulation simulation) {

                return simulation.suicideProbability() <= simulation.killedEnemies();

            }

        },

        ;

        /**

         * Does the simulation is allowed about the suicide probability ?

         *

         * @param simulation The cast simulation to check

         *

         * @return false if the cast must not be performed

         */

        public abstract boolean allow(CastSimulation simulation);

    }

}