{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeApplications  #-}
{-# OPTIONS_GHC -fno-warn-deprecations #-}
{-|
Module      :  HsLua.CoreTests
Copyright   :  © 2017-2021 Albert Krewinkel
License     :  MIT

Maintainer  :  Albert Krewinkel <tarleb+hslua@zeitkraut.de>
Stability   :  stable
Portability :  portable

Tests for Lua C API-like functions.
-}
module HsLua.CoreTests (tests) where

import Prelude hiding (compare)

import Data.ByteString (append)
import Data.Maybe (fromMaybe)
import Lua.Lib (luaopen_debug)
import HsLua.Core as Lua
import HsLua.Core.Types (toType)
import Lua.Arbitrary ()
import Test.Tasty.HsLua ( (?:), (=:), shouldBeErrorMessageOf, shouldBeResultOf
                        , shouldHoldForResultOf, pushLuaExpr )
import Test.QuickCheck (Property, (.&&.))
import Test.QuickCheck.Monadic (assert, monadicIO)
import Test.Tasty (TestTree, testGroup)
import Test.Tasty.HUnit (assertBool, assertEqual, testCase)
import Test.Tasty.QuickCheck (testProperty)

import qualified Prelude
import qualified Data.ByteString as B
import qualified HsLua.Core.AuxiliaryTests
import qualified HsLua.Core.ErrorTests
import qualified HsLua.Core.RunTests
import qualified HsLua.Core.UnsafeTests
import qualified HsLua.Core.UserdataTests
import qualified Foreign.Marshal as Foreign
import qualified Foreign.Ptr as Foreign
import qualified Test.QuickCheck.Monadic as QCMonadic


-- | Specifications for Attributes parsing functions.
tests :: TestTree
tests = testGroup "Core module"
  [ HsLua.Core.ErrorTests.tests
  , HsLua.Core.AuxiliaryTests.tests
  , testGroup "copy"
    [ "copies stack elements using positive indices" ?: do
        pushLuaExpr @Lua.Exception "5, 4, 3, 2, 1"
        copy 4 3
        rawequal (nthBottom 4) (nthBottom 3)

    , "copies stack elements using negative indices" ?: do
        pushLuaExpr @Lua.Exception "5, 4, 3, 2, 1"
        copy (-1) (-3)
        rawequal (-1) (-3)
    ]

  , testGroup "insert"
    [ "inserts stack elements using positive indices" ?: do
        pushLuaExpr @Lua.Exception "1, 2, 3, 4, 5, 6, 7, 8, 9"
        insert 4
        movedEl <- tointeger (nthBottom 4)
        newTop <- tointeger (nth 1)
        return (movedEl == Just 9 && newTop == Just 8)

    , "inserts stack elements using negative indices" ?: do
        pushLuaExpr @Lua.Exception "1, 2, 3, 4, 5, 6, 7, 8, 9"
        insert (-6)
        movedEl <- tointeger (nth 6)
        newTop <- tointeger (nth 1)
        return (movedEl == Just 9 && newTop == Just 8)
    ]

  , testCase "absindex" . run @Lua.Exception $ do
      pushLuaExpr "1, 2, 3, 4"
      liftIO . assertEqual "index from bottom doesn't change" (nthBottom 3)
        =<< absindex (nthBottom 3)
      liftIO . assertEqual "index from top is made absolute" (nthBottom 2)
        =<< absindex (nth 3)
      liftIO . assertEqual "pseudo indices are left unchanged" registryindex
        =<< absindex registryindex

  , "gettable gets a table value" =:
    Just 13.37 `shouldBeResultOf` do
      pushLuaExpr @Lua.Exception "{sum = 13.37}"
      pushstring "sum"
      gettable (nth 2)
      tonumber top

  , "rawlen gives the length of a list" =:
    7 `shouldBeResultOf` do
      pushLuaExpr @Lua.Exception "{1, 1, 2, 3, 5, 8, 13}"
      rawlen top

  , testGroup "Type checking"
    [ "isfunction" ?: do
        pushLuaExpr @Lua.Exception "function () print \"hi!\" end"
        isfunction (-1)

    , "isnil" ?: pushLuaExpr @Lua.Exception "nil" *> isnil (-1)

    , "isnone" ?: isnone 5 -- stack index 5 does not exist

    , "isnoneornil" ?: do
        pushLuaExpr @Lua.Exception "nil"
        (&&) <$> isnoneornil 5 <*> isnoneornil (-1)
    ]

