/** @file
  This module provide help function for displaying unicode string.

  Copyright (c) 2006 - 2008, Intel Corporation<BR>
  All rights reserved. This program and the accompanying materials                          
  are licensed and made available under the terms and conditions of the BSD License         
  which accompanies this distribution.  The full text of the license may be found at        
  http://opensource.org/licenses/bsd-license.php                                            

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

**/




#include "UefiLibInternal.h"

typedef struct {
  CHAR16  WChar;
  UINT32  Width;
} UNICODE_WIDTH_ENTRY;

GLOBAL_REMOVE_IF_UNREFERENCED CONST UNICODE_WIDTH_ENTRY mUnicodeWidthTable[] = {
  //
  // General script area
  //
  {(CHAR16)0x1FFF,  1},
  /*
   * Merge the blocks and replace them with the above entry as they fall to 
   * the same category and they are all narrow glyph. This will reduce search
   * time and table size. The merge will omit the reserved code.
   *
   * Remove the above item if below is un-commented.
   *
  {(CHAR16)0x007F,  1},       // C0 controls and basic Latin. 0x0000-0x007F
  {(CHAR16)0x00FF,  1},       // C1 controls and Latin-1 support. 0x0080-0x00FF
  {(CHAR16)0x017F,  1},       // Latin extended-A. 0x0100-0x017F
  {(CHAR16)0x024F,  1},       // Latin extended-B. 0x0180-0x024F
  {(CHAR16)0x02AF,  1},       // IPA extensions. 0x0250-0x02AF
  {(CHAR16)0x02FF,  1},       // Spacing modifier letters. 0x02B0-0x02FF
  {(CHAR16)0x036F,  1},       // Combining diacritical marks. 0x0300-0x036F
  {(CHAR16)0x03FF,  1},       // Greek. 0x0370-0x03FF
  {(CHAR16)0x04FF,  1},       // Cyrillic. 0x0400-0x04FF
  {(CHAR16)0x052F,  0},       // Unassigned. As Armenian in ver3.0. 0x0500-0x052F
  {(CHAR16)0x058F,  1},       // Armenian. 0x0530-0x058F
  {(CHAR16)0x05FF,  1},       // Hebrew. 0x0590-0x05FF
  {(CHAR16)0x06FF,  1},       // Arabic. 0x0600-0x06FF
  {(CHAR16)0x08FF,  0},       // Unassigned. 0x0700-0x08FF
  {(CHAR16)0x097F,  1},       // Devanagari. 0x0900-0x097F
  {(CHAR16)0x09FF,  1},       // Bengali. 0x0980-0x09FF
  {(CHAR16)0x0A7F,  1},       // Gurmukhi. 0x0A00-0x0A7F
  {(CHAR16)0x0AFF,  1},       // Gujarati. 0x0A80-0x0AFF
  {(CHAR16)0x0B7F,  1},       // Oriya. 0x0B00-0x0B7F
  {(CHAR16)0x0BFF,  1},       // Tamil. (See page 7-92). 0x0B80-0x0BFF
  {(CHAR16)0x0C7F,  1},       // Telugu. 0x0C00-0x0C7F
  {(CHAR16)0x0CFF,  1},       // Kannada. (See page 7-100). 0x0C80-0x0CFF
  {(CHAR16)0x0D7F,  1},       // Malayalam (See page 7-104). 0x0D00-0x0D7F
  {(CHAR16)0x0DFF,  0},       // Unassigned. 0x0D80-0x0DFF
  {(CHAR16)0x0E7F,  1},       // Thai. 0x0E00-0x0E7F
  {(CHAR16)0x0EFF,  1},       // Lao. 0x0E80-0x0EFF
  {(CHAR16)0x0FBF,  1},       // Tibetan. 0x0F00-0x0FBF
  {(CHAR16)0x109F,  0},       // Unassigned. 0x0FC0-0x109F
  {(CHAR16)0x10FF,  1},       // Georgian. 0x10A0-0x10FF
  {(CHAR16)0x11FF,  1},       // Hangul Jamo. 0x1100-0x11FF
  {(CHAR16)0x1DFF,  0},       // Unassigned. 0x1200-0x1DFF
  {(CHAR16)0x1EFF,  1},       // Latin extended additional. 0x1E00-0x1EFF
  {(CHAR16)0x1FFF,  1},       // Greek extended. 0x1F00-0x1FFF
  *
  */

