--
-- Copyright (c) 2004-06 Don Stewart - http://www.cse.unsw.edu.au/~dons
-- GPL version 2 or later (see http://www.gnu.org/copyleft/gpl.html)
-- 
-- | Dynamic module, binding to the dynamic linker
--
module Plugin.Dynamic (theModule) where

import {-# SOURCE #-} Modules   (plugins)

import Plugin
import Control.Monad.State

PLUGIN Dynamic

instance Module DynamicModule () where

    moduleSticky _ = True
    moduleHelp _ _ = "An interface to dynamic linker"
    modulePrivs  _ = ["dynamic-load","dynamic-unload","dynamic-reload"]

    moduleInit   _ = do
        mapM_ (\p -> load p >> liftIO (putChar '!' >> hFlush stdout)) plugins

    process_ _ s rest = case s of
        "dynamic-load"      -> load rest                >> return ["module loaded"]
        "dynamic-unload"    -> unload rest              >> return ["module unloaded"]
        "dynamic-reload"    -> unload rest >> load rest >> return ["module reloaded"]

--
-- | Load value "theModule" from each plugin, given simple name of a
-- plugin, i.e. "google"
--
load :: String -> LB Bool
load nm = do
    let file = getModuleFile nm
    catchError
        (do (_,md) <- ircLoad file "theModule"
            ircInstallModule md nm
            return True) -- need to put mod in state
        (\_ -> do
            ircUnload file
            liftIO $ putStrLn $ "\nCouldn't load "++nm++", ignoring"
            return False)

--
-- | Unload a module, e.g. "vixen"
--
unload :: String -> LB ()
unload nm = do
        unless (nm `elem` plugins) $ error "unknown or static module"
        ircUnloadModule nm
        ircUnload (getModuleFile nm)

--
-- | Convert simple plugin name to a valid plugin. Could sanity check.
--
getModuleFile :: [Char] -> [Char]
getModuleFile s = "Plugin/" ++ upperise s ++ ".o"
    where
        upperise :: [Char] -> [Char]
        upperise []     = []
        upperise (c:cs) = toUpper c:cs