module Quox.CharExtra

import Derive.Prelude


%default total
%language ElabReflection


namespace Letter
  public export
  data Letter = Uppercase | Lowercase | Titlecase | Modifier | Other
  %runElab derive "Letter" [Eq, Ord, Show]

namespace Mark
  public export
  data Mark = NonSpacing | SpacingCombining | Enclosing
  %runElab derive "Mark" [Eq, Ord, Show]

namespace Number
  public export
  data Number = Decimal | Letter | Other
  %runElab derive "Number" [Eq, Ord, Show]

namespace Punctuation
  public export
  data Punctuation = Connector | Dash | Open | Close
                   | InitialQuote | FinalQuote | Other
  %runElab derive "Punctuation" [Eq, Ord, Show]

namespace Symbol
  public export
  data Symbol = Math | Currency | Modifier | Other
  %runElab derive "Symbol" [Eq, Ord, Show]

namespace Separator
  public export
  data Separator = Space | Line | Paragraph
  %runElab derive "Separator" [Eq, Ord, Show]

namespace Other
  public export
  data Other = Control | Format | Surrogate | PrivateUse | NotAssigned
  %runElab derive "Other" [Eq, Ord, Show]


public export
data GeneralCategory
= Letter      Letter
| Mark        Mark
| Number      Number
| Punctuation Punctuation
| Symbol      Symbol
| Separator   Separator
| Other       Other
%runElab derive "GeneralCategory" [Eq, Ord, Show]

private
%foreign "scheme:(lambda (c) (symbol->string (char-general-category c)))"
prim__genCat : Char -> String

export
genCat : Char -> GeneralCategory
genCat ch = assert_total $
  case prim__genCat ch of
    "Lu" => Letter      Uppercase
    "Ll" => Letter      Lowercase
    "Lt" => Letter      Titlecase
    "Lm" => Letter      Modifier
    "Lo" => Letter      Other
    "Mn" => Mark        NonSpacing
    "Mc" => Mark        SpacingCombining
    "Me" => Mark        Enclosing
    "Nd" => Number      Decimal
    "Nl" => Number      Letter
    "No" => Number      Other
    "Pc" => Punctuation Connector
    "Pd" => Punctuation Dash
    "Ps" => Punctuation Open
    "Pe" => Punctuation Close
    "Pi" => Punctuation InitialQuote
    "Pf" => Punctuation FinalQuote
    "Po" => Punctuation Other
    "Sm" => Symbol      Math
    "Sc" => Symbol      Currency
    "Sk" => Symbol      Modifier
    "So" => Symbol      Other
    "Zs" => Separator   Space
    "Zl" => Separator   Line
    "Zp" => Separator   Paragraph
    "Cc" => Other       Control
    "Cf" => Other       Format
    "Cs" => Other       Surrogate
    "Co" => Other       PrivateUse
    "Cn" => Other       NotAssigned
    cat  => idris_crash #"Quox.Unicode.genCat: unknown category "\{cat}""#


namespace GeneralCategory
  public export %inline
  isLetter, isMark, isNumber, isPunctuation, isSymbol, isSeparator, isOther :
    GeneralCategory -> Bool
  isLetter      = \case Letter      _ => True; _ => False
  isMark        = \case Mark        _ => True; _ => False
  isNumber      = \case Number      _ => True; _ => False
  isPunctuation = \case Punctuation _ => True; _ => False
  isSymbol      = \case Symbol      _ => True; _ => False
  isSeparator   = \case Separator   _ => True; _ => False
  isOther       = \case Other       _ => True; _ => False

namespace Char
  public export %inline
  isLetter, isMark, isNumber, isPunctuation, isSymbol, isSeparator, isOther :
    Char -> Bool
  isLetter      = isLetter      . genCat
  isMark        = isMark        . genCat
  isNumber      = isNumber      . genCat
  isPunctuation = isPunctuation . genCat
  isSymbol      = isSymbol      . genCat
  isSeparator   = isSeparator   . genCat
  isOther       = isOther       . genCat


export
isSupDigit : Char -> Bool
isSupDigit ch = ch `elem` unpack "⁰¹²³⁴⁵⁶⁷⁸⁹"

export
isSubDigit : Char -> Bool
isSubDigit ch = ch `elem` unpack "₀₁₂₃₄₅₆₇₈₉"

export
isAsciiDigit : Char -> Bool
isAsciiDigit ch = '0' <= ch && ch <= '9'

export
isIdStart : Char -> Bool
isIdStart ch =
  (ch == '_' || isLetter ch || isNumber ch) &&
  not (isSupDigit ch || isAsciiDigit ch)

export
isIdCont : Char -> Bool
isIdCont ch =
  (isIdStart ch || ch == '\'' || ch == '-' || isMark ch || isNumber ch) &&
  not (isSupDigit ch)

export
isIdConnector : Char -> Bool
isIdConnector ch = genCat ch == Punctuation Connector


export
isSymChar : Char -> Bool
isSymChar ch = case genCat ch of
  Symbol      _     => True
  Punctuation Dash  => True
  Punctuation Other => True
  _                 => False

export
isWhitespace : Char -> Bool
isWhitespace ch = ch == '\t' || ch == '\r' || ch == '\n' || isSeparator ch


export
%foreign "scheme:string-normalize-nfc"
normalizeNfc : String -> String