{-
Copyright (C) 2006-2018 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
-}

{- |
   Module      : Text.Pandoc.Filter.Lua
   Copyright   : Copyright (C) 2006-2018 John MacFarlane
   License     : GNU GPL, version 2 or above

   Maintainer  : John MacFarlane <jgm@berkeley@edu>
   Stability   : alpha
   Portability : portable

Apply Lua filters to modify a pandoc documents programmatically.
-}
module Text.Pandoc.Filter.Lua (apply) where

import Control.Exception (throw)
import Text.Pandoc.Class (PandocIO)
import Text.Pandoc.Definition (Pandoc)
import Text.Pandoc.Error (PandocError (PandocFilterError))
import Text.Pandoc.Filter.Path (expandFilterPath)
import Text.Pandoc.Lua (LuaException (..), runLuaFilter)
import Text.Pandoc.Options (ReaderOptions)

apply :: ReaderOptions
      -> [String]
      -> FilePath
      -> Pandoc
      -> PandocIO Pandoc
apply ropts args f d = do
  f' <- expandFilterPath f
  let format = case args of
                 (x:_) -> x
                 _     -> error "Format not supplied for lua filter"
  res <- runLuaFilter ropts f' format d
  case res of
    Right x               -> return x
    Left (LuaException s) -> throw (PandocFilterError f s)