%!PS

% Copyright (C) 2001-2024 Artifex Software, Inc.
% All Rights Reserved.
%
% This software is provided AS-IS with no warranty, either express or
% implied.
%
% This software is distributed under license and may not be copied,
% modified or distributed except as expressly authorized under the terms
% of the license contained in the file LICENSE in this distribution.
%
% Refer to licensing information at http://www.artifex.com or contact
% Artifex Software, Inc.,  39 Mesa Street, Suite 108A, San Francisco,
% CA 94129, USA, for further information.
%
% ZUGFeRD.ps
% This program will create an (unsigned) ZUGFeRD compliant PDF file.
% In order to do so the user must provide certain information, or edit
% this program.
%
% Required information is the path to the XML file containing the invoice
% data, and the path to an ICC profile appropriate for the chosen
% ColorConversionStrategy.
%
% -sZUGFeRDXMLFile defines a path to the XML invoice file.
%
% -sZUGFeRDProfile defines the path to the ICC profile.
%
% -sZUGFeRDVersion defines the version of the ZUGFeRD standard to be used.
% Missing or invalid values would be silently replaced by the default ("2p1").
%
% -sZUGFeRDConformanceLevel defines the level of conformance.
% Missing or invalid values would be silently replaced by the default ("BASIC").
%
% Note that the ZUGFeRD standard states:
%
%   The content of the field fx:ConformanceLevel has to be picked from
%   the content of the element "GuidelineSpecifiedDocumentContextParameter"
%   (specification identifier BT-24) of the XML instance file.
%
% Optionally:
%   -sZUGFeRDDateTime can be used to set a string representing the modification
%   date of the XML invoice file. If this is ommitted a dummy value will be
%   used. It is up to the user to create a correctly formatted PDF date/time
%   string. See section 7.9.4 of the PDF 2.0 specification (ISO-32000-2:2017)
%   for details of the format.
%
% The user must additionally set -dPDFA=3 and -sColorConversionStrategy
% on the Ghostscript command line, and set the permissions for Ghostscript
% to read both these files. It is simplest to put the files in a directory
% and then permit reading of the entire directory.
%
% Example command line :
%
% gs --permit-file-read=/usr/home/me/zugferd/          \
%    -sDEVICE=pdfwrite                                 \
%    -dPDFA=3                                          \
%    -sColorConversionStrategy=RGB                     \
%    -sZUGFeRDXMLFile=/usr/home/me/zugferd/invoice.xml \
%    -sZUGFeRDProfile=/usr/home/me/zugferd/rgb.icc     \
%    -sZUGFeRDVersion=2p1                              \
%    -sZUGFeRDConformanceLevel=BASIC                   \
%    -o /usr/home/me/zugferd/zugferd.pdf               \
%    /usr/home/me/zugferd/zugferd.ps                   \
%    /usr/home/me/zugferd/original.pdf
%
% Much of this program results from a Ghostscript bug report, the thread
% can be found at
%   https://bugs.ghostscript.com/show_bug.cgi?id=696472
% Portions of the code below were supplied by Reinhard Nissl and
% I'm indebted to him for his efforts in helping me create a solution for
% this problem as well as for the code he supplied, particularly for the
% SimpleUTF16BE routine.
%
% The program was further refined and expanded by Adrian Devries in :
%   https://bugs.ghostscript.com/show_bug.cgi?id=703862
%
% And refined again following feedback from Thorsten Engel in:
%   https://bugs.ghostscript.com/show_bug.cgi?id=707694
%
% It should not be necessary to modify this program, the comments in the
% code are there purely for information, but there is one area which
% might reasonably be altered. The section with the --8<-- lines could be
% replaced with a simpler /N 3 or /N 4 if you always intend to produce
% the same kind of files; RGB or CMYK.
%
% Remaining tasks have been marked with "TODO".