  , testCase "CFunction handling" . run $ do
      pushcfunction luaopen_debug
      liftIO . assertBool "not recognized as CFunction" =<< iscfunction (-1)
      liftIO . assertEqual "CFunction changed after receiving it from the stack"
        (Just luaopen_debug) =<< tocfunction (-1)

  , testGroup "getting values"
    [ testGroup "tointeger"
      [ "tointeger returns numbers verbatim" =:
        Just 149 `shouldBeResultOf` do
          pushLuaExpr @Lua.Exception "149"
          tointeger (-1)

      , "tointeger accepts strings coercible to integers" =:
        Just 451 `shouldBeResultOf` do
          pushLuaExpr @Lua.Exception "'451'"
          tointeger (-1)

      , "tointeger returns Nothing when given a boolean" =:
        Nothing `shouldBeResultOf` do
          pushLuaExpr @Lua.Exception "true"
          tointeger (-1)
      ]

    , testGroup "tonumber"
      [ "tonumber returns numbers verbatim" =:
        Just 14.9 `shouldBeResultOf` do
          pushLuaExpr @Lua.Exception "14.9"
          tonumber (-1)

      , "tonumber accepts strings as numbers" =:
        Just 42.23 `shouldBeResultOf` do
          pushLuaExpr @Lua.Exception "'42.23'"
          tonumber (-1)

      , "tonumber returns Nothing when given a boolean" =:
        Nothing `shouldBeResultOf` do
          pushLuaExpr @Lua.Exception "true"
          tonumber (-1)
      ]

    , testGroup "tostring"
      [ "get a string" =:
        Just "a string" `shouldBeResultOf` do
          pushLuaExpr @Lua.Exception "'a string'"
          tostring top

      , "get a number as string" =:
        Just "17.0" `shouldBeResultOf` do
          pushnumber 17
          tostring top

      , "fail when looking at a boolean" =:
        Nothing `shouldBeResultOf` do
          pushboolean True
          tostring top
      ]
    ]

  , "setting and getting a global works" =:
    Just "Moin" `shouldBeResultOf` do
      pushLuaExpr @Lua.Exception "{'Moin', Hello = 'World'}"
      setglobal "hamburg"

      -- get first field
      getglobal "hamburg"
      rawgeti top 1 -- first field
      tostring top

  , testGroup "get functions (Lua to stack)"
    [ "unicode characters in field name are ok" =:
      True `shouldBeResultOf` do
        pushLuaExpr @Lua.Exception "{['\xE2\x9A\x94'] = true}"
        getfield top "⚔"
        toboolean top
    ]

  , "setting and getting a global works" =:
    Just "Fisch" `shouldBeResultOf` do
      newhsuserdata ()
      pushstring "Fisch"
      setuservalue (nth 2)

      -- get uservalue again
      TypeString <- getuservalue top
      tostring top

  , "can push and receive a thread" ?: do
      luaSt <- state
      isMain <- pushthread
      liftIO (assertBool "pushing the main thread should return True" isMain)
      luaSt' <- tothread top
      return (Just luaSt == luaSt')

  , "different threads are not equal in Haskell" ?:
    liftIO
      (do luaSt1 <- newstate
          luaSt2 <- newstate
          let result = luaSt1 /= luaSt2
          close luaSt1
          close luaSt2
          return result)

  , testGroup "thread status"
    [ "OK is base thread status" =:
      OK `shouldBeResultOf` status

    , "Yield is the thread status after yielding" =:
      Yield `shouldBeResultOf` do
        openlibs
        getglobal "coroutine"
        getfield top "resume"
        pushLuaExpr @Lua.Exception "coroutine.create(function() coroutine.yield(9) end)"
        contThread <- fromMaybe (Prelude.error "not a thread at top of stack")
                      <$> tothread top
        call 1 0
        liftIO $ runWith contThread status
    ]

  , testGroup "miscellaneous functions"
    [ testGroup "pushglobaltable"
      [ "globals are fields in global table" =:
        "yep" `shouldBeResultOf` do
          pushstring "yep"
          setglobal "TEST"
          pushglobaltable
          getfield top "TEST"
          tostring' top
      ]
    ]

  , testGroup "auxiliary functions"
    [ testGroup "tostring'"
      [ "integers are converted in base10" =:
        "5" `shouldBeResultOf` do
          pushinteger 5
          tostring' top

