{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE ViewPatterns #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE OverloadedStrings #-}

module TestDocs where

import Prelude ()
import Prelude.Compat

import Control.Arrow (first)
import Control.Monad.IO.Class (liftIO)

import Data.Foldable
import Data.Maybe (fromMaybe)
import Data.Monoid
import Data.Text (Text)
import qualified Data.Text as T
import Data.Time.Clock (getCurrentTime)
import Data.Version (Version(..))
import System.Exit

import qualified Language.PureScript as P
import qualified Language.PureScript.Docs as Docs
import Language.PureScript.Docs.AsMarkdown (codeToString)
import qualified Language.PureScript.Publish as Publish
import qualified Language.PureScript.Publish.ErrorsWarnings as Publish

import Web.Bower.PackageMeta (parsePackageName)

import TestUtils

publishOpts :: Publish.PublishOptions
publishOpts = Publish.defaultPublishOptions
  { Publish.publishGetVersion = return testVersion
  , Publish.publishGetTagTime = const (liftIO getCurrentTime)
  , Publish.publishWorkingTreeDirty = return ()
  }
  where testVersion = ("v999.0.0", Version [999,0,0] [])

main :: IO ()
main = pushd "examples/docs" $ do
  res <- Publish.preparePackage "bower.json" "resolutions.json" publishOpts
  case res of
    Left e -> Publish.printErrorToStdout e >> exitFailure
    Right pkg@Docs.Package{..} ->
      forM_ testCases $ \(P.moduleNameFromString -> mn, pragmas) ->
        let mdl = takeJust ("module not found in docs: " ++ T.unpack (P.runModuleName mn))
                          (find ((==) mn . Docs.modName) pkgModules)
            linksCtx = Docs.getLinksContext pkg
        in forM_ pragmas (\a -> runAssertionIO a linksCtx mdl)


takeJust :: String -> Maybe a -> a
takeJust msg = fromMaybe (error msg)

data Assertion
  -- | Assert that a particular declaration is documented with the given
  -- children
  = ShouldBeDocumented P.ModuleName Text [Text]
  -- | Assert that a particular declaration is not documented
  | ShouldNotBeDocumented P.ModuleName Text
  -- | Assert that a particular declaration exists, but without a particular
  -- child.
  | ChildShouldNotBeDocumented P.ModuleName Text Text
  -- | Assert that a particular declaration has a particular type class
  -- constraint.
  | ShouldBeConstrained P.ModuleName Text Text
  -- | Assert that a particular typeclass declaration has a functional
  -- dependency list.
  | ShouldHaveFunDeps P.ModuleName Text [([Text],[Text])]
  -- | Assert that a particular value declaration exists, and its type
  -- satisfies the given predicate.
  | ValueShouldHaveTypeSignature P.ModuleName Text (ShowFn (P.Type -> Bool))
  -- | Assert that a particular type alias exists, and its corresponding
  -- type, when rendered, matches a given string exactly
  -- fields: module, type synonym name, expected type
  | TypeSynonymShouldRenderAs P.ModuleName Text Text
  -- | Assert that a documented declaration includes a documentation comment
  -- containing a particular string
  | ShouldHaveDocComment P.ModuleName Text Text
  -- | Assert that there should be some declarations re-exported from a
  -- particular module in a particular package.
  | ShouldHaveReExport (Docs.InPackage P.ModuleName)
  -- | Assert that a link to some specific declaration exists within the
  -- rendered code for a declaration. Fields are: local module, local
  -- declaration title, title of linked declaration, namespace of linked
  -- declaration, destination of link.
  | ShouldHaveLink P.ModuleName Text Text Docs.Namespace Docs.LinkLocation
  deriving (Show)

newtype ShowFn a = ShowFn a

instance Show (ShowFn a) where
  show _ = "<function>"

