#include <vector>
#include <string>
#include <map>
#include <unordered_map>
#include <utility>
#include <set>
#include <functional>

bool operator>(const GameObject &a, const GameObject &b) {
    return a.id > b.id;
}

bool operator<(const GameObject &a, const GameObject &b) {
    return a.id < b.id;
}

template<class Tp, template<class> class Compare>
class DereferenceCompare {
public:
    Compare<Tp> comp;

    bool operator()(const Tp *const a, const Tp *const b) const {
        return comp(*a, *b);
    }
};

class GameDatabase {
public:
    GameDatabase() = default;

    void Insert(ObjectId id, std::string name, size_t x, size_t y) {
        this->Remove(id);
        GameObject tmp{id, name, x, y};
        this->byId.insert(std::pair<ObjectId, GameObject>(id, tmp));
        this->byPos[std::pair<size_t, size_t>(x, y)].insert(tmp);
        this->byName[name].insert(tmp);
    }

    void Remove(ObjectId id) {
        if (this->byId.find(id) != this->byId.end()) {
            GameObject tmp = this->byId.at(id);
            this->byPos[{tmp.x, tmp.y}].erase(tmp);
            this->byName[tmp.name].erase(tmp);
            this->byId.erase(id);
        }
    }

    std::vector<GameObject> DataByName(std::string name) const {
        std::vector<GameObject> tmp;
        if (this->byName.find(name) != this->byName.end()) {
            for (auto obj = this->byName.at(name).rbegin();
                 obj != this->byName.at(name).rend(); ++obj) {
                tmp.push_back(*obj);
            }
        }
        return tmp;
    }

    std::vector<GameObject> DataByPosition(size_t x, size_t y) const {
        std::vector<GameObject> tmp;
        if (this->byPos.find({x, y}) != this->byPos.end()) {
            for (auto obj = this->byPos.at({x, y}).rbegin();
                 obj != this->byPos.at({x, y}).rend(); ++obj) {
                tmp.push_back(*obj);
            }
        }
        return tmp;
    }

    std::vector<GameObject> Data() const {
        std::vector<GameObject> tmp;
        for (auto pair = this->byId.rbegin();
             pair != this->byId.rend(); ++pair) {
            tmp.push_back(pair->second);
        }
        return tmp;
    }

private:
    std::map<ObjectId, GameObject> byId{};

    std::map<std::pair<size_t, size_t>, std::set<GameObject>> byPos;

    std::unordered_map<std::string, std::set<GameObject>> byName;
};