/*
 *
 *  Copyright (C) 1994-2018, 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, Joerg Riesmeier
 *
 *  Purpose: Interface of class DcmDateTime
 *
 */

#ifndef DCVRDT_H
#define DCVRDT_H

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

#include "dcmtk/dcmdata/dcbytstr.h"
#include "dcmtk/ofstd/ofdatime.h"


/** a class representing the DICOM value representation 'Date Time' (DT)
 */
class DCMTK_DCMDATA_EXPORT DcmDateTime
  : public DcmByteString
{

  public:

    /** constructor.
     *  Create new element from given tag and length.
     *  @param tag DICOM tag for the new element
     *  @param len value length for the new element
     */
    DcmDateTime(const DcmTag &tag,
                const Uint32 len = 0);

    /** copy constructor
     *  @param old element to be copied
     */
    DcmDateTime(const DcmDateTime &old);

    /** destructor
     */
    virtual ~DcmDateTime();

    /** assignment operator
     *  @param obj element to be assigned/copied
     *  @return reference to this object
     */
    DcmDateTime &operator=(const DcmDateTime &obj);

    /** clone method
     *  @return deep copy of this object
     */
    virtual DcmObject *clone() const
    {
      return new DcmDateTime(*this);
    }

    /** Virtual object copying. This method can be used for DcmObject
     *  and derived classes to get a deep copy of an object. Internally
     *  the assignment operator is called if the given DcmObject parameter
     *  is of the same type as "this" object instance. If not, an error
     *  is returned. This function permits copying an object by value
     *  in a virtual way which therefore is different to just calling the
     *  assignment operator of DcmElement which could result in slicing
     *  the object.
     *  @param rhs - [in] The instance to copy from. Has to be of the same
     *                class type as "this" object
     *  @return EC_Normal if copying was successful, error otherwise
     */
    virtual OFCondition copyFrom(const DcmObject& rhs);

    /** get element type identifier
     *  @return type identifier of this class (EVR_DT)
     */
    virtual DcmEVR ident() const;

    /** check whether stored value conforms to the VR and to the specified VM
     *  @param vm value multiplicity (according to the data dictionary) to be checked for.
     *    (See DcmElement::checkVM() for a list of valid values.)
     *  @param oldFormat parameter not used for this VR (only for DA, TM)
     *  @return status of the check, EC_Normal if value is correct, an error code otherwise
     */
    virtual OFCondition checkValue(const OFString &vm = "1-n",
                                   const OFBool oldFormat = OFFalse);

    /** get a copy of a particular string component
     *  @param stringValue variable in which the result value is stored
     *  @param pos index of the value in case of multi-valued elements (0..vm-1)
     *  @param normalize delete trailing spaces if OFTrue
     *  @return status, EC_Normal if successful, an error code otherwise
     */
    virtual OFCondition getOFString(OFString &stringValue,
                                    const unsigned long pos,
                                    OFBool normalize = OFTrue);

    /** set the element value to the current system date and time.
     *  The DICOM DT format supported by this function is "YYYYMMDDHHMM[SS[.FFFFFF]][&ZZZZ]"
     *  where the brackets enclose optional parts. If the current system date/time or parts
     *  of it are unavailable the corresponding values are set to "0" and an error code is
     *  returned - in fact, the date is set to "19000101" if unavailable.
     *  @param seconds add optional seconds ("SS") if OFTrue
     *  @param fraction add optional fractional part of a second (".FFFFFF") if OFTrue
     *   (requires parameter 'seconds' to be also OFTrue)
     *  @param timeZone add optional time zone ("&ZZZZ" where "&" is "+" or "-") if OFTrue.
     *   The time zone is given as the offset (hours and minutes) from Coordinated Universal
     *   Time (UTC).
     *  @return EC_Normal upon success, an error code otherwise
     */
    OFCondition setCurrentDateTime(const OFBool seconds = OFTrue,
                                   const OFBool fraction = OFFalse,
                                   const OFBool timeZone = OFFalse);

    /** set the element value to the given date and time
     *  @param dateTimeValue date to be set (should be a valid date and time)
     *  @return EC_Normal upon success, an error code otherwise
     */
    OFCondition setOFDateTime(const OFDateTime &dateTimeValue);

    /** get the current element value in OFDateTime format.
     *  Please note that the element value is expected to be in valid DICOM DT format
     *  ("YYYYMMDD[HH[MM[SS[.FFFFFF]]]][&ZZZZ]"). If the optional time zone ("&ZZZZ") is
     *  missing the local time zone is used.
     *  If this function fails the result variable 'dateTimeValue' is cleared automatically.
     *  @param dateTimeValue reference to OFDateTime variable where the result is stored
     *  @param pos index of the element component in case of value multiplicity (0..vm-1)
     *  @return EC_Normal upon success, an error code otherwise
     */
    OFCondition getOFDateTime(OFDateTime &dateTimeValue,
                              const unsigned long pos = 0);

