/*

 * Copyright © 2009  Red Hat, Inc.

 * Copyright © 2009  Keith Stribley

 * Copyright © 2011  Google, Inc.

 *

 *  This is part of HarfBuzz, a text shaping library.

 *

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 *

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 *

 * Red Hat Author(s): Behdad Esfahbod

 * Google Author(s): Behdad Esfahbod

 */

#include "hb-private.hh"

#include "hb-icu.h"

#include "hb-unicode-private.hh"

#include <unicode/uchar.h>

#include <unicode/unorm.h>

#include <unicode/ustring.h>

#include <unicode/utf16.h>

#include <unicode/uversion.h>

hb_script_t

hb_icu_script_to_script (UScriptCode script)

{

  if (unlikely (script == USCRIPT_INVALID_CODE))

    return HB_SCRIPT_INVALID;

  return hb_script_from_string (uscript_getShortName (script), -1);

}

UScriptCode

hb_icu_script_from_script (hb_script_t script)

{

  if (unlikely (script == HB_SCRIPT_INVALID))

    return USCRIPT_INVALID_CODE;

  for (unsigned int i = 0; i < USCRIPT_CODE_LIMIT; i++)

    if (unlikely (hb_icu_script_to_script ((UScriptCode) i) == script))

      return (UScriptCode) i;

  return USCRIPT_UNKNOWN;

}

static hb_unicode_combining_class_t

hb_icu_unicode_combining_class (hb_unicode_funcs_t *ufuncs HB_UNUSED,

				hb_codepoint_t      unicode,

				void               *user_data HB_UNUSED)

{

  return (hb_unicode_combining_class_t) u_getCombiningClass (unicode);

}

static unsigned int

hb_icu_unicode_eastasian_width (hb_unicode_funcs_t *ufuncs HB_UNUSED,

				hb_codepoint_t      unicode,

				void               *user_data HB_UNUSED)

{

  switch (u_getIntPropertyValue(unicode, UCHAR_EAST_ASIAN_WIDTH))

  {

  case U_EA_WIDE:

  case U_EA_FULLWIDTH:

    return 2;

  case U_EA_NEUTRAL:

  case U_EA_AMBIGUOUS:

  case U_EA_HALFWIDTH:

  case U_EA_NARROW:

    return 1;

  }

  return 1;

}

static hb_unicode_general_category_t

hb_icu_unicode_general_category (hb_unicode_funcs_t *ufuncs HB_UNUSED,

				 hb_codepoint_t      unicode,

				 void               *user_data HB_UNUSED)

{

  switch (u_getIntPropertyValue(unicode, UCHAR_GENERAL_CATEGORY))

  {

  case U_UNASSIGNED:			return HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED;

  case U_UPPERCASE_LETTER:		return HB_UNICODE_GENERAL_CATEGORY_UPPERCASE_LETTER;

  case U_LOWERCASE_LETTER:		return HB_UNICODE_GENERAL_CATEGORY_LOWERCASE_LETTER;

  case U_TITLECASE_LETTER:		return HB_UNICODE_GENERAL_CATEGORY_TITLECASE_LETTER;

  case U_MODIFIER_LETTER:		return HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER;

  case U_OTHER_LETTER:			return HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER;

  case U_NON_SPACING_MARK:		return HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK;

  case U_ENCLOSING_MARK:		return HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK;

  case U_COMBINING_SPACING_MARK:	return HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK;

  case U_DECIMAL_DIGIT_NUMBER:		return HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER;

  case U_LETTER_NUMBER:			return HB_UNICODE_GENERAL_CATEGORY_LETTER_NUMBER;

  case U_OTHER_NUMBER:			return HB_UNICODE_GENERAL_CATEGORY_OTHER_NUMBER;

  case U_SPACE_SEPARATOR:		return HB_UNICODE_GENERAL_CATEGORY_SPACE_SEPARATOR;

  case U_LINE_SEPARATOR:		return HB_UNICODE_GENERAL_CATEGORY_LINE_SEPARATOR;

  case U_PARAGRAPH_SEPARATOR:		return HB_UNICODE_GENERAL_CATEGORY_PARAGRAPH_SEPARATOR;

  case U_CONTROL_CHAR:			return HB_UNICODE_GENERAL_CATEGORY_CONTROL;

  case U_FORMAT_CHAR:			return HB_UNICODE_GENERAL_CATEGORY_FORMAT;

  case U_PRIVATE_USE_CHAR:		return HB_UNICODE_GENERAL_CATEGORY_PRIVATE_USE;

  case U_SURROGATE:			return HB_UNICODE_GENERAL_CATEGORY_SURROGATE;

  case U_DASH_PUNCTUATION:		return HB_UNICODE_GENERAL_CATEGORY_DASH_PUNCTUATION;

