80 lines
2 KiB
Haskell
80 lines
2 KiB
Haskell
{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE TypeFamilies #-}
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{-# LANGUAGE DeriveGeneric #-}
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{-# LANGUAGE TypeOperators #-}
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module GS3 where
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import Control.Monad.Trans.Either
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import Data.Aeson
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import Data.List
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import GHC.Generics
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import Network.Wai
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import Servant
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data Position = Position
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{ x :: Int
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, y :: Int
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} deriving Generic
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instance ToJSON Position
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newtype HelloMessage = HelloMessage { msg :: String }
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deriving Generic
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instance ToJSON HelloMessage
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data ClientInfo = ClientInfo
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{ name :: String
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, email :: String
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, age :: Int
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, interested_in :: [String]
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} deriving Generic
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instance FromJSON ClientInfo
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data Email = Email
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{ from :: String
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, to :: String
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, subject :: String
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, body :: String
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} deriving Generic
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instance ToJSON Email
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emailForClient :: ClientInfo -> Email
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emailForClient c = Email from' to' subject' body'
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where from' = "great@company.com"
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to' = email c
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subject' = "Hey " ++ name c ++ ", we miss you!"
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body' = "Hi " ++ name c ++ ",\n\n"
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++ "Since you've recently turned " ++ show (age c)
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++ ", have you checked out our latest "
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++ intercalate ", " (interested_in c)
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++ " products? Give us a visit!"
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type API = "position" :> Capture "x" Int :> Capture "y" Int :> Get '[JSON] Position
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:<|> "hello" :> QueryParam "name" String :> Get '[JSON] HelloMessage
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:<|> "marketing" :> ReqBody '[JSON] ClientInfo :> Post '[JSON] Email
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api :: Proxy API
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api = Proxy
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server :: Server API
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server = position
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:<|> hello
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:<|> marketing
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where position :: Int -> Int -> EitherT ServantErr IO Position
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position x y = return (Position x y)
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hello :: Maybe String -> EitherT ServantErr IO HelloMessage
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hello mname = return . HelloMessage $ case mname of
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Nothing -> "Hello, anonymous coward"
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Just n -> "Hello, " ++ n
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marketing :: ClientInfo -> EitherT ServantErr IO Email
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marketing clientinfo = return (emailForClient clientinfo)
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app :: Application
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app = serve api server
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