/////////////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2017 Statoil ASA
//
//  ResInsight is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  ResInsight is distributed in the hope that it will be useful, but WITHOUT ANY
//  WARRANTY; without even the implied warranty of MERCHANTABILITY or
//  FITNESS FOR A PARTICULAR PURPOSE.
//
//  See the GNU General Public License at <http://www.gnu.org/licenses/gpl.html>
//  for more details.
//
/////////////////////////////////////////////////////////////////////////////////

#include "RifHdf5Reader.h"

#include "RiaLogging.h"

#include "RiaQDateTimeTools.h"

#ifdef _MSC_VER
#pragma warning( disable : 4251 )
#endif
#include "H5Cpp.h"

#include "cvfAssert.h"
#include "cvfMath.h"

#include <QDateTime>
#include <QDir>
#include <QStringList>

#include <algorithm>

//--------------------------------------------------------------------------------------------------
/// May reduce constructor content upon discussion of overlying framework.
///
/// std::string dateString = getStringAttribute(file, "/KaseStudy/TransientSections", "initial_date");
/// QDateTime initalDateTime = sourSimDateTimeToQDateTime(dateString);   // may rearrange/change to be a call in
/// timeSteps()
//--------------------------------------------------------------------------------------------------
RifHdf5Reader::RifHdf5Reader( const QString& fileName )
    : m_fileName( fileName )
    , m_fileStrategy( 0 )
{
    try
    {
        H5::H5File file( fileName.toStdString().c_str(), H5F_ACC_RDONLY ); // evt fileName.toLatin1().data()

        m_fileStrategy = getIntAttribute( file, "/", "file_strategy" ); // fileStrategy == 1 means one time step per file

        if ( m_fileStrategy == 1 )
        {
            m_timeStepFileNames = getSourSimTimeStepFileNames( fileName );
        }
    }

    catch ( ... ) // catch any failure
    {
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
RifHdf5Reader::~RifHdf5Reader()
{
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
bool RifHdf5Reader::dynamicResult( const QString& result, size_t stepIndex, std::vector<double>* values ) const
{
    if ( m_fileStrategy != 1 ) return false; // NB: currently incapable of handling all results in one sourres file

    try
    {
        QStringList props = propertyNames();

        QStringList::iterator it = std::find( props.begin(), props.end(), result );

        int propIdx = ( it != props.end() ) ? it - props.begin() : 0; // index to 'result' in QStringList props (usually
                                                                      // size_t but int gave no warning)

        H5::Exception::dontPrint(); // Turn off auto-printing of failures to handle the errors appropriately

        std::string fileName      = m_timeStepFileNames[stepIndex];
        std::string timeStepGroup = "/Timestep_" + getTimeStepNumberAs5DigitString( fileName );

        H5::H5File file( fileName.c_str(), H5F_ACC_RDONLY );

        std::string groupName = timeStepGroup + "/GridFunctions/GridPart_00000/GridFunction_" +
                                IntTo5DigitString( propIdx + 1 ); // adjust to HDF5 one based indexing

        getElementResultValues( file, groupName, values );

        return true;
    }

    catch ( ... ) // catch any failure
    {
        RiaLogging::error( QString( "Failed to read SourSimRL dynamic results" ) );

        return false;
    }
}

//--------------------------------------------------------------------------------------------------
/// Qt alternative fileName.toLatin1().data()
//--------------------------------------------------------------------------------------------------
std::vector<QDateTime> RifHdf5Reader::timeSteps() const
{
    std::vector<QDateTime> times;

    if ( m_fileStrategy != 1 ) return times; // NB: currently incapable of handling all results in one sourres file

    try
    {
        H5::Exception::dontPrint(); // Turn off auto-printing of failures to handle the errors appropriately

        H5::H5File mainFile( m_fileName.toStdString().c_str(),
                             H5F_ACC_RDONLY ); // initial date part is an attribute of SourSimRL main file

        std::string dateString = getStringAttribute( mainFile, "/KaseStudy/TransientSections", "initial_date" );

        QDateTime dtInitial = sourSimDateTimeToQDateTime( dateString );

        for ( size_t i = 0; i < m_timeStepFileNames.size(); i++ )
        {
            std::string fileName      = m_timeStepFileNames[i];
            std::string timeStepGroup = "/Timestep_" + getTimeStepNumberAs5DigitString( fileName );

