// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

#ifndef __C_COLLADA_MESH_FILE_LOADER_H_INCLUDED__
#define __C_COLLADA_MESH_FILE_LOADER_H_INCLUDED__

#include "IMeshLoader.h"
#include "IFileSystem.h"
#include "IVideoDriver.h"
#include "irrString.h"
#include "SMesh.h"
#include "SMeshBuffer.h"
#include "ISceneManager.h"
#include "irrMap.h"
#include "CAttributes.h"

namespace irr
{
namespace scene
{

#ifdef _DEBUG
//#define COLLADA_READER_DEBUG
#endif

class IColladaPrefab;

enum ECOLLADA_PARAM_NAME
{
	ECPN_COLOR = 0,
	ECPN_AMBIENT,
	ECPN_DIFFUSE,
	ECPN_SPECULAR,
	ECPN_SHININESS,
	ECPN_TRANSPARENCY,
	ECPN_YFOV,
	ECPN_ZNEAR,
	ECPN_ZFAR,

	ECPN_COUNT
};

enum ECOLLADA_PARAM_TYPE
{
	ECPT_FLOAT = 0,
	ECPT_FLOAT2,
	ECPT_FLOAT3,
	ECPT_FLOAT4,

	ECPT_COUNT
};

//! Collada Parameter
struct SColladaParam
{
	SColladaParam()
		: Name(ECPN_COUNT), Type(ECPT_COUNT)
	{
		for (int i=0; i<4; ++i) Floats[i] = 0;
	}

	ECOLLADA_PARAM_NAME Name;
	ECOLLADA_PARAM_TYPE Type;

	f32 Floats[4];
};

enum ECOLLADA_INPUT_SEMANTIC
{
	ECIS_POSITION = 0,
	ECIS_VERTEX,
	ECIS_NORMAL,
	ECIS_TEXCOORD,
	ECIS_UV,
	ECIS_TANGENT,
	ECIS_IMAGE,
	ECIS_TEXTURE,
	ECIS_COLOR,

	ECIS_COUNT
};

//! Collada Input
struct SColladaInput
{
	SColladaInput()
		: Semantic(ECIS_COUNT), Data(0), Offset(0), Set(0), Stride(1)
	{
	}

	ECOLLADA_INPUT_SEMANTIC Semantic;
	core::stringc Source;
	f32* Data;
	u32 Offset;
	u32 Set;
	u32 Stride;
};

//! Collada images
struct SColladaImage
{
	core::stringc Id;
	core::stringc Source;
	core::dimension2du Dimension;
	bool SourceIsFilename;
};


//! Collada texture
struct SColladaTexture
{
	video::ITexture* Texture;
	core::stringc Id;
};


//! Collada material
struct SColladaMaterial
{
	video::SMaterial Mat;
	core::stringc Id;
	core::stringc InstanceEffectId;
	f32 Transparency;

	inline bool operator< (const SColladaMaterial & other) const
	{
		return Id < other.Id;
	}
};

//! Collada effect (materials, shaders, and programs)
struct SColladaEffect
{
	core::stringc Id;
	f32 Transparency;
	core::array<core::stringc> Textures;
	video::SMaterial Mat;
	// TODO: Parameters looks somewhat lazy workaround, I think we should really read all parameters correct.
	io::IAttributes * Parameters;

	inline bool operator< (const SColladaEffect & other) const
	{
		return Id < other.Id;
	}
};


struct SNumberArray // for storing float and int arrays
{
	core::stringc Name;
	core::array<f32> Data;
};

struct SAccessor
{
	SAccessor()
		: Count(0), Offset(0), Stride(1) {}
	// I don't store the source of the accessor here because I assume
	// it to use the array of the source this accessor is located in.

	int Count;
	int Offset;
	int Stride;

	core::array<SColladaParam> Parameters; // parameters defining the accessor
};

struct SSource
{
	core::stringc Id;
	SNumberArray Array;
	core::array<SAccessor> Accessors;
};

class CScenePrefab;

//! Meshloader capable of loading COLLADA meshes and scene descriptions into Irrlicht.
class CColladaFileLoader : public IMeshLoader
{
public:

	//! Constructor
	CColladaFileLoader(scene::ISceneManager* smgr, io::IFileSystem* fs);

	//! destructor
	virtual ~CColladaFileLoader();

	//! returns true if the file maybe is able to be loaded by this class
	//! based on the file extension (e.g. ".cob")
	virtual bool isALoadableFileExtension(const io::path& filename) const IRR_OVERRIDE;

