%  Copyright (C) 2002,2003,2005 David Roundy
%
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%  along with this program; see the file COPYING.  If not, write to
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\begin{code}
module Darcs.Commands ( CommandControl( Command_data, Hidden_command, Group_name ),
                       DarcsCommand( DarcsCommand, command_name,
                                     command_help, command_description,
                                     command_basic_options, command_advanced_options,
                                     command_command,
                                     command_prereq,
                                     command_extra_arg_help,
                                     command_extra_args,
                                     command_argdefaults,
                                     command_get_arg_possibilities,
                                     SuperCommand,
                                     command_sub_commands ),
                       command_alias, command_stub,
                       command_options, command_alloptions,
                       disambiguate_commands, CommandArgs(..),
                       get_command_help, get_command_mini_help,
                       get_subcommands,
                       usage, subusage, chomp_newline,
                       extract_commands,
                       super_name,
                       nodefaults,
                       loggers,
                     ) where

import System.Console.GetOpt( OptDescr, usageInfo )

import Data.List ( sort, isPrefixOf )
import Darcs.Arguments ( DarcsFlag, DarcsOption, disable, help,
                         any_verbosity, posthook_cmd, posthook_prompt,
                         prehook_cmd, prehook_prompt, option_from_darcsoption )
import Darcs.RepoPath ( AbsolutePath, rootDirectory )
import Darcs.Utils ( putStrLnError )
import Printer ( Doc, putDocLn )
\end{code}

The general format of a darcs command is
\begin{verbatim}
% darcs COMMAND OPTIONS ARGUMENTS ...
\end{verbatim}
Here \verb|COMMAND| is a command such as \verb|add| or \verb|record|, which of
course may have one or more arguments.  Options have the form
\verb!--option! or \verb!-o!, while arguments vary from command to
command.  There are many options which are common to a number of different
commands, which will be summarized here.

If you wish, you may use any unambiguous beginning of a command name as a
shortcut: for \verb!darcs record!, you could type \verb!darcs recor! or
\verb!darcs rec!, but not \verb!darcs re! since that could be confused with
\verb!darcs replace!, \verb!darcs revert! and \verb!darcs remove!.

In some cases, \verb|COMMAND| actually consists of two words, a
super-command and a subcommand.  For example, the ``display the
manifest'' command has the form \verb|darcs query manifest|.

\paragraph{Command overview}

Not all commands modify the ``patches'' of your repository (that
is, the named patches which other users can pull); some commands only
affect the copy of the source tree you're working on (your ``working
directory''), and some affect both. This table summarizes what you should
expect from each one and will hopefully serve as guide when you're having
doubts about which command to use.

\begin{center}
\footnotetext[1]{But it affects the repository and working directory targeted
  by the push}
\footnotetext[2]{As for the other end, see apply}
\begin{tabular}{|c|c|c|}
\hline
affects & patches & working directory\\
\hline
record & yes & no\\
\hline
unrecord & yes & no\\
\hline
rollback & yes & yes\\
\hline
revert & no & yes\\
\hline
unrevert & no & yes\\
\hline
pull & yes & yes\\
\hline
obliterate & yes & yes\\
\hline
apply & yes & yes\\
\hline
push\footnote{But it affects the repository and working directory targeted by
the push} & no & no\\
\hline
send\footnote{As for the other end, see apply} & no & no\\
\hline
put\footnote{Creates a new repository} & no & no\\
\hline
\end{tabular}
\end{center}

\begin{code}
extract_commands, extract_hidden_commands :: [CommandControl] -> [DarcsCommand]
extract_commands cs = concatMap (\x -> case x of { Command_data cmd_d -> [cmd_d]; _ -> []}) cs
extract_hidden_commands cs = concatMap (\x -> case x of { Hidden_command cmd_d -> [cmd_d]; _ -> []}) cs
\end{code}

\input{Darcs/Arguments.lhs}

\begin{code}
data CommandControl = Command_data DarcsCommand
                    | Hidden_command DarcsCommand
                    | Group_name String

data DarcsCommand =
    DarcsCommand {command_name, command_help, command_description :: String,
                  command_extra_args :: Int,
                  command_extra_arg_help :: [String],
                  command_command :: [DarcsFlag] -> [String] -> IO (),
                  command_prereq :: [DarcsFlag] -> IO (Either String ()),
                  command_get_arg_possibilities :: IO [String],
                  command_argdefaults :: [DarcsFlag] -> AbsolutePath -> [String] -> IO [String],
                  command_basic_options :: [DarcsOption],
                  command_advanced_options :: [DarcsOption]}
  | SuperCommand {command_name, command_help, command_description :: String,
                  command_prereq :: [DarcsFlag] -> IO (Either String ()),
                  command_sub_commands :: [CommandControl]}

command_alloptions :: DarcsCommand -> ([DarcsOption], [DarcsOption])
command_alloptions DarcsCommand { command_basic_options = opts1
                                , command_advanced_options = opts2 }
    = (opts1 ++ [disable, help],
       any_verbosity ++ opts2 ++
                [posthook_cmd, posthook_prompt
                ,prehook_cmd, prehook_prompt])

--  Supercommands cannot be disabled.
command_alloptions SuperCommand { } = ([help],[])

