// Fill out your copyright notice in the Description page of Project Settings.

#include "HDF5Library.h"
#include "Runtime/Core/Public/Misc/Paths.h"
#include "Runtime/Core/Public/GenericPlatform/GenericPlatformFile.h"
using namespace H5;

DataSet UHDF5Library::getDatasetByName(Group & group, char * name)
{
	DataSet dataset;
	try {
		dataset = group.openDataSet(name);
	}
	catch (...)
	{
		FString adjustedName = FString(name);
		if (islower(*name))
		{
			adjustedName = adjustedName.ToUpper();
		}
		else
		{
			adjustedName = adjustedName.ToLower();
		}
		char* adjustedNameAsCharArray = TCHAR_TO_ANSI(*adjustedName);

		dataset = group.openDataSet(adjustedNameAsCharArray);
	}
	return dataset;
}

Group UHDF5Library::getGroupByName(H5File & file, FString name)
{
	char* NameAsCharArray = NULL;
	NameAsCharArray = TCHAR_TO_ANSI(*name);
	Group group = file.openGroup(NameAsCharArray);
	return group;
}

/*
Group UHDF5Library::getGroupByName(H5File & file, FString name)
{
	for (int i = 0; i < 1000; ++i)
	{
		Group group;
		FString Number;
		FString Cat;
		char* CatAsCharArray = NULL;
		try {
			Number = FString::FromInt(i);
			Cat = name + Number;
			CatAsCharArray = TCHAR_TO_ANSI(*Cat);
			group = file.openGroup(CatAsCharArray);
			return group;
		}
		catch (...)
		{
			FString adjustedName = FString(CatAsCharArray).ToLower();
			char* adjustedNameAsCharArray = TCHAR_TO_ANSI(*adjustedName);

			try {
				group = file.openGroup(adjustedNameAsCharArray);
				return group;
			}
			catch (...)
			{
			}
		}
	}

	return Group();
}*/

bool UHDF5Library::ImportData(FString FileName, TArray<float>& X, TArray<float>& Y, TArray<float>& Z, TArray<float>& U, TArray<float>& V, TArray<float>& W)
{
	return false;
}

H5File UHDF5Library::LoadFile(FString FileName, TArray<FString>& GroupNames)
{
	/*
	* Turn off the auto-printing when failure occurs so that we can
	* handle the errors appropriately
	*/
	Exception::dontPrint();

	/*
	 * Open the file and group
	 */

	FString relpath = FPaths::ProjectDir();

	//TCHAR *dirname = TEXT("Resources");
	//relpath.PathAppend(dirname, _tcslen(dirname));

	relpath += FString("/Resources/");

	//TCHAR *filename = TEXT("abc64x64x64.h5part");
	//relpath.PathAppend(filename, _tcslen(filename));

	relpath += FileName;

	FString abspath = IFileManager::Get().ConvertToAbsolutePathForExternalAppForRead(*relpath);
	char* pathAsCharArray = TCHAR_TO_ANSI(*abspath);

	H5File File = H5File(pathAsCharArray, H5F_ACC_RDONLY);
	
	Group Root = File.openGroup("/");

	GroupNames = TArray<FString>();

	for (int i = 0; i < Root.getNumObjs(); i++) {
		std::string GroupName;

		switch (Root.getObjTypeByIdx((size_t)i))
		{
		case H5G_GROUP:
			GroupName = Root.getObjnameByIdx((size_t)i);
			GroupNames.Emplace(FString(GroupName.c_str()));
			break;
		default:
			break;
		}

	}

	return File;
}

bool UHDF5Library::LoadGroup(H5File File, FString GroupName, TArray<float>& X, TArray<float>& Y, TArray<float>& Z, TArray<float>& U, TArray<float>& V, TArray<float>& W)
{
	Group group = getGroupByName(File, GroupName);

	// Get dataspace of one dataset to get the dimension. (Dimensions must be equal for all sets.)
	DataSet dataset = getDatasetByName(group, "X");
	DataSpace dataspace = dataset.getSpace();
	int rank = dataspace.getSimpleExtentNdims();
	hsize_t dims_out[1];
	int ndims = dataspace.getSimpleExtentDims(dims_out, NULL);
	int32 dimension = dims_out[0];
	dataspace.selectAll(); // needed?

	// Output buffer initialization
	float* data_out = new float[dimension];

	// Read datasets
	dataset.read(data_out, PredType::NATIVE_FLOAT);
	X = TArray<float>(data_out, dims_out[0]);

	dataset = getDatasetByName(group, "Y");
	dataset.read(data_out, PredType::NATIVE_FLOAT);
	Y = TArray<float>(data_out, dims_out[0]);

	dataset = getDatasetByName(group, "Z");
	dataset.read(data_out, PredType::NATIVE_FLOAT);
	Z = TArray<float>(data_out, dims_out[0]);

	dataset = getDatasetByName(group, "U");
	dataset.read(data_out, PredType::NATIVE_FLOAT);
	U = TArray<float>(data_out, dims_out[0]);

	dataset = getDatasetByName(group, "V");
	dataset.read(data_out, PredType::NATIVE_FLOAT);
	V = TArray<float>(data_out, dims_out[0]);

	dataset = getDatasetByName(group, "W");
	dataset.read(data_out, PredType::NATIVE_FLOAT);
	W = TArray<float>(data_out, dims_out[0]);

	delete[] data_out;

	return true;
}