//
// Licensed under Apache License v2.0.  See the file "LICENSE" for more
// information.
//

#include "qpdf-cm-private.h"
#include <stdio.h>
#include "cupsfilters/debug-internal.h"
#include <limits.h>

#include <stdexcept>

// TODO? instead use qpdf's StreamDataProvider, FileInputSource, Buffer etc.
static std::string
load_file(const char *filename) // {{{
{
  if (!filename)
    throw std::invalid_argument("NULL filename not allowed");

  FILE *f = fopen(filename, "r");
  if (!f)
    throw std::runtime_error(std::string("file ") + filename + " could not be opened");

  const int bsize = 2048;
  unsigned int pos = 0;

  std::string ret;
  while (!feof(f))
  {
    if ((UINT_MAX - bsize) < pos)
    {
      ret.resize(pos);
      break;
    }

    ret.resize(pos + bsize);
    int res = fread(&ret[pos], 1, bsize, f);

    if ((UINT_MAX - res) < pos)
    {
      ret.resize(pos);
      break;
    }

    pos += res;
    if (res < bsize)
    {
      ret.resize(pos);
      break;
    }
  }

  fclose(f);
  return (ret);
}
// }}}


// TODO?
// TODO? test
bool
_cfPDFToPDFHasOutputIntent(QPDF &pdf) // {{{
{
  auto catalog = pdf.getRoot();
  if (!catalog.hasKey("/OutputIntents"))
    return (false);
  return (true); // TODO?
}
// }}}

// TODO: test
// TODO? find existing , replace and return  (?)
void
_cfPDFToPDFAddOutputIntent(QPDF &pdf,
			   const char *filename) // {{{
{
  std::string icc = load_file(filename);
  // TODO: check icc  fitness
  // ICC data, subject to "version limitations" per pdf version...

  QPDFObjectHandle outicc = QPDFObjectHandle::newStream(&pdf, icc);

  auto sdict = outicc.getDict();
  sdict.replaceKey("/N",QPDFObjectHandle::newInteger(4)); // must match ICC
  // /Range ?  // must match ICC, default [0.0 1.0 ...]
  // /Alternate ?  (/DeviceCMYK for N=4)

  auto intent = QPDFObjectHandle::parse(
    "<<"
    "  /Type /OutputIntent"       // Must be so (the standard requires).
    "  /S /GTS_PDFX"              // Must be so (the standard requires).
    "  /OutputCondition (Commercial and specialty printing)"  // TODO: Customize [optional(?)]
    "  /Info (none)"              // TODO: Customize
    "  /OutputConditionIdentifier (CGATS TR001)"  // TODO: FIXME: Customize
    "  /RegistryName (http://www.color.org)"      // Must be so (the standard requires).
    "  /DestOutputProfile null "
    ">>");
  intent.replaceKey("/DestOutputProfile", outicc);

  auto catalog = pdf.getRoot();
  if (!catalog.hasKey("/OutputIntents"))
    catalog.replaceKey("/OutputIntents", QPDFObjectHandle::newArray());
  catalog.getKey("/OutputIntents").appendItem(intent);
}
// }}}

//
// for color management:
// Use /DefaultGray, /DefaultRGB, /DefaultCMYK ...  from *current* resource
// dictionary ...
// i.e. set 
// /Resources <<
// /ColorSpace <<    --- can use just one indirect ref for this (probably)
// /DefaultRGB [/ICCBased 5 0 R]  ... sensible use is sRGB  for DefaultRGB, etc.
// >>
// >>
// for every page  (what with form /XObjects?)  and most importantly RGB
// (leave CMYK, Gray for now, as this is already printer native(?))
//
// ? also every  form XObject, pattern, type3 font, annotation appearance
//   stream(=form xobject +X)
//
// ? what if page already defines /Default?   -- probably keep!
//
// ? maybe we need to set /ColorSpace  in /Images ?
//   [gs idea is to just add the /Default-key and then reprocess...]
//


// TODO? test
void
_cfPDFToPDFAddDefaultRGB(QPDF &pdf, QPDFObjectHandle srcicc) // {{{
{
  srcicc.assertStream();

  auto pages = pdf.getAllPages();
  for (auto it = pages.begin(), end = pages.end(); it != end; ++ it)
  {
    if (!it->hasKey("/Resources"))
      it->replaceKey("/Resources", QPDFObjectHandle::newDictionary());

    auto rdict = it->getKey("/Resources");

    if (!rdict.hasKey("/ColorSpace"))
      rdict.replaceKey("/ColorSpace", QPDFObjectHandle::newDictionary());

    auto cdict = rdict.getKey("/ColorSpace");

    if (!cdict.hasKey("/DefaultRGB"))
    {
      cdict.replaceKey("/DefaultRGB", QPDFObjectHandle::parse("[/ICCBased ]"));
      cdict.getKey("/DefaultRGB").appendItem(srcicc);
    }
  }
}
// }}}

// TODO? test
// TODO: find existing , replace and return  (?)
// TODO: check icc  fitness
QPDFObjectHandle
_cfPDFToPDFSetDefaultICC(QPDF &pdf,
			 const char *filename) // {{{
{
  // TODO: find existing, replace and return  (?)

  std::string icc = load_file(filename);
  // TODO: check icc  fitness
  // ICC data, subject to "version limitations" per pdf version...

  QPDFObjectHandle ret = QPDFObjectHandle::newStream(&pdf, icc);

  auto sdict = ret.getDict();
  sdict.replaceKey("/N", QPDFObjectHandle::newInteger(3)); // must match ICC
  // /Range ?  // must match ICC, default [0.0 1.0 ...]
  // /Alternate ?  (/DeviceRGB for N=3)

  return ret;
}
// }}}