jellyfin/Emby.Server.Implementations/TextEncoding/NLangDetect/Extensions/CharExtensions.cs

using System;

namespace NLangDetect.Core.Extensions
{
  public static class CharExtensions
  {
    private const int MIN_CODE_POINT = 0x000000;
    private const int MAX_CODE_POINT = 0x10ffff;

    private static readonly int[] _unicodeBlockStarts =
      {
        #region Unicode block starts

        0x0000, // Basic Latin
        0x0080, // Latin-1 Supplement
        0x0100, // Latin Extended-A
        0x0180, // Latin Extended-B
        0x0250, // IPA Extensions
        0x02B0, // Spacing Modifier Letters
        0x0300, // Combining Diacritical Marks
        0x0370, // Greek and Coptic
        0x0400, // Cyrillic
        0x0500, // Cyrillic Supplementary
        0x0530, // Armenian
        0x0590, // Hebrew
        0x0600, // Arabic
        0x0700, // Syriac
        0x0750, // unassigned
        0x0780, // Thaana
        0x07C0, // unassigned
        0x0900, // Devanagari
        0x0980, // Bengali
        0x0A00, // Gurmukhi
        0x0A80, // Gujarati
        0x0B00, // Oriya
        0x0B80, // Tamil
        0x0C00, // Telugu
        0x0C80, // Kannada
        0x0D00, // Malayalam
        0x0D80, // Sinhala
        0x0E00, // Thai
        0x0E80, // Lao
        0x0F00, // Tibetan
        0x1000, // Myanmar
        0x10A0, // Georgian
        0x1100, // Hangul Jamo
        0x1200, // Ethiopic
        0x1380, // unassigned
        0x13A0, // Cherokee
        0x1400, // Unified Canadian Aboriginal Syllabics
        0x1680, // Ogham
        0x16A0, // Runic
        0x1700, // Tagalog
        0x1720, // Hanunoo
        0x1740, // Buhid
        0x1760, // Tagbanwa
        0x1780, // Khmer
        0x1800, // Mongolian
        0x18B0, // unassigned
        0x1900, // Limbu
        0x1950, // Tai Le
        0x1980, // unassigned
        0x19E0, // Khmer Symbols
        0x1A00, // unassigned
        0x1D00, // Phonetic Extensions
        0x1D80, // unassigned
        0x1E00, // Latin Extended Additional
        0x1F00, // Greek Extended
        0x2000, // General Punctuation
        0x2070, // Superscripts and Subscripts
        0x20A0, // Currency Symbols
        0x20D0, // Combining Diacritical Marks for Symbols
        0x2100, // Letterlike Symbols
        0x2150, // Number Forms
        0x2190, // Arrows
        0x2200, // Mathematical Operators
        0x2300, // Miscellaneous Technical
        0x2400, // Control Pictures
        0x2440, // Optical Character Recognition
        0x2460, // Enclosed Alphanumerics
        0x2500, // Box Drawing
        0x2580, // Block Elements
        0x25A0, // Geometric Shapes
        0x2600, // Miscellaneous Symbols
        0x2700, // Dingbats
        0x27C0, // Miscellaneous Mathematical Symbols-A
        0x27F0, // Supplemental Arrows-A
        0x2800, // Braille Patterns
        0x2900, // Supplemental Arrows-B
        0x2980, // Miscellaneous Mathematical Symbols-B
        0x2A00, // Supplemental Mathematical Operators
        0x2B00, // Miscellaneous Symbols and Arrows
        0x2C00, // unassigned
        0x2E80, // CJK Radicals Supplement
        0x2F00, // Kangxi Radicals
        0x2FE0, // unassigned
        0x2FF0, // Ideographic Description Characters
        0x3000, // CJK Symbols and Punctuation
        0x3040, // Hiragana
        0x30A0, // Katakana
        0x3100, // Bopomofo
        0x3130, // Hangul Compatibility Jamo
        0x3190, // Kanbun
        0x31A0, // Bopomofo Extended
        0x31C0, // unassigned
        0x31F0, // Katakana Phonetic Extensions
        0x3200, // Enclosed CJK Letters and Months
        0x3300, // CJK Compatibility
        0x3400, // CJK Unified Ideographs Extension A
        0x4DC0, // Yijing Hexagram Symbols
        0x4E00, // CJK Unified Ideographs
        0xA000, // Yi Syllables
        0xA490, // Yi Radicals
        0xA4D0, // unassigned
        0xAC00, // Hangul Syllables
        0xD7B0, // unassigned
        0xD800, // High Surrogates
        0xDB80, // High Private Use Surrogates
        0xDC00, // Low Surrogates
        0xE000, // Private Use
        0xF900, // CJK Compatibility Ideographs
        0xFB00, // Alphabetic Presentation Forms
        0xFB50, // Arabic Presentation Forms-A
        0xFE00, // Variation Selectors
        0xFE10, // unassigned
        0xFE20, // Combining Half Marks
        0xFE30, // CJK Compatibility Forms
        0xFE50, // Small Form Variants
        0xFE70, // Arabic Presentation Forms-B
        0xFF00, // Halfwidth and Fullwidth Forms
        0xFFF0, // Specials
        0x10000, // Linear B Syllabary
        0x10080, // Linear B Ideograms
        0x10100, // Aegean Numbers
        0x10140, // unassigned
        0x10300, // Old Italic
        0x10330, // Gothic
        0x10350, // unassigned
        0x10380, // Ugaritic
        0x103A0, // unassigned
        0x10400, // Deseret
        0x10450, // Shavian
        0x10480, // Osmanya
        0x104B0, // unassigned
        0x10800, // Cypriot Syllabary
        0x10840, // unassigned
        0x1D000, // Byzantine Musical Symbols
        0x1D100, // Musical Symbols
        0x1D200, // unassigned
        0x1D300, // Tai Xuan Jing Symbols
        0x1D360, // unassigned
        0x1D400, // Mathematical Alphanumeric Symbols
        0x1D800, // unassigned
        0x20000, // CJK Unified Ideographs Extension B
        0x2A6E0, // unassigned
        0x2F800, // CJK Compatibility Ideographs Supplement
        0x2FA20, // unassigned
        0xE0000, // Tags
        0xE0080, // unassigned
        0xE0100, // Variation Selectors Supplement
        0xE01F0, // unassigned
        0xF0000, // Supplementary Private Use Area-A
        0x100000, // Supplementary Private Use Area-B

