#pragma once

#include <QXmlStreamWriter>
#include <QXmlStreamReader>
#include <QTextStream>

#include "cafInternalPdmStreamOperators.h"
#include "cafInternalPdmFilePathStreamOperators.h"
#include "cafPdmReferenceHelper.h"
#include "cafInternalPdmFieldIoHelper.h"



namespace caf
{
    class PdmObjectFactory;
    template <typename T> class PdmPointer;


//--------------------------------------------------------------------------------------------------
/// Generic write method for fields. Will work as long as DataType supports the stream operator 
/// towards a QTextStream. Some special datatype should not specialize this method unless it is 
/// impossible/awkward to implement the stream operator
/// Implemented in a proxy class to allow  partial specialization 
//--------------------------------------------------------------------------------------------------
template <typename DataType>
struct PdmFieldWriter
{
    static void    writeFieldData(const DataType & fieldValue, QXmlStreamWriter& xmlStream)
    {
        QString dataString; 
        QTextStream data(&dataString, QIODevice::WriteOnly); 

        // Use precision of 15 to cover most value ranges for double values
        // Default Qt behavior is precision of 6
        data.setRealNumberPrecision(15);

        data << fieldValue; 
        xmlStream.writeCharacters(dataString);
    }
};

template <typename DataType>
struct PdmFieldReader
{
    static void    readFieldData(DataType & fieldValue, QXmlStreamReader& xmlStream, PdmObjectFactory* objectFactory);
};

//--------------------------------------------------------------------------------------------------
/// Generic read method for fields. Will work as long as DataType supports the stream operator 
/// towards a QTextStream. Some special datatype should not specialize this method unless it is 
/// impossible/awkward to implement the stream operator
//--------------------------------------------------------------------------------------------------
template<typename DataType >
void PdmFieldReader<DataType>::readFieldData(DataType & fieldValue, QXmlStreamReader& xmlStream, PdmObjectFactory* objectFactory)
{
    PdmFieldIOHelper::skipComments(xmlStream);
    if (!xmlStream.isCharacters()) return;

    QString dataString = xmlStream.text().toString();
    QTextStream data(&dataString, QIODevice::ReadOnly);  
    data >> fieldValue;

    // Make stream point to end of element
    QXmlStreamReader::TokenType type;
    type = xmlStream.readNext();
    PdmFieldIOHelper::skipCharactersAndComments(xmlStream);
}

//--------------------------------------------------------------------------------------------------
/// Specialized read function for QStrings, because the >> operator only can read word by word
//--------------------------------------------------------------------------------------------------
template<>
void PdmFieldReader<QString>::readFieldData(QString & field, QXmlStreamReader& xmlStream, PdmObjectFactory* objectFactory);

#if 0
//--------------------------------------------------------------------------------------------------
/// Specialized IO for PdmPointer
//--------------------------------------------------------------------------------------------------
template <typename DataType>
struct PdmFieldWriter< PdmPointer<DataType> >
{
    static void writeFieldData(const PdmPointer<DataType> & fieldValue, QXmlStreamWriter& xmlStream, PdmReferenceHelper* referenceHelper)
    {
        QString dataString; 

        CAF_ASSERT(referenceHelper);

        if (fieldValue.isNull())
        {
            dataString = "NULL";
        }
        else
        {
            dataString = referenceHelper->referenceFromRootToObject(fieldValue.p());
        }

        xmlStream.writeCharacters(dataString);  
    }
};

template <typename DataType>
struct PdmFieldReader< PdmPointer<DataType> >
{
    static void readFieldData(PdmPointer<DataType> & fieldValue, QXmlStreamReader& xmlStream, PdmObjectFactory*, PdmReferenceHelper* referenceHelper)
    {
        PdmFieldIOHelper::skipComments(xmlStream);
        if (!xmlStream.isCharacters()) return;

        QString dataString = xmlStream.text().toString();

        // Make stream point to end of element
        QXmlStreamReader::TokenType type;
        type = xmlStream.readNext();
        PdmFieldIOHelper::skipCharactersAndComments(xmlStream);

        if (dataString != "NULL")
        {
            CAF_ASSERT(referenceHelper);
            
            PdmObjectHandle* objHandle = referenceHelper->objectFromReference(dataString);
            fieldValue.setRawPtr(objHandle);
        }
    }
};

#endif
} // End of namespace caf