{-# LANGUAGE OverloadedStrings #-}

module Main where

import Text.Megaparsec (Parsec, parseMaybe)

import Text.URI

import System.Environment (getEnv)

import Data.Text (Text, pack, unpack)

import Data.Maybe

import Control.Monad (when)

import Network.AMQP

import qualified Data.ByteString.Lazy.Char8 as BL

assert :: String -> Bool -> a -> a

assert message False x = error message

assert _ _ x = x

unRpack = unpack . unRText

main :: IO ()

main = do

    amqpUri <- getEnv "AMQP_URL"

    let uri = fromJust $ parseMaybe (parser :: Parsec Int Text URI) $ pack amqpUri

    when (uriScheme uri /= mkScheme "amqp") $ error "AMQP_URL environment variable scheme should be amqp"

    let Right (Authority (Just (UserInfo username (Just password))) rHost maybePort) = uriAuthority uri

    conn <- openConnection' (unRpack rHost) (fromInteger . toInteger $ fromMaybe 5672 maybePort) "/" (unRText username) (unRText password)

    chan <- openChannel conn

    (queueName, messageCount, consumerCount) <- declareQueue chan newQueue

    bindQueue chan queueName "irc" "cmd.echo.hedgewars"

    -- subscribe to the queue

    consumeMsgs chan queueName Ack (myCallback chan)

    getLine -- wait for keypress

    closeConnection conn

    putStrLn "connection closed"

myCallback :: Channel -> (Message,Envelope) -> IO ()

myCallback chan (msg, env) = do

    let message = BL.tail . BL.dropWhile (/= '\n') $ msgBody msg

    putStrLn $ "received message: " ++ (BL.unpack $ message)

    publishMsg chan "irc" "say.hedgewars"

        newMsg {msgBody = message}

    ackEnv env