/*
  ttf.cc --  implement ttf -> pfa routine.

  source file of the GNU LilyPond music typesetter

  (c) 2005--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
*/

#include <cstdio>
#include "freetype.hh"

#include <freetype/tttables.h>

#include "international.hh"
#include "memory-stream.hh"
#include "warn.hh"
#include "lily-guile.hh"
#include "main.hh"
#include "open-type-font.hh"


Index_to_charcode_map
make_index_to_charcode_map (FT_Face face)
{
  Index_to_charcode_map m;
  FT_ULong charcode;
  FT_UInt gindex;

  FT_CharMap current_cmap = face->charmap;
  FT_Select_Charmap (face, FT_ENCODING_UNICODE);

  int j = 0;
  for (charcode = FT_Get_First_Char (face, &gindex); gindex != 0;
       charcode = FT_Get_Next_Char (face, charcode, &gindex))
    {
      m[gindex] = charcode;
      j ++;
    }
  FT_Set_Charmap (face, current_cmap);

  return m;
}

/*
  Based on ttfps by Juliusz Chroboczek
*/
static void
print_header (void *out, FT_Face face)
{
  lily_cookie_fprintf (out, "%%!PS-TrueTypeFont\n");

  TT_Postscript *pt
    = (TT_Postscript *) FT_Get_Sfnt_Table (face, ft_sfnt_post);

  if (pt->maxMemType42)
    lily_cookie_fprintf (out, "%%%%VMUsage: %d %d\n", 0, 0);

  lily_cookie_fprintf (out, "%d dict begin\n", 11);
  lily_cookie_fprintf (out, "/FontName /%s def\n",
		       FT_Get_Postscript_Name (face));

  lily_cookie_fprintf (out, "/Encoding StandardEncoding def\n");
  lily_cookie_fprintf (out, "/PaintType 0 def\n");
  lily_cookie_fprintf (out, "/FontMatrix [1 0 0 1 0 0] def\n");

  TT_Header *ht
    = (TT_Header *)FT_Get_Sfnt_Table (face, ft_sfnt_head);

  lily_cookie_fprintf (out, "/FontBBox [%lf %lf %lf %lf] def\n",
		       float (ht->xMin) / ht->Units_Per_EM,
		       float (ht->yMin) / ht->Units_Per_EM,
		       float (ht->xMax) / ht->Units_Per_EM,
		       float (ht->yMax) / ht->Units_Per_EM);

  lily_cookie_fprintf (out, "/FontType 42 def\n");
  lily_cookie_fprintf (out, "/FontInfo 8 dict dup begin\n");
  lily_cookie_fprintf (out, "/version (%.3f) def\n",
		       ht->Font_Revision / 65536.0);

#if 0
  if (strings[0])
    {
      lily_cookie_fprintf (out, "/Notice (");
      fputpss (strings[0], out);
      lily_cookie_fprintf (out, ") def\n");
    }
  if (strings[4])
    {
      lily_cookie_fprintf (out, "/FullName (");
      fputpss (strings[4], out);
      lily_cookie_fprintf (out, ") def\n");
    }
  if (strings[1])
    {
      lily_cookie_fprintf (out, "/FamilyName (");
      fputpss (strings[1], out);
      lily_cookie_fprintf (out, ") def\n");
    }
#endif

  lily_cookie_fprintf (out, "/isFixedPitch %s def\n",
		       pt->isFixedPitch ? "true" : "false");
  lily_cookie_fprintf (out, "/UnderlinePosition %lf def\n",
		       float (pt->underlinePosition) / ht->Units_Per_EM);
  lily_cookie_fprintf (out, "/UnderlineThickness %lf def\n",
		       float (pt->underlineThickness) / ht->Units_Per_EM);
  lily_cookie_fprintf (out, "end readonly def\n");
}

#define CHUNKSIZE 65534

const FT_ULong FT_ENC_TAG (glyf_tag, 'g', 'l', 'y', 'f');
const FT_ULong FT_ENC_TAG (head_tag, 'h', 'e', 'a', 'd');
const FT_ULong FT_ENC_TAG (loca_tag, 'l', 'o', 'c', 'a');

static
void t42_write_table (void *out, FT_Face face, unsigned char const *buffer,
		      size_t s, bool is_glyf,
		      FT_ULong head_length, FT_ULong loca_length)
{
  vector<FT_UShort> chunks;

  if (is_glyf)
    {
      /* compute chunk sizes */
      unsigned char *head_buf = new unsigned char[head_length];
      FT_Error error = FT_Load_Sfnt_Table (face, head_tag, 0, head_buf, NULL);
      if (error)
	programming_error ("FT_Load_Sfnt_Table (): error.");