--  Obtain options suitable as input to
--  System.Console.Getopt, including the --disable option (which is
--  not listed explicitly in the DarcsCommand definitions).
command_options :: AbsolutePath -> DarcsCommand -> ([OptDescr DarcsFlag], [OptDescr DarcsFlag])
command_options cwd c = (convert basic, convert advanced)
 where (basic, advanced) = command_alloptions c
       convert = concatMap (option_from_darcsoption cwd)

nodefaults :: [DarcsFlag] -> AbsolutePath -> [String] -> IO [String]
nodefaults _ _ xs = return xs

get_subcommands :: DarcsCommand -> [CommandControl]
get_subcommands c@(SuperCommand {}) = command_sub_commands c
get_subcommands _ = []

command_alias :: String -> DarcsCommand -> DarcsCommand
command_alias n c =
  c { command_name = n
    , command_help = desc ++ "\n" ++ command_help c
    , command_description = desc
    }
 where desc = "Alias for " ++ command_name c

command_stub :: String -> String -> String -> DarcsCommand -> DarcsCommand
command_stub n h d c =
  c { command_name = n
    , command_help = h
    , command_description = d
    , command_command = \_ _ -> putStr h
    }
\end{code}

\begin{code}
usage :: [CommandControl] -> String
usage cs = "Usage: darcs COMMAND ...\n\nCommands:\n" ++
           usage_helper cs ++ "\n" ++
           "Use 'darcs COMMAND --help' for help on a single command.\n" ++
           "Use 'darcs --version' to see the darcs version number.\n" ++
           "Use 'darcs --exact-version' to get the exact version of this darcs instance.\n\n" ++
           "Check bug reports at http://bugs.darcs.net/\n"

subusage :: DarcsCommand -> String
subusage super =
    (usageInfo
     ("Usage: darcs "++command_name super++" SUBCOMMAND ... " ++
      "\n\n"++ command_description super++
      "\n\nSubcommands:\n" ++ usage_helper (get_subcommands super) ++ "\nOptions:")
     (option_from_darcsoption rootDirectory help))
    ++ "\n" ++ command_help super

usage_helper :: [CommandControl] -> String
usage_helper [] = ""
usage_helper (Hidden_command _:cs) = usage_helper cs
usage_helper ((Command_data c):cs) = "  "++pad_spaces (command_name c) 15 ++
                      chomp_newline (command_description c)++"\n"++usage_helper cs
usage_helper ((Group_name n):cs) = n ++ "\n" ++ usage_helper cs

chomp_newline :: String -> String
chomp_newline "" = ""
chomp_newline s = if last s == '\n' then init s else s

pad_spaces :: String -> Int -> String
pad_spaces s n = s ++ replicate (n - length s) ' '

super_name :: Maybe DarcsCommand -> String
super_name Nothing  = ""
super_name (Just x) = command_name x ++ " "

get_command_mini_help :: Maybe DarcsCommand -> DarcsCommand -> String
get_command_mini_help msuper cmd =
  get_command_help_core msuper cmd ++
  "\n\nSee darcs help "
  ++ (maybe "" (\c -> command_name c ++ " ") msuper)
  ++ command_name cmd ++ " for details."

get_command_help :: Maybe DarcsCommand -> DarcsCommand -> String
get_command_help msuper cmd =
    unlines (reverse basicR)
    ++ (if null advanced then ""
        else "\nAdvanced options:\n" ++ unlines (reverse advancedR))
    ++ "\n" ++ command_help cmd
    where -- we could just call usageInfo twice, but then the advanced
          -- options might not line up with the basic ones (no short flags)
          (advancedR, basicR) =
             splitAt (length advanced) $ reverse $ lines combinedUsage
          combinedUsage = usageInfo
            (get_command_help_core msuper cmd ++ subcommands ++ "\n\nOptions:")
            (basic ++ advanced)
          (basic, advanced) = command_options rootDirectory cmd
          subcommands =
            case msuper of
            Nothing -> case get_subcommands cmd of
                       [] -> []
                       s  -> "\n\nSubcommands:\n" ++ (usage_helper s)
            -- we don't want to list subcommands if we're already specifying them
            Just _  -> ""

get_command_help_core :: Maybe DarcsCommand -> DarcsCommand -> String
get_command_help_core msuper cmd =
    "Usage: darcs "++super_name msuper++command_name cmd++
    " [OPTION]... " ++ unwords args_help ++
    "\n"++ command_description cmd
    where args_help = case cmd of
            (DarcsCommand _ _ _ _ _ _ _ _ _ _ _) ->
              command_extra_arg_help cmd
            _ -> []
\end{code}

\begin{code}
data CommandArgs = CommandOnly      DarcsCommand
                 | SuperCommandOnly DarcsCommand
                 | SuperCommandSub  DarcsCommand DarcsCommand

-- Parses a darcs command line with potentially abbreviated commands
disambiguate_commands :: [CommandControl] -> String -> [String]
                      -> Either String (CommandArgs, [String])
disambiguate_commands allcs cmd args =
 do c <- extract cmd allcs
    case (get_subcommands c, args) of
      ([], _)         -> return (CommandOnly c, args)
      (_ ,[])         -> return (SuperCommandOnly c, args)
      (subcs, (a:as)) -> case extract a subcs of
                         Left _   -> return (SuperCommandOnly c, args)
                         Right sc -> return (SuperCommandSub c sc, as)

extract :: String -> [CommandControl] -> Either String DarcsCommand
extract cmd cs =
 case [ c | c <- extract_commands cs, cmd `isPrefixOf` command_name c ] ++
      [ h | h <- extract_hidden_commands cs,    cmd == command_name h ] of
   []  -> Left $ "No such command '" ++ cmd ++ "'\n"
   [c] -> Right c
   cs' -> Left $ "Ambiguous command...\n\n" ++
                    "The command '"++cmd++"' could mean one of:\n" ++
                    unwords (sort $ map command_name cs')
\end{code}

\begin{code}
-- | Output functions equivalent to (putStrLn, hPutStrLn stderr, putDocLn)
loggers :: [DarcsFlag] -> ( String -> IO ()
                          , String -> IO ()
                          , Doc -> IO ())
loggers _ = (putStrLn, putStrLnError, putDocLn)
\end{code}