{-# LANGUAGE ExplicitForAll            #-}
{-# LANGUAGE FlexibleContexts          #-}
{-# LANGUAGE FlexibleInstances         #-}
{-# LANGUAGE InstanceSigs              #-}
{-# LANGUAGE MultiParamTypeClasses     #-}
{-# LANGUAGE NoMonomorphismRestriction #-}
{-# LANGUAGE OverloadedStrings         #-}
{-# LANGUAGE ScopedTypeVariables       #-}
{-# LANGUAGE TupleSections             #-}

{-# OPTIONS_GHC -fno-warn-missing-signatures #-}

module HaskellWorks.Data.Json.LightJsonSpec (spec) where

import Control.Monad
import Data.Text
import HaskellWorks.Data.BalancedParens.BalancedParens
import HaskellWorks.Data.Bits.BitWise
import HaskellWorks.Data.Json.DecodeError
import HaskellWorks.Data.Json.LightJson
import HaskellWorks.Data.Json.Standard.Cursor.Generic
import HaskellWorks.Data.Json.Value
import HaskellWorks.Data.RankSelect.Base.Rank0
import HaskellWorks.Data.RankSelect.Base.Rank1
import HaskellWorks.Data.RankSelect.Base.Select1
import HaskellWorks.Hspec.Hedgehog
import Hedgehog
import Test.Hspec

import qualified Data.Aeson.Parser.Internal                  as AP
import qualified Data.Attoparsec.ByteString                  as PBS
import qualified Data.ByteString                             as BS
import qualified Data.Scientific                             as S
import qualified Data.Text                                   as T
import qualified HaskellWorks.Data.Json.Standard.Cursor.Fast as FAST
import qualified HaskellWorks.Data.Json.Standard.Cursor.Slow as SLOW
import qualified HaskellWorks.Data.TreeCursor                as TC

{-# ANN module ("HLint: ignore Redundant do"        :: String) #-}
{-# ANN module ("HLint: ignore Reduce duplication"  :: String) #-}
{-# ANN module ("HLint: ignore Redundant bracket"   :: String) #-}

fc = TC.firstChild
ns = TC.nextSibling

spec :: Spec
spec = describe "HaskellWorks.Data.Json.LightJsonSpec" $ do
  genSpec "DVS.Vector Word64" SLOW.fromString
  genSpec "CsPoppy"           FAST.fromString

jsonValueVia  :: forall t u.
  ( BalancedParens u
  , Rank0 u
  , Rank1 u
  , Select1 t
  , TestBit u)
  => Maybe (GenericCursor BS.ByteString t u)
  -> Either DecodeError JsonValue
jsonValueVia mk = case mk of
  Just k  -> case lightJsonAt k of
    LightJsonString t  -> Right (JsonString t)
    LightJsonNumber bs -> case PBS.parseOnly AP.scientific bs of
      Right s  -> Right (JsonNumber (S.toRealFloat s))
      Left msg -> Left (DecodeError msg)
    LightJsonObject ps -> fmap JsonObject (traverse fields ps)
    LightJsonArray cs  -> fmap JsonArray (traverse elements cs)
    LightJsonBool v    -> Right (JsonBool v)
    LightJsonNull      -> Right JsonNull
    LightJsonError msg -> Left (DecodeError (T.unpack msg))
  Nothing -> Left (DecodeError "No such element")
  where fields :: (Text, GenericCursor BS.ByteString t u) -> Either DecodeError (Text, JsonValue)
        fields (f, c) = (f,) <$> jsonValueVia (Just c)
        elements :: GenericCursor BS.ByteString t u -> Either DecodeError JsonValue
        elements c = jsonValueVia (Just c)