        #endregion
      };

    private static readonly UnicodeBlock?[] _unicodeBlocks =
      {
        #region Unicode blocks
        UnicodeBlock.BasicLatin,
        UnicodeBlock.Latin1Supplement,
        UnicodeBlock.LatinExtendedA,
        UnicodeBlock.LatinExtendedB,
        UnicodeBlock.IpaExtensions,
        UnicodeBlock.SpacingModifierLetters,
        UnicodeBlock.CombiningDiacriticalMarks,
        UnicodeBlock.Greek,
        UnicodeBlock.Cyrillic,
        UnicodeBlock.CyrillicSupplementary,
        UnicodeBlock.Armenian,
        UnicodeBlock.Hebrew,
        UnicodeBlock.Arabic,
        UnicodeBlock.Syriac,
        null,
        UnicodeBlock.Thaana,
        null,
        UnicodeBlock.Devanagari,
        UnicodeBlock.Bengali,
        UnicodeBlock.Gurmukhi,
        UnicodeBlock.Gujarati,
        UnicodeBlock.Oriya,
        UnicodeBlock.Tamil,
        UnicodeBlock.Telugu,
        UnicodeBlock.Kannada,
        UnicodeBlock.Malayalam,
        UnicodeBlock.Sinhala,
        UnicodeBlock.Thai,
        UnicodeBlock.Lao,
        UnicodeBlock.Tibetan,
        UnicodeBlock.Myanmar,
        UnicodeBlock.Georgian,
        UnicodeBlock.HangulJamo,
        UnicodeBlock.Ethiopic,
        null,
        UnicodeBlock.Cherokee,
        UnicodeBlock.UnifiedCanadianAboriginalSyllabics,
        UnicodeBlock.Ogham,
        UnicodeBlock.Runic,
        UnicodeBlock.Tagalog,
        UnicodeBlock.Hanunoo,
        UnicodeBlock.Buhid,
        UnicodeBlock.Tagbanwa,
        UnicodeBlock.Khmer,
        UnicodeBlock.Mongolian,
        null,
        UnicodeBlock.Limbu,
        UnicodeBlock.TaiLe,
        null,
        UnicodeBlock.KhmerSymbols,
        null,
        UnicodeBlock.PhoneticExtensions,
        null,
        UnicodeBlock.LatinExtendedAdditional,
        UnicodeBlock.GreekExtended,
        UnicodeBlock.GeneralPunctuation,
        UnicodeBlock.SuperscriptsAndSubscripts,
        UnicodeBlock.CurrencySymbols,
        UnicodeBlock.CombiningMarksForSymbols,
        UnicodeBlock.LetterlikeSymbols,
        UnicodeBlock.NumberForms,
        UnicodeBlock.Arrows,
        UnicodeBlock.MathematicalOperators,
        UnicodeBlock.MiscellaneousTechnical,
        UnicodeBlock.ControlPictures,
        UnicodeBlock.OpticalCharacterRecognition,
        UnicodeBlock.EnclosedAlphanumerics,
        UnicodeBlock.BoxDrawing,
        UnicodeBlock.BlockElements,
        UnicodeBlock.GeometricShapes,
        UnicodeBlock.MiscellaneousSymbols,
        UnicodeBlock.Dingbats,
        UnicodeBlock.MiscellaneousMathematicalSymbolsA,
        UnicodeBlock.SupplementalArrowsA,
        UnicodeBlock.BraillePatterns,
        UnicodeBlock.SupplementalArrowsB,
        UnicodeBlock.MiscellaneousMathematicalSymbolsB,
        UnicodeBlock.SupplementalMathematicalOperators,
        UnicodeBlock.MiscellaneousSymbolsAndArrows,
        null,
        UnicodeBlock.CjkRadicalsSupplement,
        UnicodeBlock.KangxiRadicals,
        null,
        UnicodeBlock.IdeographicDescriptionCharacters,
        UnicodeBlock.CjkSymbolsAndPunctuation,
        UnicodeBlock.Hiragana,
        UnicodeBlock.Katakana,
        UnicodeBlock.Bopomofo,
        UnicodeBlock.HangulCompatibilityJamo,
        UnicodeBlock.Kanbun,
        UnicodeBlock.BopomofoExtended,
