#include "UnitTestPCH.h"

#include <assimp/mesh.h>
#include <assimp/scene.h>
#include <assimp/Importer.hpp>
#include <ScenePreprocessor.h>

using namespace std;
using namespace Assimp;


class ScenePreprocessorTest : public ::testing::Test
{
public:

	virtual void SetUp();
	virtual void TearDown();

protected:

	void CheckIfOnly(aiMesh* p, unsigned int num, unsigned flag);

	void ProcessAnimation(aiAnimation* anim) { pp->ProcessAnimation(anim); }
	void ProcessMesh(aiMesh* mesh) { pp->ProcessMesh(mesh); }

	ScenePreprocessor* pp;
	aiScene* scene;
};

// ------------------------------------------------------------------------------------------------
void ScenePreprocessorTest::SetUp()
{
	// setup a dummy scene with a single node
	scene = new aiScene();
	scene->mRootNode = new aiNode();
	scene->mRootNode->mName.Set("<test>");

	// add some translation
	scene->mRootNode->mTransformation.a4 = 1.f;
	scene->mRootNode->mTransformation.b4 = 2.f;
	scene->mRootNode->mTransformation.c4 = 3.f;

	// and allocate a ScenePreprocessor to operate on the scene
	pp = new ScenePreprocessor(scene);
}

// ------------------------------------------------------------------------------------------------
void ScenePreprocessorTest::TearDown()
{
	delete pp;
	delete scene;
}

// ------------------------------------------------------------------------------------------------
// Check whether ProcessMesh() returns flag for a mesh that consist of primitives with num indices
void ScenePreprocessorTest::CheckIfOnly(aiMesh* p, unsigned int num, unsigned int flag)
{
	// Triangles only
	for (unsigned i = 0; i < p->mNumFaces;++i) {
		p->mFaces[i].mNumIndices = num;
	}
	pp->ProcessMesh(p);
	EXPECT_EQ(flag, p->mPrimitiveTypes);
	p->mPrimitiveTypes = 0;
}

// ------------------------------------------------------------------------------------------------
// Check whether a mesh is preprocessed correctly. Case 1: The mesh needs preprocessing
TEST_F(ScenePreprocessorTest, testMeshPreprocessingPos)
{
	aiMesh* p = new aiMesh();
	p->mNumFaces = 100;
	p->mFaces = new aiFace[p->mNumFaces];

	p->mTextureCoords[0] = new aiVector3D[10];
	p->mNumUVComponents[0] = 0;
	p->mNumUVComponents[1] = 0;

	CheckIfOnly(p,1,aiPrimitiveType_POINT);
	CheckIfOnly(p,2,aiPrimitiveType_LINE);
	CheckIfOnly(p,3,aiPrimitiveType_TRIANGLE);
	CheckIfOnly(p,4,aiPrimitiveType_POLYGON);
	CheckIfOnly(p,1249,aiPrimitiveType_POLYGON);

	// Polygons and triangles mixed
	unsigned i;
	for (i = 0; i < p->mNumFaces/2;++i)	{
		p->mFaces[i].mNumIndices = 3;
	}
	for (; i < p->mNumFaces-p->mNumFaces/4;++i)	{
		p->mFaces[i].mNumIndices = 4;
	}
	for (; i < p->mNumFaces;++i)	{
		p->mFaces[i].mNumIndices = 10;
	}
	ProcessMesh(p);
	EXPECT_EQ(static_cast<unsigned int>(aiPrimitiveType_TRIANGLE|aiPrimitiveType_POLYGON),
	          p->mPrimitiveTypes);
	EXPECT_EQ(2U, p->mNumUVComponents[0]);
	EXPECT_EQ(0U, p->mNumUVComponents[1]);
	delete p;
}

// ------------------------------------------------------------------------------------------------
// Check whether a mesh is preprocessed correctly. Case 1: The mesh doesn't need preprocessing
TEST_F(ScenePreprocessorTest, testMeshPreprocessingNeg)
{
	aiMesh* p = new aiMesh();
	p->mPrimitiveTypes = aiPrimitiveType_TRIANGLE|aiPrimitiveType_POLYGON;
	ProcessMesh(p);

	// should be unmodified
	EXPECT_EQ(static_cast<unsigned int>(aiPrimitiveType_TRIANGLE|aiPrimitiveType_POLYGON),
	          p->mPrimitiveTypes);

	delete p;
}

// ------------------------------------------------------------------------------------------------
// Make a dummy animation with a single channel, '<test>'
aiAnimation* MakeDummyAnimation()
{
	aiAnimation* p = new aiAnimation();
	p->mNumChannels = 1;
	p->mChannels = new aiNodeAnim*[1];
	aiNodeAnim* anim = p->mChannels[0] = new aiNodeAnim();
	anim->mNodeName.Set("<test>");
	return p;
}

// ------------------------------------------------------------------------------------------------
// Check whether an anim is preprocessed correctly. Case 1: The anim needs preprocessing
TEST_F(ScenePreprocessorTest, testAnimationPreprocessingPos)
{
	aiAnimation* p = MakeDummyAnimation();
	aiNodeAnim* anim = p->mChannels[0];

	// we don't set the animation duration, but generate scaling channels
	anim->mNumScalingKeys = 10;
	anim->mScalingKeys = new aiVectorKey[10];

	for (unsigned int i = 0; i < 10;++i)	{
		anim->mScalingKeys[i].mTime = i;
		anim->mScalingKeys[i].mValue = aiVector3D((float)i);
	}
	ProcessAnimation(p);

	// we should now have a proper duration
	EXPECT_NEAR(p->mDuration, 9., 0.005);

	// ... one scaling key
	EXPECT_TRUE(anim->mNumPositionKeys == 1 &&
		anim->mPositionKeys &&
		anim->mPositionKeys[0].mTime == 0.0 &&
		anim->mPositionKeys[0].mValue == aiVector3D(1.f,2.f,3.f));

	// ... and one rotation key
	EXPECT_TRUE(anim->mNumRotationKeys == 1 && anim->mRotationKeys &&
		anim->mRotationKeys[0].mTime == 0.0);

	delete p;
}