{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Hcompta.CLI.Format.Ledger where

import           Control.Exception (tryJust)
import           Control.Monad (Monad(..), guard)
import           Data.Either (Either(..))
import qualified Data.List as List
import qualified Data.Text.Lazy as TL
import           Prelude (($), (.), FilePath, IO)
import           System.Environment as Env (getEnv)
import           System.IO.Error (isDoesNotExistError)
import           Text.Show (Show(..))

import qualified Hcompta.Balance as Balance
import qualified Hcompta.CLI.Context as C
import qualified Hcompta.CLI.Lang as Lang
import qualified Hcompta.CLI.Write as Write
import qualified Hcompta.Format.Ledger as Ledger
import qualified Hcompta.Format.Ledger.Amount as Ledger.Amount
import qualified Hcompta.Format.Ledger.Read as Ledger.Read
import qualified Hcompta.Format.Ledger.Write as Ledger.Write
import           Hcompta.Lib.Leijen (ToDoc(..))
import qualified Hcompta.Lib.Leijen as W
import qualified Hcompta.Polarize as Polarize

-- | Return 'FilePath's containing 'Hcompta.Format.Ledger.Journal's:
--
-- * either those given if any,
-- * or the one in LEDGER_FILE environment variable if any,
-- * or the one in LEDGER environment variable if any.
paths :: C.Context -> [FilePath] -> IO [FilePath]
paths c [] = do
	tryJust (guard . isDoesNotExistError) $ Env.getEnv "LEDGER_FILE"
	>>= \x -> case x of
	 Right ok -> return [ok]
	 Left  _ko -> do
		tryJust (guard . isDoesNotExistError) $ Env.getEnv "LEDGER"
		>>= \xx -> case xx of
		 Right ok  -> return [ok]
		 Left  _ko -> Write.fatal c Lang.Error_No_input_file_given
paths _c ps = return ps

instance Lang.Translate Ledger.Read.Error W.Doc where
	translate lang err =
		case err of
		 Ledger.Read.Error_date date -> toDoc lang date
		 Ledger.Read.Error_transaction_not_equilibrated styles tr unit_sums ->
			i18n_transaction_not_equilibrated styles tr unit_sums
			 Lang.Error_Transaction_The_following_transaction_is_not_equilibrated_because
		 Ledger.Read.Error_virtual_transaction_not_equilibrated styles tr unit_sums ->
			i18n_transaction_not_equilibrated styles tr unit_sums
			 Lang.Error_Transaction_The_following_virtual_transaction_is_not_equilibrated_because
		 Ledger.Read.Error_reading_file file_path exn ->
			W.vsep $
			 [ Lang.translate lang $ Lang.Error_Failed_to_read_file file_path
			 , W.text $ TL.pack $ show exn
			 ]
		 Ledger.Read.Error_including_file file_path errs ->
			W.vsep $
			 [ Lang.translate lang $ Lang.Error_Failed_to_include_file file_path
			 , Lang.translate lang errs
			 ]
		where
			i18n_transaction_not_equilibrated styles tr unit_sums msg =
				W.vsep $
				 [ Lang.translate lang msg
				 , W.vsep $ List.map
					 (\(unit, Balance.Unit_Sum{Balance.unit_sum_quantity}) ->
						Lang.translate lang $
						Lang.Error_Transaction_Unit_sums_up_to_the_non_null_amount unit $
						Ledger.Amount.style styles $
						Ledger.Amount unit $
						Polarize.depolarize unit_sum_quantity
					 ) unit_sums
				 , W.space
				 , Ledger.Write.transaction styles tr
				 ]