/*
 *
 *  Copyright (C) 1994-2015, 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:  dcmdata
 *
 *  Author:  Gerd Ehlers, Andreas Barth, Joerg Riesmeier
 *
 *  Purpose: Implementation of class DcmDateTime
 *
 */

#include "dcmtk/config/osconfig.h"    /* make sure OS specific configuration is included first */

#include "dcmtk/dcmdata/dcvrdt.h"
#include "dcmtk/dcmdata/dcvrda.h"
#include "dcmtk/dcmdata/dcvrtm.h"
#include "dcmtk/ofstd/ofstring.h"
#include "dcmtk/ofstd/ofstd.h"

#define INCLUDE_CSTDIO
#include "dcmtk/ofstd/ofstdinc.h"


#define MAX_DT_LENGTH 26


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


DcmDateTime::DcmDateTime(const DcmTag &tag,
                         const Uint32 len)
  : DcmByteString(tag, len)
{
    setMaxLength(MAX_DT_LENGTH);
    setNonSignificantChars(" \\");
}

DcmDateTime::DcmDateTime(const DcmDateTime &old)
  : DcmByteString(old)
{
}


DcmDateTime::~DcmDateTime()
{
}


DcmDateTime &DcmDateTime::operator=(const DcmDateTime &obj)
{
    DcmByteString::operator=(obj);
    return *this;
}


OFCondition DcmDateTime::copyFrom(const DcmObject& rhs)
{
  if (this != &rhs)
  {
    if (rhs.ident() != ident()) return EC_IllegalCall;
    *this = OFstatic_cast(const DcmDateTime &, rhs);
  }
  return EC_Normal;
}

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


DcmEVR DcmDateTime::ident() const
{
    return EVR_DT;
}


OFCondition DcmDateTime::checkValue(const OFString &vm,
                                    const OFBool /*oldFormat*/)
{
    OFString strVal;
    /* get "raw value" without any modifications (if possible) */
    OFCondition l_error = getStringValue(strVal);
    if (l_error.good())
        l_error = DcmDateTime::checkStringValue(strVal, vm);
    return l_error;
}


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


OFCondition DcmDateTime::getOFString(OFString &stringVal,
                                     const unsigned long pos,
                                     OFBool normalize)
{
    OFCondition l_error = DcmByteString::getOFString(stringVal, pos, normalize);
    if (l_error.good() && normalize)
        normalizeString(stringVal, !MULTIPART, !DELETE_LEADING, DELETE_TRAILING);
    return l_error;
}


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


OFCondition DcmDateTime::getOFDateTime(OFDateTime &dateTimeValue,
                                       const unsigned long pos)
{
    OFString dicomDateTime;
    /* convert the current element value to OFDateTime format */
    OFCondition l_error = getOFString(dicomDateTime, pos);
    if (l_error.good())
        l_error = getOFDateTimeFromString(dicomDateTime, dateTimeValue);
    else
        dateTimeValue.clear();
    return l_error;
}


OFCondition DcmDateTime::getISOFormattedDateTime(OFString &formattedDateTime,
                                                 const unsigned long pos,
                                                 const OFBool seconds,
                                                 const OFBool fraction,
                                                 const OFBool timeZone,
                                                 const OFBool createMissingPart,
                                                 const OFString &dateTimeSeparator,
                                                 const OFString &timeZoneSeparator)
{
    OFString dicomDateTime;
    /* get current element value and convert to ISO formatted date/time */
    OFCondition l_error = getOFString(dicomDateTime, pos);
    if (l_error.good())
    {
        l_error = getISOFormattedDateTimeFromString(dicomDateTime, formattedDateTime, seconds, fraction,
            timeZone, createMissingPart, dateTimeSeparator, timeZoneSeparator);
    } else
        formattedDateTime.clear();
    return l_error;
}


OFCondition DcmDateTime::setCurrentDateTime(const OFBool seconds,
                                            const OFBool fraction,
                                            const OFBool timeZone)
{
    OFString dicomDateTime;
    OFCondition l_error = getCurrentDateTime(dicomDateTime, seconds, fraction, timeZone);
    if (l_error.good())
        l_error = putOFStringArray(dicomDateTime);
    return l_error;
}