      /* we access the lower byte of indexToLocFormat */
      bool long_offsets = head_buf[4*4 + 2*2 + 2*8 + 4*2 + 3*2 + 1] == 1;

      delete[] head_buf;

      unsigned char *loca_buf = new unsigned char[loca_length];
      error = FT_Load_Sfnt_Table (face, loca_tag, 0, loca_buf, NULL);
      if (error)
	programming_error ("FT_Load_Sfnt_Table (): error.");

      unsigned char *p = loca_buf;
      unsigned char *endp = loca_buf + loca_length;

      FT_ULong offset = 0, last_offset = 0, last_chunk = 0;
      while (p < endp)
      {
	if (long_offsets)
	  {
	    offset = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
	    p += 4;
	  }
	else
	  {
	    offset = ((p[0] << 8) | p[1]) << 1;
	    p += 2;
	  }
	if (offset > last_offset + CHUNKSIZE)
	  {
	    if (last_chunk != last_offset)
	      chunks.push_back (last_offset - last_chunk);
	    /*
	      a single glyph with more than 64k data
	      is a pathological case but...
	     */
	    FT_ULong rest = offset - last_offset;
	    while (rest > CHUNKSIZE)
	      {
		chunks.push_back (CHUNKSIZE);
		rest -= CHUNKSIZE;
	      }
	    chunks.push_back (rest);
	    last_chunk = offset;
	  }
	else if (offset > last_chunk + CHUNKSIZE)
	  {
	    chunks.push_back (last_offset - last_chunk);
	    last_chunk = last_offset;
	  }

	last_offset = offset;
      }
      chunks.push_back (s - last_chunk);

      delete[] loca_buf;
    }
  else if (s > CHUNKSIZE)
    {
      FT_ULong rest = s;
      while (rest > CHUNKSIZE)
	{
	  chunks.push_back (CHUNKSIZE);
	  rest -= CHUNKSIZE;
	}
      chunks.push_back (rest);
    }
  else
    chunks.push_back (CHUNKSIZE);

  lily_cookie_fprintf (out, "\n"
			    " <");

  int l = 0;
  static char xdigits[] = "0123456789ABCDEF";

  int cur_chunk_idx = 0;
  for (size_t j = 0; j < s; j++)
    {
      if (l >= chunks[cur_chunk_idx])
	{
	  lily_cookie_fprintf (out, "\n"
				    " 00>\n"
				    " <");
	  l = 0;
	  cur_chunk_idx ++;
	}

      if (l % 31 == 0)
	lily_cookie_fprintf (out, "\n"
				  "  ");

      /* lily_cookie_fprintf (out,"%02X",(int)buffer[j]) is too slow */
      lily_cookie_putc (xdigits[(buffer[j] & 0xF0) >> 4], out);
      lily_cookie_putc (xdigits[buffer[j] & 0x0F], out);

      l ++;
    }

  /* pad to four-byte boundary */
  while ((s ++) % 4 != 0)
    lily_cookie_fprintf (out, "00");

  lily_cookie_fprintf (out, "\n"
			    "  00\n"
			    " >");
}

static void
print_body (void *out, FT_Face face)
{
  FT_UInt idx = 0;
  FT_ULong head_length = 0, loca_length = 0;
  FT_ULong tag, length;
  vector<FT_ULong> lengths, tags;

  /*
    we must build our own TTF header -- the original font
    might be a TTC where tables are not contiguous, or the font
    contains tables which aren't indexed at all
   */
  while (FT_Sfnt_Table_Info (face, idx, &tag, &length)
	 != FT_Err_Table_Missing)
  {
    lengths.push_back (length);
    tags.push_back (tag);
    if (tag == head_tag)
      head_length = length;
    else if (tag == loca_tag)
      loca_length = length;
    idx ++;
  }

  FT_ULong hlength = 12 + 16 * idx;

  unsigned char *hbuf = new unsigned char[hlength];
  unsigned char *p;

  hbuf[0] = 0x00;			/* version */
  hbuf[1] = 0x01;
  hbuf[2] = 0x00;
  hbuf[3] = 0x00;
  hbuf[4] = (idx & 0xFF00) >> 8;	/* numTables */
  hbuf[5] = idx & 0x00FF;

  FT_UInt searchRange, entrySelector, rangeShift;
  FT_UInt i, j;
  for (i = 1, j = 2; j <= idx; i++, j <<= 1)
    ;
  entrySelector = i - 1;
  searchRange = 0x10 << entrySelector;
  rangeShift = (idx << 4) - searchRange;

  hbuf[6] = (searchRange & 0xFF00) >> 8;
  hbuf[7] = searchRange & 0x00FF;
  hbuf[8] = (entrySelector & 0xFF00) >> 8;
  hbuf[9] = entrySelector & 0x00FF;
  hbuf[10] = (rangeShift & 0xFF00) >> 8;
  hbuf[11] = rangeShift & 0x00FF;

  p = &hbuf[12];

