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

import           Control.Monad.IO.Class (liftIO)
import           Control.Monad.Trans.Except (runExceptT)
import qualified Data.Either
import qualified Data.Foldable
import qualified Data.List
import qualified Data.Map.Strict as Data.Map
import qualified Data.Text.Lazy as TL
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           Text.Show.Pretty (ppShow) -- TODO: may be not necessary

import qualified Hcompta.Calc.Balance as Balance
import qualified Hcompta.CLI.Args as Args
import qualified Hcompta.CLI.Context as Context
import qualified Hcompta.CLI.Format.Ledger as CLI.Ledger
import qualified Hcompta.CLI.Lib.Shakespeare.Leijen as I18N
import qualified Hcompta.CLI.Lib.Leijen.Table as Table
import qualified Hcompta.CLI.Write as Write
import qualified Hcompta.Format.Ledger as Ledger
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.Lib.TreeMap as Lib.TreeMap
import qualified Hcompta.Lib.Leijen as W
import           Hcompta.Lib.Leijen (toDoc, ToDoc(..))
import qualified Hcompta.Model.Amount as Amount
import           Hcompta.Model.Amount (Amount, Unit)

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

nil :: Ctx
nil =
	Ctx
	 { ctx_input     = []
	 , ctx_redundant = False
	 }

usage :: IO String
usage = do
	bin <- Env.getProgName
	return $ unlines $
		[ "SYNTAX "
		, "  "++bin++" balance [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"
	, Option "" ["redundant"]
	 (OptArg (\arg context ctx -> do
		redundant <- case arg of
		 Nothing    -> return $ True
		 Just "yes" -> return $ True
		 Just "no"  -> return $ False
		 Just _     -> Write.fatal context $
			W.text "--redundant option expects \"yes\", or \"no\" as value"
		return $ ctx{ctx_redundant=redundant})
	  "[yes|no]")
	 "also print accounts with zero amount or the same amounts than its ascending account"
	]

run :: Context.Context -> [String] -> IO ()
run context args = do
	(ctx, _) <- Args.parse context usage options (nil, args)
	koks <- do
		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
	case koks of
	 (kos@(_:_), _oks) ->
		(flip mapM_) kos $ \(_path, ko) -> do
			Write.debug context $ ppShow $ ko
			Write.fatal context $ toDoc context ko
	 ([], journals) -> do
		let balance =
			Data.List.foldr
			 (Ledger.Journal.fold
				 (flip (Data.Foldable.foldr
					 (flip (Data.Foldable.foldr
						 ( flip Balance.union
						 . Ledger.transaction_postings_balance))))
				 . Ledger.journal_transactions))
			 Balance.balance
			 journals
		let expanded = Balance.expanded $ Balance.balance_by_account balance
		style_color <- Write.with_color context IO.stdout
		Ledger.Write.put Ledger.Write.Style
		 { Ledger.Write.style_align = True
		 , Ledger.Write.style_color
		 } IO.stdout $ do
			toDoc () $
				let title = TL.toStrict . W.displayT . W.renderCompact False .
					I18N.renderMessage Context.App (Context.langs context) in
				zipWith id
				[ Table.column (title Write.I18N_Balance_debit)  Table.Align_Right
				, Table.column (title Write.I18N_Balance_credit) Table.Align_Right
				, Table.column (title Write.I18N_Balance_total)  Table.Align_Right
				, Table.column (title Write.I18N_Account)        Table.Align_Left
				] $
				flip (write_by_accounts ctx) expanded $
				zipWith (:)
					[ Table.Cell_Line '=' 0
					, Table.Cell_Line '=' 0
					, Table.Cell_Line '=' 0
					, Table.Cell_Line ' ' 0
					] $
				write_by_amounts (repeat []) $
					Data.Map.map
					 Balance.unit_sum_amount
					 (Balance.balance_by_unit balance)
write_by_accounts
 :: Ctx
 -> [[Table.Cell]]
 -> Balance.Expanded Amount Unit
 -> [[Table.Cell]]
write_by_accounts ctx =
	let posting_type = Ledger.Posting_Type_Regular in
	Lib.TreeMap.foldr_with_Path_and_Node
	 (\account node balance rows -> do
		let descendants = Lib.TreeMap.nodes
			 (Lib.TreeMap.node_descendants node)
		let is_worth =
			ctx_redundant ctx
			|| Data.Map.size
				 (Data.Map.filter
					 (not . Amount.is_zero)
					 (Balance.exclusive balance)) > 0
			|| Data.Map.size
				 (Data.Map.filter
					 ( maybe False (not . Amount.are_zero . Balance.amount_sum_balance . Balance.inclusive)
					 . Lib.TreeMap.node_value )
					 descendants) > 1
		case is_worth of
		 False -> rows
		 True ->
			Data.List.foldr
			 (\(amount_positive, amount_negative, amount) ->
				zipWith (:)
					[ Table.cell
					 { Table.cell_content = maybe W.empty Ledger.Write.amount  amount_positive
					 , Table.cell_width   = maybe 0 Ledger.Write.amount_length amount_positive
					 }
					, Table.cell
					 { Table.cell_content = maybe W.empty Ledger.Write.amount  amount_negative
					 , Table.cell_width   = maybe 0 Ledger.Write.amount_length amount_negative
					 }
					, Table.cell
					 { Table.cell_content = Ledger.Write.amount        $ amount
					 , Table.cell_width   = Ledger.Write.amount_length $ amount
					 }
					, Table.cell
					 { Table.cell_content = Ledger.Write.account        posting_type account
					 , Table.cell_width   = Ledger.Write.account_length posting_type account
					 }
					]
			 )
			 rows
			 (zipWith3 (,,)
				 ((map Just $ Data.Map.elems $ Balance.amount_sum_positive $ Balance.inclusive balance) ++ repeat Nothing)
				 ((map Just $ Data.Map.elems $ Balance.amount_sum_negative $ Balance.inclusive balance) ++ repeat Nothing)
				 (Data.Map.elems $ Balance.amount_sum_balance $ Balance.inclusive balance))
	 )

write_by_amounts
 :: [[Table.Cell]]
 -> Data.Map.Map Unit (Balance.Amount_Sum Amount ())
 -> [[Table.Cell]]
write_by_amounts =
	Data.Map.foldr
	 (\amount_sum ->
		zipWith (:)
			[ let amt = Data.Map.lookup () $ Balance.amount_sum_positive amount_sum in
				Table.cell
				 { Table.cell_content = maybe W.empty Ledger.Write.amount  amt
				 , Table.cell_width   = maybe 0 Ledger.Write.amount_length amt
				 }
			, let amt = Data.Map.lookup () $ Balance.amount_sum_negative amount_sum in
				Table.cell
				 { Table.cell_content = maybe W.empty Ledger.Write.amount  amt
				 , Table.cell_width   = maybe 0 Ledger.Write.amount_length amt
				 }
			, let amt = Data.Map.lookup () $ Balance.amount_sum_balance amount_sum in
				Table.cell
				 { Table.cell_content = maybe W.empty Ledger.Write.amount  amt
				 , Table.cell_width   = maybe 0 Ledger.Write.amount_length amt
				 }
			, Table.cell
				 { Table.cell_content = W.empty
				 , Table.cell_width   = 0
				 }
			]
	 )