OFCondition DcmDateTime::setOFDateTime(const OFDateTime &dateTimeValue)
{
    OFString dicomDateTime;
    /* convert OFDateTime value to DICOM DT format and set the element value */
    OFCondition l_error = getDicomDateTimeFromOFDateTime(dateTimeValue, dicomDateTime);
    if (l_error.good())
        l_error = putOFStringArray(dicomDateTime);
    return l_error;
}


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


OFCondition DcmDateTime::getCurrentDateTime(OFString &dicomDateTime,
                                            const OFBool seconds,
                                            const OFBool fraction,
                                            const OFBool timeZone)
{
    OFCondition l_error = EC_IllegalCall;
    OFDateTime dateTimeValue;
    /* get the current system time */
    if (dateTimeValue.setCurrentDateTime())
    {
        /* format: YYYYMMDDHHMM[SS[.FFFFFF]] */
        if (dateTimeValue.getISOFormattedDateTime(dicomDateTime, seconds, fraction, timeZone, OFFalse /*showDelimiter*/))
            l_error = EC_Normal;
    }
    /* set default date/time if an error occurred */
    if (l_error.bad())
    {
        /* format: YYYYMMDDHHMM */
        dicomDateTime = "190001010000";
        if (seconds)
        {
            /* format: SS */
            dicomDateTime += "00";
            if (fraction)
            {
                /* format: .FFFFFF */
                dicomDateTime += ".000000";
            }
        }
        if (timeZone)
        {
            /* format: CHHMM */
            dicomDateTime += "+0000";
        }
    }
    return l_error;
}


OFCondition DcmDateTime::getDicomDateTimeFromOFDateTime(const OFDateTime &dateTimeValue,
                                                        OFString &dicomDateTime,
                                                        const OFBool seconds,
                                                        const OFBool fraction,
                                                        const OFBool timeZone)
{
    OFCondition l_error = EC_IllegalParameter;
    /* convert OFDateTime value to DICOM DT format */
    if (dateTimeValue.getISOFormattedDateTime(dicomDateTime, seconds, fraction, timeZone, OFFalse /*showDelimiter*/))
        l_error = EC_Normal;
    return l_error;
}

OFCondition DcmDateTime::getOFDateTimeFromString(const OFString &dicomDateTime,
                                                 OFDateTime &dateTimeValue)
{
    return getOFDateTimeFromString(dicomDateTime.c_str(), dicomDateTime.size(), dateTimeValue);
}

OFCondition DcmDateTime::getOFDateTimeFromString(const char *dicomDateTime,
                                                 size_t dicomDateTimeSize,
                                                 OFDateTime &dateTimeValue)
{
    // clear result variable
    dateTimeValue.clear();
    /* minimal check for valid format: YYYY */
    if (dicomDateTimeSize < 4 || !OFStandard::checkDigits<4>(dicomDateTime))
        return EC_IllegalParameter;
    unsigned int month = 1;
    unsigned int day = 1;
    double timeZone;
    // check for/extract time zone
    if (dicomDateTimeSize >= 9 && DcmTime::getTimeZoneFromString(dicomDateTime + dicomDateTimeSize - 5, 5, timeZone).good())
        dicomDateTimeSize -= 5;
    else
        timeZone = OFTime::getLocalTimeZone();
    switch(dicomDateTimeSize)
    {
    default:
        // check whether a time value is contained or it is simply an error
        if (dicomDateTimeSize >= 10)
        {
            OFCondition status = DcmTime::getOFTimeFromString(dicomDateTime + 8,
                                                              dicomDateTimeSize - 8,
                                                              dateTimeValue.Time,
                                                              OFFalse, // no support for HH:MM:SS in VR=DT
                                                              timeZone);
            if (status.bad())
                return status;
        }
        else break;

    case 8:
        if (OFStandard::checkDigits<2>(dicomDateTime + 6))
            day = OFStandard::extractDigits<unsigned int,2>(dicomDateTime + 6);
        else
            break;
    case 6:
        if (OFStandard::checkDigits<2>(dicomDateTime + 4))
            month = OFStandard::extractDigits<unsigned int,2>(dicomDateTime + 4);
        else
            break;
    case 4:
        if (dateTimeValue.Date.setDate(OFStandard::extractDigits<unsigned int,4>(dicomDateTime), month, day))
        {
            // set timezone if it hasn't been set
            if (dicomDateTimeSize <= 8)
                dateTimeValue.Time.setTimeZone(timeZone);
            return EC_Normal;
        }
        break;
    }
    return EC_IllegalParameter;
}