  case U_START_PUNCTUATION:		return HB_UNICODE_GENERAL_CATEGORY_OPEN_PUNCTUATION;

  case U_END_PUNCTUATION:		return HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION;

  case U_CONNECTOR_PUNCTUATION:		return HB_UNICODE_GENERAL_CATEGORY_CONNECT_PUNCTUATION;

  case U_OTHER_PUNCTUATION:		return HB_UNICODE_GENERAL_CATEGORY_OTHER_PUNCTUATION;

  case U_MATH_SYMBOL:			return HB_UNICODE_GENERAL_CATEGORY_MATH_SYMBOL;

  case U_CURRENCY_SYMBOL:		return HB_UNICODE_GENERAL_CATEGORY_CURRENCY_SYMBOL;

  case U_MODIFIER_SYMBOL:		return HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL;

  case U_OTHER_SYMBOL:			return HB_UNICODE_GENERAL_CATEGORY_OTHER_SYMBOL;

  case U_INITIAL_PUNCTUATION:		return HB_UNICODE_GENERAL_CATEGORY_INITIAL_PUNCTUATION;

  case U_FINAL_PUNCTUATION:		return HB_UNICODE_GENERAL_CATEGORY_FINAL_PUNCTUATION;

  }

  return HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED;

}

static hb_codepoint_t

hb_icu_unicode_mirroring (hb_unicode_funcs_t *ufuncs HB_UNUSED,

			  hb_codepoint_t      unicode,

			  void               *user_data HB_UNUSED)

{

  return u_charMirror(unicode);

}

static hb_script_t

hb_icu_unicode_script (hb_unicode_funcs_t *ufuncs HB_UNUSED,

		       hb_codepoint_t      unicode,

		       void               *user_data HB_UNUSED)

{

  UErrorCode status = U_ZERO_ERROR;

  UScriptCode scriptCode = uscript_getScript(unicode, &status);

  if (unlikely (U_FAILURE (status)))

    return HB_SCRIPT_UNKNOWN;

  return hb_icu_script_to_script (scriptCode);

}

#if U_ICU_VERSION_MAJOR_NUM >= 49

static const UNormalizer2 *normalizer;

#endif

static hb_bool_t

hb_icu_unicode_compose (hb_unicode_funcs_t *ufuncs HB_UNUSED,

			hb_codepoint_t      a,

			hb_codepoint_t      b,

			hb_codepoint_t     *ab,

			void               *user_data HB_UNUSED)

{

#if U_ICU_VERSION_MAJOR_NUM >= 49

  {

    UChar32 ret = unorm2_composePair (normalizer, a, b);

    if (ret < 0) return false;

    *ab = ret;

    return true;

  }

#endif

  /* We don't ifdef-out the fallback code such that compiler always

   * sees it and makes sure it's compilable. */

  UChar utf16[4], normalized[5];

  unsigned int len;

  hb_bool_t ret, err;

  UErrorCode icu_err;

  len = 0;

  err = false;

  U16_APPEND (utf16, len, ARRAY_LENGTH (utf16), a, err);

  if (err) return false;

  U16_APPEND (utf16, len, ARRAY_LENGTH (utf16), b, err);

  if (err) return false;

  icu_err = U_ZERO_ERROR;

  len = unorm_normalize (utf16, len, UNORM_NFC, 0, normalized, ARRAY_LENGTH (normalized), &icu_err);

  if (U_FAILURE (icu_err))

    return false;

  if (u_countChar32 (normalized, len) == 1) {

    U16_GET_UNSAFE (normalized, 0, *ab);

    ret = true;

  } else {

    ret = false;

  }

  return ret;

}

static hb_bool_t

hb_icu_unicode_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,

			  hb_codepoint_t      ab,

			  hb_codepoint_t     *a,

			  hb_codepoint_t     *b,

			  void               *user_data HB_UNUSED)

{

#if U_ICU_VERSION_MAJOR_NUM >= 49

  {

    UChar decomposed[4];

    int len;

    UErrorCode icu_err = U_ZERO_ERROR;

    len = unorm2_getRawDecomposition (normalizer, ab, decomposed,

				      ARRAY_LENGTH (decomposed), &icu_err);

    if (U_FAILURE (icu_err) || len < 0) return false;

    len = u_countChar32 (decomposed, len);

    if (len == 1) {

      U16_GET_UNSAFE (decomposed, 0, *a);

      *b = 0;

      return *a != ab;

    } else if (len == 2) {

      len =0;

      U16_NEXT_UNSAFE (decomposed, len, *a);

      U16_NEXT_UNSAFE (decomposed, len, *b);

    }

    return true;

  }

#endif

  /* We don't ifdef-out the fallback code such that compiler always

   * sees it and makes sure it's compilable. */

  UChar utf16[2], normalized[2 * HB_UNICODE_MAX_DECOMPOSITION_LEN + 1];

  unsigned int len;

  hb_bool_t ret, err;