  //
  // Symbol area
  //
  {(CHAR16)0x2FFF,  1},
  /*
   * Merge the blocks and replace them with the above entry as they fall to 
   * the same category and they are all narrow glyph. This will reduce search
   * time and table size. The merge will omit the reserved code.
   *
   * Remove the above item if below is un-commented.
   *
  {(CHAR16)0x206F,  1},       // General punctuation. (See page7-154). 0x200-0x206F
  {(CHAR16)0x209F,  1},       // Superscripts and subscripts. 0x2070-0x209F
  {(CHAR16)0x20CF,  1},       // Currency symbols. 0x20A0-0x20CF
  {(CHAR16)0x20FF,  1},       // Combining diacritical marks for symbols. 0x20D0-0x20FF
  {(CHAR16)0x214F,  1},       // Letterlike sympbols. 0x2100-0x214F
  {(CHAR16)0x218F,  1},       // Number forms. 0x2150-0x218F
  {(CHAR16)0x21FF,  1},       // Arrows. 0x2190-0x21FF
  {(CHAR16)0x22FF,  1},       // Mathematical operators. 0x2200-0x22FF
  {(CHAR16)0x23FF,  1},       // Miscellaneous technical. 0x2300-0x23FF
  {(CHAR16)0x243F,  1},       // Control pictures. 0x2400-0x243F
  {(CHAR16)0x245F,  1},       // Optical character recognition. 0x2440-0x245F
  {(CHAR16)0x24FF,  1},       // Enclosed alphanumerics. 0x2460-0x24FF
  {(CHAR16)0x257F,  1},       // Box drawing. 0x2500-0x257F
  {(CHAR16)0x259F,  1},       // Block elements. 0x2580-0x259F
  {(CHAR16)0x25FF,  1},       // Geometric shapes. 0x25A0-0x25FF
  {(CHAR16)0x26FF,  1},       // Miscellaneous symbols. 0x2600-0x26FF
  {(CHAR16)0x27BF,  1},       // Dingbats. 0x2700-0x27BF
  {(CHAR16)0x2FFF,  0},       // Reserved. 0x27C0-0x2FFF
  *
  */

  //
  // CJK phonetics and symbol area
  //
  {(CHAR16)0x33FF,  2},
  /*
   * Merge the blocks and replace them with the above entry as they fall to 
   * the same category and they are all wide glyph. This will reduce search
   * time and table size. The merge will omit the reserved code.
   *
   * Remove the above item if below is un-commented.
   *
  {(CHAR16)0x303F,  2},       // CJK symbols and punctuation. 0x3000-0x303F
  {(CHAR16)0x309F,  2},       // Hiragana. 0x3040-0x309F
  {(CHAR16)0x30FF,  2},       // Katakana. 0x30A0-0x30FF
  {(CHAR16)0x312F,  2},       // Bopomofo. 0x3100-0x312F
  {(CHAR16)0x318F,  2},       // Hangul compatibility jamo. 0x3130-0x318F
  {(CHAR16)0x319F,  2},       // Kanbun. 0x3190-0x319F
  {(CHAR16)0x31FF,  0},       // Reserved. As Bopomofo extended in ver3.0. 0x31A0-0x31FF
  {(CHAR16)0x32FF,  2},       // Enclosed CJK letters and months. 0x3200-0x32FF
  {(CHAR16)0x33FF,  2},       // CJK compatibility. 0x3300-0x33FF
  *
  */

  //
  // CJK ideograph area
  //
  {(CHAR16)0x9FFF,  2},
  /*
   * Merge the blocks and replace them with the above entry as they fall to 
   * the same category and they are all wide glyph. This will reduce search
   * time and table size. The merge will omit the reserved code.
   *
   * Remove the above item if below is un-commented.
   *
  {(CHAR16)0x4DFF,  0},       // Reserved. 0x3400-0x4DBF as CJK unified ideographs 
                      // extension A in ver3.0. 0x3400-0x4DFF
  {(CHAR16)0x9FFF,  2},       // CJK unified ideographs. 0x4E00-0x9FFF
  *
  */

