module Main (main) where

import Data.Char
import Data.Foldable
import Text.Grammar.Distributor
import Test.Hspec

expectedRegexGrammar :: [(String, RegEx)]
expectedRegexGrammar =
  [("start",NonTerminal "regex")
  ,("alternate",Sequence (NonTerminal "sequence") (KleeneStar (Sequence (Terminal "|") (NonTerminal "sequence"))))
  ,("any",Terminal ".")
  ,("atom",Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (NonTerminal "nonterminal") (NonTerminal "fail")) (NonTerminal "class-in")) (NonTerminal "class-not-in")) (NonTerminal "category-in")) (NonTerminal "category-not-in")) (NonTerminal "char")) (NonTerminal "any")) (NonTerminal "parenthesized"))
  ,("category",Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Alternate (Terminal "Ll") (Terminal "Lu")) (Terminal "Lt")) (Terminal "Lm")) (Terminal "Lo")) (Terminal "Mn")) (Terminal "Mc")) (Terminal "Me")) (Terminal "Nd")) (Terminal "Nl")) (Terminal "No")) (Terminal "Pc")) (Terminal "Pd")) (Terminal "Ps")) (Terminal "Pe")) (Terminal "Pi")) (Terminal "Pf")) (Terminal "Po")) (Terminal "Sm")) (Terminal "Sc")) (Terminal "Sk")) (Terminal "So")) (Terminal "Zs")) (Terminal "Zl")) (Terminal "Zp")) (Terminal "Cc")) (Terminal "Cf")) (Terminal "Cs")) (Terminal "Co")) (Terminal "Cn"))
  ,("category-in",Sequence (Sequence (Terminal "\\p{") (NonTerminal "category")) (Terminal "}"))
  ,("category-not-in",Sequence (Sequence (Terminal "\\P{") (NonTerminal "category")) (Terminal "}"))
  ,("char",Alternate (NonTerminal "char-literal") (NonTerminal "char-escaped"))
  ,("char-escaped",Sequence (Terminal "\\") (InClass "$()*+.?[\\]^{|}"))
  ,("char-literal",NotInClass "$()*+.?[\\]^{|}")
  ,("class-in",Sequence (Sequence (Terminal "[") (KleeneStar (NonTerminal "char"))) (Terminal "]"))
  ,("class-not-in",Sequence (Sequence (Terminal "[^") (KleeneStar (NonTerminal "char"))) (Terminal "]"))
  ,("expression",Alternate (Alternate (Alternate (Alternate (NonTerminal "terminal") (NonTerminal "kleene-optional")) (NonTerminal "kleene-star")) (NonTerminal "kleene-plus")) (NonTerminal "atom"))
  ,("fail",Terminal "\\q")
  ,("kleene-optional",Sequence (NonTerminal "atom") (Terminal "?"))
  ,("kleene-plus",Sequence (NonTerminal "atom") (Terminal "+"))
  ,("kleene-star",Sequence (NonTerminal "atom") (Terminal "*"))
  ,("nonterminal",Sequence (Sequence (Terminal "\\q{") (KleeneStar (NonTerminal "char"))) (Terminal "}"))
  ,("parenthesized",Sequence (Sequence (Terminal "(") (NonTerminal "regex")) (Terminal ")"))
  ,("regex",NonTerminal "alternate")
  ,("sequence",KleeneStar (NonTerminal "expression"))
  ,("terminal",KleenePlus (NonTerminal "char"))
  ]

regexExamples :: [(RegEx, String)]
regexExamples =
  [ (Terminal "abc123etc.", "abc123etc\\.")
  , (Sequence (Terminal "x") (Terminal "y"), "xy")
  , (Fail, "\\q")
  , (Alternate (Terminal "x") (Terminal "y"), "x|y")
  , (KleeneOpt (Terminal "x"), "x?")
  , (KleeneStar (Terminal "x"), "x*")
  , (KleenePlus (Terminal "x"), "x+")
  , (AnyChar, ".")
  , (InClass "abc", "[abc]")
  , (NotInClass "abc", "[^abc]")
  , (InCategory UppercaseLetter, "\\p{Lu}")
  , (NotInCategory LowercaseLetter, "\\P{Ll}")
  , (NonTerminal "rule-name", "\\q{rule-name}")
  , (Terminal "", "")
  ]

main :: IO ()
main = hspec $ do
  describe "regexGrammar" $ do
    it "should generate a correct grammar" $
      genGrammar regexGrammar `shouldBe` expectedRegexGrammar
    for_ regexExamples $ \(rex, str) -> do
      it ("should print " <> show rex <> " correctly") $
        showGrammar regexGrammar rex `shouldBe` Just str
    for_ regexExamples $ \(rex, str) -> do
      it ("should parse " <> str <> " correctly") $
        readGrammar regexGrammar str `shouldSatisfy` elem rex