      , "a nil value is converted into the literal string 'nil'" =:
        "nil" `shouldBeResultOf` do
          pushnil
          tostring' top

      , "strings are returned verbatim" =:
        "Hello\NULWorld" `shouldBeResultOf` do
          pushstring "Hello\NULWorld"
          tostring' top

      , "string for userdata shows the pointer value" =:
        ("userdata: " `B.isPrefixOf`) `shouldHoldForResultOf` do
          l <- state
          liftIO . Foreign.alloca $ \ptr ->
            runWith l (pushlightuserdata (ptr :: Foreign.Ptr Int))
          tostring' top

      , "string is also pushed to the stack" =:
        Just "true" `shouldBeResultOf` do
          pushboolean True
          _ <- tostring' top
          tostring top  -- note the use of tostring instead of tostring'

      , "errors during metamethod execution are caught" =:
        "'__tostring' must return a string" `shouldBeErrorMessageOf` do
          -- create a table with a faulty `__tostring` metamethod
          let mt = "{__tostring = function() return nil end }"
          let tbl = "return setmetatable({}, " `append` mt `append` ")"
          openlibs <* dostring tbl
          tostring' top
      ]

    , testGroup "ref and unref"
      [ "store nil value to registry" =:
        Lua.RefNil `shouldBeResultOf` do
          Lua.pushnil
          Lua.ref Lua.registryindex

      , "get referenced value from registry" =:
        Just "Berlin" `shouldBeResultOf` do
          Lua.pushstring "Berlin"
          cityref <- Lua.ref Lua.registryindex
          Lua.pushnil -- dummy op
          Lua.getref Lua.registryindex cityref
          Lua.tostring Lua.top

      , "references become invalid after unref" =:
        Nothing `shouldBeResultOf` do
          Lua.pushstring "Heidelberg"
          cityref <- Lua.ref Lua.registryindex
          Lua.unref Lua.registryindex cityref
          Lua.getref Lua.registryindex cityref
          Lua.tostring Lua.top
      ]
    ]

  , testGroup "loading"
    [ testGroup "loadstring"
      [ "loading a valid string should succeed" =:
        OK `shouldBeResultOf` loadstring "return 1"

      , "loading an invalid string should give a syntax error" =:
        ErrSyntax `shouldBeResultOf` loadstring "marzipan"
      ]

    , testGroup "dostring"
      [ "loading a string which fails should give a run error" =:
        ErrRun `shouldBeResultOf` dostring "error 'this fails'"

      , "loading an invalid string should return a syntax error" =:
        ErrSyntax `shouldBeResultOf` dostring "marzipan"

      , "loading a valid program should succeed" =:
        OK `shouldBeResultOf` dostring "return 1"

      , "top of the stack should be result of last computation" =:
        Just 5 `shouldBeResultOf`
          (dostring "return (2+3)" *> tointeger top)
      ]

    , testGroup "loadbuffer"
      [ "loading a valid string should succeed" =:
        OK `shouldBeResultOf` loadbuffer "return '\NUL'" "test"

      , "loading a string containing NUL should be correct" =:
        Just "\NUL" `shouldBeResultOf` do
          _ <- loadbuffer "return '\NUL'" "test"
          call 0 1
          tostring top
      ]

    , testGroup "loadfile"
      [ "file error should be returned when file does not exist" =:
        ErrFile `shouldBeResultOf` loadfile "./file-does-not-exist.lua"

      , "loading an invalid file should give a syntax error" =:
        ErrSyntax `shouldBeResultOf` loadfile "test/lua/syntax-error.lua"

      , "loading a valid program should succeed" =:
        OK `shouldBeResultOf` loadfile "./test/lua/example.lua"

      , "example fib program should be loaded correctly" =:
        Just 8 `shouldBeResultOf` do
          loadfile "./test/lua/example.lua" *> call 0 0
          getglobal "fib"
          pushinteger 6
          call 1 1
          tointeger top
      ]

    , testGroup "dofile"
      [ "file error should be returned when file does not exist" =:
        ErrFile `shouldBeResultOf` dofile "./file-does-not-exist.lua"

      , "loading an invalid file should give a syntax error" =:
        ErrSyntax `shouldBeResultOf` dofile "test/lua/syntax-error.lua"

      , "loading a failing program should give an run error" =:
        ErrRun `shouldBeResultOf` dofile "test/lua/error.lua"