data AssertionFailure
  -- | A declaration was not documented, but should have been
  = NotDocumented P.ModuleName Text
  -- | The expected list of child declarations did not match the actual list
  | ChildrenNotDocumented P.ModuleName Text [Text]
  -- | A declaration was documented, but should not have been
  | Documented P.ModuleName Text
  -- | A child declaration was documented, but should not have been
  | ChildDocumented P.ModuleName Text Text
  -- | A constraint was missing.
  | ConstraintMissing P.ModuleName Text Text
  -- | A functional dependency was missing.
  | FunDepMissing P.ModuleName Text [([Text], [Text])]
  -- | A declaration had the wrong "type" (ie, value, type, type class)
  -- Fields: declaration title, expected "type", actual "type".
  | WrongDeclarationType P.ModuleName Text Text Text
  -- | A value declaration had the wrong type (in the sense of "type
  -- checking"), eg, because the inferred type was used when the explicit type
  -- should have been.
  -- Fields: module name, declaration name, actual type.
  | ValueDeclarationWrongType P.ModuleName Text P.Type
  -- | A Type synonym has been rendered in an unexpected format
  -- Fields: module name, declaration name, expected rendering, actual rendering
  | TypeSynonymMismatch P.ModuleName Text Text Text
  -- | A doc comment was not found or did not match what was expected
  -- Fields: module name, expected substring, actual comments
  | DocCommentMissing P.ModuleName Text (Maybe Text)
  -- | A module was missing re-exports from a particular module.
  -- Fields: module name, expected re-export, actual re-exports.
  | ReExportMissing P.ModuleName (Docs.InPackage P.ModuleName) [Docs.InPackage P.ModuleName]
  -- | Expected to find some other declaration mentioned in this declaration's
  -- rendered code, but did not find anything.
  -- Fields: module name, declaration title, title of declaration which was
  -- expected but not found in.
  | LinkedDeclarationMissing P.ModuleName Text Text
  -- | Expected one link location for a declaration mentioned in some other
  -- declaration's rendered code, but found a different one. Fields: module
  -- name, title of the local declaration which links to some other
  -- declaration, title of the linked declaration, expected location, actual
  -- location.
  | BadLinkLocation P.ModuleName Text Text Docs.LinkLocation Docs.LinkLocation
  deriving (Show)

data AssertionResult
  = Pass
  | Fail AssertionFailure
  deriving (Show)

runAssertion :: Assertion -> Docs.LinksContext -> Docs.Module -> AssertionResult
runAssertion assertion linksCtx Docs.Module{..} =
  case assertion of
    ShouldBeDocumented mn decl children ->
      case findChildren decl (declarationsFor mn) of
        Nothing ->
          Fail (NotDocumented mn decl)
        Just actualChildren ->
          if children == actualChildren
            then Pass
            else Fail (ChildrenNotDocumented mn decl actualChildren)

    ShouldNotBeDocumented mn decl ->
      case findChildren decl (declarationsFor mn) of
        Just _ ->
          Fail (Documented mn decl)
        Nothing ->
          Pass

    ChildShouldNotBeDocumented mn decl child ->
      case findChildren decl (declarationsFor mn) of
        Just children ->
          if child `elem` children
            then Fail (ChildDocumented mn decl child)
            else Pass
        Nothing ->
          Fail (NotDocumented mn decl)

    ShouldBeConstrained mn decl tyClass ->
      findDecl mn decl $ \Docs.Declaration{..} ->
        case declInfo of
          Docs.ValueDeclaration ty ->
            if checkConstrained ty tyClass
              then Pass
              else Fail (ConstraintMissing mn decl tyClass)
          _ ->
            Fail (WrongDeclarationType mn decl "value"
                   (Docs.declInfoToString declInfo))

    ShouldHaveFunDeps mn decl fds ->
      findDecl mn decl $ \Docs.Declaration{..} ->
        case declInfo of
          Docs.TypeClassDeclaration _ _ fundeps ->
            if fundeps == fds
              then Pass
              else Fail (FunDepMissing mn decl fds)
          _ ->
            Fail (WrongDeclarationType mn decl "value"
                   (Docs.declInfoToString declInfo))

    ValueShouldHaveTypeSignature mn decl (ShowFn tyPredicate) ->
      findDecl mn decl $ \Docs.Declaration{..} ->
        case declInfo of
          Docs.ValueDeclaration ty ->
            if tyPredicate ty
              then Pass
              else Fail
                (ValueDeclarationWrongType mn decl ty)
          _ ->
            Fail (WrongDeclarationType mn decl "value"
                   (Docs.declInfoToString declInfo))

    TypeSynonymShouldRenderAs mn decl expected ->
      findDecl mn decl $ \Docs.Declaration{..} ->
        case declInfo of
          Docs.TypeSynonymDeclaration [] ty ->
            let actual = codeToString (Docs.renderType ty) in
            if actual == expected
               then Pass
               else Fail (TypeSynonymMismatch mn decl expected actual)
          _ ->
            Fail (WrongDeclarationType mn decl "synonym"
                  (Docs.declInfoToString declInfo))

    ShouldHaveDocComment mn decl expected ->
      findDecl mn decl $ \Docs.Declaration{..} ->
        if maybe False (expected `T.isInfixOf`) declComments
          then Pass
          else Fail (DocCommentMissing mn decl declComments)