% istring SimpleUTF16BE ostring
/SimpleUTF16BE
{
    dup length
    1 add
    2 mul
    string
    % istring ostring
    dup 0 16#FE put
    dup 1 16#FF put
    2
    3 -1 roll
    % ostring index istring
    {
        % ostring index ichar
        3 1 roll
        % ichar ostring index
        2 copy 16#00 put
        1 add
        2 copy
        5 -1 roll
        % ostring index ostring index ichar
        put
        1 add
        % ostring index
    }
    forall
    % ostring index
    pop
}
bind def

% Cf. https://en.wikibooks.org/wiki/PostScript_FAQ#How_to_concatenate_strings%3F
/concatstringarray { % [(a) (b) ... (z)] --> (ab...z)
  0 1 index {
    length add
  } forall
  string
  0 3 2 roll {
    3 copy putinterval
    length add
  } forall
  pop
} bind def

/ZUGFeRDVersion where {
  pop % Discard the dictionary
  ZUGFeRDVersion (rc) ne {
    ZUGFeRDVersion (1p0) ne {
      ZUGFeRDVersion (2p0) ne {
        ZUGFeRDVersion (2p1) ne {
          /ZUGFeRDVersion (2p1) def
        } if
      } if
    } if
  } if
}{
  /ZUGFeRDVersion (2p1) def
} ifelse

/ZUGFeRDConformanceLevel where {
  pop % Discard the dictionary
  ZUGFeRDVersion (rc)  eq
  ZUGFeRDVersion (1p0) eq or {
    ZUGFeRDConformanceLevel (BASIC) ne {
      ZUGFeRDConformanceLevel (COMFORT) ne {
        ZUGFeRDConformanceLevel (EXTENDED) ne {
          /ZUGFeRDConformanceLevel (BASIC) def
        } if
      } if
    } if
  } if
  ZUGFeRDVersion (2p0) eq
  ZUGFeRDVersion (2p1) eq or {
    ZUGFeRDConformanceLevel (MINIMUM) ne {
      ZUGFeRDConformanceLevel (BASIC WL) ne {
        ZUGFeRDConformanceLevel (BASIC) ne {
          ZUGFeRDConformanceLevel (EN 16931) ne {
            ZUGFeRDConformanceLevel (EXTENDED) ne {
              ZUGFeRDConformanceLevel (XRECHNUNG) ne {
                /ZUGFeRDConformanceLevel (BASIC) def
              } if
            } if
          } if
        } if
      } if
    } if
  } if
}{
  /ZUGFeRDConformanceLevel (BASIC) def
} ifelse

% ZUGFeRDSchema
/ZUGFeRDSchema () def
ZUGFeRDVersion (rc)  eq
ZUGFeRDVersion (1p0) eq or
ZUGFeRDVersion (2p0) eq or {
  /ZUGFeRDSchema (ZUGFeRD PDFA Extension Schema) def
} if
ZUGFeRDVersion (2p1) eq {
  /ZUGFeRDSchema (Factur-X PDFA Extension Schema) def
} if

% ZUGFeRDNamespaceURI
/ZUGFeRDNamespaceURI () def
ZUGFeRDVersion (rc)  eq {
  /ZUGFeRDNamespaceURI (urn:ferd:pdfa:invoice:rc#) def
} if
ZUGFeRDVersion (1p0) eq {
  /ZUGFeRDNamespaceURI (urn:ferd:pdfa:CrossIndustryDocument:invoice:1p0#) def
} if
ZUGFeRDVersion (2p0) eq {
  /ZUGFeRDNamespaceURI (urn:zugferd:pdfa:CrossIndustryDocument:invoice:2p0#) def
} if
ZUGFeRDVersion (2p1) eq {
  /ZUGFeRDNamespaceURI (urn:factur-x:pdfa:CrossIndustryDocument:invoice:1p0#) def
} if

% ZUGFeRDPrefix
/ZUGFeRDPrefix () def
ZUGFeRDVersion (rc)  eq
ZUGFeRDVersion (1p0) eq or
ZUGFeRDVersion (2p0) eq or {
  /ZUGFeRDPrefix (zf) def
} if
ZUGFeRDVersion (2p1) eq {
  /ZUGFeRDPrefix (fx) def
} if

% ZUGFeRDVersionDescription
/ZUGFeRDVersionDescription () def
ZUGFeRDVersion (rc)  eq
ZUGFeRDVersion (1p0) eq or
ZUGFeRDVersion (2p0) eq or {
  /ZUGFeRDVersionDescription (The actual version of the ZUGFeRD XML schema) def
} if
ZUGFeRDVersion (2p1) eq {
  /ZUGFeRDVersionDescription (The actual version of the Factur-X XML schema) def
} if

