/*
---------------------------------------------------------------------------
Open Asset Import Library (assimp)
---------------------------------------------------------------------------

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/** @file  MS3DLoader.cpp
 *  @brief Implementation of the Ms3D importer class.
 *  Written against http://chumbalum.swissquake.ch/ms3d/ms3dspec.txt
 */

#include "AssimpPCH.h"
#ifndef ASSIMP_BUILD_NO_MS3D_IMPORTER

// internal headers
#include "MS3DLoader.h"
#include "StreamReader.h"
using namespace Assimp;

static const aiImporterDesc desc = {
	"Milkshape 3D Importer",
	"",
	"",
	"http://chumbalum.swissquake.ch/",
	aiImporterFlags_SupportBinaryFlavour,
	0,
	0,
	0,
	0,
	"ms3d" 
};

// ASSIMP_BUILD_MS3D_ONE_NODE_PER_MESH
//   (enable old code path, which generates extra nodes per mesh while
//    the newer code uses aiMesh::mName to express the name of the
//    meshes (a.k.a. groups in MS3D))

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
MS3DImporter::MS3DImporter()
{}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well 
MS3DImporter::~MS3DImporter()
{}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file. 
bool MS3DImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const
{
	// first call - simple extension check
	const std::string extension = GetExtension(pFile);
	if (extension == "ms3d") {
		return true;
	}

	// second call - check for magic identifiers
	else if (!extension.length() || checkSig)	{
		if (!pIOHandler) {
			return true;
		}
		const char* tokens[] = {"MS3D000000"};
		return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1);
	}
	return false;
}

// ------------------------------------------------------------------------------------------------
const aiImporterDesc* MS3DImporter::GetInfo () const
{
	return &desc;
}

// ------------------------------------------------------------------------------------------------
void ReadColor(StreamReaderLE& stream, aiColor4D& ambient)
{
	// aiColor4D is packed on gcc, implicit binding to float& fails therefore.
	stream >> (float&)ambient.r >> (float&)ambient.g >> (float&)ambient.b >> (float&)ambient.a;
}

// ------------------------------------------------------------------------------------------------
void ReadVector(StreamReaderLE& stream, aiVector3D& pos)
{
	// See note in ReadColor()
	stream >> (float&)pos.x >> (float&)pos.y >> (float&)pos.z;
}

// ------------------------------------------------------------------------------------------------
template<typename T> 
void MS3DImporter :: ReadComments(StreamReaderLE& stream, std::vector<T>& outp)
{
	uint16_t cnt;
	stream >> cnt;

	for(unsigned int i = 0; i < cnt; ++i) {
		uint32_t index, clength;
		stream >> index >> clength;

		if(index >= outp.size()) {
			DefaultLogger::get()->warn("MS3D: Invalid index in comment section");
		}
		else if (clength > stream.GetRemainingSize()) {
			throw DeadlyImportError("MS3D: Failure reading comment, length field is out of range");
		}
		else {
			outp[index].comment = std::string(reinterpret_cast<char*>(stream.GetPtr()),clength);
		}
		stream.IncPtr(clength);
	}
}

// ------------------------------------------------------------------------------------------------
template <typename T, typename T2, typename T3> bool inrange(const T& in, const T2& lower, const T3& higher)
{
	return in > lower && in <= higher;
}

// ------------------------------------------------------------------------------------------------
void MS3DImporter :: CollectChildJoints(const std::vector<TempJoint>& joints,
	std::vector<bool>& hadit, 
	aiNode* nd, 
	const aiMatrix4x4& absTrafo)
{
	unsigned int cnt = 0;
	for(size_t i = 0; i < joints.size(); ++i) {
		if (!hadit[i] && !strcmp(joints[i].parentName,nd->mName.data)) {
			++cnt;
		}
	}

	nd->mChildren = new aiNode*[nd->mNumChildren = cnt];
	cnt = 0;
	for(size_t i = 0; i < joints.size(); ++i) {
		if (!hadit[i] && !strcmp(joints[i].parentName,nd->mName.data)) {
			aiNode* ch = nd->mChildren[cnt++] = new aiNode(joints[i].name);
			ch->mParent = nd;

			ch->mTransformation = aiMatrix4x4::Translation(joints[i].position,aiMatrix4x4()=aiMatrix4x4())*
				// XXX actually, I don't *know* why we need the inverse here. Probably column vs. row order?
				aiMatrix4x4().FromEulerAnglesXYZ(joints[i].rotation).Transpose();

