{-# LANGUAGE DataKinds #-}
module DiffSummarySpec where

import Category
import Data.Functor.Both
import Data.List (partition)
import Data.RandomWalkSimilarity
import Data.Record
import Diff
import Diff.Arbitrary
import DiffSummary
import Info
import Interpreter
import Patch
import Prologue
import Source
import Syntax
import Term
import Term.Arbitrary
import Test.Hspec
import Test.Hspec.QuickCheck

arrayInfo :: Record '[Category, Range]
arrayInfo = ArrayLiteral .: Range 0 3 .: RNil

literalInfo :: Record '[Category, Range]
literalInfo = StringLiteral .: Range 1 2 .: RNil

testDiff :: Diff Text (Record '[Category, Range])
testDiff = free $ Free (pure arrayInfo :< Indexed [ free $ Pure (Insert (cofree $ literalInfo :< Leaf "a")) ])

testSummary :: DiffSummary DiffInfo
testSummary = DiffSummary { patch = Insert (LeafInfo "string" "a"), parentAnnotation = Nothing }

replacementSummary :: DiffSummary DiffInfo
replacementSummary = DiffSummary { patch = Replace (LeafInfo "string" "a") (LeafInfo "symbol" "b"), parentAnnotation = Just (Info.FunctionCall, "foo") }

sources :: Both (Source Char)
sources = both (fromText "[]") (fromText "[a]")

spec :: Spec
spec = parallel $ do
  describe "diffSummaries" $ do
    it "outputs a diff summary" $ do
      diffSummaries sources testDiff `shouldBe` [ DiffSummary { patch = Insert (LeafInfo "string" "a"), parentAnnotation = Nothing } ]

    prop "equal terms produce identity diffs" $
      \ a -> let term = defaultFeatureVectorDecorator (category . headF) (toTerm (a :: ArbitraryTerm Text (Record '[Category, Range]))) in
        diffSummaries sources (diffTerms wrap (==) diffCost term term) `shouldBe` []

  describe "annotatedSummaries" $ do
    it "should print adds" $
      annotatedSummaries testSummary `shouldBe` ["Added the 'a' string"]
    it "prints a replacement" $ do
      annotatedSummaries replacementSummary `shouldBe` ["Replaced the 'a' string with the 'b' symbol in the foo function call"]
  describe "DiffInfo" $ do
    prop "patches in summaries match the patches in diffs" $
      \a -> let
        diff = (toDiff (a :: ArbitraryDiff Text (Record '[Category, Cost, Range])))
        summaries = diffSummaries sources diff
        patches = toList diff
        in
          case (partition isBranchNode (patch <$> summaries), partition isIndexedOrFixed patches) of
            ((branchPatches, otherPatches), (branchDiffPatches, otherDiffPatches)) ->
              (() <$ branchPatches, () <$ otherPatches) `shouldBe` (() <$ branchDiffPatches, () <$ otherDiffPatches)
    prop "generates one LeafInfo for each child in an arbitrary branch patch" $
      \a -> let
        diff = (toDiff (a :: ArbitraryDiff Text (Record '[Category, Range])))
        diffInfoPatches = patch <$> diffSummaries sources diff
        syntaxPatches = toList diff
        extractLeaves :: DiffInfo -> [DiffInfo]
        extractLeaves (BranchInfo children _ _) = join $ extractLeaves <$> children
        extractLeaves leaf = [ leaf ]

        extractDiffLeaves :: Term Text (Record '[Category, Range]) -> [ Term Text (Record '[Category, Range]) ]
        extractDiffLeaves term = case unwrap term of
          (Indexed children) -> join $ extractDiffLeaves <$> children
          (Fixed children) -> join $ extractDiffLeaves <$> children
          Commented children leaf -> children <> maybeToList leaf >>= extractDiffLeaves
          _ -> [ term ]
        in
          case (partition isBranchNode diffInfoPatches, partition isIndexedOrFixed syntaxPatches) of
            ((branchPatches, _), (diffPatches, _)) ->
              let listOfLeaves = foldMap extractLeaves (join $ toList <$> branchPatches)
                  listOfDiffLeaves = foldMap extractDiffLeaves (diffPatches >>= toList)
               in
                length listOfLeaves `shouldBe` length listOfDiffLeaves

isIndexedOrFixed :: Patch (Term a annotation) -> Bool
isIndexedOrFixed = any (isIndexedOrFixed' . unwrap)

isIndexedOrFixed' :: Syntax a f -> Bool
isIndexedOrFixed' syntax = case syntax of
  (Indexed _) -> True
  (Fixed _) -> True
  _ -> False

isBranchInfo :: DiffInfo -> Bool
isBranchInfo info = case info of
  (BranchInfo _ _ _) -> True
  _ -> False

isBranchNode :: Patch DiffInfo -> Bool
isBranchNode = any isBranchInfo