{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeOperators #-}

module Servant.ServerSpec where


import Data.Aeson
import Data.Proxy
import GHC.Generics
import Network.HTTP.Types
import Network.Wai
import Network.Wai.Test
import Test.Hspec
import Test.Hspec.Wai

import Servant.API.Get
import Servant.API.GetParam
import Servant.API.Post
import Servant.API.RQBody
import Servant.API.Sub
import Servant.API.Union
import Servant.Server


-- * test data types

data Person = Person {
  name :: String,
  age :: Integer
 }
  deriving (Eq, Show, Generic)

instance ToJSON Person
instance FromJSON Person

alice :: Person
alice = Person "Alice" 42

data Animal = Animal {
  species :: String,
  numberOfLegs :: Integer
 }
  deriving (Eq, Show, Generic)

instance ToJSON Animal
instance FromJSON Animal

jerry :: Animal
jerry = Animal "Mouse" 4


-- * specs

spec :: Spec
spec = do
  getSpec
  getParamSpec
  postSpec
  unionSpec


type GetApi = Get Person
getApi :: Proxy GetApi
getApi = Proxy

getSpec :: Spec = do
  describe "Servant.API.Get" $ do
    with (return (serve getApi (return alice))) $ do
      it "allows to GET a Person" $ do
        response <- get "/"
        return response `shouldRespondWith` 200
        liftIO $ do
          decode' (simpleBody response) `shouldBe` Just alice

      it "throws 404 on POSTs" $ do
        post "/" "" `shouldRespondWith` 404


type GetParamApi = GetParam "name" String :> Get Person
getParamApi :: Proxy GetParamApi
getParamApi = Proxy

getParamServer :: Server GetParamApi
getParamServer (Just name) = return alice{name = name}
getParamServer Nothing = return alice

getParamSpec :: Spec
getParamSpec = do
  describe "Servant.API.GetParam" $ do
    it "allows to retrieve GET parameters" $ do
      (flip runSession) (serve getParamApi getParamServer) $ do
        let params = "?name=bob"
        response <- Network.Wai.Test.request defaultRequest{
          rawQueryString = params,
          queryString = parseQuery params
         }
        liftIO $ do
          decode' (simpleBody response) `shouldBe` Just alice{
            name = "bob"
           }


type PostApi = RQBody Person :> (Post Integer)
postApi :: Proxy PostApi
postApi = Proxy

postSpec :: Spec
postSpec = do
  describe "Servant.API.Post and .RQBody" $ do
    with (return (serve postApi (return . age))) $ do
      it "allows to POST a Person" $ do
        post "/" (encode alice) `shouldRespondWith` "42"{
          matchStatus = 201
         }


type UnionApi =
       "foo" :> Get Person
  :<|> "bar" :> Get Animal
unionApi :: Proxy UnionApi
unionApi = Proxy

unionServer :: Server UnionApi
unionServer =
       return alice
  :<|> return jerry

unionSpec :: Spec
unionSpec = do
  describe "Servant.API.Union" $ do
    with (return $ serve unionApi unionServer) $ do
      it "unions endpoints" $ do
        response <- get "/foo"
        liftIO $ do
          decode' (simpleBody response) `shouldBe`
            Just alice
        response <- get "/bar"
        liftIO $ do
          decode' (simpleBody response) `shouldBe`
            Just jerry