{-
Copyright (C) 2008 Joachim Breitner

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
-}

module Darcs.Watch.PullRepos where

import Control.Monad
import Control.Concurrent
import Control.Applicative
import Control.Exception
import Prelude hiding (catch)
import System.Environment (getArgs)
import System.Directory
import System.Posix.Files
import System.Time
import System.IO
import System.Terminal.Concurrent

import qualified Data.Map as M
import qualified Data.Set as S
import qualified MultiMap as MM
import MultiMap ((!!!!))
import Data.Char
import Data.List

import qualified Data.ByteString.Char8 as B
import Data.ByteString.Char8 (ByteString)
import Data.Digest.OpenSSL.MD5 (md5sum)
import Data.Maybe
import System.FilePath

-- Darcs stuff
import Darcs
import Darcs.Watch.Storage
import Darcs.Watch.Data
-- Web ouput
import HTML
--import LockRestart


pullRepos :: DarcsWatchConfig -> IO Bool
pullRepos config = do
	writeC <- getConcurrentOutputter

        putStrLn "Updating repositories..."
	let updateRepo rep = do
                writeC $ "Updating " ++ rep ++ ":\n"
		catch ( do
			thisNew <- updateRepository (cData config) writeC rep
			writeC (if thisNew then "Repostory is new.\n" else "Repository is cached.\n")
			return thisNew
		 ) (\e -> writeC ("Error Updateing " ++ rep ++ ": " ++ show (e::SomeException) ++ "\n") >> return False)
	new <- or <$> forkSequence (map updateRepo (cRepositories config))

        unless new $ putStrLn "Nothing new found"
	return new

{- forkSequence = sequence -}
-- Enable for parallel downloads
forkSequence acts = do
    sem <- newQSem 5
    mvars <- forM acts $ \act -> do
        mvar <- newEmptyMVar
        forkIO $ do 
            waitQSem sem
            catch (act >>= putMVar mvar) (\e -> putMVar mvar (throw (e::SomeException)))
            signalQSem sem
        return mvar
    mapM takeMVar mvars