			const aiMatrix4x4 abs = absTrafo*ch->mTransformation;
			for(unsigned int a = 0; a < mScene->mNumMeshes; ++a) {
				aiMesh* const msh = mScene->mMeshes[a];
				for(unsigned int n = 0; n < msh->mNumBones; ++n) {
					aiBone* const bone = msh->mBones[n];

					if(bone->mName == ch->mName) {
						bone->mOffsetMatrix = aiMatrix4x4(abs).Inverse();
					}
				}
			}
	
			hadit[i] = true;
			CollectChildJoints(joints,hadit,ch,abs);
		}
	}
}

// ------------------------------------------------------------------------------------------------
void MS3DImporter :: CollectChildJoints(const std::vector<TempJoint>& joints, aiNode* nd)
{
	 std::vector<bool> hadit(joints.size(),false);
	 aiMatrix4x4 trafo;

	 CollectChildJoints(joints,hadit,nd,trafo);
}

// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure. 
void MS3DImporter::InternReadFile( const std::string& pFile, 
	aiScene* pScene, IOSystem* pIOHandler)
{
	StreamReaderLE stream(pIOHandler->Open(pFile,"rb"));

	// CanRead() should have done this already
	char head[10];
	int32_t version;

	mScene = pScene;


	// 1 ------------ read into temporary data structures mirroring the original file

	stream.CopyAndAdvance(head,10);
	stream >> version;
	if (strncmp(head,"MS3D000000",10)) {
		throw DeadlyImportError("Not a MS3D file, magic string MS3D000000 not found: "+pFile);
	}

	if (version != 4) {
		throw DeadlyImportError("MS3D: Unsupported file format version, 4 was expected");
	}

	uint16_t verts;
	stream >> verts;

	std::vector<TempVertex> vertices(verts);
	for (unsigned int i = 0; i < verts; ++i) {
		TempVertex& v = vertices[i];

		stream.IncPtr(1);
		ReadVector(stream,v.pos);
		v.bone_id[0] = stream.GetI1(); 
		v.ref_cnt = stream.GetI1();

		v.bone_id[1] = v.bone_id[2] = v.bone_id[3] = UINT_MAX;
		v.weights[1] = v.weights[2] = v.weights[3] = 0.f;
		v.weights[0] = 1.f;
	}

	uint16_t tris;
	stream >> tris;

	std::vector<TempTriangle> triangles(tris);
	for (unsigned int i = 0;i < tris; ++i) {
		TempTriangle& t = triangles[i];

		stream.IncPtr(2);
		for (unsigned int i = 0; i < 3; ++i) {
			t.indices[i] = stream.GetI2();
		}

		for (unsigned int i = 0; i < 3; ++i) {
			ReadVector(stream,t.normals[i]);
		}

		for (unsigned int i = 0; i < 3; ++i) {
			stream >> (float&)(t.uv[i].x); // see note in ReadColor()
		}
		for (unsigned int i = 0; i < 3; ++i) {
			stream >> (float&)(t.uv[i].y);
		}

		t.sg    = stream.GetI1(); 
		t.group = stream.GetI1(); 
	}

	uint16_t grp;
	stream >> grp;

	bool need_default = false;
	std::vector<TempGroup> groups(grp);
	for (unsigned int i = 0;i < grp; ++i) {
		TempGroup& t = groups[i];

		stream.IncPtr(1);
		stream.CopyAndAdvance(t.name,32);

		t.name[32] = '\0';
		uint16_t num;
		stream >> num;

		t.triangles.resize(num);
		for (unsigned int i = 0; i < num; ++i) {
			t.triangles[i] = stream.GetI2(); 
		}
		t.mat = stream.GetI1(); 
		if (t.mat == UINT_MAX) {
			need_default = true;
		}
	}

	uint16_t mat;
	stream >> mat;

	std::vector<TempMaterial> materials(mat);
	for (unsigned int i = 0;i < mat; ++i) {
		TempMaterial& t = materials[i];

		stream.CopyAndAdvance(t.name,32);
		t.name[32] = '\0';

		ReadColor(stream,t.ambient);
		ReadColor(stream,t.diffuse);
		ReadColor(stream,t.specular);
		ReadColor(stream,t.emissive);
		stream >> t.shininess  >> t.transparency;

		stream.IncPtr(1);

		stream.CopyAndAdvance(t.texture,128);
		t.texture[128] = '\0';

		stream.CopyAndAdvance(t.alphamap,128);
		t.alphamap[128] = '\0';
	}

	float animfps, currenttime;
	uint32_t totalframes;
	stream >> animfps >> currenttime >> totalframes;

	uint16_t joint;
	stream >> joint;

	std::vector<TempJoint> joints(joint);
	for(unsigned int i = 0; i < joint; ++i) {
		TempJoint& j = joints[i];

		stream.IncPtr(1);
		stream.CopyAndAdvance(j.name,32);
		j.name[32] = '\0';

		stream.CopyAndAdvance(j.parentName,32);
		j.parentName[32] = '\0';