  FT_ULong checksum, font_checksum = 0;

  FT_ULong offset = hlength;		/* first table offset */

  for (FT_UInt i = 0; i < idx; i++)
  {
    /* here, the buffer length must be a multiple of 4 */
    FT_ULong len = (lengths[i] + 3) & ~3;
    unsigned char *buf = new unsigned char[len];

    buf[len - 1] = 0x00;		/* assure padding with zeros */
    buf[len - 2] = 0x00;
    buf[len - 3] = 0x00;

    FT_Error error = FT_Load_Sfnt_Table (face, tags[i], 0, buf, NULL);
    if (error)
      programming_error ("FT_Load_Sfnt_Table (): error.");

    if (tag == head_tag)
      {
	/*
	  first pass of computing the font checksum
	  needs checkSumAdjustment = 0
	 */
	buf[8] = 0x00;
	buf[9] = 0x00;
	buf[10] = 0x00;
	buf[11] = 0x00;
      }

    checksum = 0;
    unsigned char *endq = buf + len;
    for (unsigned char *q = buf; q < endq; q += 4)
      checksum += (q[0] << 24) | (q[1] << 16) | (q[2] << 8) | q[3];
    font_checksum += checksum;

    delete[] buf;

    *(p++) = (tags[i] & 0xFF000000UL) >> 24;
    *(p++) = (tags[i] & 0x00FF0000UL) >> 16;
    *(p++) = (tags[i] & 0x0000FF00UL) >> 8;
    *(p++) = tags[i] & 0x000000FFUL;

    *(p++) = (checksum & 0xFF000000UL) >> 24;
    *(p++) = (checksum & 0x00FF0000UL) >> 16;
    *(p++) = (checksum & 0x0000FF00UL) >> 8;
    *(p++) = checksum & 0x000000FFUL;

    *(p++) = (offset & 0xFF000000UL) >> 24;
    *(p++) = (offset & 0x00FF0000UL) >> 16;
    *(p++) = (offset & 0x0000FF00UL) >> 8;
    *(p++) = offset & 0x000000FFUL;

    *(p++) = (lengths[i] & 0xFF000000UL) >> 24;
    *(p++) = (lengths[i] & 0x00FF0000UL) >> 16;
    *(p++) = (lengths[i] & 0x0000FF00UL) >> 8;
    *(p++) = lengths[i] & 0x000000FFUL;

    /* offset must be a multiple of 4 */
    offset += (lengths[i] + 3) & ~3;
  }

  /* add checksum of TTF header */
  checksum = 0;
  for (unsigned char *q = hbuf; q < p; q += 4)
    checksum += (q[0] << 24) | (q[1] << 16) | (q[2] << 8) | q[3];
  font_checksum += checksum;
  font_checksum = 0xB1B0AFBAUL - font_checksum;

  /*
    see Adobe technical note 5012.Type42_Spec.pdf for details how
    the /sfnts array must be constructed
   */
  lily_cookie_fprintf (out, "/sfnts [");
  t42_write_table (out, face, hbuf, hlength, false,
		   head_length, loca_length);
  delete[] hbuf;

  idx = 0;

  while (FT_Sfnt_Table_Info (face, idx, &tag, &length)
	 != FT_Err_Table_Missing)
    {
      unsigned char *buf = new unsigned char[length];
      FT_Error error = FT_Load_Sfnt_Table (face, tag, 0, buf, NULL);
      if (error)
	programming_error ("FT_Load_Sfnt_Table (): error.");

      if (tag == head_tag)
	{
	  /* in the second pass simply store the computed font checksum */
	  buf[8] = (font_checksum & 0xFF000000UL) >> 24;
	  buf[9] = (font_checksum & 0x00FF0000UL) >> 16;
	  buf[10] = (font_checksum & 0x0000FF00UL) >> 8;
	  buf[11] = font_checksum & 0x000000FFUL;
	}

      bool is_glyf_table = tag == glyf_tag && length > CHUNKSIZE;
      t42_write_table (out, face, buf, length, is_glyf_table,
		       head_length, loca_length);

      delete[] buf;
      idx ++;
    }
  lily_cookie_fprintf (out, "\n] def\n");
}

static void
print_trailer (void *out,
	       FT_Face face)
{
  const int GLYPH_NAME_LEN = 256;
  char glyph_name[GLYPH_NAME_LEN];

  TT_MaxProfile *mp
    = (TT_MaxProfile *)FT_Get_Sfnt_Table (face, ft_sfnt_maxp);

  lily_cookie_fprintf (out, "/CharStrings %d dict dup begin\n", mp->numGlyphs);