	//! creates/loads an animated mesh from the file.
	//! \return Pointer to the created mesh. Returns 0 if loading failed.
	//! If you no longer need the mesh, you should call IAnimatedMesh::drop().
	//! See IReferenceCounted::drop() for more information.
	virtual IAnimatedMesh* createMesh(io::IReadFile* file) IRR_OVERRIDE;

private:

	//! skips an (unknown) section in the collada document
	void skipSection(io::IXMLReaderUTF8* reader, bool reportSkipping);

	//! reads the <COLLADA> section and its content
	void readColladaSection(io::IXMLReaderUTF8* reader);

	//! reads a <library> section and its content
	void readLibrarySection(io::IXMLReaderUTF8* reader);

	//! reads a <visual_scene> element and stores it as a prefab
	void readVisualScene(io::IXMLReaderUTF8* reader);

	//! reads a <scene> section and its content
	void readSceneSection(io::IXMLReaderUTF8* reader);

	//! reads a <asset> section and its content
	void readAssetSection(io::IXMLReaderUTF8* reader);

	//! reads a <node> section and its content
	//! if a prefab pointer is passed the nodes are created as scene prefabs children of that prefab
	void readNodeSection(io::IXMLReaderUTF8* reader, scene::ISceneNode* parent, CScenePrefab* p=0);

	//! reads a <lookat> element and its content and creates a matrix from it
	core::matrix4 readLookAtNode(io::IXMLReaderUTF8* reader);

	//! reads a <matrix> element and its content and creates a matrix from it
	core::matrix4 readMatrixNode(io::IXMLReaderUTF8* reader);

	//! reads a <perspective> element and its content and creates a matrix from it
	core::matrix4 readPerspectiveNode(io::IXMLReaderUTF8* reader);

	//! reads a <rotate> element and its content and creates a matrix from it
	core::matrix4 readRotateNode(io::IXMLReaderUTF8* reader);

	//! reads a <skew> element and its content and creates a matrix from it
	core::matrix4 readSkewNode(io::IXMLReaderUTF8* reader);

	//! reads a <boundingbox> element and its content and stores it in bbox
	void readBboxNode(io::IXMLReaderUTF8* reader, core::aabbox3df& bbox);

	//! reads a <scale> element and its content and creates a matrix from it
	core::matrix4 readScaleNode(io::IXMLReaderUTF8* reader);

	//! reads a <translate> element and its content and creates a matrix from it
	core::matrix4 readTranslateNode(io::IXMLReaderUTF8* reader);

	//! reads a <color> element
	video::SColorf readColorNode(io::IXMLReaderUTF8* reader);

	//! reads a <float> element
	f32 readFloatNode(io::IXMLReaderUTF8* reader);

	//! reads a <instance> node
	void readInstanceNode(io::IXMLReaderUTF8* reader,
			scene::ISceneNode* parent, scene::ISceneNode** outNode,
			CScenePrefab* p=0, const core::stringc& type=core::stringc());

	//! creates a scene node from Prefabs (with name given in 'url')
	void instantiateNode(scene::ISceneNode* parent, scene::ISceneNode** outNode=0,
			CScenePrefab* p=0, const core::stringc& url="",
			const core::stringc& type=core::stringc());

	//! reads a <light> element and stores it as prefab
	void readLightPrefab(io::IXMLReaderUTF8* reader);

	//! reads a <camera> element and stores it as prefab
	void readCameraPrefab(io::IXMLReaderUTF8* reader);

	//! reads a <image> element and stores it in the image section
	void readImage(io::IXMLReaderUTF8* reader);

	//! reads a <texture> element and stores it in the texture section
	void readTexture(io::IXMLReaderUTF8* reader);

	//! reads a <material> element and stores it in the material section
	void readMaterial(io::IXMLReaderUTF8* reader);

	//! reads a <effect> element and stores it in the effects section
	void readEffect(io::IXMLReaderUTF8* reader, SColladaEffect * effect = 0);

	//! reads a <geometry> element and stores it as mesh if possible
	void readGeometry(io::IXMLReaderUTF8* reader);

	//! parses a float from a char pointer and moves the pointer to
	//! the end of the parsed float
	inline f32 readFloat(const c8** p);

	//! parses an int from a char pointer and moves the pointer to
	//! the end of the parsed float
	inline s32 readInt(const c8** p);

