{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RankNTypes #-}

-- | HTTP\/2 client library.
--
--  Example:
--
-- > {-# LANGUAGE OverloadedStrings #-}
-- >
-- > module Main where
-- >
-- > import Control.Concurrent.Async
-- > import qualified Control.Exception as E
-- > import qualified Data.ByteString.Char8 as C8
-- > import Network.HTTP.Types
-- > import Network.Run.TCP (runTCPClient) -- network-run
-- >
-- > import Network.HTTP2.Client
-- >
-- > serverName :: String
-- > serverName = "127.0.0.1"
-- >
-- > main :: IO ()
-- > main = runTCPClient serverName "80" $ runHTTP2Client serverName
-- >   where
-- >     cliconf host = ClientConfig "http" (C8.pack host) 20
-- >     runHTTP2Client host s = E.bracket (allocSimpleConfig s 4096)
-- >                                       freeSimpleConfig
-- >                                       (\conf -> run (cliconf host) conf client)
-- >     client sendRequest = do
-- >         let req0 = requestNoBody methodGet "/" []
-- >             client0 = sendRequest req0 $ \rsp -> do
-- >                 print rsp
-- >                 getResponseBodyChunk rsp >>= C8.putStrLn
-- >             req1 = requestNoBody methodGet "/foo" []
-- >             client1 = sendRequest req1 $ \rsp -> do
-- >                 print rsp
-- >                 getResponseBodyChunk rsp >>= C8.putStrLn
-- >         ex <- E.try $ concurrently_ client0 client1
-- >         case ex of
-- >           Left  e  -> print (e :: HTTP2Error)
-- >           Right () -> putStrLn "OK"

module Network.HTTP2.Client (
  -- * Runner
    run
  , Scheme
  , Authority
  -- * Runner arguments
  , ClientConfig(..)
  , Config(..)
  , allocSimpleConfig
  , freeSimpleConfig
  -- * HTTP\/2 client
  , Client
  -- * Request
  , Request
  -- * Creating request
  , requestNoBody
  , requestFile
  , requestStreaming
  , requestStreamingUnmask
  , requestBuilder
  -- ** Trailers maker
  , TrailersMaker
  , NextTrailersMaker(..)
  , defaultTrailersMaker
  , setRequestTrailersMaker
  -- * Response
  , Response
  -- ** Accessing response
  , responseStatus
  , responseHeaders
  , responseBodySize
  , getResponseBodyChunk
  , getResponseTrailers
  -- * Types
  , Method
  , Path
  , FileSpec(..)
  , FileOffset
  , ByteCount
  -- * Error
  , HTTP2Error(..)
  , ErrorCode(ErrorCode,NoError,ProtocolError,InternalError,FlowControlError,SettingsTimeout,StreamClosed,FrameSizeError,RefusedStream,Cancel,CompressionError,ConnectError,EnhanceYourCalm,InadequateSecurity,HTTP11Required)
  -- * RecvN
  , defaultReadN
  -- * Position read for files
  , PositionReadMaker
  , PositionRead
  , Sentinel(..)
  , defaultPositionReadMaker
  ) where

import Data.ByteString (ByteString)
import Data.ByteString.Builder (Builder)
import Data.IORef (readIORef)
import Network.HTTP.Types

import Network.HPACK
import Network.HTTP2.Arch
import Network.HTTP2.Client.Run
import Network.HTTP2.Client.Types
import Network.HTTP2.Frame

----------------------------------------------------------------

-- | Creating request without body.
requestNoBody :: Method -> Path -> RequestHeaders -> Request
requestNoBody m p hdr = Request $ OutObj hdr' OutBodyNone defaultTrailersMaker
  where
    hdr' = addHeaders m p hdr

-- | Creating request with file.
requestFile :: Method -> Path -> RequestHeaders -> FileSpec -> Request
requestFile m p hdr fileSpec = Request $ OutObj hdr' (OutBodyFile fileSpec) defaultTrailersMaker
  where
    hdr' = addHeaders m p hdr

-- | Creating request with builder.
requestBuilder :: Method -> Path -> RequestHeaders -> Builder -> Request
requestBuilder m p hdr builder = Request $ OutObj hdr' (OutBodyBuilder builder) defaultTrailersMaker
  where
    hdr' = addHeaders m p hdr

-- | Creating request with streaming.
requestStreaming :: Method -> Path -> RequestHeaders
                 -> ((Builder -> IO ()) -> IO () -> IO ())
                 -> Request
requestStreaming m p hdr strmbdy = Request $ OutObj hdr' (OutBodyStreaming strmbdy) defaultTrailersMaker
  where
    hdr' = addHeaders m p hdr

-- | Like 'requestStreaming', but run the action with exceptions masked
requestStreamingUnmask :: Method -> Path -> RequestHeaders
                       -> ((forall x. IO x -> IO x) -> (Builder -> IO ()) -> IO () -> IO ())
                       -> Request
requestStreamingUnmask m p hdr strmbdy = Request $ OutObj hdr' (OutBodyStreamingUnmask strmbdy) defaultTrailersMaker
  where
    hdr' = addHeaders m p hdr

addHeaders :: Method -> Path -> RequestHeaders -> RequestHeaders
addHeaders m p hdr = (":method", m) : (":path", p) : hdr

-- | Setting 'TrailersMaker' to 'Response'.
setRequestTrailersMaker :: Request -> TrailersMaker -> Request
setRequestTrailersMaker (Request req) tm = Request req { outObjTrailers = tm }

----------------------------------------------------------------

-- | Getting the status of a response.
responseStatus :: Response -> Maybe Status
responseStatus (Response rsp) = getStatus $ inpObjHeaders rsp

-- | Getting the headers from a response.
responseHeaders :: Response -> HeaderTable
responseHeaders (Response rsp) = inpObjHeaders rsp

-- | Getting the body size from a response.
responseBodySize :: Response -> Maybe Int
responseBodySize (Response rsp) = inpObjBodySize rsp

-- | Reading a chunk of the response body.
--   An empty 'ByteString' returned when finished.
getResponseBodyChunk :: Response -> IO ByteString
getResponseBodyChunk (Response rsp) = inpObjBody rsp

-- | Reading response trailers.
--   This function must be called after 'getResponseBodyChunk'
--   returns an empty.
getResponseTrailers :: Response -> IO (Maybe HeaderTable)
getResponseTrailers (Response rsp) = readIORef (inpObjTrailers rsp)