{-# LANGUAGE OverloadedStrings #-}

import Network.Socks5

import Network.Socket hiding (recv, sClose)

import Network.Socket.ByteString

import Network.BSD

import Network

import Data.ByteString.Char8 ()

import qualified Data.ByteString.Char8 as BC

import System.IO (hClose, hFlush)

import System.Environment (getArgs)

main = do

    args <- getArgs

    let serverName = "localhost"

    let serverPort = 1080

    let destinationName = case args of

            []    -> "www.google.com"

            (x:_) -> x

    -- socks server is expected to be running on localhost port 1080

    he     <- getHostByName serverName

    let socksServerAddr = SockAddrInet serverPort (head $ hostAddresses he)

    example1 socksServerAddr destinationName

    example2 socksServerAddr destinationName

    example3 serverName serverPort destinationName 80

  where

        -- connect to @destName on port 80 through the socks server

        -- www.google.com get resolve on the client here and then the sockaddr is

        -- passed to socksConnectAddr

        example1 socksServerAddr destName = do

            socket <- socket AF_INET Stream defaultProtocol

            socksConnectWithSocket socket (defaultSocksConfFromSockAddr socksServerAddr)

                        (SocksAddress (SocksAddrDomainName $ BC.pack destName) 80)

            sendAll socket "GET / HTTP/1.0\r\n\r\n"

            recv socket 4096 >>= putStrLn . show

            sClose socket

        -- connect to @destName on port 80 through the socks server

        -- the server is doing the resolution itself

        example2 socksServerAddr destName = do

            socket <- socket AF_INET Stream defaultProtocol

            socksConnectName socket socksServerAddr destName 80

            sendAll socket "GET / HTTP/1.0\r\n\r\n"

            recv socket 4096 >>= putStrLn . show

            sClose socket

        example3 sname sport dname dport = do    

            handle <- socksConnectTo sname (PortNumber sport) dname (PortNumber dport)

            BC.hPut handle "GET / HTTP/1.0\r\n\r\n"

            hFlush handle

            BC.hGet handle 1024 >>= putStrLn . show

            hClose handle