      , "loading a valid program should succeed" =:
        OK `shouldBeResultOf` dofile "./test/lua/example.lua"

      , "example fib program should be loaded correctly" =:
        Just 21 `shouldBeResultOf` do
          _ <- dofile "./test/lua/example.lua"
          getglobal "fib"
          pushinteger 8
          call 1 1
          tointeger top
      ]
    ]

  , testGroup "pcall"
    [ "raising an error should lead to an error status" =:
      ErrRun `shouldBeResultOf` do
        _ <- loadstring "error \"this fails\""
        pcall 0 0 Nothing

    , "raising an error in the error handler should give a 'double error'" =:
      ErrErr `shouldBeResultOf` do
        pushLuaExpr @Lua.Exception "function () error 'error in error handler' end"
        _ <- loadstring "error \"this fails\""
        pcall 0 0 (Just (nth 2))
    ]

  , testCase "garbage collection" . run $
      -- test that gc can be called with all constructors of type GCControl.
      mapM_ gc [ GCStop, GCRestart, GCCollect, GCCollect, GCCountb
               , GCStep, GCSetPause 23, GCSetStepMul 5, GCIsRunning ]

  , testGroup "compare"
    [ testProperty "identifies strictly smaller values" $ compareWith (<) Lua.LT
    , testProperty "identifies smaller or equal values" $ compareWith (<=) Lua.LE
    , testProperty "identifies equal values" $ compareWith (==) Lua.EQ
    ]

  , testProperty "lessthan works" $ \n1 n2 -> monadicIO $ do
      luaCmp <- QCMonadic.run . run @Lua.Exception $ do
        pushnumber n2
        pushnumber n1
        lessthan (-1) (-2) <* pop 2
      assert $ luaCmp == (n1 < n2)

  , testProperty "order of Lua types is consistent" $ \ lt1 lt2 ->
      let n1 = toType lt1
          n2 = toType lt2
      in Prelude.compare n1 n2 == Prelude.compare lt1 lt2

  , testCase "boolean values are correct" $ do
      trueIsCorrect <- run $
        pushboolean True *> dostring "return true" *> rawequal (-1) (-2)
      falseIsCorrect <- run $
        pushboolean False *> dostring "return false" *> rawequal (-1) (-2)
      assertBool "LuaBool true is not equal to Lua's true" trueIsCorrect
      assertBool "LuaBool false is not equal to Lua's false" falseIsCorrect

  , testCase "functions can throw a table as error message" $ do
      let mt = "{__tostring = function (e) return e.error_code end}"
      let err = "error(setmetatable({error_code = 23}," `append` mt `append` "))"
      res <- run . try $ openbase *> loadstring err *> call 0 0
      assertEqual "wrong error message" (Left (Lua.Exception "23")) res

  , testCase "handling table errors won't leak" $ do
      let mt = "{__tostring = function (e) return e.code end}"
      let err = "error(setmetatable({code = 5}," `append` mt `append` "))"
      let luaOp = do
            openbase
            oldtop <- gettop
            _ <- try $ loadstring err *> call 0 0
            newtop <- gettop
            return (newtop - oldtop)
      res <- run @Lua.Exception luaOp
      assertEqual "error handling leaks values to the stack" 0 res

  , HsLua.Core.RunTests.tests
  , HsLua.Core.UnsafeTests.tests
  , HsLua.Core.UserdataTests.tests
  ]

compareWith :: (Lua.Integer -> Lua.Integer -> Bool)
            -> RelationalOperator -> Lua.Integer -> Property
compareWith op luaOp n = compareLT .&&. compareEQ .&&. compareGT
 where
  compareLT :: Property
  compareLT = monadicIO  $ do
    luaCmp <- QCMonadic.run . run $ do
      pushinteger $ n - 1
      pushinteger n
      compare @Lua.Exception (-2) (-1) luaOp
    assert $ luaCmp == op (n - 1) n

  compareEQ :: Property
  compareEQ = monadicIO  $ do
    luaCmp <- QCMonadic.run . run $ do
      pushinteger n
      pushinteger n
      compare @Lua.Exception (-2) (-1) luaOp
    assert $ luaCmp == op n n

  compareGT :: Property
  compareGT = monadicIO $ do
    luaRes <- QCMonadic.run . run $ do
      pushinteger $ n + 1
      pushinteger n
      compare @Lua.Exception (-2) (-1) luaOp
    assert $ luaRes == op (n + 1) n