% ZUGFeRDConformanceLevelDescription
/ZUGFeRDConformanceLevelDescription () def
ZUGFeRDVersion (rc)  eq
ZUGFeRDVersion (1p0) eq or
ZUGFeRDVersion (2p0) eq or {
  /ZUGFeRDConformanceLevelDescription (The conformance level of the embedded ZUGFeRD data) def
} if
ZUGFeRDVersion (2p1) eq {
  /ZUGFeRDConformanceLevelDescription (The conformance level of the embedded Factur-X data) def
} if

% ZUGFeRDDocumentFileName
/ZUGFeRDDocumentFileName () def
ZUGFeRDVersion (rc)  eq {
  /ZUGFeRDDocumentFileName (ZUGFeRD-invoice.xml) def
} if
ZUGFeRDVersion (1p0) eq {
  /ZUGFeRDDocumentFileName (ZUGFeRD-invoice.xml) def
} if
ZUGFeRDVersion (2p0) eq {
  ZUGFeRDConformanceLevel (XRECHNUNG) ne {
    /ZUGFeRDDocumentFileName (zugferd-invoice.xml) def
  }{
    /ZUGFeRDDocumentFileName (xrechnung.xml) def
  } ifelse
} if
ZUGFeRDVersion (2p1) eq {
  ZUGFeRDConformanceLevel (XRECHNUNG) ne {
    /ZUGFeRDDocumentFileName (factur-x.xml) def
  }{
    /ZUGFeRDDocumentFileName (xrechnung.xml) def
  } ifelse
} if

% ZUGFeRDVersionData
/ZUGFeRDVersionData () def
ZUGFeRDVersion (rc)  eq {
  /ZUGFeRDVersionData (RC) def
} if
ZUGFeRDVersion (1p0) eq {
  /ZUGFeRDVersionData (1.0) def
} if
ZUGFeRDVersion (2p0) eq {
  ZUGFeRDConformanceLevel (XRECHNUNG) ne {
    /ZUGFeRDVersionData (2p0) def
  }{
    /ZUGFeRDVersionData (1p2) def
  } ifelse
} if
ZUGFeRDVersion (2p1) eq {
  ZUGFeRDConformanceLevel (XRECHNUNG) ne {
    /ZUGFeRDVersionData (1.0) def
  }{
    /ZUGFeRDVersionData (1p2) def
  } ifelse
} if

/ZUGFeRDMetadata [
(
<rdf:Description)
( xmlns:pdfaExtension="http://www.aiim.org/pdfa/ns/extension/")
( xmlns:pdfaProperty="http://www.aiim.org/pdfa/ns/property#")
( xmlns:pdfaSchema="http://www.aiim.org/pdfa/ns/schema#")
( rdf:about="">
  <pdfaExtension:schemas>
    <rdf:Bag>
      <rdf:li rdf:parseType="Resource">
        <pdfaSchema:schema>)ZUGFeRDSchema(</pdfaSchema:schema>
        <pdfaSchema:namespaceURI>)ZUGFeRDNamespaceURI(</pdfaSchema:namespaceURI>
        <pdfaSchema:prefix>)ZUGFeRDPrefix(</pdfaSchema:prefix>
        <pdfaSchema:property>
          <rdf:Seq>
            <rdf:li rdf:parseType="Resource">
              <pdfaProperty:name>DocumentFileName</pdfaProperty:name>
              <pdfaProperty:valueType>Text</pdfaProperty:valueType>
              <pdfaProperty:category>external</pdfaProperty:category>
              <pdfaProperty:description>Name of the embedded XML invoice file</pdfaProperty:description>
            </rdf:li>
            <rdf:li rdf:parseType="Resource">
              <pdfaProperty:name>DocumentType</pdfaProperty:name>
              <pdfaProperty:valueType>Text</pdfaProperty:valueType>
              <pdfaProperty:category>external</pdfaProperty:category>
              <pdfaProperty:description>INVOICE</pdfaProperty:description>
            </rdf:li>
            <rdf:li rdf:parseType="Resource">
              <pdfaProperty:name>Version</pdfaProperty:name>
              <pdfaProperty:valueType>Text</pdfaProperty:valueType>
              <pdfaProperty:category>external</pdfaProperty:category>
              <pdfaProperty:description>)ZUGFeRDVersionDescription(</pdfaProperty:description>
            </rdf:li>
            <rdf:li rdf:parseType="Resource">
              <pdfaProperty:name>ConformanceLevel</pdfaProperty:name>
              <pdfaProperty:valueType>Text</pdfaProperty:valueType>
              <pdfaProperty:category>external</pdfaProperty:category>
              <pdfaProperty:description>)ZUGFeRDConformanceLevelDescription(</pdfaProperty:description>
            </rdf:li>
          </rdf:Seq>
        </pdfaSchema:property>
      </rdf:li>
    </rdf:Bag>
  </pdfaExtension:schemas>
</rdf:Description>
<rdf:Description xmlns:)ZUGFeRDPrefix(=")ZUGFeRDNamespaceURI(" rdf:about="">
  <)ZUGFeRDPrefix(:ConformanceLevel>)ZUGFeRDConformanceLevel(</)ZUGFeRDPrefix(:ConformanceLevel>
  <)ZUGFeRDPrefix(:DocumentFileName>)ZUGFeRDDocumentFileName(</)ZUGFeRDPrefix(:DocumentFileName>
  <)ZUGFeRDPrefix(:DocumentType>INVOICE</)ZUGFeRDPrefix(:DocumentType>
  <)ZUGFeRDPrefix(:Version>)ZUGFeRDVersionData(</)ZUGFeRDPrefix(:Version>
</rdf:Description>
)
  ] concatstringarray def

