PkmnLibAI/src/DepthSearchAI.hpp

#ifndef PKMNLIB_AI_DEPTHSEARCHAI_HPP
#define PKMNLIB_AI_DEPTHSEARCHAI_HPP
#include <CreatureLib/Battling/TurnChoices/AttackTurnChoice.hpp>
#include <CreatureLib/Battling/TurnChoices/PassTurnChoice.hpp>
#include <CreatureLib/Battling/TurnChoices/SwitchTurnChoice.hpp>
#include <PkmnLib/Battling/Pokemon/LearnedMove.hpp>
#include <algorithm>
#include <future>
#include <thread>
#include "../cmake-build-release/PkmnLib/src/pkmnlib/src/Battling/Pokemon/PokemonParty.hpp"
#include "NaiveAI.hpp"
#include "PokemonAI.hpp"

namespace PkmnLibAI {
    class DepthSearchAI : public PokemonAI {
        NaiveAI _naive;

    private:
        float ScoreBattle(PkmnLib::Battling::Battle* battle, PkmnLib::Battling::Pokemon* user) {
            auto side = user->GetBattleSide().GetValue();
            if (battle->HasEnded()) {
                if (battle->GetResult().GetWinningSide() == side->GetSideIndex()) {
                    return std::numeric_limits<float>::max();
                } else {
                    return std::numeric_limits<float>::min();
                }
            }
            float score = 0.0;
            auto opposite = GetOppositeIndex(user);
            for (auto* party : battle->GetParties()) {
                if (party->IsResponsibleForIndex(side->GetSideIndex(), 0)) {
                    for (auto& mon : party->GetParty()->GetParty()) {
                        score += mon->GetCurrentHealth() / (float)mon->GetMaxHealth();
                    }
                }
                if (party->IsResponsibleForIndex(opposite)) {
                    for (auto& mon : party->GetParty()->GetParty()) {
                        score -= (mon->GetCurrentHealth() / (float)mon->GetMaxHealth());
                    }
                }
            }
            return score;
        }

        struct BattlePointerWrapper {
            PkmnLib::Battling::Battle* Battle;

            BattlePointerWrapper(PkmnLib::Battling::Battle* battle) : Battle(battle) {}

            inline PkmnLib::Battling::Battle* operator->() const noexcept { return Battle; }

            ~BattlePointerWrapper() {
                std::vector<const CreatureLib::Battling::CreatureParty*> parties;
                for (auto party : Battle->GetParties()) {
                    parties.push_back(party->GetParty().GetRaw());
                }
                delete Battle;
                for (auto party : parties) {
                    delete party;
                }
            }
        };

        std::vector<std::tuple<u8, float>> ScoreChoicesThreaded(PkmnLib::Battling::Battle* battle,
                                                                PkmnLib::Battling::Pokemon* user, uint8_t depth) {
            std::vector<std::future<std::tuple<u8, float>>> threadPool;
            auto side = user->GetBattleSide().GetValue();
            for (u8 moveIndex = 0; moveIndex < (u8)user->GetMoves().Count(); ++moveIndex) {
                auto move = user->GetMoves()[moveIndex];
                if (move->GetRemainingUses() == 0) {
                    continue;
                }
                threadPool.push_back(std::async([=] {
                    auto v = std::tuple(moveIndex, SimulateTurn(battle, side->GetSideIndex(), 0, moveIndex, depth));
                    asThreadCleanup();
                    return v;
                }));
            }
            auto& party = battle->GetParties()[side->GetSideIndex()]->GetParty()->GetParty();
            for (u8 i = 0; i < party.Count(); ++i) {
                auto mon = party[i];
                if (!mon.HasValue()) {
                    continue;
                }
                if (mon.GetValue()->IsFainted()) {
                    continue;
                }
                threadPool.push_back(std::async([=] {
                    auto v = std::tuple((u8)(i + 4), SimulateTurn(battle, side->GetSideIndex(), 0, i + 4, depth));
                    asThreadCleanup();
                    return v;
                }));
            }
            std::vector<std::tuple<u8, float>> results(threadPool.size());
            for (int i = 0; i < threadPool.size(); ++i) {
                results[i] = threadPool[i].get();
            }
            return results;
        }

