% GenI surface realiser
% Copyright (C) 2005 Carlos Areces and Eric Kow
%
% 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
% of the License, 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; if not, write to the Free Software
% Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

\chapter{Main}

Welcome to the GenI source code.  The main module is where everything
starts from.  If you're trying to figure out how GenI works, the main
action is in Geni and Tags 
(chapters \ref{cha:Geni} and \ref{cha:Tags}).  

\begin{code}
module Main (main) where
\end{code}

\ignore{
\begin{code}
import Control.Applicative ((<$>))
import Data.IORef(newIORef)
import Data.Typeable( Typeable )
import Data.Version ( showVersion )
import System.Environment(getArgs, getProgName)

import Paths_GenI ( version )

import NLP.GenI.Geni(emptyProgState)
import NLP.GenI.Console(consoleGeni)
import NLP.GenI.Configuration (treatArgs, optionsForStandardGenI, processInstructions,
                               usage, optionsSections, Params,
                               hasFlagP, BatchDirFlg(..), DisableGuiFlg(..),
                               DumpDerivationFlg(..),  FromStdinFlg(..),
                               HelpFlg(..), VersionFlg(..), TestCaseFlg(..),
                               RegressionTestModeFlg(..), RunUnitTestFlg(..),
                              )
import NLP.GenI.Regression (regressionGeni)
import NLP.GenI.Test (runTests)

#ifdef DISABLE_GUI
import NLP.GenI.Configuration(setFlagP)
import NLP.GenI.Geni(ProgStateRef)
#else
import NLP.GenI.Gui(guiGeni)
#endif

#ifdef DISABLE_GUI
guiGeni :: ProgStateRef -> IO ()
guiGeni = consoleGeni
#endif
\end{code}
}

In figure \ref{fig:code-outline-main} we show what happens from main: First, we
hand control off to either the console or the graphical user interface.  These
functions then do all the business stuff like loading files and figuring out
what to generate.  From there, they invoke the the generation step
\fnref{runGeni} which does surface realisation from A-Z.  Alternately, the
graphical interface could invoke a graphical debugger which also does surface
realisation from A-Z but allows you to intervene, inspect and stop at each
step.

\begin{figure}
\begin{center}
\includegraphics[scale=0.25]{images/code-outline-main}
\label{fig:code-outline-main}
\caption{How the GenI entry point is used}
\end{center}
\end{figure}

\begin{code}
main :: IO ()
main = do       
  pname <- getProgName
  args  <- getArgs
  confArgs <- forceGuiFlag <$> (processInstructions =<< treatArgs optionsForStandardGenI args)
  let pst = emptyProgState confArgs
  pstRef <- newIORef pst
  let has :: (Typeable f, Typeable x) => (x -> f) -> Bool
      has = flip hasFlagP confArgs
      mustRunInConsole = has DumpDerivationFlg || has FromStdinFlg || has BatchDirFlg
      canRunInConsole  = has TestCaseFlg
  case () of
   _ | has HelpFlg               -> putStrLn (usage optionsSections pname)
     | has VersionFlg            -> putStrLn ("GenI " ++ showVersion version)
     | has RunUnitTestFlg        -> runTests
     | has RegressionTestModeFlg -> regressionGeni pstRef
     | mustRunInConsole          -> consoleGeni pstRef
     | not (has DisableGuiFlg)   -> guiGeni pstRef
     | canRunInConsole           -> consoleGeni pstRef
     | otherwise                 -> fail $ unlines
        [ "GenI must either be run..."
        , " - with the graphical interface enabled"
        , " - in regression testing mode"
        , " - in self-diagnostic unit test mode"
        , " - with a test case specified"
        , " - with a batch directory specified or"
        , " - with --dump"
        , " - with --from-stdin"
        ]

forceGuiFlag :: Params -> Params
#ifdef DISABLE_GUI
forceGuiFlag = setFlagP DisableGuiFlg ()
#else
forceGuiFlag = id
#endif
\end{code}

% TODO
% Define what is and what is not exported from the modules.  
%      In particular in BTypes take care to export the inspection function 
%      but not the types.
%      Re-write functions in Main as needed.
% Change input in Lexicon and Grammar to allow more than one anchor.