/Usage {
  (example usage:                                               \n) print
  (      gs --permit-file-read=/usr/home/me/zugferd/          \\\n) print
  (         -sDEVICE=pdfwrite                                 \\\n) print
  (         -dPDFA=3                                          \\\n) print
  (         -sColorConversionStrategy=RGB                     \\\n) print
  (         -sZUGFeRDXMLFile=/usr/home/me/zugferd/invoice.xml \\\n) print
  (         -sZUGFeRDProfile=/usr/home/me/zugferd\rgb.icc     \\\n) print
  (         -sZUGFeRDVersion=2p1                              \\\n) print
  (         -sZUGFeRDConformanceLevel=BASIC                   \\\n) print
  (         -o /usr/home/me/zugferd/zugferd.pdf               \\\n) print
  (         /usr/home/me/zugferd/zugferd.ps                   \\\n) print
  (         /usr/home/me/zugferd/original.pdf                   \n) print
  flush
} def

% First check that the user has defined the XML invoice file on the command line
%
/ZUGFeRDXMLFile where {
  pop % Discard the dictionary
  %
  % Now check that the ICC Profile is defined
  %
  /ZUGFeRDProfile where {
    pop % Discard the dictionary

    % Step 1, add the required PDF/A boilerplate.
    % This is mostly copied from lib/pdfa_def.ps

    % Create a PDF stream object to hold the ICC profile.
    [ /_objdef {icc_PDFA} /type /stream /OBJ pdfmark

    % Add the required entries to the stream dictionary (/N only)
    [ {icc_PDFA}
    <<
    %% This code attempts to set the /N (number of components) key for the ICC colour space.
    %% To do this it checks the ColorConversionStrategy or the device ProcessColorModel if
    %% ColorConversionStrategy is not set.
    %% This is not 100% reliable. A better solution is for the user to edit this and replace
    %% the code between the ---8<--- lines with a simple declaration like:
    %%   /N 3
    %% where the value of N is the number of components from the profile defined in ZUGFeRDProfile.
    %%
    %% ----------8<--------------8<-------------8<--------------8<----------
      systemdict /ColorConversionStrategy known {
        systemdict /ColorConversionStrategy get cvn dup /Gray eq {
          pop /N 1 false
        }{
          dup /RGB eq {
            pop /N 3 false
          }{
            /CMYK eq {
              /N 4 false
            }{
              (ColorConversionStrategy not a device space, falling back to ProcessColorModel, output may not be valid PDF/A.)=
              true
            } ifelse
          } ifelse
        } ifelse
      } {
        (ColorConversionStrategy not set, falling back to ProcessColorModel, output may not be valid PDF/A.)=
        true
      } ifelse

      {
        currentpagedevice /ProcessColorModel get
        dup /DeviceGray eq {
          pop /N 1
        }{
          dup /DeviceRGB eq {
            pop /N 3
          }{
            dup /DeviceCMYK eq {
              pop /N 4
            } {
              (ProcessColorModel not a device space.)=
              /ProcessColorModel cvx /rangecheck signalerror
            } ifelse
          } ifelse
        } ifelse
      } if
    %% ----------8<--------------8<-------------8<--------------8<----------
    >> /PUT pdfmark

