Types.hs

-- |
-- Module:     Network.IHttp.Types
-- Copyright:  (c) 2010 Ertugrul Soeylemez
-- License:    BSD3
-- Maintainer: Ertugrul Soeylemez <es@ertes.de>
-- Stability:  beta
--
-- Types for ihttp.

{-# LANGUAGE DeriveDataTypeable #-}

module Network.IHttp.Types
    ( -- * Protocol data
      HeaderMap,
      HttpMethod(..),
      HttpVersion(..),
      Request(..),
      Response(..),

      -- * Miscellaneous types
      HttpError(..)
    )
    where

import Control.Exception as Ex
import Data.ByteString.Char8 (ByteString)
import Data.Map (Map)
import Data.Typeable


-- TODO: Common HTTP headers with correct types.

-- data CommonHeaders =
--     CommonHeaders {
--       contentCharsetHeader :: Maybe ByteString,  -- ^ Document character set.
--       contentLengthHeader  :: Maybe Integer,     -- ^ Length of document in bytes.
--       contentTypeHeader    :: Maybe ByteString   -- ^ MIME type of document.
--     }


-- | Map of HTTP headers.

type HeaderMap = Map ByteString ByteString


-- | HTTP error.

data HttpError
    -- | Invalid headers from client/server.
    = InvalidHeaderError { httpErrorMessage :: String }

    -- | Invalid requests from client.
    | InvalidRequestError { httpErrorMessage :: String }

    -- | Invalid responses from server.
    | InvalidResponseError { httpErrorMessage :: String }

    -- | Unsupported HTTP version.
    | UnsupportedVersionError { httpErrorMessage :: String }
    deriving (Eq, Typeable)

instance Exception HttpError

instance Show HttpError where
    show (InvalidHeaderError msg)      = "Invalid HTTP header: " ++ msg
    show (InvalidRequestError msg)     = "Invalid HTTP request: " ++ msg
    show (InvalidResponseError msg)    = "Invalid HTTP response: " ++ msg
    show (UnsupportedVersionError msg) = "Unsupported HTTP version: " ++ msg


-- | HTTP request method.

data HttpMethod
    = ConnectMethod  -- ^ CONNECT
    | DeleteMethod   -- ^ DELETE
    | GetMethod      -- ^ GET
    | HeadMethod     -- ^ HEAD
    | OptionsMethod  -- ^ OPTIONS
    | PatchMethod    -- ^ PATCH
    | PostMethod     -- ^ POST
    | PutMethod      -- ^ PUT
    | TraceMethod    -- ^ TRACE
    | XMethod ByteString  -- ^ Methods this library doesn't know.
    deriving (Eq, Read, Show)


-- | HTTP protocol version.

data HttpVersion
    = Http1_0  -- ^ Version 1.0 of HTTP.
    | Http1_1  -- ^ Version 1.1 of HTTP.
    deriving (Eq, Ord, Read, Show)


-- | HTTP request line with status code.

data Request =
    Request {
      requestHeaders :: HeaderMap,   -- ^ Request headers.
      requestMethod  :: HttpMethod,  -- ^ Request method.
      requestUri     :: ByteString,  -- ^ Request URI.
      requestVersion :: HttpVersion  -- ^ HTTP version of request.
    }
    deriving (Eq, Read, Show)


-- | HTTP response line with the status code.

data Response =
    Response {
      responseCode    :: Int,         -- ^ HTTP response code.
      responseHeaders :: HeaderMap,   -- ^ Response headers.
      responseMessage :: ByteString,  -- ^ Response message.
      responseVersion :: HttpVersion  -- ^ Protocol version of response.
    }
    deriving (Eq, Read, Show)