            H5::H5File file( fileName.c_str(), H5F_ACC_RDONLY );

            double timeStepValue = getDoubleAttribute( file, timeStepGroup,
                                                       "timestep" ); // Assumes only one time step per file
            int    timeStepDays  = cvf::Math::floor( timeStepValue );

            double fractionOfDay = timeStepValue - timeStepDays;
            double milliseconds  = fractionOfDay * 24.0 * 60.0 * 60.0 * 1000.0;

            QDateTime dt = dtInitial;
            dt           = RiaQDateTimeTools::addDays( dt, timeStepDays );
            dt           = RiaQDateTimeTools::addMSecs( dt, milliseconds );

            times.push_back( dt );
        }
    }

    catch ( ... ) // catch any failure
    {
        times.clear();

        RiaLogging::error( QString( "Failed to read SourSimRL time steps" ) );
    }

    return times;
}

//---------------------------------------------------------------------------------------------------
/// Result variables of first timestep listed by HDF5 subgroups to the following base group:
/// "/Timestep_00001/GridFunctions/GridPart_00000"
/// According to sourres file description, it seems safe to assume equal presence for all time steps.
//---------------------------------------------------------------------------------------------------
QStringList RifHdf5Reader::propertyNames() const
{
    QStringList propNames;

    if ( m_fileStrategy != 1 ) return propNames; // NB: currently incapable of handling all results in one sourres file

    if ( m_timeStepFileNames.empty() )
    {
        RiaLogging::error( QString( "Failed to read properties. Transient data does not exist." ) );
        return propNames;
    }

    std::string fileName = m_timeStepFileNames[0]; // assume the result variables to be identical across time steps =>
                                                   // extract names from first time step file
    std::string groupName = "/Timestep_" + getTimeStepNumberAs5DigitString( fileName ) + "/GridFunctions/GridPart_00000";

    try
    {
        H5::Exception::dontPrint(); // Turn off auto-printing of failures to handle the errors appropriately

        H5::H5File file( fileName.c_str(), H5F_ACC_RDONLY );

        std::vector<std::string> resultNames = getResultNames( file, groupName );

        for ( const std::string& s : resultNames )
        {
            propNames.push_back( s.c_str() );
        }
    }

    catch ( ... ) // catch any failure
    {
        propNames.clear();

        RiaLogging::error( QString( "Failed to read properties from file : '%1'" ).arg( fileName.c_str() ) );
    }

    return propNames;
}

//=========================== PRIVATE METHODS =====================================================
//
//
//
//==================================================================================================

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
std::vector<std::string> RifHdf5Reader::getSourSimTimeStepFileNames( const QString& fileName ) const
{
    QFileInfo fi( fileName );
    QString   name = fi.fileName();
    QString   dir  = fi.path();

    QDir baseDir( dir );
    baseDir.setFilter( QDir::Files );

    QStringList nameFilters;
    nameFilters << name + ".?????";
    baseDir.setNameFilters( nameFilters );

    QStringList fileNames = baseDir.entryList();

    std::vector<std::string> timeStepFileNames;

    for ( int i = 0; i < fileNames.size(); i++ )
    {
        std::string fullPath = dir.toStdString() + "/" + fileNames[i].toStdString();

        timeStepFileNames.push_back( fullPath );
    }

    return timeStepFileNames;
}

//--------------------------------------------------------------------------------------------------
/// Build a QDateTime based on a SourSimRL HDF date attribute
/// Did not succeed with QDateTime dt = QDateTime::fromString(dateString, "YYYY MM DD hh mm ss");
/// Thus a conversion of substrings via integers
//--------------------------------------------------------------------------------------------------
QDateTime RifHdf5Reader::sourSimDateTimeToQDateTime( std::string dateString ) const
{
    int year  = std::stoi( dateString.substr( 0, 4 ) );
    int month = std::stoi( dateString.substr( 5, 2 ) );
    int day   = std::stoi( dateString.substr( 8, 2 ) );

    int hours   = std::stoi( dateString.substr( 11, 2 ) );
    int minutes = std::stoi( dateString.substr( 14, 2 ) );
    int seconds = std::stoi( dateString.substr( 17, 2 ) );

    QDate d( year, month, day );
    QTime t( hours, minutes, seconds );

    QDateTime dt = RiaQDateTimeTools::createUtcDateTime( d, t );

    return dt;
}

//--------------------------------------------------------------------------------------------------
/// Build a string based on an int that consists of exactly 5 characters for HDF5 numbering
//--------------------------------------------------------------------------------------------------
std::string RifHdf5Reader::getTimeStepNumberAs5DigitString( std::string fileName ) const
{
    return fileName.substr( fileName.size() - 5 ); // extract the 5 last characters/digits
}

