// Copyright (C) 2004-2021 Artifex Software, Inc.

//

// This file is part of MuPDF.

//

// MuPDF is free software: you can redistribute it and/or modify it under the

// terms of the GNU Affero General Public License as published by the Free

// Software Foundation, either version 3 of the License, or (at your option)

// any later version.

//

// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY

// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more

// details.

//

// You should have received a copy of the GNU Affero General Public License

// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>

//

// Alternative licensing terms are available from the licensor.

// For commercial licensing, see <https://www.artifex.com/> or contact

// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,

// CA 94129, USA, for further information.

#include "mupdf/fitz.h"

#include "mupdf/pdf.h"

#include <string.h>

/* Load or synthesize ToUnicode map for fonts */

static void

pdf_remap_cmap_range(fz_context *ctx, pdf_cmap *ucs_from_gid,

  unsigned int cpt, unsigned int gid, unsigned int n, pdf_cmap *ucs_from_cpt)

{

  unsigned int k;

  int ucsbuf[PDF_MRANGE_CAP];

  int ucslen;

  for (k = 0; k <= n; ++k)

  {

    ucslen = pdf_lookup_cmap_full(ucs_from_cpt, cpt + k, ucsbuf);

    if (ucslen == 1)

      pdf_map_range_to_range(ctx, ucs_from_gid, gid + k, gid + k, ucsbuf[0]);

    else if (ucslen > 1)

      pdf_map_one_to_many(ctx, ucs_from_gid, gid + k, ucsbuf, ucslen);

  }

}

static pdf_cmap *

pdf_remap_cmap(fz_context *ctx, pdf_cmap *gid_from_cpt, pdf_cmap *ucs_from_cpt)

{

  pdf_cmap *ucs_from_gid;

  unsigned int a, b, x;

  int i;

  ucs_from_gid = pdf_new_cmap(ctx);

  fz_try(ctx)

  {

    if (gid_from_cpt->usecmap)

      ucs_from_gid->usecmap = pdf_remap_cmap(ctx, gid_from_cpt->usecmap, ucs_from_cpt);

    pdf_add_codespace(ctx, ucs_from_gid, 0, 0x7fffffff, 4);

    for (i = 0; i < gid_from_cpt->rlen; ++i)

    {

      a = gid_from_cpt->ranges[i].low;

      b = gid_from_cpt->ranges[i].high;

      x = gid_from_cpt->ranges[i].out;

      pdf_remap_cmap_range(ctx, ucs_from_gid, a, x, b - a, ucs_from_cpt);

    }

    for (i = 0; i < gid_from_cpt->xlen; ++i)

    {

      a = gid_from_cpt->xranges[i].low;

      b = gid_from_cpt->xranges[i].high;

      x = gid_from_cpt->xranges[i].out;

      pdf_remap_cmap_range(ctx, ucs_from_gid, a, x, b - a, ucs_from_cpt);

    }

    /* Font encoding CMaps don't have one-to-many mappings, so we can ignore the mranges. */

    pdf_sort_cmap(ctx, ucs_from_gid);

  }

  fz_catch(ctx)

  {

    pdf_drop_cmap(ctx, ucs_from_gid);

    fz_rethrow(ctx);

  }

  return ucs_from_gid;

}

void

pdf_load_to_unicode(fz_context *ctx, pdf_document *doc, pdf_font_desc *font,

  const char **strings, char *collection, pdf_obj *cmapstm)

{

  unsigned int cpt;

  if (pdf_is_stream(ctx, cmapstm))

  {

    pdf_cmap *ucs_from_cpt = pdf_load_embedded_cmap(ctx, doc, cmapstm);

    fz_try(ctx)

      font->to_unicode = pdf_remap_cmap(ctx, font->encoding, ucs_from_cpt);

    fz_always(ctx)

      pdf_drop_cmap(ctx, ucs_from_cpt);

    fz_catch(ctx)

      fz_rethrow(ctx);

    font->size += pdf_cmap_size(ctx, font->to_unicode);

  }

  else if (pdf_is_name(ctx, cmapstm))

  {

    pdf_cmap *ucs_from_cpt = pdf_load_system_cmap(ctx, pdf_to_name(ctx, cmapstm));

    fz_try(ctx)

      font->to_unicode = pdf_remap_cmap(ctx, font->encoding, ucs_from_cpt);

    fz_always(ctx)

      pdf_drop_cmap(ctx, ucs_from_cpt);

    fz_catch(ctx)

      fz_rethrow(ctx);

    font->size += pdf_cmap_size(ctx, font->to_unicode);

  }

  else if (collection)

  {

    if (!strcmp(collection, "Adobe-CNS1"))

      font->to_unicode = pdf_load_system_cmap(ctx, "Adobe-CNS1-UCS2");

    else if (!strcmp(collection, "Adobe-GB1"))

      font->to_unicode = pdf_load_system_cmap(ctx, "Adobe-GB1-UCS2");

    else if (!strcmp(collection, "Adobe-Japan1"))

      font->to_unicode = pdf_load_system_cmap(ctx, "Adobe-Japan1-UCS2");

    else if (!strcmp(collection, "Adobe-Korea1"))

      font->to_unicode = pdf_load_system_cmap(ctx, "Adobe-Korea1-UCS2");

  }

  if (strings)

  {

    /* TODO one-to-many mappings */

    font->cid_to_ucs = Memento_label(fz_malloc_array(ctx, 256, unsigned short), "cid_to_ucs");

    font->cid_to_ucs_len = 256;

    font->size += 256 * sizeof *font->cid_to_ucs;

    for (cpt = 0; cpt < 256; cpt++)

    {

      if (strings[cpt])

        font->cid_to_ucs[cpt] = fz_unicode_from_glyph_name(strings[cpt]);

      else

        font->cid_to_ucs[cpt] = FZ_REPLACEMENT_CHARACTER;

    }

  }

  if (!font->to_unicode && !font->cid_to_ucs)

  {

    /* TODO: synthesize a ToUnicode if it's a freetype font with

     * cmap and/or post tables or if it has glyph names. */

  }

}