#pragma once

#include <string>
#include <thread>
#include "../data/math.hpp"
#include "../data/safe_queue.hpp"
#include "../data/safe_priority_queue.hpp"
#include "../data/circular_buffer.hpp"
#include "../data/geometry/Ray.hpp"
#include "../data/geometry/Frustum.hpp"
#include "forward.h"
#include "Area.hpp"
#include "Voxel.hpp"

namespace contouring {
    class Abstract;
};
namespace buffer {
    class Abstract;
}

using namespace data;
/// Universe data
namespace world {
    /// Whole universe container
    class Universe {
    public:
        /// Distance management
        struct options {
            /// Radius in chunks to load if missing
            int loadDistance = 5;
            /// Radius in chunks to keep in memory
            int keepDistance = 6;
            /// Storage path
            std::string folderPath = "world";
        };

        Universe(const options &);
        ~Universe();

        /// Update physics and contouring
        void update(const voxel_pos &pos, float deltaTime);
        /// Apply new options
        void setOptions(const options &);

        struct ray_target {
            area_<voxel_pos> pos;
            Voxel value;
            voxel_pos offset;
        };
        /// Get nearest voxel colliding ray
        /// @note ray in world scale
        std::optional<ray_target> raycast(const geometry::Ray &ray) const;
        /// Set voxel at pos
        std::optional<Item> set(const area_<voxel_pos> &pos, const Voxel &val);
        /// Set cube of voxel with pos as center
        /// MAYBE: allow set multi area
        ItemList setCube(const area_<voxel_pos> &pos, const Voxel &val, int radius);
        /// Check for collision on movement
        bool collide(const glm::ifvec3 &pos, const glm::vec3 &vel, int density, float radius = 0) const;
        /// Move with collision check
        /// @note must remove velocity after colision
        bool move(glm::ifvec3 &pos, const glm::vec3 &vel, int density, float radius = 0) const;

        /// Entities commun properties
        struct Entity {
            Entity(buffer::Abstract* buffer, const glm::vec3& size = glm::vec3(1), const glm::vec3& scale = glm::vec3(1)):
                buffer(buffer), size(size), scale(scale) { };
            buffer::Abstract* buffer;
            glm::vec3 size;
            glm::vec3 scale;
            struct Instance {
                glm::ifvec3 pos;
                glm::vec3 velocity;
            };
            data::generational::vector<Instance> instances;
        };
        /// Instante entity
        entity_instance_id addEntity(entity_id type, const Entity::Instance &instance);
        void getEntitiesModels(std::vector<std::pair<std::vector<glm::mat4>, buffer::Abstract *const>> &buffers, const std::optional<geometry::Frustum> &frustum, const glm::llvec3 &offset, int density);

        /// Change contouring worker
        void setContouring(const std::shared_ptr<contouring::Abstract>& ct);
        /// Get current contouring worker
        std::shared_ptr<contouring::Abstract> getContouring() const {
            return contouring;
        }

    private:
        chunk_pos last_pos = chunk_pos(INT_MAX);

        /// Alive areas containing chunks
        area_map areas;
        using area_it_t = robin_hood::pair<area_id, std::shared_ptr<Area>>;
        /// Dead areas
        data::generational::vector<Area::params> far_areas;
        void saveAreas() const;

        data::generational::vector<Entity> entities;

        bool running = true;
        std::vector<std::thread> workers;
        safe_priority_queue_map<area_<chunk_pos>, std::shared_ptr<Area>, int, area_hash> loadQueue; //NOTE: consider Area const (getRegion uses mutex)
        safe_queue<robin_hood::pair<area_<chunk_pos>, std::shared_ptr<Chunk>>> loadedQueue;

        using save_task_t = std::pair<area_it_t, robin_hood::pair<chunk_pos, std::shared_ptr<Chunk>>>;
        data::safe_queue<save_task_t> saveQueue; //NOTE: consider Area and Chunk const

        int loadDistance;
        int keepDistance;
        std::string folderPath;

        dict_set dicts;

        /// Contouring worker
        std::shared_ptr<contouring::Abstract> contouring;
    };
}