--------------------------------------------------------------------------------
--  $Id: HaskellConfig.hs,v 1.3 2003/12/18 18:29:03 graham Exp $
--
--  Copyright (c) 2004, G. KLYNE.  All rights reserved.
--  See end of this file for licence information.
--------------------------------------------------------------------------------
-- |
--  Module      :  HaskellConfig
--  Copyright   :  (c) 2003, Graham Klyne
--  License     :  GPL V2
--
--  Maintainer  :  Graham Klyne
--  Stability   :  provisional
--  Portability :  H98
--
--  This module contains functions that retrieve information about the
--  Haskell installation and configuration parameters for the system
--  under which the current program is running.
--
--  The intent is that this module can be easily replaced to capture the
--  idiosyncrasies of different systems and Haskell installations.
--
--------------------------------------------------------------------------------

module Distribution.HaskellConfig
    ( HaskellConfig(..)
    , getHaskellConfig
    , ProgramConfig(..)
    , getProgramConfig
    )
where

import Distribution.Version
    ( Version(..) )

import Time
    ( Month(..) )

import Directory
    ( getCurrentDirectory )

import System
    ( getProgName, getArgs, getEnv )

import Monad
    ( liftM )

------------------------------------------------------------
--  System and Haskell configuration information datatype
------------------------------------------------------------

data HaskellConfig = HaskellConfig
    { machineType   :: [String]         -- Machine architecture name
    , intBigEndian  :: Bool             -- Big-endian?  (else little-endian)
    , systemType    :: [String]         -- Identify system type
    , haskellName   :: String           -- Haskell compiler name
    , haskellVers   :: Version          -- Haskell compiler version
    , intSize       :: Int              -- Number of bits in an Int
    , configDir     :: FilePath         -- Base directory for config files
    -- , configKey     :: String           -- Configuration key string
    }

--  Machine CPU type identifiers
--  Additional list elements may be added to refine the machine information
machineI86      = ["I86"]
machineSparc    = ["Sparc"]
machinePPC      = ["PPC"]
machineARM      = ["ARM"]

--  System type identifiers:
--  Start with generic classification and add refining information
--  finer refinements may be added over time, as needed.  For most
--  purposes, the first component should be sufficient to determine
--  system-dependent behaviours.
--
systemRedHat    = ["Posix","Linux","RedHat"]
systemSuse      = ["Posix","Linux","Suse"]
systemMaxOSX    = ["Posix","Linux","Suse"]
systemWin2000   = ["Win32","Win2K"]
systemWinXP     = ["Win32","WinXP"]
systemWinNT     = ["Win32","WinNT"]

-- Haskell compiler names
--
haskellGHC      = "GHC"
haskellHugs     = "Hugs"
haskellNHC      = "NHC"
haskellHBC      = "HBC"
haskellHBI      = "HBI"

------------------------------------------------------------
--  getHaskellConfig
------------------------------------------------------------

getHaskellConfig :: (HaskellConfig -> a) -> IO a
getHaskellConfig sel = liftM sel haskellConfig

--  Static implementation;  could use system calls to be more flexible.
--  (Does memoization work inside the I/O monad?  Does it matter?)
haskellConfig :: IO HaskellConfig
haskellConfig = return HaskellConfig
    { machineType   = machineI86
    , intBigEndian  = False
    , systemType    = systemWinXP
    , haskellName   = "Hugs"
    , haskellVers   = DateVersion 2002 November 0
    , intSize       = 32
    , configDir     = "C:\\DEV\\Hugs98"
    }

------------------------------------------------------------
--  Running program configuration data
------------------------------------------------------------

{- programArgs included here for experimentation, and is not needed -}

data ProgramConfig = ProgramConfig
    { programFile   :: FilePath         -- Program file name
    , programArgs   :: [String]         -- Program arguments
    , programDir    :: FilePath         -- Base directory for config files
    }

--  Parameterized by base program name, as Hugs doesn't seem to provide a
--  way to get at the main program module name.  The actual program name
--  should be used where available.
--
getProgramConfig :: String -> (ProgramConfig -> a) -> IO a
getProgramConfig pn sel = liftM sel (programConfig pn)

--  This needs working on.  The idea is to return information that allows a
--  program to access associated data and configuration information.
--
programConfig :: String -> IO ProgramConfig
programConfig pn =
    do  { -- pn <- getProgName
        ; ar <- getArgs
        ; cd <- getCurrentDirectory
        ; return ProgramConfig
            { programFile   = cd++"\\"++pn
            , programArgs   = ar
            , programDir    = cd
            }
        }

--------------------------------------------------------------------------------
--
--  Copyright (c) 2004, G. KLYNE.  All rights reserved.
--
--  This 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 software 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 Swish; if not, write to:
--    The Free Software Foundation, Inc.,
--    59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
--
--------------------------------------------------------------------------------
-- $Source: /file/cvsdev/HaskellRDF/HaskellConfig.hs,v $
-- $Author: graham $
-- $Revision: 1.3 $
-- $Log: HaskellConfig.hs,v $