//--------------------------------------------------------------------------------------------------
/// Build a string based on an int that consists of exactly 5 characters for HDF5 numbering
//--------------------------------------------------------------------------------------------------
std::string RifHdf5Reader::IntTo5DigitString( int i ) const
{
    std::string numString = "00000" + std::to_string( i );

    return numString.substr( numString.size() - 5 ); // extract the 5 last characters/digits
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
int RifHdf5Reader::getIntAttribute( H5::H5File file, std::string groupName, std::string attributeName ) const
{
    try
    {
        H5::Exception::dontPrint(); // Turn off auto-printing of failures to handle the errors appropriately

        H5::Group     group = file.openGroup( groupName.c_str() );
        H5::Attribute attr  = group.openAttribute( attributeName.c_str() );

        int value = 0;

        H5::DataType type = attr.getDataType();
        attr.read( type, &value );

        return value;
    }

    catch ( ... )
    {
        return 0;
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
double RifHdf5Reader::getDoubleAttribute( H5::H5File file, std::string groupName, std::string attributeName ) const
{
    try
    {
        H5::Exception::dontPrint(); // Turn off auto-printing of failures to handle the errors appropriately

        H5::Group     group = file.openGroup( groupName.c_str() );
        H5::Attribute attr  = group.openAttribute( attributeName.c_str() );

        double value = 0.0;

        H5::DataType type = attr.getDataType();
        attr.read( type, &value );

        return value;
    }

    catch ( ... )
    {
        return 0.0;
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
std::string RifHdf5Reader::getStringAttribute( H5::H5File file, std::string groupName, std::string attributeName ) const
{
    try
    {
        H5::Exception::dontPrint(); // Turn off auto-printing of failures to handle the errors appropriately

        H5::Group     group = file.openGroup( groupName.c_str() );
        H5::Attribute attr  = group.openAttribute( attributeName.c_str() );

        std::string stringAttribute( 1024, '\0' );

        H5::DataType nameType = attr.getDataType();
        attr.read( nameType, &stringAttribute[0] );

        return stringAttribute;
    }

    catch ( ... )
    {
        return "";
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
std::vector<std::string> RifHdf5Reader::getSubGroupNames( H5::H5File file, std::string baseGroupName ) const
{
    return RifHdf5ReaderTools::getSubGroupNames( &file, baseGroupName );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
std::vector<std::string> RifHdf5Reader::getResultNames( H5::H5File file, std::string baseGroupName ) const
{
    std::vector<std::string> subGroupNames = getSubGroupNames( file, baseGroupName );

    std::vector<std::string> resultNames;

    for ( std::vector<std::string>::iterator it = subGroupNames.begin(); it != subGroupNames.end(); it++ )
    {
        std::string groupName = baseGroupName + "/" + *it;

        std::string name = getStringAttribute( file, groupName, "name" );

        resultNames.push_back( name );
    }

    return resultNames;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RifHdf5Reader::getElementResultValues( H5::H5File file, std::string groupName, std::vector<double>* resultValues ) const
{
    try
    {
        H5::Exception::dontPrint(); // Turn off auto-printing of failures to handle the errors appropriately

        H5::Group   group   = file.openGroup( groupName.c_str() );
        H5::DataSet dataset = H5::DataSet( group.openDataSet( "values" ) );

        hsize_t       dims[2];
        H5::DataSpace dataspace = dataset.getSpace();
        dataspace.getSimpleExtentDims( dims, nullptr );

        ( *resultValues ).resize( dims[0] );
        dataset.read( resultValues->data(), H5::PredType::NATIVE_DOUBLE );
    }
    catch ( ... )
    {
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
std::vector<std::string> RifHdf5ReaderTools::getSubGroupNames( H5::H5File* file, const std::string& baseGroupName )
{
    if ( file )
    {
        try
        {
            H5::Exception::dontPrint(); // Turn off auto-printing of failures to handle the errors appropriately

            H5::Group baseGroup = file->openGroup( baseGroupName.c_str() );

            std::vector<std::string> subGroupNames;

            hsize_t groupSize = baseGroup.getNumObjs();

            for ( hsize_t i = 0; i < groupSize; i++ )
            {
                std::string nodeName( 1024, '\0' );

                ssize_t slen = baseGroup.getObjnameByIdx( i, &nodeName[0], 1023 );

                nodeName.resize( slen + 1 );

                subGroupNames.push_back( nodeName );
            }

            return subGroupNames;
        }
        catch ( ... )
        {
        }
    }

    return {};
}