    ShouldHaveReExport reExp ->
      let
        reExps = map fst modReExports
      in
        if reExp `elem` reExps
          then Pass
          else Fail (ReExportMissing modName reExp reExps)

    ShouldHaveLink mn decl destTitle destNs expectedLoc ->
      findDecl mn decl $ \decl' ->
        let
          rendered = Docs.renderDeclaration decl'
        in
          case extract rendered destNs destTitle of
            Just (Docs.linkLocation -> actualLoc) ->
              if expectedLoc == actualLoc
                then Pass
                else Fail (BadLinkLocation mn decl destTitle expectedLoc actualLoc)
            Nothing ->
              Fail (LinkedDeclarationMissing mn decl destTitle)

  where
  declarationsFor mn =
    if mn == modName
      then modDeclarations
      else fromMaybe [] (lookup mn (map (first Docs.ignorePackage) modReExports))

  findChildren title =
    fmap childrenTitles . find ((==) title . Docs.declTitle)

  findDecl mn title f =
      case find ((==) title . Docs.declTitle) (declarationsFor mn) of
        Nothing ->
          Fail (NotDocumented mn title)
        Just decl ->
          f decl

  childrenTitles = map Docs.cdeclTitle . Docs.declChildren

  extract :: Docs.RenderedCode -> Docs.Namespace -> Text -> Maybe Docs.DocLink
  extract rc ns title = getFirst (Docs.outputWith (First . go) rc) >>= getLink
    where
      getLink =
        Docs.getLink linksCtx (P.moduleNameFromString "$DocsTest") ns title
      go = \case
        Docs.Symbol ns' title' (Docs.Link containingMod)
          | ns' == ns && title' == title -> Just containingMod
        _ ->
          Nothing

checkConstrained :: P.Type -> Text -> Bool
checkConstrained ty tyClass =
  case ty of
    P.ConstrainedType c ty'
      | matches tyClass c -> True
      | otherwise -> checkConstrained ty' tyClass
    P.ForAll _ ty' _ ->
      checkConstrained ty' tyClass
    _ ->
      False
  where
  matches className =
    (==) className . P.runProperName . P.disqualify . P.constraintClass

runAssertionIO :: Assertion -> Docs.LinksContext -> Docs.Module -> IO ()
runAssertionIO assertion linksCtx mdl = do
  putStrLn ("In " ++ T.unpack (P.runModuleName (Docs.modName mdl)) ++ ": " ++ show assertion)
  case runAssertion assertion linksCtx mdl of
    Pass -> pure ()
    Fail reason -> do
      putStrLn ("Failed: " <> show reason)
      exitFailure

testCases :: [(Text, [Assertion])]
testCases =
  [ ("Example",
      [ -- From dependencies
        ShouldBeDocumented    (n "Prelude") "Unit" []
      , ShouldNotBeDocumented (n "Prelude") "unit"

        -- From local files
      , ShouldBeDocumented    (n "Example2") "one" []
      , ShouldNotBeDocumented (n "Example2") "two"

        -- Re-exports
      , ShouldHaveReExport (Docs.FromDep (pkg "purescript-prelude") (n "Prelude"))
      , ShouldHaveReExport (Docs.Local (n "Example2"))
      ])

  , ("Example2",
      [ ShouldBeDocumented (n "Example2") "one" []
      , ShouldBeDocumented (n "Example2") "two" []

      , ShouldHaveLink (n "Example2") "one" "Int" Docs.TypeLevel (Docs.BuiltinModule (n "Prim"))
      ])

  , ("UTF8",
      [ ShouldBeDocumented (n "UTF8") "thing" []
      ])

  , ("Transitive1",
      [ ShouldBeDocumented (n "Transitive2") "transitive3" []
      ])

  , ("NotAllCtors",
      [ ShouldBeDocumented         (n "Prelude") "Boolean2" ["True"]
      , ChildShouldNotBeDocumented (n "Prelude") "Boolean2" "False"
      ])

  , ("DuplicateNames",
      [ ShouldBeDocumented    (n "Prelude")        "Unit" []
      , ShouldBeDocumented    (n "DuplicateNames") "unit" []
      , ShouldNotBeDocumented (n "Prelude")        "unit"
      ])

  , ("MultiVirtual",
      [ ShouldBeDocumented (n "MultiVirtual1") "foo" []
      , ShouldBeDocumented (n "MultiVirtual2") "bar" []
      , ShouldBeDocumented (n "MultiVirtual2") "baz" []
      ])

