module Tests.Lexer

import Quox.Name
import Quox.Parser.Lexer
import TAP


private
data Failure = LexError Lexer.Error
             | WrongLex (List Token) (List Token)
             | ExpectedFail (List Token)

private
ToInfo Failure where
  toInfo (LexError err) =
    [("type", "LexError"),
     ("info", show err)]
  toInfo (WrongLex want got) =
    [("type", "WrongLex"),
     ("want", show want),
     ("got",  show got)]
  toInfo (ExpectedFail got) =
    [("type", "ExpectedFail"),
     ("got",  show got)]


private
denewline : String -> String
denewline = pack . map (\case '\n' => '␤'; c => c) . unpack

private
lexes : String -> List Token -> Test
lexes str toks = test "｢\{denewline str}｣" $ do
  res <- bimap LexError (map val) $ lex str
  unless (toks == res) $ throwError $ WrongLex toks res

private
lexFail : String -> Test
lexFail str = test "｢\{denewline str}｣   # fails" $
  either (const $ Right ()) (Left . ExpectedFail . map val) $ lex str

export
tests : Test
tests = "lexer" :- [
  "comments" :- [
    lexes "" [],
    lexes "    " [],
    lexes "-- line comment" [],
    lexes "name -- line comment" [Name "name"],
    lexes "-- line comment\nnameBetween -- and another" [Name "nameBetween"],
    lexes "{- block comment -}" [],
    lexes "{- {- nested -} block comment -}" []
  ],

  "identifiers & keywords" :- [
    lexes "abc" [Name "abc"],
    lexes "abc def" [Name "abc", Reserved "def"],
    lexes "abc_def" [Name "abc_def"],
    lexes "abc-def" [Name "abc-def"],
    lexes "abc{-comment-}def" [Name "abc", Reserved "def"],
    lexes "λ" [Reserved "λ"],
    lexes "fun" [Reserved "λ"],
    lexes "δ" [Reserved "δ"],
    lexes "dfun" [Reserved "δ"],
    lexes "funky" [Name "funky"],
    lexes "δελτα" [Name "δελτα"],
    lexes "★★" [Name "★★"],
    lexes "Types" [Name "Types"],
    lexes "a.b.c.d.e" [Name $ MakePName [< "a","b","c","d"] "e"],
    lexes "normalïse" [Name "normalïse"],
      -- ↑ replace i + combining ¨ with precomposed ï
    lexes "map#" [Name "map#"],
    lexes "write!" [Name "write!"],
    lexes "uhh??!?!?!?" [Name "uhh??!?!?!?"],

    todo "check for reserved words in a qname",
    {-
    lexes "abc.fun.def"
      [Name "abc", Reserved ".", Reserved "λ", Reserved ".", Name "def"],
    -}

    lexes "+" [Name "+"],
    lexes "*" [Name "*"],
    lexes "**" [Reserved "×"],
    lexes "***" [Name "***"],
    lexes "+**" [Name "+**"],
    lexes "+#" [Name "+#"],
    lexes "+.+.+" [Name $ MakePName [< "+", "+"] "+"],
    lexes "a.+" [Name $ MakePName [< "a"] "+"],
    lexes "+.a" [Name $ MakePName [< "+"] "a"],

    lexes "+a" [Name "+", Name "a"],

    lexes "x." [Name "x", Reserved "."],
    lexes "&." [Name "&", Reserved "."],
    lexes ".x" [Reserved ".", Name "x"],
    lexes "a.b.c." [Name $ MakePName [< "a", "b"] "c", Reserved "."],

    lexes "case" [Reserved "case"],
    lexes "caseω" [Reserved "caseω"],
    lexes "case#" [Reserved "caseω"],
    lexes "case1" [Reserved "case1"],
    lexes "case0" [Reserved "case0"],
    lexes "case##" [Name "case##"],

    lexes "_" [Reserved "_"],
    lexes "_a" [Name "_a"],
    lexes "a_" [Name "a_"],

    lexes "a'" [Name "a'"],
    lexes "+'" [Name "+'"],

    lexes "0.x" [Nat 0, Reserved ".", Name "x"],
    lexes "1.x" [Nat 1, Reserved ".", Name "x"],
    lexes "ω.x" [Reserved "ω", Reserved ".", Name "x"],
    lexes "#.x" [Reserved "ω", Reserved ".", Name "x"]
  ],

  "syntax characters" :- [
    lexes "()" [Reserved "(", Reserved ")"],
    lexes "(a)" [Reserved "(", Name "a", Reserved ")"],
    lexes "(^)" [Reserved "(", Name "^", Reserved ")"],
    lexes "{a,b}"
      [Reserved "{", Name "a", Reserved ",", Name "b", Reserved "}"],
    lexes "{+,-}"
      [Reserved "{", Name "+", Reserved ",", Name "-", Reserved "}"]
  ],

  "tags" :- [
    lexes #" 'a "# [Tag "a"],
    lexes #" 'abc "# [Tag "abc"],
    lexes #" '+ "# [Tag "+"],
    lexes #" '$$$ "# [Tag "$$$"],
    lexes #" 'tag.with.dots "# [Tag "tag.with.dots"],
    lexes #" '"multi word tag" "# [Tag "multi word tag"],
    lexes #" '"" "# [Tag ""],
    lexFail #" ' "#,
    lexFail #" '' "#
  ],

  "strings" :- [
    lexes #" "" "# [Str ""],
    lexes #" "abc" "# [Str "abc"],
    lexes #" "\"" "# [Str "\""],
    lexes #" "\\" "# [Str "\\"],
    lexes #" "\\\"" "# [Str "\\\""],
    todo "other escapes"
  ],

  todo "naturals",

  "universes" :- [
    lexes "Type0" [TYPE 0],
    lexes "Type₀" [TYPE 0],
    lexes "Type9999999" [TYPE 9999999],
    lexes "★₀" [TYPE 0],
    lexes "★₆₉" [TYPE 69],
    lexes "★4" [TYPE 4],
    lexes "Type" [Reserved "★"],
    lexes "★" [Reserved "★"]
  ]
]