/*
Minetest
Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#pragma once

#include "irrlichttypes_extrabloated.h"
#include "map.h"
#include "camera.h"
#include <set>
#include <map>

struct MapDrawControl
{
	// Wanted drawing range
	float wanted_range = 0.0f;
	// Overrides limits by drawing everything
	bool range_all = false;
	// Allow rendering out of bounds
	bool allow_noclip = false;
	// show a wire frame for debugging
	bool show_wireframe = false;
};

struct MeshBufList
{
	video::SMaterial m;
	std::vector<std::pair<v3s16,scene::IMeshBuffer*>> bufs;
};

struct MeshBufListList
{
	/*!
	 * Stores the mesh buffers of the world.
	 * The array index is the material's layer.
	 * The vector part groups vertices by material.
	 */
	std::vector<MeshBufList> lists[MAX_TILE_LAYERS];

	void clear();
	void add(scene::IMeshBuffer *buf, v3s16 position, u8 layer);
};

class Client;
class ITextureSource;
class PartialMeshBuffer;

/*
	ClientMap

	This is the only map class that is able to render itself on screen.
*/

class ClientMap : public Map, public scene::ISceneNode
{
public:
	ClientMap(
			Client *client,
			RenderingEngine *rendering_engine,
			MapDrawControl &control,
			s32 id
	);

	virtual ~ClientMap();

	bool maySaveBlocks() override
	{
		return false;
	}

	void drop() override
	{
		ISceneNode::drop(); // calls destructor
	}

	void updateCamera(v3f pos, v3f dir, f32 fov, v3s16 offset);

	/*
		Forcefully get a sector from somewhere
	*/
	MapSector * emergeSector(v2s16 p) override;

	/*
		ISceneNode methods
	*/

	virtual void OnRegisterSceneNode() override;

	virtual void render() override
	{
		video::IVideoDriver* driver = SceneManager->getVideoDriver();
		driver->setTransform(video::ETS_WORLD, AbsoluteTransformation);
		renderMap(driver, SceneManager->getSceneNodeRenderPass());
	}

	virtual const aabb3f &getBoundingBox() const override
	{
		return m_box;
	}

	void getBlocksInViewRange(v3s16 cam_pos_nodes,
		v3s16 *p_blocks_min, v3s16 *p_blocks_max, float range=-1.0f);
	void updateDrawList();
	// @brief Calculate statistics about the map and keep the blocks alive
	void touchMapBlocks();
	void updateDrawListShadow(v3f shadow_light_pos, v3f shadow_light_dir, float radius, float length);
	// Returns true if draw list needs updating before drawing the next frame.
	bool needsUpdateDrawList() { return m_needs_update_drawlist; }
	void renderMap(video::IVideoDriver* driver, s32 pass);

	void renderMapShadows(video::IVideoDriver *driver,
			const video::SMaterial &material, s32 pass, int frame, int total_frames);

	int getBackgroundBrightness(float max_d, u32 daylight_factor,
			int oldvalue, bool *sunlight_seen_result);

	void renderPostFx(CameraMode cam_mode);

	// For debug printing
	void PrintInfo(std::ostream &out) override;

	const MapDrawControl & getControl() const { return m_control; }
	f32 getWantedRange() const { return m_control.wanted_range; }
	f32 getCameraFov() const { return m_camera_fov; }

	void onSettingChanged(const std::string &name);

protected:
	void reportMetrics(u64 save_time_us, u32 saved_blocks, u32 all_blocks) override;
private:

	// update the vertex order in transparent mesh buffers
	void updateTransparentMeshBuffers();


	// Orders blocks by distance to the camera
	class MapBlockComparer
	{
	public:
		MapBlockComparer(const v3s16 &camera_block) : m_camera_block(camera_block) {}

		bool operator() (const v3s16 &left, const v3s16 &right) const
		{
			auto distance_left = left.getDistanceFromSQ(m_camera_block);
			auto distance_right = right.getDistanceFromSQ(m_camera_block);
			return distance_left > distance_right || (distance_left == distance_right && left > right);
		}

	private:
		v3s16 m_camera_block;
	};


	// reference to a mesh buffer used when rendering the map.
	struct DrawDescriptor {
		v3s16 m_pos;
		union {
			scene::IMeshBuffer *m_buffer;
			const PartialMeshBuffer *m_partial_buffer;
		};
		bool m_reuse_material:1;
		bool m_use_partial_buffer:1;

		DrawDescriptor(v3s16 pos, scene::IMeshBuffer *buffer, bool reuse_material) :
			m_pos(pos), m_buffer(buffer), m_reuse_material(reuse_material), m_use_partial_buffer(false)
		{}

		DrawDescriptor(v3s16 pos, const PartialMeshBuffer *buffer) :
			m_pos(pos), m_partial_buffer(buffer), m_reuse_material(false), m_use_partial_buffer(true)
		{}

		scene::IMeshBuffer* getBuffer();
		void draw(video::IVideoDriver* driver);
	};

	Client *m_client;
	RenderingEngine *m_rendering_engine;

	aabb3f m_box = aabb3f(-BS * 1000000, -BS * 1000000, -BS * 1000000,
		BS * 1000000, BS * 1000000, BS * 1000000);

	MapDrawControl &m_control;

	v3f m_camera_position = v3f(0,0,0);
	v3f m_camera_direction = v3f(0,0,1);
	f32 m_camera_fov = M_PI;
	v3s16 m_camera_offset;
	bool m_needs_update_transparent_meshes = true;

	std::map<v3s16, MapBlock*, MapBlockComparer> m_drawlist;
	std::map<v3s16, MapBlock*> m_drawlist_shadow;
	bool m_needs_update_drawlist;

	std::set<v2s16> m_last_drawn_sectors;

	bool m_cache_trilinear_filter;
	bool m_cache_bilinear_filter;
	bool m_cache_anistropic_filter;
	u16 m_cache_transparency_sorting_distance;

	bool m_new_occlusion_culler;
	bool m_enable_raytraced_culling;
};