    /** get the current element value in ISO date/time format.
     *  The ISO date/time format supported by this function is "YYYY-MM-DD[ HH:MM[:SS[.FFFFFF]]]
     *  [&HH:MM]" where the brackets enclose optional parts. Please note that the element value
     *  is expected to be in valid DICOM DT format ("YYYYMMDD[HH[MM[SS[.FFFFFF]]]][&ZZZZ]").
     *  If this function fails or the current element value is empty, the result variable
     *  'formattedDateTime' is cleared automatically.
     *  @param formattedDateTime reference to string variable where the result is stored
     *  @param pos index of the element component in case of value multiplicity (0..vm-1)
     *  @param seconds add optional seconds (":SS") if OFTrue
     *  @param fraction add optional fractional part of a second (".FFFFFF") if OFTrue
     *   (requires parameter 'seconds' to be also OFTrue)
     *  @param timeZone add optional time zone ("&HH:MM" where "&" is "+" or "-") if OFTrue.
     *   The time zone is given as the offset (hours and minutes) from Coordinated Universal
     *   Time (UTC). Please note that the formatted time output is not adapted to the local
     *   time if the time zone is omitted.
     *  @param createMissingPart if OFTrue create optional parts (seconds, fractional part of
     *   a seconds and/or time zone) if absent in the element value
     *  @param dateTimeSeparator separator between ISO date and time value
     *  @param timeZoneSeparator separator between ISO time value and time zone
     *  @return EC_Normal upon success, an error code otherwise
     */
    OFCondition getISOFormattedDateTime(OFString &formattedDateTime,
                                        const unsigned long pos = 0,
                                        const OFBool seconds = OFTrue,
                                        const OFBool fraction = OFFalse,
                                        const OFBool timeZone = OFTrue,
                                        const OFBool createMissingPart = OFFalse,
                                        const OFString &dateTimeSeparator = " ",
                                        const OFString &timeZoneSeparator = " ");

    // ensure inherited overloads of matches take part in overload resolution
    using DcmByteString::matches;

    /// @copydoc DcmByteString::matches(OFString,OFString,OFBool)
    virtual OFBool matches(const OFString& key,
                           const OFString& candidate,
                           const OFBool enableWildCardMatching = OFTrue) const;

    /* --- static helper functions --- */

    /** get the current system date and time.
     *  The DICOM DT format supported by this function is "YYYYMMDDHHMM[SS[.FFFFFF]][&ZZZZ]"
     *  where the brackets enclose optional parts. If the current system date/time or parts
     *  of it are unavailable the corresponding values are set to "0" and an error code is
     *  returned - in fact, the date is set to "19000101" if unavailable.
     *  @param dicomDateTime reference to string variable where the result is stored
     *  @param seconds add optional seconds ("SS") if OFTrue
     *  @param fraction add optional fractional part of a second (".FFFFFF") if OFTrue
     *   (requires parameter 'seconds' to be also OFTrue)
     *  @param timeZone add optional time zone ("&ZZZZ" where "&" is "+" or "-") if OFTrue.
     *   The time zone is given as the offset (hours and minutes) from Coordinated Universal
     *   Time (UTC).
     *  @return EC_Normal upon success, an error code otherwise
     */
    static OFCondition getCurrentDateTime(OFString &dicomDateTime,
                                          const OFBool seconds = OFTrue,
                                          const OFBool fraction = OFFalse,
                                          const OFBool timeZone = OFFalse);

    /** get the specified OFDateTime value in DICOM format.
     *  The DICOM DT format supported by this function is "YYYYMMDDHHMM[SS[.FFFFFF]][&ZZZZ]"
     *  where the brackets enclose optional parts. If the current system date/time or parts
     *  of it are unavailable the corresponding values are set to "0" and an error code is
     *  returned - in fact, the date is set to "19000101" if unavailable.
     *  @param dateTimeValue date and time to be converted to DICOM format
     *  @param dicomDateTime reference to string variable where the result is stored
     *  @param seconds add optional seconds ("SS") if OFTrue
     *  @param fraction add optional fractional part of a second (".FFFFFF") if OFTrue
     *   (requires parameter 'seconds' to be also OFTrue)
     *  @param timeZone add optional time zone ("&ZZZZ" where "&" is "+" or "-") if OFTrue.
     *   The time zone is given as the offset (hours and minutes) from Coordinated Universal
     *   Time (UTC).
     *  @return EC_Normal upon success, an error code otherwise
     */
    static OFCondition getDicomDateTimeFromOFDateTime(const OFDateTime &dateTimeValue,
                                                      OFString &dicomDateTime,
                                                      const OFBool seconds = OFTrue,
                                                      const OFBool fraction = OFFalse,
                                                      const OFBool timeZone = OFFalse);

