/*
Minetest-c55
Copyright (C) 2010 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 General Public License as published by
the Free Software Foundation; either version 2 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 General Public License for more details.

You should have received a copy of the GNU 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.
*/

#ifndef VOXEL_HEADER
#define VOXEL_HEADER

#include "common_irrlicht.h"
#include <iostream>
#include "debug.h"
#include "mapnode.h"

// For VC++
#undef min
#undef max

/*
	A fast voxel manipulator class

	Not thread-safe.
*/

/*
	Debug stuff
*/
extern u32 emerge_time;
extern u32 emerge_load_time;

/*
	This class resembles aabbox3d<s16> a lot, but has inclusive
	edges for saner handling of integer sizes
*/
class VoxelArea
{
public:
	// Starts as zero sized
	VoxelArea():
		MinEdge(1,1,1),
		MaxEdge(0,0,0)
	{
	}
	VoxelArea(v3s16 min_edge, v3s16 max_edge):
		MinEdge(min_edge),
		MaxEdge(max_edge)
	{
	}
	VoxelArea(v3s16 p):
		MinEdge(p),
		MaxEdge(p)
	{
	}
	
	/*
		Modifying methods
	*/

	void addArea(VoxelArea &a)
	{
		if(getExtent() == v3s16(0,0,0))
		{
			*this = a;
			return;
		}
		if(a.MinEdge.X < MinEdge.X) MinEdge.X = a.MinEdge.X;
		if(a.MinEdge.Y < MinEdge.Y) MinEdge.Y = a.MinEdge.Y;
		if(a.MinEdge.Z < MinEdge.Z) MinEdge.Z = a.MinEdge.Z;
		if(a.MaxEdge.X > MaxEdge.X) MaxEdge.X = a.MaxEdge.X;
		if(a.MaxEdge.Y > MaxEdge.Y) MaxEdge.Y = a.MaxEdge.Y;
		if(a.MaxEdge.Z > MaxEdge.Z) MaxEdge.Z = a.MaxEdge.Z;
	}
	void addPoint(v3s16 p)
	{
		if(getExtent() == v3s16(0,0,0))
		{
			MinEdge = p;
			MaxEdge = p;
			return;
		}
		if(p.X < MinEdge.X) MinEdge.X = p.X;
		if(p.Y < MinEdge.Y) MinEdge.Y = p.Y;
		if(p.Z < MinEdge.Z) MinEdge.Z = p.Z;
		if(p.X > MaxEdge.X) MaxEdge.X = p.X;
		if(p.Y > MaxEdge.Y) MaxEdge.Y = p.Y;
		if(p.Z > MaxEdge.Z) MaxEdge.Z = p.Z;
	}
	
	// Pad with d nodes
	void pad(v3s16 d)
	{
		MinEdge -= d;
		MaxEdge += d;
	}
	
	/*void operator+=(v3s16 off)
	{
		MinEdge += off;
		MaxEdge += off;
	}

	void operator-=(v3s16 off)
	{
		MinEdge -= off;
		MaxEdge -= off;
	}*/

	/*
		const methods
	*/

	v3s16 getExtent() const
	{
		return MaxEdge - MinEdge + v3s16(1,1,1);
	}
	s32 getVolume() const
	{
		v3s16 e = getExtent();
		return (s32)e.X * (s32)e.Y * (s32)e.Z;
	}
	bool contains(const VoxelArea &a) const
	{
		// No area contains an empty area
		// NOTE: Algorithms depend on this, so do not change.
		if(a.getExtent() == v3s16(0,0,0))
			return false;

		return(
			a.MinEdge.X >= MinEdge.X && a.MaxEdge.X <= MaxEdge.X &&
			a.MinEdge.Y >= MinEdge.Y && a.MaxEdge.Y <= MaxEdge.Y &&
			a.MinEdge.Z >= MinEdge.Z && a.MaxEdge.Z <= MaxEdge.Z
		);
	}
	bool contains(v3s16 p) const
	{
		return(
			p.X >= MinEdge.X && p.X <= MaxEdge.X &&
			p.Y >= MinEdge.Y && p.Y <= MaxEdge.Y &&
			p.Z >= MinEdge.Z && p.Z <= MaxEdge.Z
		);
	}
	bool contains(s32 i) const
	{
		return (i >= 0 && i < getVolume());
	}
	bool operator==(const VoxelArea &other) const
	{
		return (MinEdge == other.MinEdge
				&& MaxEdge == other.MaxEdge);
	}

	VoxelArea operator+(v3s16 off) const
	{
		return VoxelArea(MinEdge+off, MaxEdge+off);
	}

	VoxelArea operator-(v3s16 off) const
	{
		return VoxelArea(MinEdge-off, MaxEdge-off);
	}

	/*
		Returns 0-6 non-overlapping areas that can be added to
		a to make up this area.

		a: area inside *this
	*/
	void diff(const VoxelArea &a, core::list<VoxelArea> &result)
	{
		/*
			This can result in a maximum of 6 areas
		*/

