module Tests.FromPTerm

import Quox.Parser.FromParser
import Quox.Parser
import TypingImpls
import Tests.Parser as TParser
import Quox.EffExtra
import TAP
import AstExtra
import PrettyExtra

import System.File
import Derive.Prelude
%language ElabReflection

%hide TParser.Failure
%hide TParser.ExpectedFail

PError  = Parser.Error
FPError = FromParser.Error

public export
data Failure =
    ParseError   PError
  | FromParser   FPError
  | WrongResult  String
  | ExpectedFail String

%runElab derive "FileError" [Show]

export
ToInfo Failure where
  toInfo (ParseError err) = toInfo err
  toInfo (FromParser err) =
    [("type", "FromParserError"),
     ("got", prettyStr $ prettyError True err)]
  toInfo (WrongResult got) =
    [("type", "WrongResult"), ("got", got)]
  toInfo (ExpectedFail got) =
    [("type", "ExpectedFail"), ("got", got)]


parameters {c : Bool} {auto _ : Show b}
           (grm : FileName -> Grammar c a)
           (fromP : a -> Either FPError b)
           (inp : String)
  parsesWith : String -> (b -> Bool) -> Test
  parsesWith label p = test label $ do
    pres <- mapFst ParseError $ lexParseWith (grm "‹test›") inp
    res  <- mapFst FromParser $ fromP pres
    unless (p res) $ Left $ WrongResult $ show res

  %macro
  parseMatch : {default (ltrim inp) label : String} -> TTImp -> Elab Test
  parseMatch {label} pat =
    parsesWith label <$> check `(\case ~(pat) => True; _ => False)

  parseFails : {default "\{ltrim inp}  # fails" label : String} -> Test
  parseFails {label} = test label $ do
    pres <- mapFst ParseError $ lexParseWith (grm "‹test›") inp
    either (const $ Right ()) (Left . ExpectedFail . show) $ fromP pres


runFromParser : Definitions -> Eff FromParserPure a -> Either FPError a
runFromParser defs = map val . fromParserPure [<] 0 defs initStack

export
tests : Test
tests = "PTerm → Term" :- [
  "dimensions" :-
  let fromPDim = runFromParser empty . fromPDimWith [< "𝑖", "𝑗"]
  in [
    note "dim ctx: [𝑖, 𝑗]",
    parseMatch dim fromPDim "𝑖" `(B (VS VZ) _),
    parseMatch dim fromPDim "𝑗" `(B VZ _),
    parseFails dim fromPDim "𝑘",
    parseMatch dim fromPDim "0" `(K Zero _),
    parseMatch dim fromPDim "1" `(K One _)
  ],

  "terms" :-
  let defs = fromList [("f", mkDef GAny (^NAT) (^Zero))]
        -- doesn't have to be well typed yet, just well scoped
      fromPTerm = runFromParser defs .
                  fromPTermWith [< "𝑖", "𝑗"] [< "A", "x", "y", "z"]
  in [
    note "dim ctx: [𝑖, 𝑗]; term ctx: [A, x, y, z]",
    parseMatch term fromPTerm "x" `(E $ B (VS $ VS VZ) _),
    parseFails term fromPTerm "𝑖",
    parseMatch term fromPTerm "f" `(E $ F "f" {}),
    parseMatch term fromPTerm "λ w ⇒ w"
      `(Lam (S _ $ Y $ E $ B VZ _) _),
    parseMatch term fromPTerm "λ w ⇒ x"
      `(Lam (S _ $ Y $ E $ B (VS $ VS $ VS VZ) _) _),
    parseMatch term fromPTerm "λ x ⇒ x"
      `(Lam (S _ $ Y $ E $ B VZ _) _),
    parseMatch term fromPTerm "λ a b ⇒ f a b"
      `(Lam (S _ $ Y $
          Lam (S _ $ Y $
            E $ App (App (F "f" {}) (E $ B (VS VZ) _) _) (E $ B VZ _) _) _) _),
    parseMatch term fromPTerm "f @𝑖" $
      `(E $ DApp (F "f" {}) (B (VS VZ) _) _),
    parseFails term fromPTerm "λ x ⇒ x¹"
  ],

  todo "everything else"
]