/*PVUnion.cpp*/
/**
 * Copyright - See the COPYRIGHT that is included with this distribution.
 * EPICS pvData is distributed subject to a Software License Agreement found
 * in file LICENSE that is included with this distribution.
 */
/**
 *  @author mse
 */
#include <cstddef>
#include <cstdlib>
#include <string>
#include <cstdio>
#include <vector>
#include <pv/pvData.h>
#include <pv/pvIntrospect.h>
#include <pv/convert.h>
#include <pv/factory.h>
#include <pv/serializeHelper.h>

using std::tr1::static_pointer_cast;
using std::size_t;

namespace epics { namespace pvData {
	
int32 PVUnion::UNDEFINED_INDEX = -1;
PVDataCreatePtr PVUnion::pvDataCreate = getPVDataCreate();


PVUnion::PVUnion(UnionConstPtr const & unionPtr)
: PVField(unionPtr),
  unionPtr(unionPtr),
  selector(UNDEFINED_INDEX),
  value(),
  variant(unionPtr->isVariant())
{
}

PVUnion::~PVUnion()
{
}

UnionConstPtr PVUnion::getUnion() const
{
    return unionPtr;
}

PVFieldPtr PVUnion::get() const
{
    return value;
}

int32 PVUnion::getSelectedIndex() const
{
    return selector;
}

String PVUnion::getSelectedFieldName() const
{
    // no name for undefined and for variant unions
    if (selector == UNDEFINED_INDEX)
        return String();
    else
        return unionPtr->getFieldName(selector);
}

PVFieldPtr PVUnion::select(int32 index)
{
    // no change
    if (selector == index)
        return value;

    if (index == UNDEFINED_INDEX)
    {
        selector = UNDEFINED_INDEX;
        value.reset();
        return value;
    }
    else if (variant)
        throw std::invalid_argument("index out of bounds");
    else if (index < 0 || index > static_cast<int32>(unionPtr->getFields().size()))
        throw std::invalid_argument("index out of bounds");

    FieldConstPtr field = unionPtr->getField(index);
    selector = index;
    value = pvDataCreate->createPVField(field);
    
    return value;
}
	
PVFieldPtr PVUnion::select(String const & fieldName)
{
    int32 index = variant ? -1 : unionPtr->getFieldIndex(fieldName);
	if (index == -1)
        throw std::invalid_argument("no such fieldName");
        
	return select(index);
}
	
void PVUnion::set(PVFieldPtr const & value)
{
    set(selector, value);
}

void PVUnion::set(int32 index, PVFieldPtr const & value)
{
    if (variant && index != UNDEFINED_INDEX)
        throw std::invalid_argument("index out of bounds");
    else if (!variant)
    {
        if (index == UNDEFINED_INDEX)
        {
            // for undefined index we accept only null values
            if (value.get())
				throw std::invalid_argument("non-null value for index == UNDEFINED_INDEX");
        }
        else if (index < 0 || index > static_cast<int32>(unionPtr->getFields().size()))
            throw std::invalid_argument("index out of bounds");

        // value type must match
        if (value->getField() != unionPtr->getField(index))
			throw std::invalid_argument("selected field and its introspection data do not match");
    }

    selector = index;
    this->value = value;
}

void PVUnion::set(String const & fieldName, PVFieldPtr const & value)
{
    int32 index = variant ? -1 : unionPtr->getFieldIndex(fieldName);
    if (index == -1)
        throw std::invalid_argument("no such fieldName");

	set(index, value);
}

void PVUnion::serialize(ByteBuffer *pbuffer, SerializableControl *pflusher) const
{
    if (variant)
    {
        // write introspection data
        if (value.get() == 0)
            pbuffer->put((int8)-1);
        else
        {
            pflusher->cachedSerialize(value->getField(), pbuffer);
            value->serialize(pbuffer, pflusher);
        }
    }
    else
    {
        // write selector value
        SerializeHelper::writeSize(selector, pbuffer, pflusher);
        // write value, no value for UNDEFINED_INDEX
        if (selector != UNDEFINED_INDEX) 
            value->serialize(pbuffer, pflusher);
    }
}

void PVUnion::deserialize(ByteBuffer *pbuffer, DeserializableControl *pcontrol)
{
    if (variant)
    {
        FieldConstPtr field = pcontrol->cachedDeserialize(pbuffer);
        if (field.get())
        {
            value = pvDataCreate->createPVField(field);
            value->deserialize(pbuffer, pcontrol);
        }
        else
            value.reset();
    }
    else
    {
        selector = SerializeHelper::readSize(pbuffer, pcontrol);
        if (selector != UNDEFINED_INDEX)
        {
            FieldConstPtr field = unionPtr->getField(selector);
            value = pvDataCreate->createPVField(field);
            value->deserialize(pbuffer, pcontrol);
        }
        else
            value.reset();
    }
}

std::ostream& PVUnion::dumpValue(std::ostream& o) const
{
    o << format::indent() << getUnion()->getID() << ' ' << getFieldName() << std::endl;
    {
    	format::indent_scope s(o);
		PVFieldPtr fieldField = get();
		if (fieldField.get() == NULL)
		  o << format::indent() << "(none)" << std::endl;
		else
		{
    		Type type = fieldField->getField()->getType();
    		if (type == scalar || type == scalarArray)
    			o << format::indent() << fieldField->getField()->getID() << ' ' << fieldField->getFieldName() << ' ' << *(fieldField.get()) << std::endl;
    		else
    			o << *(fieldField.get());
	   } 
    }
 	return o;
}

}}