		// If a is an empty area, return the current area as a whole
		if(a.getExtent() == v3s16(0,0,0))
		{
			VoxelArea b = *this;
			if(b.getVolume() != 0)
				result.push_back(b);
			return;
		}

		assert(contains(a));
		
		// Take back area, XY inclusive
		{
			v3s16 min(MinEdge.X, MinEdge.Y, a.MaxEdge.Z+1);
			v3s16 max(MaxEdge.X, MaxEdge.Y, MaxEdge.Z);
			VoxelArea b(min, max);
			if(b.getVolume() != 0)
				result.push_back(b);
		}

		// Take front area, XY inclusive
		{
			v3s16 min(MinEdge.X, MinEdge.Y, MinEdge.Z);
			v3s16 max(MaxEdge.X, MaxEdge.Y, a.MinEdge.Z-1);
			VoxelArea b(min, max);
			if(b.getVolume() != 0)
				result.push_back(b);
		}

		// Take top area, X inclusive
		{
			v3s16 min(MinEdge.X, a.MaxEdge.Y+1, a.MinEdge.Z);
			v3s16 max(MaxEdge.X, MaxEdge.Y, a.MaxEdge.Z);
			VoxelArea b(min, max);
			if(b.getVolume() != 0)
				result.push_back(b);
		}

		// Take bottom area, X inclusive
		{
			v3s16 min(MinEdge.X, MinEdge.Y, a.MinEdge.Z);
			v3s16 max(MaxEdge.X, a.MinEdge.Y-1, a.MaxEdge.Z);
			VoxelArea b(min, max);
			if(b.getVolume() != 0)
				result.push_back(b);
		}

		// Take left area, non-inclusive
		{
			v3s16 min(MinEdge.X, a.MinEdge.Y, a.MinEdge.Z);
			v3s16 max(a.MinEdge.X-1, a.MaxEdge.Y, a.MaxEdge.Z);
			VoxelArea b(min, max);
			if(b.getVolume() != 0)
				result.push_back(b);
		}

		// Take right area, non-inclusive
		{
			v3s16 min(a.MaxEdge.X+1, a.MinEdge.Y, a.MinEdge.Z);
			v3s16 max(MaxEdge.X, a.MaxEdge.Y, a.MaxEdge.Z);
			VoxelArea b(min, max);
			if(b.getVolume() != 0)
				result.push_back(b);
		}

	}
	
	/*
		Translates position from virtual coordinates to array index
	*/
	s32 index(s16 x, s16 y, s16 z) const
	{
		v3s16 em = getExtent();
		v3s16 off = MinEdge;
		s32 i = (s32)(z-off.Z)*em.Y*em.X + (y-off.Y)*em.X + (x-off.X);
		//dstream<<" i("<<x<<","<<y<<","<<z<<")="<<i<<" ";
		return i;
	}
	s32 index(v3s16 p) const
	{
		return index(p.X, p.Y, p.Z);
	}
	
	// Translate index in the X coordinate
	void add_x(const v3s16 &extent, u32 &i, s16 a)
	{
		i += a;
	}
	// Translate index in the Y coordinate
	void add_y(const v3s16 &extent, u32 &i, s16 a)
	{
		i += a * extent.X;
	}
	// Translate index in the Z coordinate
	void add_z(const v3s16 &extent, u32 &i, s16 a)
	{
		i += a * extent.X*extent.Y;
	}
	// Translate index in space
	void add_p(const v3s16 &extent, u32 &i, v3s16 a)
	{
		i += a.Z*extent.X*extent.Y + a.Y*extent.X + a.X;
	}

	/*
		Print method for debugging
	*/
	void print(std::ostream &o) const
	{
		v3s16 e = getExtent();
		o<<"("<<MinEdge.X
		 <<","<<MinEdge.Y
		 <<","<<MinEdge.Z
		 <<")("<<MaxEdge.X
		 <<","<<MaxEdge.Y
		 <<","<<MaxEdge.Z
		 <<")"
		 <<"="<<e.X<<"x"<<e.Y<<"x"<<e.Z<<"="<<getVolume();
	}

	// Edges are inclusive
	v3s16 MinEdge;
	v3s16 MaxEdge;
};

// Hasn't been copied from source (emerged)
#define VOXELFLAG_NOT_LOADED (1<<0)
// Checked as being inexistent in source
#define VOXELFLAG_INEXISTENT (1<<1)
// Algorithm-dependent
#define VOXELFLAG_CHECKED1 (1<<2)
// Algorithm-dependent
#define VOXELFLAG_CHECKED2 (1<<3)
// Algorithm-dependent
#define VOXELFLAG_CHECKED3 (1<<4)
// Algorithm-dependent
#define VOXELFLAG_CHECKED4 (1<<5)

enum VoxelPrintMode
{
	VOXELPRINT_NOTHING,
	VOXELPRINT_MATERIAL,
	VOXELPRINT_WATERPRESSURE,
};

class VoxelManipulator /*: public NodeContainer*/
{
public:
	VoxelManipulator();
	virtual ~VoxelManipulator();
	