OFCondition DcmDateTime::getISOFormattedDateTimeFromString(const OFString &dicomDateTime,
                                                           OFString &formattedDateTime,
                                                           const OFBool seconds,
                                                           const OFBool fraction,
                                                           const OFBool timeZone,
                                                           const OFBool createMissingPart,
                                                           const OFString &dateTimeSeparator,
                                                           const OFString &timeZoneSeparator)
{
    OFCondition l_error = EC_Normal;
    const size_t length = dicomDateTime.length();
    /* minimum DT format: YYYYMMDD */
    if (length >= 8)
    {
        OFString timeString;
        OFDate dateValue;
        /* get formatted date: YYYY-MM-DD */
        l_error = DcmDate::getOFDateFromString(dicomDateTime.substr(0, 8), dateValue, OFFalse /*supportOldFormat*/);
        if (l_error.good())
        {
            dateValue.getISOFormattedDate(formattedDateTime);
            /* get formatted time: [HH[:MM[:SS[.FFFFFF]]]] */
            const size_t posSign = dicomDateTime.find_first_of("+-", 8);
            OFString dicomTime = (posSign != OFString_npos) ? dicomDateTime.substr(8, posSign - 8) : dicomDateTime.substr(8);
            l_error = DcmTime::getISOFormattedTimeFromString(dicomTime, timeString, seconds, fraction, createMissingPart, OFFalse /*supportOldFormat*/);
            if (l_error.good() && !timeString.empty())
            {
                /* add time string with separator */
                formattedDateTime += dateTimeSeparator;
                formattedDateTime += timeString;
                /* add optional time zone: [+/-HH:MM] */
                if (timeZone)
                {
                    /* check whether optional time zone is present: &ZZZZ */
                    if ((posSign != OFString_npos) && (length >= posSign + 5))
                    {
                        formattedDateTime += timeZoneSeparator;
                        formattedDateTime += dicomDateTime[posSign];
                        formattedDateTime += dicomDateTime.substr(posSign + 1, 2);
                        formattedDateTime += ":";
                        formattedDateTime += dicomDateTime.substr(posSign + 3, 2);
                    }
                    else if (createMissingPart)
                    {
                        formattedDateTime += timeZoneSeparator;
                        formattedDateTime += "+00:00";
                    }
                }
            }
        }
    }
    else if (length == 0)
    {
        /* an empty input string is no error ... */
        formattedDateTime.clear();
    } else {
        /* ... but all other formats are (if not handled before) */
        l_error = EC_IllegalParameter;
    }
    /* clear result variable in case of error */
    if (l_error.bad())
        formattedDateTime.clear();
    return l_error;
}


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


OFCondition DcmDateTime::checkStringValue(const OFString &value,
                                          const OFString &vm)
{
    OFCondition result = EC_Normal;
    const size_t valLen = value.length();
    if (valLen > 0)
    {
        size_t posStart = 0;
        unsigned long vmNum = 0;
        /* iterate over all value components */
        while (posStart != OFString_npos)
        {
            ++vmNum;
            /* search for next component separator */
            const size_t posEnd = value.find('\\', posStart);
            const size_t length = (posEnd == OFString_npos) ? valLen - posStart : posEnd - posStart;
            /* check length of current value component */
            if (length > MAX_DT_LENGTH)
            {
                result = EC_MaximumLengthViolated;
                break;
            }
            else if (dcmEnableVRCheckerForStringValues.get())
            {
                /* check value representation */
                const int vrID = DcmElement::scanValue(value, "dt", posStart, length);
                if ((vrID != 7) && (vrID != 18))
                {
                    result = EC_ValueRepresentationViolated;
                    break;
                }
            }
            posStart = (posEnd == OFString_npos) ? posEnd : posEnd + 1;
        }
        if (result.good() && !vm.empty())
        {
            /* check value multiplicity */
            result = DcmElement::checkVM(vmNum, vm);
        }
    }
    return result;
}