genSpec :: forall t u.
  ( Eq                t
  , Show              t
  , Select1           t
  , Eq                u
  , Show              u
  , Rank0             u
  , Rank1             u
  , BalancedParens    u
  , TestBit           u)
  => String -> (String -> GenericCursor BS.ByteString t u) -> SpecWith ()
genSpec t makeCursor = do
  describe ("Json cursor of type " ++ t) $ do
    let forJson s f = describe ("of value " ++ show s) (f (makeCursor s))
    forJson "{}" $ \cursor -> do
      it "should have correct value"      $ requireTest $ jsonValueVia (Just cursor) === Right (JsonObject [])
    forJson " {}" $ \cursor -> do
      it "should have correct value"      $ requireTest $ jsonValueVia (Just cursor) === Right (JsonObject [])
    forJson "1234" $ \cursor -> do
      it "should have correct value"      $ requireTest $ jsonValueVia (Just cursor) === Right (JsonNumber 1234)
    forJson "\"Hello\"" $ \cursor -> do
      it "should have correct value"      $ requireTest $ jsonValueVia (Just cursor) === Right (JsonString "Hello")
    forJson "[]" $ \cursor -> do
      it "should have correct value"      $ requireTest $ jsonValueVia (Just cursor) === Right (JsonArray [])
    forJson "true" $ \cursor -> do
      it "should have correct value"      $ requireTest $ jsonValueVia (Just cursor) === Right (JsonBool True)
    forJson "false" $ \cursor -> do
      it "should have correct value"      $ requireTest $ jsonValueVia (Just cursor) === Right (JsonBool False)
    forJson "null" $ \cursor -> do
      it "should have correct value"      $ requireTest $ jsonValueVia (Just cursor) === Right JsonNull
    forJson "[null]" $ \cursor -> do
      it "should have correct value"      $ requireTest $ jsonValueVia (Just cursor) === Right (JsonArray [JsonNull])
      it "should have correct value"      $ requireTest $ jsonValueVia (fc   cursor) === Right  JsonNull
    forJson "[null, {\"field\": 1}]" $ \cursor -> do
      it "cursor can navigate to second child of array" $ requireTest $ do
        jsonValueVia ((fc >=> ns)   cursor) === Right (                     JsonObject [("field", JsonNumber 1)] )
        jsonValueVia (Just          cursor) === Right (JsonArray [JsonNull, JsonObject [("field", JsonNumber 1)]])
    describe "For empty json array" $ do
      let cursor = makeCursor "[]"
      it "can navigate down and forwards" $ requireTest $ do
        jsonValueVia (Just cursor) === Right (JsonArray [])
    describe "For empty json array" $ do
      let cursor = makeCursor "[null]"
      it "can navigate down and forwards" $ requireTest $ do
        jsonValueVia (Just cursor) === Right (JsonArray [JsonNull])
    describe "For sample Json" $ do
      let cursor = makeCursor "{ \
                    \    \"widget\": { \
                    \        \"debug\": \"on\", \
                    \        \"window\": { \
                    \            \"name\": \"main_window\", \
                    \            \"dimensions\": [500, 600.01e-02, true, false, null] \
                    \        } \
                    \    } \
                    \}" :: GenericCursor BS.ByteString t u
      it "can navigate down and forwards" $ requireTest $ do
        let array   = JsonArray [JsonNumber 500, JsonNumber 600.01e-02, JsonBool True, JsonBool False, JsonNull] :: JsonValue
        let object1 = JsonObject ([("name", JsonString "main_window"), ("dimensions", array)]) :: JsonValue
        let object2 = JsonObject ([("debug", JsonString "on"), ("window", object1)]) :: JsonValue
        let object3 = JsonObject ([("widget", object2)]) :: JsonValue
        jsonValueVia (Just                                                                                                   cursor) === Right object3
        jsonValueVia ((fc                                                                                                  ) cursor) === Right (JsonString "widget"      )
        jsonValueVia ((fc >=> ns                                                                                           ) cursor) === Right (object2                  )
        jsonValueVia ((fc >=> ns >=> fc                                                                                    ) cursor) === Right (JsonString "debug"       )
        jsonValueVia ((fc >=> ns >=> fc >=> ns                                                                             ) cursor) === Right (JsonString "on"          )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns                                                                      ) cursor) === Right (JsonString "window"      )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns >=> ns                                                               ) cursor) === Right (object1                  )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc                                                        ) cursor) === Right (JsonString "name"        )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns                                                 ) cursor) === Right (JsonString "main_window" )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns >=> ns                                          ) cursor) === Right (JsonString "dimensions"  )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns >=> ns >=> ns                                   ) cursor) === Right (array                    )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc                            ) cursor) === Right (JsonNumber 500           )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns                     ) cursor) === Right (JsonNumber 600.01e-02    )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns >=> ns              ) cursor) === Right (JsonBool True            )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns >=> ns >=> ns       ) cursor) === Right (JsonBool False           )
        jsonValueVia ((fc >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns >=> ns >=> ns >=> fc >=> ns >=> ns >=> ns >=> ns) cursor) === Right JsonNull