SimulatedGameNode.h

// Copyright QED Software 2023.
 
#ifndef GRAIL_SIMULATED_GAME_NODE_H
#define GRAIL_SIMULATED_GAME_NODE_H
 
#include <memory>
#include <random>
#include <unordered_map>
#include <vector>
#include "ISimulatedGameAction.hh"
#include "SimulatedGameActionMetadata.hh"
 
using RandomGenerator = std::mt19937_64;
 
namespace grail
{
namespace simgames
{
 class SimulatedGameThinkingUnit;
 class ISimulatedGameUnit;
 class SimulatedGameSnapshotObserver;
 struct SimulatedGameHelper;
 
 class SimulatedGameNode
 {
 public:
 SimulatedGameNode(ISimulatedGameUnit*, SimulatedGameRuntime& runtime);
 SimulatedGameNode(SimulatedGameNode&&) = default;
 
 void Backpropagate(float score);
 
 const ISimulatedGameAction* GetRandomAction(RandomGenerator& rand_gen);
 void PerformActionByIndex(size_t actionIndex, SimulatedGameRuntime& runtime);
 
 ISimulatedGameUnit* GetActiveUnit() const;
 
 SimulatedGameNode* SelectNext(SimulatedGameHelper& helper, RandomGenerator& rand_gen);
 SimulatedGameNode* SelectNext(SimulatedGameHelper& helper,
 RandomGenerator& rand_gen,
 SimulatedGameSnapshotObserver& observer);
 SimulatedGameNode* PerformUCT(SimulatedGameHelper& helper, RandomGenerator& rand_gen);
 
 std::vector<SimulatedGameActionMetadata> GetActionsWithMetadata() const;
 void FillPlan(std::unordered_map<const ISimulatedGameUnit*, std::vector<const ISimulatedGameAction*>>& plan,
 int teamIndex) const;
 void FillPlanWithMetadata(
 std::unordered_map<const ISimulatedGameUnit*, std::vector<SimulatedGameActionMetadata>>& plan,
 int teamIndex) const;
 void FillPath(std::vector<std::pair<const ISimulatedGameUnit*, const ISimulatedGameAction*>>& path) const;
 
 const ISimulatedGameAction* GetBestAction() const;
 const SimulatedGameActionMetadata GetBestActionMetadata() const;
 const ISimulatedGameAction& GetActionByIndex(size_t actionIndex) const;
 double GetVisits() const;
 
 std::vector<std::unique_ptr<SimulatedGameNode>> children{};
 
 bool IsTerminal() const;
 private:
 size_t GetBestActionIndex() const;
 
 ISimulatedGameUnit* activeUnit = nullptr;
 double totalScore = 0.0;
 double q = 0.0;
 std::vector<std::unique_ptr<const ISimulatedGameAction>> actions{};
 std::vector<float> terminalScores{};
 
 double visits = 0.0;
 
 friend class SimulatedGame;
 };
}
}
#endif //GRAIL_SIMULATED_GAME_NODE_H