{-# LANGUAGE NamedFieldPuns #-}
module Hcompta.CLI.Command.Print where

import           Control.Arrow (first)
import           Control.Applicative ((<$>))
import           Control.Monad.IO.Class (liftIO)
import           Control.Monad.Trans.Except (runExceptT)
import qualified Data.Either
import           System.Console.GetOpt
                 ( ArgDescr(..)
                 , OptDescr(..)
                 , usageInfo )
import           System.Environment as Env (getProgName)
import           System.Exit (exitWith, ExitCode(..))
import qualified System.IO as IO

import qualified Hcompta.CLI.Args as Args
import qualified Hcompta.CLI.Context as Context
import qualified Hcompta.CLI.Write as Write
import qualified Hcompta.Format.Ledger.Journal as Ledger.Journal
import qualified Hcompta.Format.Ledger.Read as Ledger.Read
import qualified Hcompta.Format.Ledger.Write as Ledger.Write
import qualified Hcompta.CLI.Format.Ledger as CLI.Ledger

data Ctx
 =   Ctx
 { ctx_input :: [FilePath]
 } deriving (Eq, Show)

nil :: Ctx
nil =
	Ctx
	 { ctx_input = []
	 }

usage :: IO String
usage = do
	bin <- Env.getProgName
	return $unlines $
		[ "SYNTAX "
		, "  "++bin++" print [option..]"
		, ""
		, usageInfo "OPTIONS" options
		]

options :: Args.Options Ctx
options =
	[ Option "h" ["help"]
	 (NoArg (\_context _ctx -> do
		usage >>= IO.hPutStr IO.stderr
		exitWith ExitSuccess))
	 "show this help"
	, Option "i" ["input"]
	 (ReqArg (\s _context ctx -> do
		return $ ctx{ctx_input=s:ctx_input ctx}) "FILE")
	 "read data from given file, can be use multiple times"
	]

run :: Context.Context -> [String] -> IO ()
run context args = do
	(ctx, _) <-
		first (\ctx -> ctx{ctx_input=reverse $ ctx_input ctx}) <$>
		Args.parse context usage options (nil, args)
	CLI.Ledger.paths context $ ctx_input ctx
	>>= do mapM $ \path -> do
		liftIO $ runExceptT $
			Ledger.Read.file path
		>>= \x -> case x of
		 Left  ko -> return $ Left (path, ko)
		 Right ok -> return $ Right ok
	>>= return . Data.Either.partitionEithers
	>>= \x -> case x of
	 (kos@(_:_), _oks) ->
		(flip mapM_) kos $ \(_path, ko) -> Write.fatal context $ show ko
	 ([], journals) -> do
		with_color <- Write.with_color context IO.stdout
		let journal = Ledger.Journal.flatten $ Ledger.Journal.unions journals
		Ledger.Write.put with_color IO.stdout $ do
		Ledger.Write.journal journal