{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TupleSections #-}
-- | Test suite for Stack.Dot
module Stack.DotSpec where

import           Data.Functor.Identity
import           Data.List ((\\))
import qualified Data.Map as Map
import qualified Data.Set as Set
import           Distribution.License (License (BSD3))
import qualified RIO.Text as T
import           Stack.Prelude hiding (pkgName)
import           Test.Hspec
import           Test.Hspec.QuickCheck (prop)
import           Test.QuickCheck (forAll,choose,Gen)

import           Stack.Dot

dummyPayload :: DotPayload
dummyPayload = DotPayload (parseVersion "0.0.0.0") (Just (Right BSD3)) Nothing

spec :: Spec
spec = do
  let graph =
         Map.mapKeys pkgName
       . fmap (\p -> (Set.map pkgName p, dummyPayload))
       . Map.fromList $ [("one",Set.fromList ["base","free"])
                        ,("two",Set.fromList ["base","free","mtl","transformers","one"])
                        ]
  describe "Stack.Dot" $ do
    it "does nothing if depth is 0" $
      resolveDependencies (Just 0) graph stubLoader `shouldBe` return graph

    it "with depth 1, more dependencies are resolved" $ do
      let graph' = Map.insert (pkgName "cycle")
                              (Set.singleton (pkgName "cycle"), dummyPayload)
                              graph
          resultGraph = runIdentity (resolveDependencies (Just 0) graph stubLoader)
          resultGraph' = runIdentity (resolveDependencies (Just 1) graph' stubLoader)
      Map.size resultGraph < Map.size resultGraph' `shouldBe` True

    it "cycles are ignored" $ do
       let graph' = Map.insert (pkgName "cycle")
                               (Set.singleton (pkgName "cycle"), dummyPayload)
                                graph
           resultGraph = resolveDependencies Nothing graph stubLoader
           resultGraph' = resolveDependencies Nothing graph' stubLoader
       fmap Map.size resultGraph' `shouldBe` fmap ((+1) . Map.size) resultGraph

    let graphElem e = Set.member e . Set.unions . Map.elems

    prop "requested packages are pruned" $ do
      let resolvedGraph = runIdentity (resolveDependencies Nothing graph stubLoader)
          allPackages g = Map.keysSet g `Set.union` foldMap fst g
      forAll (sublistOf (Set.toList (allPackages resolvedGraph))) $ \toPrune ->
        let pruned = pruneGraph [pkgName "one", pkgName "two"] toPrune resolvedGraph
        in Set.null (allPackages pruned `Set.intersection` Set.fromList toPrune)

    prop "pruning removes orhpans" $ do
      let resolvedGraph = runIdentity (resolveDependencies Nothing graph stubLoader)
          allPackages g = Map.keysSet g `Set.union` foldMap fst g
          orphans g = Map.filterWithKey (\k _ -> not (graphElem k g)) g
      forAll (sublistOf (Set.toList (allPackages resolvedGraph))) $ \toPrune ->
        let pruned = pruneGraph [pkgName "one", pkgName "two"] toPrune resolvedGraph
        in null (Map.keys (orphans (fmap fst pruned)) \\ [pkgName "one", pkgName "two"])

{- Helper functions below -}
-- Backport from QuickCheck 2.8 to 2.7.6
sublistOf :: [a] -> Gen [a]
sublistOf = filterM (\_ -> choose (False, True))

-- Unsafe internal helper to create a package name
pkgName :: Text -> PackageName
pkgName = fromMaybe failure . parsePackageName . T.unpack
  where
   failure = error "Internal error during package name creation in DotSpec.pkgName"

-- Stub, simulates the function to load package dependecies
stubLoader :: PackageName -> Identity (Set PackageName, DotPayload)
stubLoader name = return . (, dummyPayload) . Set.fromList . map pkgName $ case show name of
  "StateVar" -> ["stm","transformers"]
  "array" -> []
  "bifunctors" -> ["semigroupoids","semigroups","tagged"]
  "binary" -> ["array","bytestring","containers"]
  "bytestring" -> ["deepseq","ghc-prim","integer-gmp"]
  "comonad" -> ["containers","contravariant","distributive"
               ,"semigroups","tagged","transformers","transformers-compat"
               ]
  "cont" -> ["StateVar","semigroups","transformers","transformers-compat","void"]
  "containers" -> ["array","deepseq","ghc-prim"]
  "deepseq" -> ["array"]
  "distributive" -> ["ghc-prim","tagged","transformers","transformers-compat"]
  "free" -> ["bifunctors","comonad","distributive","mtl"
            ,"prelude-extras","profunctors","semigroupoids"
            ,"semigroups","template-haskell","transformers"
            ]
  "ghc" -> []
  "hashable" -> ["bytestring","ghc-prim","integer-gmp","text"]
  "integer" -> []
  "mtl" -> ["transformers"]
  "nats" -> []
  "one" -> ["free"]
  "prelude" -> []
  "profunctors" -> ["comonad","distributive","semigroupoids","tagged","transformers"]
  "semigroupoids" -> ["comonad","containers","contravariant","distributive"
                     ,"semigroups","transformers","transformers-compat"
                     ]
  "semigroups" -> ["bytestring","containers","deepseq","hashable"
                  ,"nats","text","unordered-containers"
                  ]
  "stm" -> ["array"]
  "tagged" -> ["template-haskell"]
  "template" -> []
  "text" -> ["array","binary","bytestring","deepseq","ghc-prim","integer-gmp"]
  "transformers" -> []
  "two" -> ["free","mtl","one","transformers"]
  "unordered" -> ["deepseq","hashable"]
  "void" -> ["ghc-prim","hashable","semigroups"]
  _ -> []