%  Copyright (C) 2007 Florian Weimer
%
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%  the Free Software Foundation; either version 2, or (at your option)
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%  GNU General Public License for more details.
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\darcsCommand{show tags}
\begin{code}
module Darcs.Commands.ShowTags ( showTags ) where
import Darcs.Arguments ( DarcsFlag(..), workingRepoDir )
import Darcs.Commands ( DarcsCommand(..), nodefaults )
import Darcs.Hopefully ( info )
import Darcs.Repository ( amInRepository, readRepo, withRepository, ($-) )
import Darcs.Patch.Info ( piTag )
import Darcs.Patch.Set ( newset2RL )
import Darcs.Witnesses.Ordered ( mapRL )
import System.IO ( stderr, hPutStrLn )
-- import Printer ( renderPS )

showTagsDescription :: String
showTagsDescription = "Show all tags in the repository."

showTagsHelp :: String
showTagsHelp =
 "The tags command writes a list of all tags in the repository to standard\n"++
 "output.\n" ++
 "\n" ++
 "Tab characters (ASCII character 9) in tag names are changed to spaces\n" ++
 "for better interoperability with shell tools.  A warning is printed if\n" ++
 "this happens."

showTags :: DarcsCommand
showTags = DarcsCommand {
  commandName = "tags",
  commandHelp = showTagsHelp,
  commandDescription = showTagsDescription,
  commandExtraArgs = 0,
  commandExtraArgHelp = [],
  commandCommand = tagsCmd,
  commandPrereq = amInRepository,
  commandGetArgPossibilities = return [],
  commandArgdefaults = nodefaults,
  commandAdvancedOptions = [],
  commandBasicOptions = [workingRepoDir] }

tagsCmd :: [DarcsFlag] -> [String] -> IO ()
tagsCmd opts _ = withRepository opts $- \repository -> do
  patches <- readRepo repository
  sequence_ $ mapRL process $ newset2RL patches
  where process hp =
            case piTag $ info hp of
              Just t -> do
                 t' <- normalize t t False
                 putStrLn t'
              Nothing -> return ()
        normalize :: String -> String -> Bool -> IO String
        normalize _ [] _ = return []
        normalize t (x : xs) flag =
            if x == '\t' then do
                  if flag
                    then return ()
                    else hPutStrLn stderr
                             ("warning: tag with TAB character: " ++ t)
                  rest <- (normalize t xs True)
                  return $ ' ' : rest
            else do
                  rest <- (normalize t xs flag)
                  return $ x : rest

\end{code}