  Index_to_charcode_map ic_map (make_index_to_charcode_map (face));

  int output_count = 0;
  for (int i = 0; i < mp->numGlyphs; i++)
    {
      glyph_name[0] = 0;
      if (face->face_flags & FT_FACE_FLAG_GLYPH_NAMES)
	{
	  FT_Error error = FT_Get_Glyph_Name (face, i, glyph_name,
					      GLYPH_NAME_LEN);
	  if (error)
	    {
	      programming_error ("FT_Get_Glyph_Name (): error.");
	      glyph_name[0] = 0;
	    }
	}

      if (!glyph_name[0] && ic_map.find (i) != ic_map.end ())
	{
	  FT_ULong ucode = ic_map[i];
	  get_unicode_name (glyph_name, ucode);
	}

      if (i == 0)
	sprintf (glyph_name, ".notdef");
      else if (glyph_name == string (".notdef"))
	glyph_name[0] = '\0';

      if (!glyph_name[0])
	get_glyph_index_name (glyph_name, i);

      if (glyph_name[0])
	{
	  lily_cookie_fprintf (out, "/%s %d def ", glyph_name, i);
	  output_count ++;
	}
      else
	programming_error (to_string ("no name for glyph %d", i));
			
      if (! (output_count % 5))
	lily_cookie_fprintf (out, "\n");
    }

  lily_cookie_fprintf (out, "end readonly def\n");
  lily_cookie_fprintf (out, "FontName currentdict end definefont pop\n");
}

static void
create_type42_font (void *out, string name, int idx)
{
  FT_Face face;

  /* check whether font index is valid */
  if (idx > 0)
    {
      face = open_ft_face (name, -1);
      if (idx >= face->num_faces)
	{
	  warning (_f ("font index %d too large for font `%s', using index 0",
		       idx, name.c_str()));
	  idx = 0;
	}
      FT_Done_Face (face);
    }

  face = open_ft_face (name, idx);

  print_header (out, face);
  print_body (out, face);
  print_trailer (out, face);

  FT_Done_Face (face);
}

LY_DEFINE (ly_ttf_ps_name, "ly:ttf-ps-name",
	   1, 1, 0, (SCM ttf_file_name, SCM idx),
	   "Extract the PostScript name from a TrueType font.  The optional"
	   " @var{idx} argument is useful for TrueType collections (TTC)"
	   " only; it specifies the font index within the TTC.  The default"
	   " value of @var{idx} is@tie{}0.")
{
  LY_ASSERT_TYPE (scm_is_string, ttf_file_name, 1);

  int i = 0;
  if (idx != SCM_UNDEFINED)
    {
      LY_ASSERT_TYPE (scm_is_integer, idx, 2);
      i = scm_to_int (idx);
      if (i < 0)
	{
	  warning (_ ("font index must be non-negative, using index 0"));
	  i = 0;
	}
    }

  string file_name = ly_scm2string (ttf_file_name);
  if (be_verbose_global)
    progress_indication ("[" + file_name);

  FT_Face face;

  /* check whether font index is valid */
  if (i > 0)
    {
      face = open_ft_face (file_name, -1);
      if (i >= face->num_faces)
	{
	  warning (_f ("font index %d too large for font `%s', using index 0",
		       i, file_name.c_str()));
	  i = 0;
	}
      FT_Done_Face (face);
    }

  face = open_ft_face (file_name, i);
  char const *ps_name_str0 = FT_Get_Postscript_Name (face);
  SCM ps_name = scm_from_locale_string (ps_name_str0 ? ps_name_str0 : "");
  FT_Done_Face (face);

  if (be_verbose_global)
    progress_indication ("]");

  return ps_name;
}

LY_DEFINE (ly_ttf_2_pfa, "ly:ttf->pfa",
	   1, 1, 0, (SCM ttf_file_name, SCM idx),
	   "Convert the contents of a TrueType font file to PostScript"
	   " Type@tie{}42 font, returning it as a string.  The optional"
	   " @var{idx} argument is useful for TrueType collections (TTC)"
	   " only; it specifies the font index within the TTC.  The default"
	   " value of @var{idx} is@tie{}0.")
{
  LY_ASSERT_TYPE (scm_is_string, ttf_file_name, 1);

  int i = 0;
  if (idx != SCM_UNDEFINED)
    {
      LY_ASSERT_TYPE (scm_is_integer, idx, 2);
      i = scm_to_int (idx);
      if (i < 0)
	{
	  warning (_ ("font index must be non-negative, using index 0"));
	  i = 0;
	}
    }

  string file_name = ly_scm2string (ttf_file_name);
  if (be_verbose_global)
    progress_indication ("[" + file_name);

  Memory_out_stream stream;

  create_type42_font (&stream, file_name, i);
  SCM asscm = scm_from_locale_stringn (stream.get_string (),
				       stream.get_length ());

  if (be_verbose_global)
    progress_indication ("]");

  return asscm;
}