{-# LANGUAGE GADTs               #-}
{-# LANGUAGE OverloadedStrings   #-}
{-# LANGUAGE RecordWildCards     #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeFamilies        #-}

module Network.Nakadi.Internal.Http.Test
  ( testHttp
  ) where

import           ClassyPrelude
import           Control.Arrow
import           Control.Lens
import qualified Data.ByteString.Lazy         as LB
import           Network.HTTP.Client
import           Network.HTTP.Types
import           Network.Nakadi
import           Network.Nakadi.Internal.Http
import qualified Network.Nakadi.Lenses        as L
import           Test.Tasty
import           Test.Tasty.HUnit

testHttp :: TestTree
testHttp = testGroup "Http"
  [ testCase "HttpRequestModifier" testHttpRequestModifier
  , testCase "FlowIdInclusion" testFlowIdInclusion
  , testCase "FlowIdMissing" testFlowIdMissing
  , testCase "FlowIdInclusionHttp" testFlowIdInclusionHttp
  , testCase "FlowIdMissingHttp" testFlowIdMissingHttp
  ]

extractFlowId :: Request -> Maybe FlowId
extractFlowId =
  requestHeaders
  >>> filter (\ (key, _) -> key == "X-Flow-Id")
  >>> listToMaybe
  >>> fmap (FlowId . decodeUtf8 . snd)

headers :: RequestHeaders
headers = [("test-header", "header-value")]

dummyRequestModifier :: Request -> IO Request
dummyRequestModifier request = pure (request { requestHeaders = headers })

testHttpRequestModifier :: Assertion
testHttpRequestModifier = do
  let conf = newConfigIO defaultRequest
             & setRequestModifier dummyRequestModifier
  request <- runNakadiT conf $ httpBuildRequest id
  requestHeaders request @=? headers

testFlowIdInclusion :: Assertion
testFlowIdInclusion = do
  let flowId = FlowId "shalom"
      config = newConfigIO defaultRequest & setFlowId flowId
  Just flowId @=? (defaultRequest & (includeFlowId config >>> extractFlowId))

testFlowIdMissing :: Assertion
testFlowIdMissing = do
  let config = newConfigIO defaultRequest
  Nothing @=? (defaultRequest & (includeFlowId config >>> extractFlowId))

mockHttpLbs
  :: b ~ IO
  => TVar (Maybe Request)
  -> Config b
  -> Request
  -> Maybe Manager
  -> b (Response LB.ByteString)
mockHttpLbs tv _config request  _manager = do
  liftIO . atomically $ writeTVar tv (Just request)
  throwString "Mock"

testFlowIdInclusionHttp :: Assertion
testFlowIdInclusionHttp = do
  tv <- atomically $ newTVar Nothing
  let flowId      = FlowId "shalom"
      httpBackend = httpBackendIO & L.httpLbs .~ (mockHttpLbs tv)
      config      = newConfig httpBackend defaultRequest & setFlowId flowId
  Left (StringException _ _) <- try $ runNakadiT config eventTypesList
  Just requestExecuted <- liftIO . atomically $ readTVar tv
  Just flowId @=? extractFlowId requestExecuted

testFlowIdMissingHttp :: Assertion
testFlowIdMissingHttp = do
  tv <- atomically $ newTVar Nothing
  let httpBackend = httpBackendIO & L.httpLbs .~ (mockHttpLbs tv)
      config      = newConfig httpBackend defaultRequest
  Left (StringException _ _) <- try $ runNakadiT config eventTypesList
  Just requestExecuted <- liftIO . atomically $ readTVar tv
  Nothing @=? extractFlowId requestExecuted