#ifndef TERRAIN_H
#define TERRAIN_H

#include "vector.h"

#include <list>
#include <set>

class Terrain {
	private:
		std::set<std::pair<int, int> > chunk_indices;

	public:
		struct Chunk;

		struct Node {
			Chunk *chunk;
			float x, y;
			float vertex_array[12];

			Node(Chunk *chunk, float x, float y);
			virtual ~Node();

			float distance(float px, float pz);
			void fill();
			void draw();
			void draw_grid();
			void draw_normal();
			float get_height(float px, float py);
			Vector3 get_normal(int index);
		};

		struct Chunk {
			Terrain *terrain;
			Node **nodes;
			float x, y, width, height;
			int h_width, h_height;
			float *heights;
			Vector3 *normals;
			size_t buf_size;
			unsigned int vbo_object;
			unsigned int node_count;
			unsigned int vertices;
			float init_time;

			Chunk(Terrain *tree, float x, float y, float width, float height);
			~Chunk();

			float distance(float px, float pz);
			void make_vbo();
			Node *find(float x, float y);
			void calc_normals();
		};

		static const int chunk_size = 32;

		std::list<Chunk*> chunks;
		Terrain();
		virtual ~Terrain();

		float *generate_heights(int x, int y, int width, int height);
		float *get_chunk(int x, int y, int width, int height);
		bool has_chunk(int x, int y);
		void save_chunk(float *chunk, int x, int y, int width, int height);
		float *load_chunk(int x, int y, int width, int height);

		void raise(float x, float z, float radius, float focus, float strength, bool up = true);

		void update(float x, float z);
		Chunk *find_chunk(float x, float y);
		Node *find(float x, float y);
};

#endif