	//	DefaultLogger::get()->debug(j.name);
	//	DefaultLogger::get()->debug(j.parentName);

		ReadVector(stream,j.rotation);
		ReadVector(stream,j.position);

		j.rotFrames.resize(stream.GetI2());
		j.posFrames.resize(stream.GetI2());

		for(unsigned int a = 0; a < j.rotFrames.size(); ++a) {
			TempKeyFrame& kf = j.rotFrames[a];
			stream >> kf.time;
			ReadVector(stream,kf.value);
		}
		for(unsigned int a = 0; a < j.posFrames.size(); ++a) {
			TempKeyFrame& kf = j.posFrames[a];
			stream >> kf.time;
			ReadVector(stream,kf.value);
		}
	}

	if(stream.GetRemainingSize() > 4) {
		uint32_t subversion;
		stream >> subversion;
		if (subversion == 1) {
			ReadComments<TempGroup>(stream,groups);
			ReadComments<TempMaterial>(stream,materials);
			ReadComments<TempJoint>(stream,joints);
			
			// model comment - print it for we have such a nice log.
			if (stream.GetI4()) {
				const size_t len = static_cast<size_t>(stream.GetI4());
				if (len > stream.GetRemainingSize()) {
					throw DeadlyImportError("MS3D: Model comment is too long");
				}

				const std::string& s = std::string(reinterpret_cast<char*>(stream.GetPtr()),len);
				DefaultLogger::get()->debug("MS3D: Model comment: " + s);
			}

			if(stream.GetRemainingSize() > 4 && inrange((stream >> subversion,subversion),1u,3u)) {
				for(unsigned int i = 0; i < verts; ++i) {
					TempVertex& v = vertices[i];
					v.weights[3]=1.f;
					for(unsigned int n = 0; n < 3; v.weights[3]-=v.weights[n++]) {
						v.bone_id[n+1] = stream.GetI1();
						v.weights[n] = static_cast<float>(static_cast<unsigned int>(stream.GetI1()))/255.f;
					}
					stream.IncPtr((subversion-1)<<2u);
				}

				// even further extra data is not of interest for us, at least now now.
			}
		}
	}

	// 2 ------------ convert to proper aiXX data structures -----------------------------------

	if (need_default && materials.size()) {
		DefaultLogger::get()->warn("MS3D: Found group with no material assigned, spawning default material");
		// if one of the groups has no material assigned, but there are other 
		// groups with materials, a default material needs to be added (
		// scenepreprocessor adds a default material only if nummat==0).
		materials.push_back(TempMaterial());
		TempMaterial& m = materials.back();

		strcpy(m.name,"<MS3D_DefaultMat>");
		m.diffuse = aiColor4D(0.6f,0.6f,0.6f,1.0);
		m.transparency = 1.f;
		m.shininess = 0.f;

		// this is because these TempXXX struct's have no c'tors.
		m.texture[0] = m.alphamap[0] = '\0';

		for (unsigned int i = 0; i < groups.size(); ++i) {
			TempGroup& g = groups[i];
			if (g.mat == UINT_MAX) {
				g.mat = materials.size()-1;
			}
		}
	}

	// convert materials to our generic key-value dict-alike
	if (materials.size()) {
		pScene->mMaterials = new aiMaterial*[materials.size()];
		for (size_t i = 0; i < materials.size(); ++i) {

			aiMaterial* mo = new aiMaterial();
			pScene->mMaterials[pScene->mNumMaterials++] = mo;

			const TempMaterial& mi = materials[i];

			aiString tmp;
			if (0[mi.alphamap]) {
				tmp = aiString(mi.alphamap);
				mo->AddProperty(&tmp,AI_MATKEY_TEXTURE_OPACITY(0));
			}
			if (0[mi.texture]) {
				tmp = aiString(mi.texture);
				mo->AddProperty(&tmp,AI_MATKEY_TEXTURE_DIFFUSE(0));
			}
			if (0[mi.name]) {
				tmp = aiString(mi.name);
				mo->AddProperty(&tmp,AI_MATKEY_NAME);
			}