    % Now read the ICC profile from the file into the stream
    [ {icc_PDFA} ZUGFeRDProfile (r) file /PUT pdfmark

    % Define the output intent dictionary :
    [/_objdef {OutputIntent_PDFA} /type /dict /OBJ pdfmark

    % Add the required keys to the dictionary
    [{OutputIntent_PDFA} <<
        /Type /OutputIntent
        /S /GTS_PDFA1                       % Required for PDF/A.
        /DestOutputProfile {icc_PDFA}       % The actual profile.
        /OutputConditionIdentifier (Custom) % TODO: A better solution is a
                                            %       a string from the ICC
                                            %       Registry, but Custom
                                            %       is always valid.
      >> /PUT pdfmark

    % And now add the OutputIntent to the Catalog dictionary
    [ {Catalog} << /OutputIntents [ {OutputIntent_PDFA} ]>> /PUT pdfmark

    % Step 2, define the XML file and read it into the PDF
    % First we define the PDF stream to contain the XML invoice
    [ /_objdef {InvoiceStream} /type /stream /OBJ pdfmark
    % Fill in the dictionary elements we need. We believe the
    % ModDate is not useful so it's just set to a valid value.
    [ {InvoiceStream} <<
        /Type /EmbeddedFile
        /Subtype (text/xml) cvn
        /Params <<
          /ModDate systemdict /ZUGFeRDDateTime known
            {ZUGFeRDDateTime}
            {(D:20130121081433+01'00')}
            ifelse
          /Size ZUGFeRDXMLFile status
            {pop pop exch pop}
            {(Failed to get file status!\n)print /status load /ioerror signalerror}
            ifelse
        >>
      >> /PUT pdfmark
    % Now read the data from the file and store it in the stream
    [ {InvoiceStream} ZUGFeRDXMLFile (r) file /PUT pdfmark
    % and close the stream
    [ {InvoiceStream} /CLOSE pdfmark

    % Step 3 create the File Specification dictionary for the embedded file
    % Create the dictionary
    [ /_objdef {FSDict} /type /dict /OBJ pdfmark
    % Fill in the required dictionary elements
    [ {FSDict}    <<
      /Type /Filespec
      /F ZUGFeRDDocumentFileName
      /UF ZUGFeRDDocumentFileName SimpleUTF16BE
      /Desc (ZUGFeRD electronic invoice)
      /AFRelationship /Alternative
      /EF <<
          /F {InvoiceStream}
          /UF {InvoiceStream}
        >>
      >>
    /PUT pdfmark

    % Step 4 Create the Associated Files dictionary to hold the FS dict
    % Create the dictionary
    [ /_objdef {AFArray} /type /array /OBJ pdfmark
    % Put (append) the FS dictionary into the Associated Files array
    [ {AFArray} {FSDict} /APPEND pdfmark

    % Step 5 Add an entry in the Catalog dictionary containing the AF array
    % Since Ghostscript 10.04.0 this is no longer required, providing the output file is
    % PDF/A-3 or higher. The PDF/A-3 tech note 0010 (p28) clarifies that the /AF in the Catalog
    % is mandatory and GS 10.04.0 will emit one itself.
    %
    % This line retained for historical reference, and as an example for cases where the output
    % is not PDF/A-3
    %
    %    [ {Catalog} << /AF {AFArray} >> /PUT pdfmark

    % Step 6 use the EMBED pdfmark to add the XML file and FS dictionary to the PDF name tree
    [ /Name ZUGFeRDDocumentFileName /FS {FSDict} /EMBED pdfmark

    % Step 7 Add the extra ZUGFeRD XML data to the Metadata
    [ /XML ZUGFeRDMetadata /Ext_Metadata pdfmark
  }
  {
    % No ICC Profile definition on the command line;
    % chide the user and give them an example
    (\nERROR - ZUGFeRDProfile has not been supplied, you must supply an ICC profile) print
    (\n        Producing a potentially INVALID PDF/A file.                       \n) print
    Usage
  } ifelse
}
{
  % No XML invoice definition on the command line;
  % chide the user and give them an example
  (\nERROR - ZUGFeRDXMLFile has not been supplied, you must supply a XML invoice file) print
  (\n        Producing a PDF/A file, NOT a ZUGFeRD file.                           \n) print
  Usage
} ifelse

% That's all the ZUGFeRD and PDF/A-3 setup completed,
% all that remains now is to run the input file

%%EOF