        null,
        UnicodeBlock.KatakanaPhoneticExtensions,
        UnicodeBlock.EnclosedCjkLettersAndMonths,
        UnicodeBlock.CjkCompatibility,
        UnicodeBlock.CjkUnifiedIdeographsExtensionA,
        UnicodeBlock.YijingHexagramSymbols,
        UnicodeBlock.CjkUnifiedIdeographs,
        UnicodeBlock.YiSyllables,
        UnicodeBlock.YiRadicals,
        null,
        UnicodeBlock.HangulSyllables,
        null,
        UnicodeBlock.HighSurrogates,
        UnicodeBlock.HighPrivateUseSurrogates,
        UnicodeBlock.LowSurrogates,
        UnicodeBlock.PrivateUseArea,
        UnicodeBlock.CjkCompatibilityIdeographs,
        UnicodeBlock.AlphabeticPresentationForms,
        UnicodeBlock.ArabicPresentationFormsA,
        UnicodeBlock.VariationSelectors,
        null,
        UnicodeBlock.CombiningHalfMarks,
        UnicodeBlock.CjkCompatibilityForms,
        UnicodeBlock.SmallFormVariants,
        UnicodeBlock.ArabicPresentationFormsB,
        UnicodeBlock.HalfwidthAndFullwidthForms,
        UnicodeBlock.Specials,
        UnicodeBlock.LinearBSyllabary,
        UnicodeBlock.LinearBIdeograms,
        UnicodeBlock.AegeanNumbers,
        null,
        UnicodeBlock.OldItalic,
        UnicodeBlock.Gothic,
        null,
        UnicodeBlock.Ugaritic,
        null,
        UnicodeBlock.Deseret,
        UnicodeBlock.Shavian,
        UnicodeBlock.Osmanya,
        null,
        UnicodeBlock.CypriotSyllabary,
        null,
        UnicodeBlock.ByzantineMusicalSymbols,
        UnicodeBlock.MusicalSymbols,
        null,
        UnicodeBlock.TaiXuanJingSymbols,
        null,
        UnicodeBlock.MathematicalAlphanumericSymbols,
        null,
        UnicodeBlock.CjkUnifiedIdeographsExtensionB,
        null,
        UnicodeBlock.CjkCompatibilityIdeographsSupplement,
        null,
        UnicodeBlock.Tags,
        null,
        UnicodeBlock.VariationSelectorsSupplement,
        null,
        UnicodeBlock.SupplementaryPrivateUseAreaA,
        UnicodeBlock.SupplementaryPrivateUseAreaB,

        #endregion
      };

    #region Public methods

    /// <remarks>
    /// Taken from JDK source: http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/java/lang/Character.java#Character.UnicodeBlock.0LATIN_EXTENDED_ADDITIONAL
    /// </remarks>
    public static UnicodeBlock? GetUnicodeBlock(this char ch)
    {
      int codePoint = ch;

      if (!IsValidCodePoint(codePoint))
      {
        throw new ArgumentException("Argument is not a valid code point.", nameof(ch));
      }

      int top, bottom, current;

      bottom = 0;
      top = _unicodeBlockStarts.Length;
      current = top / 2;

      // invariant: top > current >= bottom && codePoint >= unicodeBlockStarts[bottom]
      while (top - bottom > 1)
      {
        if (codePoint >= _unicodeBlockStarts[current])
        {
          bottom = current;
        }
        else
        {
          top = current;
        }

        current = (top + bottom) / 2;
      }

      return _unicodeBlocks[current];
    }

    #endregion

    #region Private helper methods

    private static bool IsValidCodePoint(int codePoint)
    {
      return codePoint >= MIN_CODE_POINT && codePoint <= MAX_CODE_POINT;
    }

    #endregion
  }
}