{-# LANGUAGE TemplateHaskell #-}

module Main (
	main
	) where

import Control.Monad
import Data.List
import Data.Char
import Data.Maybe (listToMaybe, mapMaybe)
import Network.Socket (withSocketsDo)
import System.Environment (getArgs)
import System.Exit
import System.IO
import Text.Read (readMaybe)

import Control.Apply.Util (chain)
import System.Console.Cmd
import qualified System.Console.Cmd as C (brief)

import qualified HsDev.Client.Commands as Client (commands)
import qualified HsDev.Server.Commands as Server
import HsDev.Version

main :: IO ()
main = withSocketsDo $ do
	hSetBuffering stdout LineBuffering
	hSetEncoding stdout utf8
	as <- getArgs
	when (null as) $ do
		printUsage
		exitSuccess
	let
		asr = if last as == "-?" then "help" : init as else as 
	run mainCommands onDef onError asr
	where
		onError :: String -> IO ()
		onError errs = do
			putStrLn errs
			exitFailure

		onDef :: IO ()
		onDef = do
			putStrLn "Unknown command"
			exitFailure

mainCommands :: [Cmd (IO ())]
mainCommands = withHelp "hsdev" (printWith putStrLn) $ concat [
	[cmd "version" [] [] "hsdev version" version'],
	map (chain [validateOpts, noArgs]) Server.commands,
	map Server.clientCmd Client.commands]
	where
		version' _ = putStrLn $cabalVersion

printUsage :: IO ()
printUsage = mapM_ (putStrLn . ('\t':) . ("hsdev " ++) . C.brief) mainCommands

-- | Check that specified options are numbers
validateNums :: [String] -> Cmd a -> Cmd a
validateNums ns = validateArgs (check . namedArgs) where
	check os = forM_ ns $ \n -> case fmap (readMaybe :: String -> Maybe Int) $ arg n os of
		Just Nothing -> failMatch "Must be a number"
		_ -> return ()

-- | Check, that 'port' and 'timeout' are numbers
validateOpts :: Cmd a -> Cmd a
validateOpts = validateNums ["port", "timeout"]

-- | Ensure no positional arguments provided
noArgs :: Cmd a -> Cmd a
noArgs = validateArgs (noPos . posArgs) where
	noPos ps =
		guard (null ps)
		`mplus`
		failMatch "positional arguments are not expected"