	//! places pointer to next begin of a token
	void findNextNoneWhiteSpace(const c8** p);

	//! reads floats from inside of xml element until end of xml element
	void readFloatsInsideElement(io::IXMLReaderUTF8* reader, f32* floats, u32 count);

	//! reads ints from inside of xml element until end of xml element
	void readIntsInsideElement(io::IXMLReaderUTF8* reader, s32* ints, u32 count);

	//! clears all loaded data
	void clearData();

	//! parses all collada parameters inside an element and stores them in ColladaParameters
	void readColladaParameters(io::IXMLReaderUTF8* reader, const core::stringc& parentName);

	//! returns a collada parameter or none if not found
	SColladaParam* getColladaParameter(ECOLLADA_PARAM_NAME name);

	//! parses all collada inputs inside an element and stores them in Inputs. Reads
	//! until first tag which is not an input tag or the end of the parent is reached
	void readColladaInputs(io::IXMLReaderUTF8* reader, const core::stringc& parentName);

	//! reads a collada input tag and adds it to the input parameter
	void readColladaInput(io::IXMLReaderUTF8* reader, core::array<SColladaInput>& inputs);

	//! returns a collada input or none if not found
	SColladaInput* getColladaInput(ECOLLADA_INPUT_SEMANTIC input);

	//! read Collada Id, uses id or name if id is missing
	core::stringc readId(io::IXMLReaderUTF8* reader);

	//! changes the XML URI into an internal id
	void uriToId(core::stringc& str);

	//! reads a polygons section and creates a mesh from it
	void readPolygonSection(io::IXMLReaderUTF8* reader,
			core::array<SSource>& sources, scene::SMesh* mesh,
			const core::stringc& geometryId);

	//! finds a material, possible instancing it
	const SColladaMaterial * findMaterial(const core::stringc & materialName);

	//! reads and bind materials as given by the symbol->target bind mapping
	void readBindMaterialSection(io::IXMLReaderUTF8* reader, const core::stringc & id);

	//! create an Irrlicht texture from the SColladaImage
	video::ITexture* getTextureFromImage(core::stringc uri, SColladaEffect * effect);

	//! read a parameter and value
	void readParameter(io::IXMLReaderUTF8* reader, io::IAttributes* parameters);

	//! Flip z axis in matrix around to convert between right-handed and left-handed coordinate system.
	//! Note that function is symmetric (no difference if called before or after a transpose).
	core::matrix4 flipZAxis(const core::matrix4& m);

	//! replace escape characters with the unescaped ones
	void unescape(irr::core::stringc& uri);

	scene::ISceneManager* SceneManager;
	io::IFileSystem* FileSystem;

	scene::IAnimatedMesh* DummyMesh;
	core::stringc CurrentlyLoadingMesh;

	scene::IAnimatedMesh* FirstLoadedMesh;
	io::path FirstLoadedMeshName;
	s32 LoadedMeshCount;
	u32 Version;
	bool FlipAxis;

	core::array<IColladaPrefab*> Prefabs;
	core::array<SColladaParam> ColladaParameters;
	core::array<SColladaImage> Images;
	core::array<SColladaTexture> Textures;
	core::array<SColladaMaterial> Materials;
	core::array<SColladaInput> Inputs;
	core::array<SColladaEffect> Effects;
	//! meshbuffer reference ("geomid/matname") -> index into MeshesToBind
	core::map<core::stringc,u32> MaterialsToBind;
	//! Array of buffers for each material binding
	core::array< core::array<irr::scene::IMeshBuffer*> > MeshesToBind;

	bool CreateInstances;

	struct EscapeCharacterURL
	{
		EscapeCharacterURL(irr::c8 c, const irr::c8* e)
			: Character(c)
		{
			Escape = e;
		}

		irr::c8 Character;		// unescaped (like ' ')
		irr::core::stringc Escape;	// escaped (like '%20')
	};
	irr::core::array<EscapeCharacterURL> EscapeCharsAnyURI;
};



//! following class is for holding and createing instances of library objects,
//! named prefabs in this loader.
class IColladaPrefab : public virtual IReferenceCounted
{
public:
	//! creates an instance of this prefab
	virtual scene::ISceneNode* addInstance(scene::ISceneNode* parent,
		scene::ISceneManager* mgr) = 0;

	//! returns id of this prefab
	virtual const core::stringc& getId() = 0;
};


} // end namespace scene
} // end namespace irr

#endif