Request.hs

{-# LANGUAGE OverloadedStrings #-}

module CoinbasePro.WebSocketFeed.Request
  ( WSConnection (..)
  , RequestMessageType (..)
  , ChannelName(..)
  , WebSocketFeedRequest (..)

  , wsEndpoint
  ) where

import           Data.Aeson              (FromJSON (..), ToJSON (..), object,
                                          withText, (.=))
import           Network.Socket          (HostName)
import           Network.Socket.Internal (PortNumber)

import           CoinbasePro.Types       (ProductId)


data WSConnection = WSConnection
    { host :: HostName
    , port :: PortNumber
    } deriving (Eq, Show)


wsEndpoint :: WSConnection
wsEndpoint = WSConnection h p
  where
    h = "ws-feed.pro.coinbase.com"
    p = 443


data RequestMessageType = Subscribe | Unsubscribe
    deriving (Eq, Ord)


instance Show RequestMessageType where
    show Subscribe   = "subscribe"
    show Unsubscribe = "unsubscribe"


data ChannelName = Heartbeat | Ticker | Level2 | Matches | Full
    deriving (Eq, Ord)


instance Show ChannelName where
    show Heartbeat = "heartbeat"
    show Ticker    = "ticker"
    show Level2    = "level2"
    show Matches   = "matches"
    show Full      = "full"


instance ToJSON ChannelName where
    toJSON Heartbeat = toJSON $ show Heartbeat
    toJSON Ticker    = toJSON $ show Ticker
    toJSON Level2    = toJSON $ show Level2
    toJSON Matches   = toJSON $ show Matches
    toJSON Full      = toJSON $ show Full


instance FromJSON ChannelName where
    parseJSON = withText "channel name" $ \t ->
      case t of
        "heartbeat" -> return Heartbeat
        "ticker"    -> return Ticker
        "level2"    -> return Level2
        "matches"   -> return Matches
        "full"      -> return Full
        _           -> fail "Unable to parse channel"


data WebSocketFeedRequest = WebSocketFeedRequest
    { reqMsgType    :: RequestMessageType
    , reqProductIds :: [ProductId]
    , reqChannels   :: [ChannelName]
    } deriving (Eq, Ord, Show)


instance ToJSON WebSocketFeedRequest where
    toJSON (WebSocketFeedRequest rmt rpi rc) = object
        [ "type" .= show rmt
        , "product_ids" .= rpi
        , "channels" .= rc
        ]