  UErrorCode icu_err;

  /* This function is a monster! Maybe it wasn't a good idea adding a

   * pairwise decompose API... */

  /* Watchout for the dragons.  Err, watchout for macros changing len. */

  len = 0;

  err = false;

  U16_APPEND (utf16, len, ARRAY_LENGTH (utf16), ab, err);

  if (err) return false;

  icu_err = U_ZERO_ERROR;

  len = unorm_normalize (utf16, len, UNORM_NFD, 0, normalized, ARRAY_LENGTH (normalized), &icu_err);

  if (U_FAILURE (icu_err))

    return false;

  len = u_countChar32 (normalized, len);

  if (len == 1) {

    U16_GET_UNSAFE (normalized, 0, *a);

    *b = 0;

    ret = *a != ab;

  } else if (len == 2) {

    len =0;

    U16_NEXT_UNSAFE (normalized, len, *a);

    U16_NEXT_UNSAFE (normalized, len, *b);

    /* Here's the ugly part: if ab decomposes to a single character and

     * that character decomposes again, we have to detect that and undo

     * the second part :-(. */

    UChar recomposed[20];

    icu_err = U_ZERO_ERROR;

    unorm_normalize (normalized, len, UNORM_NFC, 0, recomposed, ARRAY_LENGTH (recomposed), &icu_err);

    if (U_FAILURE (icu_err))

      return false;

    hb_codepoint_t c;

    U16_GET_UNSAFE (recomposed, 0, c);

    if (c != *a && c != ab) {

      *a = c;

      *b = 0;

    }

    ret = true;

  } else {

    /* If decomposed to more than two characters, take the last one,

     * and recompose the rest to get the first component. */

    U16_PREV_UNSAFE (normalized, len, *b); /* Changes len in-place. */

    UChar recomposed[18 * 2];

    icu_err = U_ZERO_ERROR;

    len = unorm_normalize (normalized, len, UNORM_NFC, 0, recomposed, ARRAY_LENGTH (recomposed), &icu_err);

    if (U_FAILURE (icu_err))

      return false;

    /* We expect that recomposed has exactly one character now. */

    if (unlikely (u_countChar32 (recomposed, len) != 1))

      return false;

    U16_GET_UNSAFE (recomposed, 0, *a);

    ret = true;

  }

  return ret;

}

static unsigned int

hb_icu_unicode_decompose_compatibility (hb_unicode_funcs_t *ufuncs HB_UNUSED,

					hb_codepoint_t      u,

					hb_codepoint_t     *decomposed,

					void               *user_data HB_UNUSED)

{

  UChar utf16[2], normalized[2 * HB_UNICODE_MAX_DECOMPOSITION_LEN + 1];

  unsigned int len;

  int32_t utf32_len;

  hb_bool_t err;

  UErrorCode icu_err;

  /* Copy @u into a UTF-16 array to be passed to ICU. */

  len = 0;

  err = false;

  U16_APPEND (utf16, len, ARRAY_LENGTH (utf16), u, err);

  if (err)

    return 0;

  /* Normalise the codepoint using NFKD mode. */

  icu_err = U_ZERO_ERROR;

  len = unorm_normalize (utf16, len, UNORM_NFKD, 0, normalized, ARRAY_LENGTH (normalized), &icu_err);

  if (icu_err)

    return 0;

  /* Convert the decomposed form from UTF-16 to UTF-32. */

  icu_err = U_ZERO_ERROR;

  u_strToUTF32 ((UChar32*) decomposed, HB_UNICODE_MAX_DECOMPOSITION_LEN, &utf32_len, normalized, len, &icu_err);

  if (icu_err)

    return 0;

  return utf32_len;

}

hb_unicode_funcs_t *

hb_icu_get_unicode_funcs (void)

{

  static const hb_unicode_funcs_t _hb_icu_unicode_funcs = {

    HB_OBJECT_HEADER_STATIC,

    NULL, /* parent */

    true, /* immutable */

    {

#define HB_UNICODE_FUNC_IMPLEMENT(name) hb_icu_unicode_##name,

      HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS

#undef HB_UNICODE_FUNC_IMPLEMENT

    }

  };

#if U_ICU_VERSION_MAJOR_NUM >= 49

  if (!hb_atomic_ptr_get (&normalizer)) {

    UErrorCode icu_err = U_ZERO_ERROR;

    /* We ignore failure in getNFCInstace(). */

    (void) hb_atomic_ptr_cmpexch (&normalizer, NULL, unorm2_getNFCInstance (&icu_err));

  }

#endif

  return const_cast<hb_unicode_funcs_t *> (&_hb_icu_unicode_funcs);

}