#pragma once

#include <stdint.h>
#include "model.h"
#include "vectors.h"
#include "matrix.h"
#include "common/rendering/i_modelvertexbuffer.h"
#include "m_swap.h"
#include "name.h"

class DBoneComponents;

struct IQMMesh
{
	FString Name;
	FString Material;
	uint32_t FirstVertex;
	uint32_t NumVertices;
	uint32_t FirstTriangle;
	uint32_t NumTriangles;
	FTextureID Skin;
};

enum IQMVertexArrayType
{
	IQM_POSITION = 0,     // float, 3
	IQM_TEXCOORD = 1,     // float, 2
	IQM_NORMAL = 2,       // float, 3
	IQM_TANGENT = 3,      // float, 4
	IQM_BLENDINDEXES = 4, // ubyte, 4
	IQM_BLENDWEIGHTS = 5, // ubyte, 4
	IQM_COLOR = 6,        // ubyte, 4
	IQM_CUSTOM = 0x10
};

enum IQMVertexArrayFormat
{
	IQM_BYTE = 0,
	IQM_UBYTE = 1,
	IQM_SHORT = 2,
	IQM_USHORT = 3,
	IQM_INT = 4,
	IQM_UINT = 5,
	IQM_HALF = 6,
	IQM_FLOAT = 7,
	IQM_DOUBLE = 8,
};

struct IQMVertexArray
{
	IQMVertexArrayType Type;
	uint32_t Flags;
	IQMVertexArrayFormat Format;
	uint32_t Size;
	uint32_t Offset;
};

struct IQMTriangle
{
	uint32_t Vertex[3];
};

struct IQMAdjacency
{
	uint32_t Triangle[3];
};

struct IQMJoint
{
	FName Name;
	int32_t Parent; // parent < 0 means this is a root bone
	TArray<int> Children; // indices of children
	FVector3 Translate;
	FQuaternion Quaternion;
	FVector3 Scale;
	FVector3 Position;
	FQuaternion Rotation;
	FVector3 Scaling;
};

struct IQMPose
{
	int32_t Parent; // parent < 0 means this is a root bone
	uint32_t ChannelMask; // mask of which 10 channels are present for this joint pose
	float ChannelOffset[10];
	float ChannelScale[10];
	// channels 0..2 are translation <Tx, Ty, Tz> and channels 3..6 are quaternion rotation <Qx, Qy, Qz, Qw>
	// rotation is in relative/parent local space
	// channels 7..9 are scale <Sx, Sy, Sz>
	// output = (input*scale)*rotation + translation
};

struct IQMAnim
{
	FString Name;
	uint32_t FirstFrame;
	uint32_t NumFrames;
	float Framerate;
	bool Loop;
};

struct IQMBounds
{
	float BBMins[3];
	float BBMaxs[3];
	float XYRadius;
	float Radius;
};

class IQMFileReader;

class IQMModel : public FModel
{
public:
	IQMModel();
	~IQMModel();

	bool Load(const char* fn, int lumpnum, const char* buffer, int length) override;
	int FindFrame(const char* name, bool nodefault) override;
	int FindFirstFrame(FName name) override;
	int FindLastFrame(FName name) override;
	double FindFramerate(FName name) override;
	void RenderFrame(FModelRenderer* renderer, FGameTexture* skin, int frame, int frame2, double inter, FTranslationID translation, const FTextureID* surfaceskinids, int boneStartPosition, void * act) override;
	void BuildVertexBuffer(FModelRenderer* renderer) override;
	void AddSkins(uint8_t* hitlist, const FTextureID* surfaceskinids) override;
	const TArray<TRS>* AttachAnimationData() override;

	ModelAnimFrame PrecalculateFrame(const ModelAnimFrame &from, const ModelAnimFrameInterp &to, float inter, const TArray<TRS>* animationData) override;
	const TArray<VSMatrix>* CalculateBones(const ModelAnimFrame &from, const ModelAnimFrameInterp &to, float inter, const TArray<TRS>* animationData, TArray<BoneOverride> *in, BoneInfo *out, double time) override;

	ModelAnimFramePrecalculatedIQM CalculateFrameIQM(int frame1, int frame2, float inter, int frame1_prev, float inter1_prev, int frame2_prev, float inter2_prev, const ModelAnimFramePrecalculatedIQM* precalculated, const TArray<TRS>* animationData);
	const TArray<VSMatrix>* CalculateBonesIQM(int frame1, int frame2, float inter, int frame1_prev, float inter1_prev, int frame2_prev, float inter2_prev, const ModelAnimFramePrecalculatedIQM* precalculated, const TArray<TRS>* animationData, TArray<BoneOverride> *in, BoneInfo *out, double time);

private:
	void LoadGeometry();
	void UnloadGeometry();

	void LoadPosition(IQMFileReader& reader, const IQMVertexArray& vertexArray);
	void LoadTexcoord(IQMFileReader& reader, const IQMVertexArray& vertexArray);
	void LoadNormal(IQMFileReader& reader, const IQMVertexArray& vertexArray);
	void LoadBlendIndexes(IQMFileReader& reader, const IQMVertexArray& vertexArray);
	void LoadBlendWeights(IQMFileReader& reader, const IQMVertexArray& vertexArray);

	int mLumpNum = -1;

