#ifndef __CHUNK_H__
#define __CHUNK_H__

#include "util/Common.h"
#include "planet/Planet.h"
#include "Camera.h"

#define CHUNK_SIZE 16

struct Vertex
{
	glm::vec3 position;
	glm::vec3 normal;
	glm::vec2 uv;
};

struct Cell
{
	GLuint internalId;
	bool isSolid()
	{
		return true;
	}
};

enum CellFace {
	CELL_FACE_BOTTOM, CELL_FACE_TOP,
	CELL_FACE_LEFT,   CELL_FACE_RIGHT,
	CELL_FACE_FRONT,  CELL_FACE_BACK
};

class Chunk
{
	public:
		Chunk(Planet* planet, class PlanetFace* face, int x, int y, int z);
		~Chunk();

		void unload();
		void load();
		void generate();

		void rebuildMesh();

		inline const glm::vec3 getPosition() const { return glm::vec3(m_cx, m_cy, m_cz); }
		const glm::vec3 getAbsolutePosition();
		inline int getX() const { return m_cx; }
		inline int getY() const { return m_cy; }
		inline int getZ() const { return m_cz; }

		inline bool isLoaded() const { return m_active; }
		inline bool isRedrawRequired() const { return m_dirty; }
		inline bool isGenerated() const { return m_generated; }

		inline bool shouldRender() const { return !m_emptyChunk && m_active && m_generated; }

		inline glm::mat4 getModelMatrix() const { return m_model; }

		bool isDetailedEnough(Camera* camera);

		void draw(Camera* camera, Shader* shader);
		void updateFlags();
	private:
		void formFace(std::vector<Vertex> &vertices, const glm::vec3 &position, CellFace face);
		void deleteBuffers();

		Planet* m_planet;
		class PlanetFace* m_planetFace;
		glm::mat4 m_model;

		bool m_dirty;
		bool m_active;
		bool m_generated;
		bool m_emptyChunk;

		int m_cx, m_cy, m_cz;

		GLuint m_vao, m_vbo;

		Cell*** m_cells;
		std::vector<Vertex> m_vertices;
};
#endif // __CHUNK_H__