{-# LANGUAGE CPP #-}
{-
Copyright (C) 2009 John MacFarlane <jgm@berkeley.edu>

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
-}

{- Functions for loading plugins.
-}

module Network.Gitit.Plugins ( loadPlugin, loadPlugins )
where
import Network.Gitit.Types
import System.FilePath (takeBaseName)
import Control.Monad (unless)
import System.Log.Logger (logM, Priority(..))
#ifdef _PLUGINS
import Data.List (isInfixOf, isPrefixOf)
import GHC
import GHC.Paths
import Unsafe.Coerce

loadPlugin :: FilePath -> IO Plugin
loadPlugin :: FilePath -> IO Plugin
loadPlugin FilePath
pluginName = do
  FilePath -> Priority -> FilePath -> IO ()
logM FilePath
"gitit" Priority
WARNING (FilePath
"Loading plugin '" FilePath -> FilePath -> FilePath
forall a. [a] -> [a] -> [a]
++ FilePath
pluginName FilePath -> FilePath -> FilePath
forall a. [a] -> [a] -> [a]
++ FilePath
"'...")
  Maybe FilePath -> Ghc Plugin -> IO Plugin
forall a. Maybe FilePath -> Ghc a -> IO a
runGhc (FilePath -> Maybe FilePath
forall a. a -> Maybe a
Just FilePath
libdir) (Ghc Plugin -> IO Plugin) -> Ghc Plugin -> IO Plugin
forall a b. (a -> b) -> a -> b
$ do
    dflags <- Ghc DynFlags
forall (m :: * -> *). GhcMonad m => m DynFlags
getSessionDynFlags
    setSessionDynFlags dflags
    -- initDynFlags
    unless ("Network.Gitit.Plugin." `isPrefixOf` pluginName)
      $ do
#if __GLASGOW_HASKELL__ >= 904
          addTarget =<< guessTarget pluginName Nothing Nothing
#else
          addTarget =<< guessTarget pluginName Nothing
#endif
          r <- load LoadAllTargets
          case r of
            SuccessFlag
Failed -> FilePath -> Ghc ()
forall a. HasCallStack => FilePath -> a
error (FilePath -> Ghc ()) -> FilePath -> Ghc ()
forall a b. (a -> b) -> a -> b
$ FilePath
"Error loading plugin: " FilePath -> FilePath -> FilePath
forall a. [a] -> [a] -> [a]
++ FilePath
pluginName
            SuccessFlag
Succeeded -> () -> Ghc ()
forall a. a -> Ghc a
forall (m :: * -> *) a. Monad m => a -> m a
return ()
    let modName =
          if FilePath
"Network.Gitit.Plugin" FilePath -> FilePath -> Bool
forall a. Eq a => [a] -> [a] -> Bool
`isPrefixOf` FilePath
pluginName
             then FilePath
pluginName
             else if FilePath
"Network/Gitit/Plugin/" FilePath -> FilePath -> Bool
forall a. Eq a => [a] -> [a] -> Bool
`isInfixOf` FilePath
pluginName
                     then FilePath
"Network.Gitit.Plugin." FilePath -> FilePath -> FilePath
forall a. [a] -> [a] -> [a]
++ FilePath -> FilePath
takeBaseName FilePath
pluginName
                     else FilePath -> FilePath
takeBaseName FilePath
pluginName
    pr <- parseImportDecl "import Prelude"
    i <- parseImportDecl "import Network.Gitit.Interface"
    m <- parseImportDecl ("import " ++ modName)
    setContext [IIDecl m, IIDecl  i, IIDecl pr]
    value <- compileExpr (modName ++ ".plugin :: Plugin")
    let value' = (HValue -> Plugin
forall a b. a -> b
unsafeCoerce HValue
value) :: Plugin
    return value'

#else

loadPlugin :: FilePath -> IO Plugin
loadPlugin pluginName = do
  error $ "Cannot load plugin '" ++ pluginName ++
          "'. gitit was not compiled with plugin support."
  return undefined

#endif

loadPlugins :: [FilePath] -> IO [Plugin]
loadPlugins :: [FilePath] -> IO [Plugin]
loadPlugins [FilePath]
pluginNames = do
  plugins' <- (FilePath -> IO Plugin) -> [FilePath] -> IO [Plugin]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
forall (m :: * -> *) a b. Monad m => (a -> m b) -> [a] -> m [b]
mapM FilePath -> IO Plugin
loadPlugin [FilePath]
pluginNames
  unless (null pluginNames) $ logM "gitit" WARNING "Finished loading plugins."
  return plugins'