  //
  // Reserved
  //
  {(CHAR16)0xABFF,  0},       // Reserved. 0xA000-0xA490 as Yi syllables. 0xA490-0xA4D0
  // as Yi radicals in ver3.0. 0xA000-0xABFF
  //
  // Hangul syllables
  //
  {(CHAR16)0xD7FF,  2},
  /*
   * Merge the blocks and replace them with the above entry as they fall to 
   * the same category and they are all wide glyph. This will reduce search
   * time and table size. The merge will omit the reserved code.
   *
   * Remove the above item if below is un-commented.
   *
  {(CHAR16)0xD7A3,  2},       // Hangul syllables. 0xAC00-0xD7A3
  {(CHAR16)0xD7FF,  0},       // Reserved. 0xD7A3-0xD7FF
  *
  */

  //
  // Surrogates area
  //
  {(CHAR16)0xDFFF,  0},       // Surrogates, not used now. 0xD800-0xDFFF

  //
  // Private use area
  //
  {(CHAR16)0xF8FF,  0},       // Private use area. 0xE000-0xF8FF

  //
  // Compatibility area and specials
  //
  {(CHAR16)0xFAFF,  2},       // CJK compatibility ideographs. 0xF900-0xFAFF
  {(CHAR16)0xFB4F,  1},       // Alphabetic presentation forms. 0xFB00-0xFB4F
  {(CHAR16)0xFDFF,  1},       // Arabic presentation forms-A. 0xFB50-0xFDFF
  {(CHAR16)0xFE1F,  0},       // Reserved. As variation selectors in ver3.0. 0xFE00-0xFE1F
  {(CHAR16)0xFE2F,  1},       // Combining half marks. 0xFE20-0xFE2F
  {(CHAR16)0xFE4F,  2},       // CJK compatibility forms. 0xFE30-0xFE4F
  {(CHAR16)0xFE6F,  1},       // Small Form Variants. 0xFE50-0xFE6F
  {(CHAR16)0xFEFF,  1},       // Arabic presentation forms-B. 0xFE70-0xFEFF
  {(CHAR16)0xFFEF,  1},       // Half width and full width forms. 0xFF00-0xFFEF
  {(CHAR16)0xFFFF,  0},       // Speicials. 0xFFF0-0xFFFF
};

/**
  Retrieves the width of a Unicode character.

  This function computes and returns the width of the Unicode character specified
  by UnicodeChar.

  @param  UnicodeChar   A Unicode character.

  @retval 0             The width if UnicodeChar could not be determined.
  @retval 1             UnicodeChar is a narrow glyph.
  @retval 2             UnicodeChar is a wide glyph.

**/
UINTN
EFIAPI
GetGlyphWidth (
  IN CHAR16  UnicodeChar
  )
{
  UINTN                     Index;
  UINTN                     Low;
  UINTN                     High;
  CONST UNICODE_WIDTH_ENTRY *Item;

  Item  = NULL;
  Low   = 0;
  High  = (sizeof (mUnicodeWidthTable)) / (sizeof (UNICODE_WIDTH_ENTRY)) - 1;
  while (Low <= High) {
    Index = (Low + High) >> 1;
    Item  = &(mUnicodeWidthTable[Index]);
    if (Index == 0) {
      if (UnicodeChar <= Item->WChar) {
        break;
      }

      return 0;
    }

    if (UnicodeChar > Item->WChar) {
      Low = Index + 1;
    } else if (UnicodeChar <= mUnicodeWidthTable[Index - 1].WChar) {
      High = Index - 1;
    } else {
      //
      // Index - 1 < UnicodeChar <= Index. Found
      //
      break;
    }
  }

  if (Low <= High) {
    return Item->Width;
  }

  return 0;
}

/**
  Computes the display length of a Null-terminated Unicode String.

  This function computes and returns the display length of the Null-terminated Unicode
  string specified by String.  If String is NULL then 0 is returned. If any of the widths
  of the Unicode characters in String can not be determined, then 0 is returned. The display
  width of String can be computed by summing the display widths of each Unicode character
  in String.  Unicode characters that are narrow glyphs have a width of 1, and Unicode
  characters that are width glyphs have a width of 2. 
  If String is not aligned on a 16-bit boundary, then ASSERT().

  @param  String      A pointer to a Null-terminated Unicode string.

  @return The display length of the Null-terminated Unicode string specified by String.
  
**/
UINTN
EFIAPI
UnicodeStringDisplayLength (
  IN CONST CHAR16  *String
  )
{
  UINTN      Length;
  UINTN      Width;

  if (String == NULL) {
    return 0;
  }

  Length = 0;
  while (*String != 0) {
    Width = GetGlyphWidth (*String);
    if (Width == 0) {
      return 0;
    }

    Length += Width;
    String++;
  }

  return Length;
}