module Darcs.Commands.ShowContents ( showContents ) where
import Control.Monad ( filterM, forM_, forM, unless )
import Control.Monad.Trans( liftIO )
import System.IO ( stdout )
import Data.Maybe( fromJust )
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as BL
import Darcs.Commands ( DarcsCommand(..), nodefaults )
import Darcs.Arguments ( DarcsFlag, matchOne,
workingRepoDir, fixSubPaths )
import Darcs.RepoPath ( sp2fn, toFilePath )
import Darcs.Patch.FileName( FileName, fp2fn )
import Darcs.Patch.ApplyMonad ( mReadFilePS, withFiles )
import Darcs.Patch.Match( Matcher )
import Darcs.Match ( haveNonrangeMatch, applyInvToMatcher, nonrangeMatcher
, InclusiveOrExclusive(..), matchExists )
import Darcs.Repository ( withRepository, RepoJob(..), findRepository, readRepo, readRecorded )
import Darcs.Patch( RepoPatch )
import qualified Storage.Hashed.Monad as HSM
import Storage.Hashed.AnchoredPath( floatPath, anchorPath )
showContentsDescription :: String
showContentsDescription = "Outputs a specific version of a file."
showContentsHelp :: String
showContentsHelp =
"Show contents can be used to display an earlier version of some file(s).\n"++
"If you give show contents no version arguments, it displays the recorded\n"++
"version of the file(s).\n"
showContents :: DarcsCommand
showContents = DarcsCommand {commandProgramName = "darcs",
commandName = "contents",
commandHelp = showContentsHelp,
commandDescription = showContentsDescription,
commandExtraArgs = 1,
commandExtraArgHelp
= ["[FILE]..."],
commandCommand = showContentsCmd,
commandPrereq = findRepository,
commandGetArgPossibilities = return [],
commandArgdefaults = nodefaults,
commandAdvancedOptions = [],
commandBasicOptions = [matchOne, workingRepoDir]}
getMatcher :: (RepoPatch p) => [DarcsFlag] -> Matcher p
getMatcher = fromJust . nonrangeMatcher
showContentsCmd :: [DarcsFlag] -> [String] -> IO ()
showContentsCmd _ [] = fail
"show contents needs at least one argument."
showContentsCmd opts args = withRepository opts $ RepoJob $ \repository -> do
path_list <- map sp2fn `fmap` fixSubPaths opts args
pristine <- readRecorded repository
let matcher = getMatcher opts
unapply_to_match = applyInvToMatcher Exclusive matcher
unapply <- if (haveNonrangeMatch opts)
then do patchset <- readRepo repository
unless (matchExists matcher patchset) $
fail $ "Couldn't match pattern " ++ show matcher
return (unapply_to_match patchset)
else return (return ())
let dump :: HSM.TreeIO [(FileName, B.ByteString)]
dump = do okpaths <- filterM HSM.fileExists $ map (floatPath . toFilePath) path_list
forM okpaths $ \f -> do content <- HSM.readFile f
return (fp2fn $ ("./" ++) $ anchorPath "" f, B.concat $ BL.toChunks content)
files <- flip withFiles unapply `fmap` fst `fmap` HSM.virtualTreeIO dump pristine
forM_ files $ \(_, f) -> B.hPut stdout f
return ()