			mo->AddProperty(&mi.ambient,1,AI_MATKEY_COLOR_AMBIENT);
			mo->AddProperty(&mi.diffuse,1,AI_MATKEY_COLOR_DIFFUSE);
			mo->AddProperty(&mi.specular,1,AI_MATKEY_COLOR_SPECULAR);
			mo->AddProperty(&mi.emissive,1,AI_MATKEY_COLOR_EMISSIVE);

			mo->AddProperty(&mi.shininess,1,AI_MATKEY_SHININESS);
			mo->AddProperty(&mi.transparency,1,AI_MATKEY_OPACITY);

			const int sm = mi.shininess>0.f?aiShadingMode_Phong:aiShadingMode_Gouraud;
			mo->AddProperty(&sm,1,AI_MATKEY_SHADING_MODEL);
		}
	}

	// convert groups to meshes
	if (groups.empty()) {
		throw DeadlyImportError("MS3D: Didn't get any group records, file is malformed");
	}

	pScene->mMeshes = new aiMesh*[pScene->mNumMeshes=static_cast<unsigned int>(groups.size())]();
	for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
	
		aiMesh* m = pScene->mMeshes[i] = new aiMesh();
		const TempGroup& g = groups[i];

		if (pScene->mNumMaterials && g.mat > pScene->mNumMaterials) {
			throw DeadlyImportError("MS3D: Encountered invalid material index, file is malformed");
		} // no error if no materials at all - scenepreprocessor adds one then

		m->mMaterialIndex  = g.mat;
		m->mPrimitiveTypes = aiPrimitiveType_TRIANGLE; 

		m->mFaces = new aiFace[m->mNumFaces = g.triangles.size()];
		m->mNumVertices = m->mNumFaces*3;

		// storage for vertices - verbose format, as requested by the postprocessing pipeline
		m->mVertices = new aiVector3D[m->mNumVertices];
		m->mNormals  = new aiVector3D[m->mNumVertices];
		m->mTextureCoords[0] = new aiVector3D[m->mNumVertices];
		m->mNumUVComponents[0] = 2;

		typedef std::map<unsigned int,unsigned int> BoneSet;
		BoneSet mybones;

		for (unsigned int i = 0,n = 0; i < m->mNumFaces; ++i) {
			aiFace& f = m->mFaces[i];
			if (g.triangles[i]>triangles.size()) {
				throw DeadlyImportError("MS3D: Encountered invalid triangle index, file is malformed");
			}

			TempTriangle& t = triangles[g.triangles[i]];
			f.mIndices = new unsigned int[f.mNumIndices=3];
			
			for (unsigned int i = 0; i < 3; ++i,++n) {
				if (t.indices[i]>vertices.size()) {
					throw DeadlyImportError("MS3D: Encountered invalid vertex index, file is malformed");
				}

				const TempVertex& v = vertices[t.indices[i]];
				for(unsigned int a = 0; a < 4; ++a) {
					if (v.bone_id[a] != UINT_MAX) {
						if (v.bone_id[a] >= joints.size()) {
							throw DeadlyImportError("MS3D: Encountered invalid bone index, file is malformed");
						}
						if (mybones.find(v.bone_id[a]) == mybones.end()) {
							 mybones[v.bone_id[a]] = 1;
						}
						else ++mybones[v.bone_id[a]];
					}
				}

				// collect vertex components
				m->mVertices[n] = v.pos;

				m->mNormals[n] = t.normals[i];
				m->mTextureCoords[0][n] = aiVector3D(t.uv[i].x,1.f-t.uv[i].y,0.0);
				f.mIndices[i] = n;
			}
		}

		// allocate storage for bones
		if(mybones.size()) {
			std::vector<unsigned int> bmap(joints.size());
			m->mBones = new aiBone*[mybones.size()]();
			for(BoneSet::const_iterator it = mybones.begin(); it != mybones.end(); ++it) {
				aiBone* const bn = m->mBones[m->mNumBones] = new aiBone();
				const TempJoint& jnt = joints[(*it).first]; 

				bn->mName.Set(jnt.name);
				bn->mWeights = new aiVertexWeight[(*it).second];

				bmap[(*it).first] = m->mNumBones++;
			}

			// .. and collect bone weights
			for (unsigned int i = 0,n = 0; i < m->mNumFaces; ++i) {
				TempTriangle& t = triangles[g.triangles[i]];

				for (unsigned int i = 0; i < 3; ++i,++n) {
					const TempVertex& v = vertices[t.indices[i]];
					for(unsigned int a = 0; a < 4; ++a) {
						const unsigned int bone = v.bone_id[a];
						if(bone==UINT_MAX){
							continue;
						}

						aiBone* const outbone = m->mBones[bmap[bone]];
						aiVertexWeight& outwght = outbone->mWeights[outbone->mNumWeights++];

						outwght.mVertexId = n;
						outwght.mWeight = v.weights[a];
					}
				}
			}
		}
	}

