/*
 *
 *  Copyright (C) 1996-2012, OFFIS e.V.
 *  All rights reserved.  See COPYRIGHT file for details.
 *
 *  This software and supporting documentation were developed by
 *
 *    OFFIS e.V.
 *    R&D Division Health
 *    Escherweg 2
 *    D-26121 Oldenburg, Germany
 *
 *
 *  Module:  dcmimgle
 *
 *  Author:  Joerg Riesmeier
 *
 *  Purpose: DicomMonochromeModality (Source)
 *
 */


#include "dcmtk/config/osconfig.h"
#include "dcmtk/dcmdata/dcdeftag.h"
#include "dcmtk/dcmdata/dcuid.h"

#include "dcmtk/dcmimgle/dimomod.h"
#include "dcmtk/dcmimgle/didocu.h"
#include "dcmtk/dcmimgle/diinpx.h"


/*----------------*
 *  constructors  *
 *----------------*/

DiMonoModality::DiMonoModality(const DiDocument *docu,
                               DiInputPixel *pixel)
  : Representation(EPR_MaxSigned),
    MinValue(0),
    MaxValue(0),
    Bits(0),
    UsedBits(0),
    AbsMinimum(0),
    AbsMaximum(0),
    RescaleIntercept(0),
    RescaleSlope(0),
    LookupTable(0),
    Rescaling(0),
    TableData(NULL)
{
    if (Init(docu, pixel))
    {
        if (docu->getFlags() & CIF_IgnoreModalityTransformation)        // ignore modality LUT and rescaling
        {
            DCMIMGLE_INFO("configuration flag set ... ignoring possible modality transform");
        }
        else if (!(docu->getFlags() & CIF_UsePresentationState))        // ignore modality LUT and rescaling
        {
            const char *sopClassUID = NULL;                             // check for XA and XRF image (ignore MLUT)
            if ((docu->getValue(DCM_SOPClassUID, sopClassUID) == 0) || (sopClassUID == NULL) ||
               ((strcmp(sopClassUID, UID_XRayAngiographicImageStorage) != 0) &&
                (strcmp(sopClassUID, UID_XRayRadiofluoroscopicImageStorage) != 0) &&
                (strcmp(sopClassUID, UID_RETIRED_XRayAngiographicBiPlaneImageStorage) != 0)))
            {
                EL_BitsPerTableEntry descMode = ELM_UseValue;          // first search on main level
                if (docu->getFlags() & CIF_IgnoreModalityLutBitDepth)
                    descMode = ELM_IgnoreValue;
                else if (docu->getFlags() & CIF_CheckLutBitDepth)
                    descMode = ELM_CheckValue;
                TableData = new DiLookupTable(docu, DCM_ModalityLUTSequence, DCM_LUTDescriptor, DCM_LUTData,
                    DCM_LUTExplanation, descMode);
                checkTable();
                if (LookupTable)
                    DCMIMGLE_DEBUG("found modality LUT on main dataset level");
                Rescaling = (docu->getValue(DCM_RescaleIntercept, RescaleIntercept) > 0);
                Rescaling &= (docu->getValue(DCM_RescaleSlope, RescaleSlope) > 0);
                if (Rescaling)
                    DCMIMGLE_DEBUG("found 'RescaleSlope/Intercept' on main dataset level");
                else if (!LookupTable)                                 // then check for functional groups sequence
                {
                    DcmSequenceOfItems *seq = NULL;
                    if (docu->getSequence(DCM_SharedFunctionalGroupsSequence, seq))
                    {
                        DcmItem *item = seq->getItem(0);
                        if ((item != NULL) && docu->getSequence(DCM_PixelValueTransformationSequence, seq, item))
                        {
                            item = seq->getItem(0);
                            if (item != NULL)
                            {
                                Rescaling = (docu->getValue(DCM_RescaleIntercept, RescaleIntercept, 0, item) > 0);
                                Rescaling &= (docu->getValue(DCM_RescaleSlope, RescaleSlope, 0, item) > 0);
                                if (Rescaling)
                                    DCMIMGLE_DEBUG("found 'RescaleSlope/Intercept' in 'SharedFunctionalGroupsSequence'");
                            }
                        }
                    }
                }
                checkRescaling(pixel);
            } else {
                /* David Clunie on comp.protocols.dicom (13.12.2000):
                   Modality LUTs in XA and XRF objects are totally screwy and
                   do not follow the normal rules. [...] A Modality LUT may be
                   included with the image to allow it to be scaled back to its
                   proportional value to X-Ray beamintensity. In otherwords,
                   for the objects that use this module (XA and XRF), the
                   Modality LUT is used BACKWARDS. It is used to convert
                   stored pixels to X-Ray beamintensityspace, but it is NOT
                   APPLIED to stored pixels for the purpose of display (or
                   more specifically prior to application of the VOI LUT Module
                   attributes to the storedpixeldata).
                */
                DCMIMGLE_INFO("processing XA or XRF image ... ignoring possible modality transform");
            }
        }
        determineRepresentation(docu);
    }
}


DiMonoModality::DiMonoModality(const DiDocument *docu,
                               DiInputPixel *pixel,
                               const double slope,
                               const double intercept)
  : Representation(EPR_MaxSigned),
    MinValue(0),
    MaxValue(0),
    Bits(0),
    UsedBits(0),
    AbsMinimum(0),
    AbsMaximum(0),
    RescaleIntercept(intercept),
    RescaleSlope(slope),
    LookupTable(0),
    Rescaling(0),
    TableData(NULL)
{
    if (Init(docu, pixel))
    {
        Rescaling = 1;
        checkRescaling(pixel);
        determineRepresentation(docu);
    }
}