	/*
		Virtuals from NodeContainer
	*/
	/*virtual u16 nodeContainerId() const
	{
		return NODECONTAINER_ID_VOXELMANIPULATOR;
	}
	bool isValidPosition(v3s16 p)
	{
		emerge(p);
		return !(m_flags[m_area.index(p)] & VOXELFLAG_INEXISTENT);
	}*/

	/*
		These are a bit slow and shouldn't be used internally.
		Use m_data[m_area.index(p)] instead.
	*/
	MapNode getNode(v3s16 p)
	{
		emerge(p);

		if(m_flags[m_area.index(p)] & VOXELFLAG_INEXISTENT)
		{
			dstream<<"EXCEPT: VoxelManipulator::getNode(): "
					<<"p=("<<p.X<<","<<p.Y<<","<<p.Z<<")"
					<<", index="<<m_area.index(p)
					<<", flags="<<(int)m_flags[m_area.index(p)]
					<<" is inexistent"<<std::endl;
			throw InvalidPositionException
			("VoxelManipulator: getNode: inexistent");
		}

		return m_data[m_area.index(p)];
	}
	void setNode(v3s16 p, MapNode &n)
	{
		emerge(p);
		
		m_data[m_area.index(p)] = n;
		m_flags[m_area.index(p)] &= ~VOXELFLAG_INEXISTENT;
		m_flags[m_area.index(p)] &= ~VOXELFLAG_NOT_LOADED;
	}
	void setNodeNoRef(v3s16 p, MapNode n)
	{
		setNode(p, n);
	}

	/*void setExists(VoxelArea a)
	{
		emerge(a);
		for(s32 z=a.MinEdge.Z; z<=a.MaxEdge.Z; z++)
		for(s32 y=a.MinEdge.Y; y<=a.MaxEdge.Y; y++)
		for(s32 x=a.MinEdge.X; x<=a.MaxEdge.X; x++)
		{
			m_flags[m_area.index(x,y,z)] &= ~VOXELFLAG_INEXISTENT;
		}
	}*/

	/*MapNode & operator[](v3s16 p)
	{
		//dstream<<"operator[] p=("<<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;
		if(isValidPosition(p) == false)
			emerge(VoxelArea(p));
		
		return m_data[m_area.index(p)];
	}*/

	/*
		Control
	*/

	virtual void clear();

	void print(std::ostream &o, VoxelPrintMode mode=VOXELPRINT_MATERIAL);
	
	void addArea(VoxelArea area);

	/*
		Copy data and set flags to 0
		dst_area.getExtent() <= src_area.getExtent()
	*/
	void copyFrom(MapNode *src, VoxelArea src_area,
			v3s16 from_pos, v3s16 to_pos, v3s16 size);
	
	// Copy data
	void copyTo(MapNode *dst, VoxelArea dst_area,
			v3s16 dst_pos, v3s16 from_pos, v3s16 size);

	/*
		Algorithms
	*/

	void clearFlag(u8 flag);
	
	void unspreadLight(enum LightBank bank, v3s16 p, u8 oldlight,
			core::map<v3s16, bool> & light_sources);
	void unspreadLight(enum LightBank bank,
			core::map<v3s16, u8> & from_nodes,
			core::map<v3s16, bool> & light_sources);
	
	void spreadLight(enum LightBank bank, v3s16 p);
	void spreadLight(enum LightBank bank,
			core::map<v3s16, bool> & from_nodes);
	
	/*
		Virtual functions
	*/
	
	/*
		Get the contents of the requested area from somewhere.
		Shall touch only nodes that have VOXELFLAG_NOT_LOADED
		Shall reset VOXELFLAG_NOT_LOADED

		If not found from source, add with VOXELFLAG_INEXISTENT
	*/
	virtual void emerge(VoxelArea a, s32 caller_id=-1)
	{
		//dstream<<"emerge p=("<<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;
		addArea(a);
		for(s32 z=a.MinEdge.Z; z<=a.MaxEdge.Z; z++)
		for(s32 y=a.MinEdge.Y; y<=a.MaxEdge.Y; y++)
		for(s32 x=a.MinEdge.X; x<=a.MaxEdge.X; x++)
		{
			s32 i = m_area.index(x,y,z);
			// Don't touch nodes that have already been loaded
			if(!(m_flags[i] & VOXELFLAG_NOT_LOADED))
				continue;
			m_flags[i] = VOXELFLAG_INEXISTENT;
		}
	}

	/*
		Member variables
	*/

	/*
		The area that is stored in m_data.
		addInternalBox should not be used if getExtent() == v3s16(0,0,0)
		MaxEdge is 1 higher than maximum allowed position
	*/
	VoxelArea m_area;
	
	/*
		NULL if data size is 0 (extent (0,0,0))
		Data is stored as [z*h*w + y*h + x]
	*/
	MapNode *m_data;

	/*
		Flags of all nodes
	*/
	u8 *m_flags;
	
	//TODO: Use these or remove them
	//TODO: Would these make any speed improvement?
	//bool m_pressure_route_valid;
	//v3s16 m_pressure_route_surface;

	/*
		Some settings
	*/
	bool m_disable_water_climb;

private:
};

#endif