{-# lANGUAGE LambdaCase #-}

import Test.Hspec
import Printcess.PrettyPrinting
import Control.Lens

main :: IO ()
main = hspec $ do
  describe "basic" $ do
    it "prints a string" $
      pretty defConfig
        "foo" `shouldBe`
        "foo"
    it "handles newlines" $
      pretty defConfig
        "foo\nbar" `shouldBe`
        "foo\nbar"
    it "indents after newlines" $
      pretty defConfig
        (indented "foo\nbar") `shouldBe`
        "  foo\n  bar"
    it "respects initial indentation" $
      pretty (cInitIndent .= 2)
        "foo\nbar" `shouldBe`
        "  foo\n  bar"

  describe "automatic line breaks" $ do
    it "breaks too long lines" $
      pretty (cMaxLineWidth .= Just 10)
        "foo bar baz boo" `shouldBe`
        "foo bar\n    baz\n    boo"
    it "breaks too long lines" $
      pretty (cMaxLineWidth .= Just 11)
        "foo bar baz boo" `shouldBe`
        "foo bar baz\n    boo"
    it "breaks too long lines twice" $
      pretty (cMaxLineWidth .= Just 10)
        "foo bar baz boo r" `shouldBe`
        "foo bar\n    baz\n    boo r"
    it "breaks too long lines four times" $
      pretty (cMaxLineWidth .= Just 10)
        "foo bar baz boo raz roo" `shouldBe`
        "foo bar\n    baz\n    boo\n    raz\n    roo"
    it "breaks too long lines" $
      pretty (cMaxLineWidth .= Just 11)
        "foo bar baz boo r" `shouldBe`
        "foo bar baz\n    boo r"
    it "breaks too long lines twice" $
      pretty (cMaxLineWidth .= Just 11)
        "foo bar baz boo raz roo" `shouldBe`
        "foo bar baz\n    boo raz\n    roo"
    it "breaks too long lines" $
      pretty (cMaxLineWidth .= Just 12)
        "foo bar baz boo r" `shouldBe`
        "foo bar baz\n    boo r"
    it "breaks too long lines & setting indentChar works" $
      pretty (do cMaxLineWidth .= Just 10; cIndentChar .= '~')
        "foo bar baz boo r" `shouldBe`
        "foo bar\n~~~~baz\n~~~~boo r"
    it "removes spaces around broken lines" $
      pretty (cMaxLineWidth .= Just 10)
        "foo bar        baz boo" `shouldBe`
        "foo bar\n    baz\n    boo"

  describe "Lambda Calculus" $ do
    it "respects associativity" $
      pretty defConfig
        e1 `shouldBe`
        "λx. λy. x y (x y)"

  describe "Blocks" $ do
    it "blocks starting on next line" $
      pretty defConfig
        ("do" ~> block [ "ma", "mb" ]) `shouldBe`
        "do \n  ma\n  mb"
    it "blocks starting on same line" $
      pretty defConfig
        ("do" ~> block' [ "ma", "mb" ]) `shouldBe`
        "do ma\n   mb"

data Expr
  = EVar String
  | EAbs String Expr
  | EApp Expr Expr

instance Pretty Expr where
  pp = \case
    EVar x     -> pp x
    EAbs x e   -> assocR 0 $ "λ" +> x +> "." ~> R e
    EApp e1 e2 -> assocL 9 $ L e1 ~> R e2

e1 = EAbs "x" $ EAbs "y" $ EApp (EApp (EVar "x") (EVar "y"))
                                (EApp (EVar "x") (EVar "y"))