DiMonoModality::DiMonoModality(const DiDocument *docu,
                               DiInputPixel *pixel,
                               const DcmUnsignedShort &data,
                               const DcmUnsignedShort &descriptor,
                               const DcmLongString *explanation)
  : Representation(EPR_MaxSigned),
    MinValue(0),
    MaxValue(0),
    Bits(0),
    UsedBits(0),
    AbsMinimum(0),
    AbsMaximum(0),
    RescaleIntercept(0),
    RescaleSlope(0),
    LookupTable(0),
    Rescaling(0),
    TableData(NULL)
{
    if (Init(docu, pixel))
    {
        EL_BitsPerTableEntry descMode = ELM_UseValue;
        if (docu->getFlags() & CIF_IgnoreModalityLutBitDepth)
            descMode = ELM_IgnoreValue;
        else if (docu->getFlags() & CIF_CheckLutBitDepth)
            descMode = ELM_CheckValue;
        TableData = new DiLookupTable(data, descriptor, explanation, descMode);
        checkTable();
        determineRepresentation(docu);
    }
}


DiMonoModality::DiMonoModality(const int bits)
  : Representation(EPR_MaxSigned),
    MinValue(0),
    MaxValue(0),
    Bits(bits),
    UsedBits(0),
    AbsMinimum(0),
    AbsMaximum(DicomImageClass::maxval(bits)),
    RescaleIntercept(0),
    RescaleSlope(0),
    LookupTable(0),
    Rescaling(0),
    TableData(NULL)
{
}


/*--------------*
 *  destructor  *
 *--------------*/

DiMonoModality::~DiMonoModality()
{
    delete TableData;
}


/*********************************************************************/


int DiMonoModality::Init(const DiDocument *docu,
                         DiInputPixel *pixel)
{
    if ((docu != NULL) && (pixel != NULL))
    {
        pixel->determineMinMax();
        MinValue = pixel->getMinValue(1 /* selected range of pixels only */);
        MaxValue = pixel->getMaxValue(1 /* selected range of pixels only */);
        Bits = pixel->getBits();
        AbsMinimum = pixel->getAbsMinimum();
        AbsMaximum = pixel->getAbsMaximum();
        Uint16 us;
        if (docu->getValue(DCM_SamplesPerPixel, us) > 0)
        {
            if (us != 1)
                DCMIMGLE_WARN("invalid value for 'SamplesPerPixel' (" << us << ") ... assuming 1");
        } else
            DCMIMGLE_WARN("missing value for 'SamplesPerPixel' ... assuming 1");
        return 1;
    }
    return 0;
}


void DiMonoModality::checkTable()
{
    if (TableData != NULL)
    {
        LookupTable = TableData->isValid();
        if (LookupTable)
        {
            MinValue = TableData->getMinValue();
            MaxValue = TableData->getMaxValue();
            Bits = TableData->getBits();
            AbsMinimum = 0;
            AbsMaximum = DicomImageClass::maxval(Bits);
        }
    }
}


void DiMonoModality::checkRescaling(const DiInputPixel *pixel)
{
    if (Rescaling)
    {
        if (LookupTable)
        {
            DCMIMGLE_WARN("redundant values for 'RescaleSlope/Intercept' ... using modality LUT transformation");
            Rescaling = 0;
        } else {
            if (RescaleSlope == 0)
            {
                DCMIMGLE_WARN("invalid value for 'RescaleSlope' (" << RescaleSlope << ") ... ignoring modality transformation");
                Rescaling = 0;
            } else {
                if (RescaleSlope < 0)                                       // negative slope value
                {
                    const double temp = MinValue;
                    MinValue = MaxValue * RescaleSlope + RescaleIntercept;
                    MaxValue = temp * RescaleSlope + RescaleIntercept;
                    AbsMinimum = pixel->getAbsMaximum() * RescaleSlope + RescaleIntercept;
                    AbsMaximum = pixel->getAbsMinimum() * RescaleSlope + RescaleIntercept;
                } else {                                                    // positive slope value
                    MinValue = MinValue * RescaleSlope + RescaleIntercept;
                    MaxValue = MaxValue * RescaleSlope + RescaleIntercept;
                    AbsMinimum = pixel->getAbsMinimum() * RescaleSlope + RescaleIntercept;
                    AbsMaximum = pixel->getAbsMaximum() * RescaleSlope + RescaleIntercept;
                }
                Bits = DicomImageClass::rangeToBits(AbsMinimum, AbsMaximum);
            }
        }
    }
}


void DiMonoModality::determineRepresentation(const DiDocument *docu)
{
    UsedBits = DicomImageClass::rangeToBits(MinValue, MaxValue);
    if ((docu != NULL) && (docu->getFlags() & CIF_UseAbsolutePixelRange))
        Representation = DicomImageClass::determineRepresentation(AbsMinimum, AbsMaximum);
    else
        Representation = DicomImageClass::determineRepresentation(MinValue, MaxValue);
    DCMIMGLE_TRACE("internal representation for monochrome images: "
        << DicomImageClass::getRepresentationBits(Representation) << " bits ("
        << (DicomImageClass::isRepresentationSigned(Representation) ? "signed" : "unsigned") << ")");
}