    /** get the specified DICOM date and time value in OFDateTime format.
     *  Please note that the element value is expected to be in valid DICOM DT format
     *  ("YYYY[MM[DD[HH[MM[SS[.FFFFFF]]]]]][&ZZZZ]"). If the "MM" and/or "DD" component from
     *  the date part is missing, a value of "1" is used for each of them. If the "HH", "MM"
     *  and/or "SS" component of the time part is missing, a value of "0" is used for each of
     *  them. If the optional time zone ("&ZZZZ") is missing, the local time zone is used.
     *  If this function fails, the result variable 'dateTimeValue' is cleared automatically.
     *  @param dicomDateTime string value in DICOM DT format to be converted to OFDateTime.
     *    An empty string is not regarded as valid input, since the date/time would be unknown.
     *  @param dateTimeValue reference to OFDateTime variable where the result is stored
     *  @return EC_Normal upon success, an error code otherwise
     */
    static OFCondition getOFDateTimeFromString(const OFString &dicomDateTime,
                                               OFDateTime &dateTimeValue);

    /** get the specified DICOM date and time value in OFDateTime format.
     *  Please note that the element value is expected to be in valid DICOM DT format
     *  ("YYYY[MM[DD[HH[MM[SS[.FFFFFF]]]]]][&ZZZZ]"). If the "MM" and/or "DD" component from
     *  the date part is missing, a value of "1" is used for each of them. If the "HH", "MM"
     *  and/or "SS" component of the time part is missing, a value of "0" is used for each of
     *  them. If the optional time zone ("&ZZZZ") is missing, the local time zone is used.
     *  If this function fails, the result variable 'dateTimeValue' is cleared automatically.
     *  @param dicomDateTime string value in DICOM DT format to be converted to OFDateTime.
     *    An empty string is not regarded as valid input, since the date/time would be unknown.
     *  @param dicomDateTimeSize the size (in bytes) of the string 'dicomDateTime' refers to
     *  @param dateTimeValue reference to OFDateTime variable where the result is stored
     *  @return EC_Normal upon success, an error code otherwise
     */
    static OFCondition getOFDateTimeFromString(const char *dicomDateTime,
                                               const size_t dicomDateTimeSize,
                                               OFDateTime &dateTimeValue);

    /** get the specified DICOM datetime value in ISO format.
     *  The ISO date/time format supported by this function is "YYYY-MM-DD[ HH:MM[:SS[.FFFFFF]]]
     *  [&HH:MM]" where the brackets enclose optional parts. Please note that the specified
     *  value is expected to be in valid DICOM DT format ("YYYYMMDD[HH[MM[SS[.FFFFFF]]]][&ZZZZ]").
     *  If this function fails or the specified DICOM datetime value is empty, the result
     *  variable 'formattedDateTime' is cleared automatically.
     *  @param dicomDateTime string value in DICOM DT format to be converted to ISO format
     *  @param formattedDateTime reference to string variable where the result is stored
     *  @param seconds add optional seconds (":SS") if OFTrue
     *  @param fraction add optional fractional part of a second (".FFFFFF") if OFTrue
     *   (requires parameter 'seconds' to be also OFTrue)
     *  @param timeZone add optional time zone ("&HH:MM" where "&" is "+" or "-") if OFTrue.
     *   The time zone is given as the offset (hours and minutes) from the Coordinated Universal
     *   Time (UTC). Please note that the formatted time output is not adapted to the local time
     *   if the time zone is omitted.
     *  @param createMissingPart if OFTrue create optional parts (seconds, fractional part of
     *   a seconds and/or time zone) if absent in the element value
     *  @param dateTimeSeparator separator between ISO date and time value
     *  @param timeZoneSeparator separator between ISO time value and time zone
     *  @return EC_Normal upon success, an error code otherwise
     */
    static OFCondition getISOFormattedDateTimeFromString(const OFString &dicomDateTime,
                                                         OFString &formattedDateTime,
                                                         const OFBool seconds = OFTrue,
                                                         const OFBool fraction = OFFalse,
                                                         const OFBool timeZone = OFTrue,
                                                         const OFBool createMissingPart = OFFalse,
                                                         const OFString &dateTimeSeparator = " ",
                                                         const OFString &timeZoneSeparator = " ");

    /** check whether the given string conforms to a single value of VR "DT" (Date Time).
     *  @param dicomDateTime string value to be checked
     *  @param dicomDateTimeSize the size (in bytes) of the string 'dicomDateTime' refers to
     *  @return OFTrue if the given string conforms to the Date Time format, OFFalse otherwise
     */
    static OFBool check(const char *dicomDateTime,
                        const size_t dicomDateTimeSize);

    /** check whether given string value conforms to the VR "DT" (Date Time)
     *  and to the specified VM.
     *  @param value string value to be checked (possibly multi-valued)
     *  @param vm value multiplicity (according to the data dictionary) to be checked for.
     *    (See DcmElement::checkVM() for a list of valid values.)
     *  @return status of the check, EC_Normal if value is correct, an error code otherwise
     */
    static OFCondition checkStringValue(const OFString &value,
                                        const OFString &vm = "1-n");
};


#endif // DCVRDT_H