	// ... add dummy nodes under a single root, each holding a reference to one
	// mesh. If we didn't do this, we'd lose the group name.
	aiNode* rt = pScene->mRootNode = new aiNode("<MS3DRoot>");
	
#ifdef ASSIMP_BUILD_MS3D_ONE_NODE_PER_MESH
	rt->mChildren = new aiNode*[rt->mNumChildren=pScene->mNumMeshes+(joints.size()?1:0)]();

	for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
		aiNode* nd = rt->mChildren[i] = new aiNode();

		const TempGroup& g = groups[i];

		// we need to generate an unique name for all mesh nodes.
		// since we want to keep the group name, a prefix is
		// prepended.
		nd->mName = aiString("<MS3DMesh>_");
		nd->mName.Append(g.name);
		nd->mParent = rt;

		nd->mMeshes = new unsigned int[nd->mNumMeshes = 1];
		nd->mMeshes[0] = i;
	}
#else
	rt->mMeshes = new unsigned int[pScene->mNumMeshes];
	for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
		rt->mMeshes[rt->mNumMeshes++] = i;
	}
#endif

	// convert animations as well
	if(joints.size()) {
#ifndef ASSIMP_BUILD_MS3D_ONE_NODE_PER_MESH
		rt->mChildren = new aiNode*[1]();
		rt->mNumChildren = 1;

		aiNode* jt = rt->mChildren[0] = new aiNode();
#else
		aiNode* jt = rt->mChildren[pScene->mNumMeshes] = new aiNode();
#endif
		jt->mParent = rt;
		CollectChildJoints(joints,jt);
		jt->mName.Set("<MS3DJointRoot>");

		pScene->mAnimations = new aiAnimation*[ pScene->mNumAnimations = 1 ];
		aiAnimation* const anim = pScene->mAnimations[0] = new aiAnimation();

		anim->mName.Set("<MS3DMasterAnim>");

		// carry the fps info to the user by scaling all times with it
		anim->mTicksPerSecond = animfps;
		
		// leave duration at its default, so ScenePreprocessor will fill an appropriate
		// value (the values taken from some MS3D files seem to be too unreliable
		// to pass the validation)
		// anim->mDuration = totalframes/animfps;

		anim->mChannels = new aiNodeAnim*[joints.size()]();
		for(std::vector<TempJoint>::const_iterator it = joints.begin(); it != joints.end(); ++it) {
			if ((*it).rotFrames.empty() && (*it).posFrames.empty()) {
				continue;
			}

			aiNodeAnim* nd = anim->mChannels[anim->mNumChannels++] = new aiNodeAnim();
			nd->mNodeName.Set((*it).name);

			if ((*it).rotFrames.size()) {
				nd->mRotationKeys = new aiQuatKey[(*it).rotFrames.size()];
				for(std::vector<TempKeyFrame>::const_iterator rot = (*it).rotFrames.begin(); rot != (*it).rotFrames.end(); ++rot) {
					aiQuatKey& q = nd->mRotationKeys[nd->mNumRotationKeys++];

					q.mTime = (*rot).time*animfps;

					// XXX it seems our matrix&quaternion code has faults in its conversion routines --
					// aiQuaternion(x,y,z) seems to besomething different as quat(matrix.fromeuler(x,y,z)).
					q.mValue = aiQuaternion(aiMatrix3x3(aiMatrix4x4().FromEulerAnglesXYZ((*rot).value)*
						aiMatrix4x4().FromEulerAnglesXYZ((*it).rotation)).Transpose());
				}
			}

			if ((*it).posFrames.size()) {
				nd->mPositionKeys = new aiVectorKey[(*it).posFrames.size()];

				aiQuatKey* qu = nd->mRotationKeys;
				for(std::vector<TempKeyFrame>::const_iterator pos = (*it).posFrames.begin(); pos != (*it).posFrames.end(); ++pos,++qu) {
					aiVectorKey& v = nd->mPositionKeys[nd->mNumPositionKeys++];

					v.mTime = (*pos).time*animfps;
					v.mValue = (*it).position + (*pos).value;
				}
			}
		}
		// fixup to pass the validation if not a single animation channel is non-trivial
		if (!anim->mNumChannels) {
			anim->mChannels = NULL;
		}
	}
}

#endif