{-# LANGUAGE OverloadedStrings #-}
module Language.GLSL.GLSLSpec where

import           Test.Hspec                       (Spec, describe, it)

import           Control.Applicative              (liftA2)
import           Data.Attoparsec.ByteString.Char8 (decimal)
import qualified Language.GLSL.AST                as GLSL
import qualified Language.GLSL.PrettyPrint        as GLSL
import           Test.GLSL                        (Transform, shouldTransformTo,
                                                   with)


newtype TestAnnot = TestAnnot Int

instance GLSL.Annot TestAnnot where
  parseAnnot = "// " >> TestAnnot <$> decimal >>= ("\n" >>) . pure
  ppAnnot (TestAnnot n) = Just $ GLSL.ppInt n


testAddAnnot :: [Int] -> Transform () TestAnnot
testAddAnnot = zipWith (fmap . setAnnot)
  where
    setAnnot i () = TestAnnot i


testJoinAnnot :: Transform () (TestAnnot, TestAnnot)
testJoinAnnot ss =
    let ss1 = testAddAnnot [0..3] ss
        ss2 = testAddAnnot (reverse [0..3]) ss
    in (zipWith . liftA2) (,) ss1 ss2


spec :: Spec
spec = do
    describe "fmap" $ do
        it "should add annotations" $
            [ "float t1 = 0;"
            , "float t2 = 0.0;"
            , "float t3 = (t2+1.1);"
            , "float t4 = (t3+vf1);"
            ] `with` testAddAnnot [0..3]
            `shouldTransformTo`
            [ "// 0"
            , "float t1 = 0;"
            , "// 1"
            , "float t2 = 0.0;"
            , "// 2"
            , "float t3 = (t2+1.1);"
            , "// 3"
            , "float t4 = (t3+vf1);"
            ]

    describe "liftA2" $ do
        it "should join annotations" $
            [ "float t1 = 0;"
            , "float t2 = 0.0;"
            , "float t3 = (t2+1.1);"
            , "float t4 = (t3+vf1);"
            ] `with` testJoinAnnot
            `shouldTransformTo`
            [ "// (0, 3)"
            , "float t1 = 0;"
            , "// (1, 2)"
            , "float t2 = 0.0;"
            , "// (2, 1)"
            , "float t3 = (t2+1.1);"
            , "// (3, 0)"
            , "float t4 = (t3+vf1);"
            ]