	TMap<FName, int> NamedAnimations;
	TMap<FName, int> NamedJoints;

	TArray<IQMMesh> Meshes;
	TArray<IQMTriangle> Triangles;
	TArray<IQMAdjacency> Adjacency;
	TArray<IQMJoint> Joints;
	
	TArray<int> RootJoints;

	TArray<IQMPose> Poses;
	TArray<IQMAnim> Anims;
	TArray<IQMBounds> Bounds;
	TArray<IQMVertexArray> VertexArrays;
	uint32_t NumVertices = 0;

	TArray<VSMatrix> boneData; // temporary array, used to hold animation data during rendering, set during CalculateBones, uploaded during RenderFrame

	TArray<FModelVertex> Vertices;

	TArray<VSMatrix> baseframe;
	TArray<VSMatrix> inversebaseframe;
	TArray<TRS> TRSData;
public:
	int NumJoints() override { return Joints.SSize(); }
	int FindJoint(FName name) override
	{
		int *j = NamedJoints.CheckKey(name);

		return j ? *j : -1;
	}

	int GetJointParent(int joint) override
	{
		return (joint >= 0 && joint < Joints.SSize()) ? Joints[joint].Parent : -1;
	}

	FName GetJointName(int joint) override
	{
		return (joint >= 0 && joint < Joints.SSize()) ? Joints[joint].Name : FName(NAME_None);
	}

	void GetRootJoints(TArray<int> &out) override
	{
		out = RootJoints;
	}

	void GetJointChildren(int joint, TArray<int> &out) override
	{
		if(joint >= 0 && joint < Joints.SSize())
		{
			out = Joints[joint].Children;
		}
	}

	FQuaternion GetJointRotation(int joint) override
	{
		return (joint >= 0 && joint < Joints.SSize()) ? Joints[joint].Rotation : FQuaternion(0.0f,0.0f,0.0f,1.0f);
	}

	FVector3 GetJointPosition(int joint) override
	{
		return (joint >= 0 && joint < Joints.SSize()) ? Joints[joint].Position : FVector3(0.0f,0.0f,0.0f);
	}

	TRS GetJointBaseTRS(int joint) override
	{
		return (joint >= 0 && joint < Joints.SSize()) ? TRS{Joints[joint].Translate, Joints[joint].Quaternion, Joints[joint].Scale} : TRS{};
	}

	TRS GetJointPose(int joint, int frame) override
	{
		return (joint >= 0 && joint < Joints.SSize() && frame >= 0 && ((frame * Joints.SSize()) + joint) < TRSData.SSize()) ? TRSData[(frame * Joints.SSize()) + joint] : TRS{} ;
	}
	virtual int NumFrames()
	{
		return Joints.SSize() > 0 ? (TRSData.SSize() / Joints.SSize()) : 0;
	}
};

struct IQMReadErrorException { };

class IQMFileReader
{
public:
	IQMFileReader(const void* buffer, int length) : buffer((const char*)buffer), length(length) { }

	uint8_t ReadUByte()
	{
		uint8_t value;
		Read(&value, sizeof(uint8_t));
		return value;
	}

	int32_t ReadInt32()
	{
		int32_t value;
		Read(&value, sizeof(int32_t));
		value = LittleLong(value);
		return value;
	}

	int16_t ReadInt16()
	{
		int16_t value;
		Read(&value, sizeof(int16_t));
		value = LittleShort(value);
		return value;
	}

	uint32_t ReadUInt32()
	{
		return ReadInt32();
	}

	uint16_t ReadUInt16()
	{
		return ReadInt16();
	}

	float ReadFloat()
	{
		float value;
		Read(&value, sizeof(float));
		return value;
	}

	FString ReadName(const TArray<char>& textBuffer)
	{
		uint32_t nameOffset = ReadUInt32();
		if (nameOffset >= textBuffer.Size())
			throw IQMReadErrorException();
		return textBuffer.Data() + nameOffset;
	}

	void Read(void* data, int size)
	{
		if (pos + size > length || size < 0 || size > 0x0fffffff)
			throw IQMReadErrorException();
		memcpy(data, buffer + pos, size);
		pos += size;
	}

	void SeekTo(int newPos)
	{
		if (newPos < 0 || newPos > length)
			throw IQMReadErrorException();
		pos = newPos;
	}

private:
	const char* buffer = nullptr;
	int length = 0;
	int pos = 0;
};