        std::vector<std::tuple<int, float>> ScoreChoices(PkmnLib::Battling::Battle* battle,
                                                         PkmnLib::Battling::Pokemon* user, uint8_t depth) {
            std::vector<std::tuple<int, float>> scoredMoves;
            auto side = user->GetBattleSide().GetValue();
            for (u8 moveIndex = 0; moveIndex < (u8)user->GetMoves().Count(); ++moveIndex) {
                auto move = user->GetMoves()[moveIndex];
                if (move->GetRemainingUses() == 0) {
                    continue;
                }
                auto scored = SimulateTurn(battle, side->GetSideIndex(), 0, moveIndex, depth);
                scoredMoves.emplace_back(moveIndex, scored);
            }
            auto& party = battle->GetParties()[side->GetSideIndex()]->GetParty()->GetParty();
            for (int i = 0; i < party.Count(); ++i) {
                auto mon = party[i];
                if (!mon.HasValue()) {
                    continue;
                }
                if (mon.GetValue()->IsFainted()) {
                    continue;
                }
                auto scored = SimulateTurn(battle, side->GetSideIndex(), 0, i + 4, depth);
                scoredMoves.emplace_back(i + 4, scored);
            }
            return scoredMoves;
        }

        float SimulateTurn(PkmnLib::Battling::Battle* originalBattle, u8 sideIndex, u8 pokemonIndex, u8 index,
                           u8 depth) {
            auto battle = BattlePointerWrapper(originalBattle->Clone());
            auto user =
                dynamic_cast<PkmnLib::Battling::Pokemon*>(battle->GetCreature(sideIndex, pokemonIndex).GetValue());
            auto target = GetOppositeIndex(user);
            if (index < 4) {
                auto move = user->GetMoves()[index];
                auto choice = new CreatureLib::Battling::AttackTurnChoice(user, move, target);
                if (!battle->TrySetChoice(choice)) {
                    delete choice;
                    return std::numeric_limits<float>::min();
                }
            } else {
                auto mon = battle->GetParties()[sideIndex]->GetParty()->GetParty().At(index - 4);
                auto choice = new CreatureLib::Battling::SwitchTurnChoice(user, mon);
                if (!battle->TrySetChoice(choice)) {
                    delete choice;
                    return std::numeric_limits<float>::min();
                }
            }
            battle->TrySetChoice(_naive.GetChoice(
                battle.Battle, dynamic_cast<PkmnLib::Battling::Pokemon*>(battle->GetCreature(target).GetValue())));

            float score;
            if (depth <= 1) {
                score = ScoreBattle(battle.Battle, user);
            } else {
                auto scoredChoices = ScoreChoices(battle.Battle, user, depth - 1);
                float summedScore = 0;
                size_t amount = 0;
                for (auto& option : scoredChoices) {
                    summedScore += std::get<1>(option);
                    amount++;
                }
                if (amount == 0) {
                    return std::numeric_limits<float>::min();
                }

                score = summedScore / amount;
            }
            return score;
        }

    public:
        std::string GetName() const noexcept override { return "depthsearch"; }

        CreatureLib::Battling::BaseTurnChoice* GetChoice(PkmnLib::Battling::Battle* battle,
                                                         PkmnLib::Battling::Pokemon* user) override {
            auto scoredChoices = ScoreChoicesThreaded(battle, user, 2);
            auto side = user->GetBattleSide().GetValue();
            auto& party = battle->GetParties()[side->GetSideIndex()]->GetParty()->GetParty();

            auto target = GetOppositeIndex(user);
            if (scoredChoices.empty()) {
                return battle->GetLibrary()->GetMiscLibrary()->ReplacementAttack(user, target);
            }

            i32 highest = -1;
            float highestScore = -std::numeric_limits<float>::infinity();
            for (auto& option : scoredChoices) {
                if (std::get<1>(option) > highestScore) {
                    highestScore = std::get<1>(option);
                    highest = std::get<0>(option);
                }
            }
            if (highest == -1) {
                return battle->GetLibrary()->GetMiscLibrary()->ReplacementAttack(user, target);
            }

            if (highest < 4) {
                return new CreatureLib::Battling::AttackTurnChoice(user, user->GetMoves()[highest], target);
            } else {
                return new CreatureLib::Battling::SwitchTurnChoice(user, party.At(highest - 4));
            }
        }
    };
}

#endif // PKMNLIB_AI_DEPTHSEARCHAI_HPP