  , ("Clash",
      [ ShouldBeDocumented (n "Clash1") "value" []
      , ShouldBeDocumented (n "Clash1") "Type" []
      , ShouldBeDocumented (n "Clash1") "TypeClass" ["typeClassMember"]
      ])

  , ("SolitaryTypeClassMember",
      [ ShouldBeDocumented    (n "SomeTypeClass") "member" []
      , ShouldNotBeDocumented (n "SomeTypeClass") "SomeClass"
      , ShouldBeConstrained   (n "SomeTypeClass") "member" "SomeClass"
      ])

  , ("ReExportedTypeClass",
      [ ShouldBeDocumented (n "SomeTypeClass") "SomeClass" ["member"]
      ])

  , ("TypeClassWithoutMembers",
      [ ShouldBeDocumented         (n "TypeClassWithoutMembersIntermediate") "SomeClass" []
      , ChildShouldNotBeDocumented (n "TypeClassWithoutMembersIntermediate") "SomeClass" "member"
      ])

  , ("TypeClassWithFunDeps",
      [ ShouldHaveFunDeps          (n "TypeClassWithFunDeps") "TypeClassWithFunDeps" [(["a","b"], ["c"]), (["c"], ["d","e"])]
      ])

  , ("NewOperators",
      [ ShouldBeDocumented (n "NewOperators2") "(>>>)" []
      ])

  , ("ExplicitTypeSignatures",
      [ ValueShouldHaveTypeSignature (n "ExplicitTypeSignatures") "explicit" (ShowFn (hasTypeVar "something"))
      , ValueShouldHaveTypeSignature (n "ExplicitTypeSignatures") "anInt"    (ShowFn (P.tyInt ==))
      , ValueShouldHaveTypeSignature (n "ExplicitTypeSignatures") "aNumber"  (ShowFn (P.tyNumber ==))
      ])

  , ("ConstrainedArgument",
      [ TypeSynonymShouldRenderAs (n "ConstrainedArgument") "WithoutArgs" "forall a. (Partial => a) -> a"
      , TypeSynonymShouldRenderAs (n "ConstrainedArgument") "WithArgs" "forall a. (Foo a => a) -> a"
      , TypeSynonymShouldRenderAs (n "ConstrainedArgument") "MultiWithoutArgs" "forall a. (Partial => Partial => a) -> a"
      , TypeSynonymShouldRenderAs (n "ConstrainedArgument") "MultiWithArgs" "forall a b. (Foo a => Foo b => a) -> a"
      ])

  , ("TypeOpAliases",
      [ ValueShouldHaveTypeSignature (n "TypeOpAliases") "test1" (renderedType "forall a b. a ~> b")
      , ValueShouldHaveTypeSignature (n "TypeOpAliases") "test2" (renderedType "forall a b c. a ~> b ~> c")
      , ValueShouldHaveTypeSignature (n "TypeOpAliases") "test3" (renderedType "forall a b c d. a ~> (b ~> c) ~> d")
      , ValueShouldHaveTypeSignature (n "TypeOpAliases") "test4" (renderedType "forall a b c d. ((a ~> b) ~> c) ~> d")
      , ValueShouldHaveTypeSignature (n "TypeOpAliases") "third" (renderedType "forall a b c. a × b × c -> c")
      ])

  , ("DocComments",
      [ ShouldHaveDocComment (n "DocComments") "example" "    example == 0"
      ])

  , ("TypeLevelString",
      [ ShouldBeDocumented (n "TypeLevelString") "Foo" ["fooBar"]
      ])

  , ("Desugar",
      [ ValueShouldHaveTypeSignature (n "Desugar") "test" (renderedType "forall a b. X (a -> b) a -> b")
      ])

  , ("ChildDeclOrder",
      [ ShouldBeDocumented (n "ChildDeclOrder") "Two" ["First", "Second", "showTwo", "fooTwo"]
      , ShouldBeDocumented (n "ChildDeclOrder") "Foo" ["foo1", "foo2", "fooTwo", "fooInt"]
      ])
  ]

  where
  n = P.moduleNameFromString
  pkg str = let Right p = parsePackageName str in p

  hasTypeVar varName =
    getAny . P.everythingOnTypes (<>) (Any . isVar varName)

  isVar varName (P.TypeVar name) | varName == T.unpack name = True
  isVar _ _ = False

  renderedType expected =
    ShowFn $ \ty -> codeToString (Docs.renderType ty) == expected