{-# LANGUAGE OverloadedStrings #-}
module Language.JVMTest where

import           SpecHelper

import           Data.Either
import qualified Data.IntMap                          as IM
import           Data.List                            as List
import qualified Data.Text                            as Text
import qualified Data.ByteString.Lazy                 as BL
import           Data.Foldable

import           Language.JVM
import qualified Language.JVM.Attribute.Code          as C
import           Language.JVM.Attribute.StackMapTable

spec_testing_example :: SpecWith ()
spec_testing_example =
  it "can read classfile from file" $ do
    eclf <- readClassFile <$> BL.readFile "test/data/project/Main.class"
    case eclf of
      Right clf -> do
        cThisClass clf `shouldBe` ClassName "Main"
        cSuperClass clf `shouldBe` ClassName "java/lang/Object"
      Left msg ->
        fail $ show msg

test_reading_classfile :: IO [TestTree]
test_reading_classfile = testAllFiles $ \bs -> do
  let d = decodeClassFile bs
  it "can parse the bytestring" $ do
    d `shouldSatisfy` isRight

  let Right cls = d
  it "has a the magic number: 0xCAFEBABE" $ do
    cMagicNumber cls `shouldBe` 0xCAFEBABE

  it "can bootstrap the constant pool" $ do
    let
      cp = bootstrapConstantPool (cConstantPool cls)
    cp `shouldSatisfy` isRight
    let Right cp' = cp
    forM_ (cMethods' cls) $ \m -> do
      case (runEvolve cp' (evolve m)) of
        Right _ -> return ()
        Left err -> do
          putStr (show err) >> putStr ": "
          print . runEvolve cp' $ do
            x <- link (mDescriptor m)
            n <- link (mName m)
            return ((n, x) :: (MethodDescriptor, Text.Text))
          forM_ (mAttributes m) $ \a -> do
            -- Assume code
            case fromAttribute' a :: Either String (C.Code Low) of
              Right c -> do
                forM_ (unByteCode . C.codeByteCode $ c) $ \i ->
                  putStr " -> " >> print i

                forM_ (C.codeAttributes c) $ \ca -> do
                  print $ runEvolve cp' (evolve ca)
                  putStrLn (hexStringS $ aInfo ca)
                  case fromAttribute' ca :: Either String (StackMapTable Low) of
                    Right x ->
                      print x
                    Left msg ->
                      print msg
              Left x ->
                print x

  describe "encoding/decoding" $ do
    let e = encodeClassFile cls
    it "should encode to the original bytestring" $
      e `shouldBe` bs

    it "should decode to the same thing" $
      decodeClassFile e `shouldBe` Right cls

  describe "evolving/devolving" $ do
    let me = evolveClassFile cls
    it "can evolve the whole class file" $ do
      me `shouldSatisfy` isRight

    let Right x = me
    it "has same or smaller constant pool" $ do
      let d' = devolveClassFile x
      (IM.size . unConstantPool $ cConstantPool d') `shouldSatisfy`
        (<= (IM.size . unConstantPool $ cConstantPool cls))

    -- it "is the same when devolving with the original constant pool" $
    --   devolveClassFile' (cConstantPool cls) x `shouldMatchClass'` cls

    it "can do full read - write - read process" $ do
      let w  = writeClassFile' (cConstantPool cls) x
      let y' = readClassFile w
      y' `shouldSatisfy` isRight
      let Right y = y'
      x `shouldMatchClass` y

shouldMatchClass :: ClassFile High -> ClassFile High -> IO ()
shouldMatchClass y x = do
  cAccessFlags' y `shouldBe` cAccessFlags' x
  cThisClass y `shouldBe` cThisClass x
  cSuperClass y `shouldBe` cSuperClass x
  cInterfaces y `shouldBe` cInterfaces x
  cFields' y `shouldBe` cFields' x
  forM_ (zip (cMethods y) (cMethods x)) $ \ (ym, xm) -> do
    ym `shouldMatchMethod` xm
  y `shouldBe` x

shouldMatchClass' :: ClassFile Low -> ClassFile Low -> IO ()
shouldMatchClass' y x = do
  cAccessFlags' y `shouldBe` cAccessFlags' x
  cThisClass y `shouldBe` cThisClass x
  cSuperClass y `shouldBe` cSuperClass x
  cInterfaces y `shouldBe` cInterfaces x
  cFields' y `shouldBe` cFields' x
  forM_ (zip (cMethods y) (cMethods x)) $ \(ym, xm) -> do
    shouldMatchMethod' ym xm

shouldMatchMethod :: Method High -> Method High -> IO ()
shouldMatchMethod ym xm = do
  mAccessFlags ym `shouldBe` mAccessFlags xm
  mName ym `shouldBe` mName xm
  mDescriptor ym `shouldBe` mDescriptor xm
  mExceptions ym `shouldMatchList` mExceptions xm
  case (mCode ym, mCode xm) of
    (Just yc, Just xc) -> do
      cmpOver C.codeByteCodeOprs yc xc $ \ yb xb -> do
        yb `shouldBe` xb
    _ -> mCode ym `shouldBe` mCode xm

shouldMatchMethod' :: Method Low -> Method Low -> IO ()
shouldMatchMethod' ym xm = do
  mAccessFlags ym `shouldBe` mAccessFlags xm
  mName ym `shouldBe` mName xm
  mDescriptor ym `shouldBe` mDescriptor xm
  forM_ (zip (unSizedList $ mAttributes ym ) (unSizedList $ mAttributes xm)) $ \(ya, xa) -> do
    case (fromAttribute' ya, fromAttribute' xa) of
      (Right yc, Right xc) -> do
        cmpOn C.codeMaxStack yc xc
        cmpOn C.codeMaxLocals yc xc
        cmpOn C.codeByteCodeInsts yc xc
        cmpOn C.codeExceptionTable yc xc
        cmpOver (List.sort . unSizedList .C.codeAttributes) yc xc $ \ yca xca -> do
          case (fromAttribute' yca, fromAttribute' xca)
             :: (Either String (StackMapTable Low), Either String (StackMapTable Low)) of
            (Right yst, Right xst) -> do
              cmpOver stackMapTable yst xst $ shouldBe
            (yst, xst) ->
              yst `shouldBe` xst
      (yc, xc) ->
        yc `shouldBe` xc

cmpOn :: (Show b, Eq b) => (a -> b) -> a -> a -> IO ()
cmpOn f a b =
  f a `shouldBe` f b

cmpOver :: (Foldable t) => (a -> t b) -> a -> a -> (b -> b -> IO ()) -> IO ()
cmpOver g ta tb f =
  forM_ (zip (toList . g $ ta) (toList . g $ tb)) (uncurry f)

cmpPrefixes :: (Foldable t) => (a -> t b) -> a -> a -> ([b] -> [b] -> IO ()) -> IO ()
cmpPrefixes g ta tb f =
  forM_ (zip (inits . toList . g $ ta) (inits . toList . g $ tb)) (uncurry f)