%  Copyright (C) 2002-2004 David Roundy
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\darcsCommand{remove}
\begin{code}
{-# OPTIONS_GHC -cpp #-}
{-# LANGUAGE CPP #-}

module Darcs.Commands.Remove ( remove, rm, unadd ) where

import Control.Monad ( when )
import Darcs.Commands ( DarcsCommand(..), nodefaults,
                        command_alias, command_stub,
                      )
import Darcs.Arguments ( DarcsFlag, fixSubPaths,
                        list_registered_files,
                        working_repo_dir, umask_option
                      )
import Darcs.RepoPath ( SubPath, toFilePath, sp2fn )
import Darcs.Repository ( Repository, withRepoLock, ($-), amInRepository,
                          slurp_pending, slurp_recorded,
                          get_unrecorded_in_files, add_to_pending )
import Darcs.Patch ( RepoPatch, Prim, apply_to_slurpy, adddir, rmdir, addfile, rmfile )
import Darcs.Ordered ( FL(..), (+>+) )
import Darcs.SlurpDirectory ( slurp_removedir, slurp_removefile )
import Darcs.Repository.Prefs ( filetype_function )
import Darcs.Diff ( unsafeDiff )
import Darcs.Gorsvet( invalidateIndex )
#include "impossible.h"

remove_description :: String
remove_description = "Remove files from version control."

remove_help :: String
remove_help =
 "The `darcs remove' command exists primarily for symmetry with `darcs\n" ++
 "add', as the normal way to remove a file from version control is\n" ++
 "simply to delete it from the working tree.  This command is only\n" ++
 "useful in the unusual case where one wants to record a removal patch\n" ++
 "WITHOUT deleting the copy in the working tree (which can be re-added).\n" ++
 "\n" ++
 "Note that applying a removal patch to a repository (e.g. by pulling\n" ++
 "the patch) will ALWAYS affect the working tree of that repository.\n"

remove :: DarcsCommand
remove = DarcsCommand {command_name = "remove",
                       command_help = remove_help,
                       command_description = remove_description,
                       command_extra_args = -1,
                       command_extra_arg_help = ["<FILE or DIRECTORY> ..."],
                       command_command = remove_cmd,
                       command_prereq = amInRepository,
                       command_get_arg_possibilities = list_registered_files,
                       command_argdefaults = nodefaults,
                       command_advanced_options = [umask_option],
                       command_basic_options =
                           [working_repo_dir]}

remove_cmd :: [DarcsFlag] -> [String] -> IO ()
remove_cmd opts relargs =
    withRepoLock opts $- \repository -> do
    args <- fixSubPaths opts relargs
    when (null args) $
      putStrLn "Nothing specified, nothing removed."
    p <- make_remove_patch repository args
    invalidateIndex repository
    add_to_pending repository p

make_remove_patch :: RepoPatch p => Repository p -> [SubPath] -> IO (FL Prim)
make_remove_patch repository files =
                          do s <- slurp_pending repository
                             srecorded <- slurp_recorded repository
                             pend <- get_unrecorded_in_files repository (map sp2fn files)
                             let sunrec = fromJust $ apply_to_slurpy pend srecorded
                             wt <- filetype_function
                             mrp wt s sunrec files
    where mrp wt s sunrec (f:fs) =
              case slurp_removedir fn s of
              Just s' ->
                  case slurp_removedir fn sunrec of
                  Just sunrec' -> do rest <- mrp wt s' sunrec' fs
                                     return $ rmdir f_fp :>: rest
                  Nothing -> do rest <- mrp wt s' sunrec fs
                                return $ adddir f_fp :>: rmdir f_fp :>: rest
              Nothing ->
                  case slurp_removefile fn s of
                  Nothing -> fail $ "Can't remove "++f_fp
                  Just s' ->
                      case slurp_removefile fn sunrec of
                      Nothing -> do rest <- mrp wt s' sunrec fs
                                    return $ addfile f_fp :>: rmfile f_fp :>: rest
                      Just sunrec' -> do rest <- mrp wt s' sunrec' fs
                                         let newp = unsafeDiff [] wt sunrec sunrec'
                                         return $ newp +>+ rest
            where fn = sp2fn f
                  f_fp = toFilePath f
          mrp _ _ _ [] = return NilFL

rm_description :: String
rm_description = "Help newbies find `darcs remove'."

rm_help :: String
rm_help =
 "The `darcs rm' command does nothing.\n" ++
 "\n" ++
 "The normal way to remove a file from version control is simply to\n" ++
 "delete it from the working tree.  To remove a file from version\n" ++
 "control WITHOUT affecting the working tree, see `darcs remove'.\n"

rm :: DarcsCommand
rm = command_stub "rm" rm_help rm_description remove

unadd :: DarcsCommand
unadd = command_alias "unadd" remove
\end{code}