pandoc/src/Text/Pandoc/Writers/Custom.hs

{-# OPTIONS_GHC -fno-warn-orphans #-}
{-# LANGUAGE CPP                  #-}
{-# LANGUAGE DeriveDataTypeable   #-}
{-# LANGUAGE FlexibleInstances    #-}
#if MIN_VERSION_base(4,8,0)
#else
{-# LANGUAGE OverlappingInstances #-}
#endif
{- Copyright (C) 2012-2015 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.Writers.Custom
   Copyright   : Copyright (C) 2012-2015 John MacFarlane
   License     : GNU GPL, version 2 or above

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

Conversion of 'Pandoc' documents to custom markup using
a lua writer.
-}
module Text.Pandoc.Writers.Custom ( writeCustom ) where
import Control.Exception
import Control.Monad (when)
import Data.Char (toLower)
import Data.List (intersperse)
import qualified Data.Map as M
import Data.Typeable
import GHC.IO.Encoding (getForeignEncoding, setForeignEncoding, utf8)
import Scripting.Lua (LuaState, StackValue, callfunc)
import qualified Scripting.Lua as Lua
import Text.Pandoc.Lua.Compat ( loadstring )
import Text.Pandoc.Lua.Util ( addValue )
import Text.Pandoc.Lua.SharedInstances ()
import Text.Pandoc.Definition
import Text.Pandoc.Options
import Text.Pandoc.Templates
import qualified Text.Pandoc.UTF8 as UTF8
import Text.Pandoc.Writers.Shared

attrToMap :: Attr -> M.Map String String
attrToMap (id',classes,keyvals) = M.fromList
    $ ("id", id')
    : ("class", unwords classes)
    : keyvals

instance StackValue Format where
  push lua (Format f) = Lua.push lua (map toLower f)
  peek l n = fmap Format `fmap` Lua.peek l n
  valuetype _ = Lua.TSTRING

#if MIN_VERSION_base(4,8,0)
instance {-# OVERLAPS #-} StackValue [Inline] where
#else
instance StackValue [Inline] where
#endif
  push l ils = Lua.push l =<< inlineListToCustom l ils
  peek _ _ = undefined
  valuetype _ = Lua.TSTRING

#if MIN_VERSION_base(4,8,0)
instance {-# OVERLAPS #-} StackValue [Block] where
#else
instance StackValue [Block] where
#endif
  push l ils = Lua.push l =<< blockListToCustom l ils
  peek _ _ = undefined
  valuetype _ = Lua.TSTRING

instance StackValue MetaValue where
  push l (MetaMap m)       = Lua.push l m
  push l (MetaList xs)     = Lua.push l xs
  push l (MetaBool x)      = Lua.push l x
  push l (MetaString s)    = Lua.push l s
  push l (MetaInlines ils) = Lua.push l ils
  push l (MetaBlocks bs)   = Lua.push l bs
  peek _ _ = undefined
  valuetype (MetaMap _)     = Lua.TTABLE
  valuetype (MetaList _)    = Lua.TTABLE
  valuetype (MetaBool _)    = Lua.TBOOLEAN
  valuetype (MetaString _)  = Lua.TSTRING
  valuetype (MetaInlines _) = Lua.TSTRING
  valuetype (MetaBlocks _)  = Lua.TSTRING

instance StackValue Citation where
  push lua cit = do
    Lua.createtable lua 6 0
    addValue lua "citationId" $ citationId cit
    addValue lua "citationPrefix" $ citationPrefix cit
    addValue lua "citationSuffix" $ citationSuffix cit
    addValue lua "citationMode" $ show (citationMode cit)
    addValue lua "citationNoteNum" $ citationNoteNum cit
    addValue lua "citationHash" $ citationHash cit
  peek = undefined
  valuetype _ = Lua.TTABLE

data PandocLuaException = PandocLuaException String
    deriving (Show, Typeable)

instance Exception PandocLuaException

-- | Convert Pandoc to custom markup.
writeCustom :: FilePath -> WriterOptions -> Pandoc -> IO String
writeCustom luaFile opts doc@(Pandoc meta _) = do
  luaScript <- UTF8.readFile luaFile
  enc <- getForeignEncoding
  setForeignEncoding utf8
  lua <- Lua.newstate
  Lua.openlibs lua
  status <- loadstring lua luaScript luaFile
  -- check for error in lua script (later we'll change the return type
  -- to handle this more gracefully):
  when (status /= 0) $
    Lua.tostring lua 1 >>= throw . PandocLuaException . UTF8.toString
  Lua.call lua 0 0
  -- TODO - call hierarchicalize, so we have that info
  rendered <- docToCustom lua opts doc
  context <- metaToJSON opts
             (blockListToCustom lua)
             (inlineListToCustom lua)
             meta
  Lua.close lua
  setForeignEncoding enc
  let body = rendered
  case writerTemplate opts of
       Nothing  -> return body
       Just tpl -> return $ renderTemplate' tpl $ setField "body" body context

docToCustom :: LuaState -> WriterOptions -> Pandoc -> IO String
docToCustom lua opts (Pandoc (Meta metamap) blocks) = do
  body <- blockListToCustom lua blocks
  callfunc lua "Doc" body metamap (writerVariables opts)

-- | Convert Pandoc block element to Custom.
blockToCustom :: LuaState      -- ^ Lua state
              -> Block         -- ^ Block element
              -> IO String

blockToCustom _ Null = return ""

blockToCustom lua (Plain inlines) = callfunc lua "Plain" inlines

blockToCustom lua (Para [Image attr txt (src,tit)]) =
  callfunc lua "CaptionedImage" src tit txt (attrToMap attr)

blockToCustom lua (Para inlines) = callfunc lua "Para" inlines

blockToCustom lua (LineBlock linesList) = callfunc lua "LineBlock" linesList

blockToCustom lua (RawBlock format str) =
  callfunc lua "RawBlock" format str

blockToCustom lua HorizontalRule = callfunc lua "HorizontalRule"

blockToCustom lua (Header level attr inlines) =
  callfunc lua "Header" level inlines (attrToMap attr)

blockToCustom lua (CodeBlock attr str) =
  callfunc lua "CodeBlock" str (attrToMap attr)

blockToCustom lua (BlockQuote blocks) = callfunc lua "BlockQuote" blocks

blockToCustom lua (Table capt aligns widths headers rows') =
  callfunc lua "Table" capt (map show aligns) widths headers rows'

blockToCustom lua (BulletList items) = callfunc lua "BulletList" items

blockToCustom lua (OrderedList (num,sty,delim) items) =
  callfunc lua "OrderedList" items num (show sty) (show delim)

blockToCustom lua (DefinitionList items) =
  callfunc lua "DefinitionList" items

blockToCustom lua (Div attr items) =
  callfunc lua "Div" items (attrToMap attr)

-- | Convert list of Pandoc block elements to Custom.
blockListToCustom :: LuaState -- ^ Options
                  -> [Block]       -- ^ List of block elements
                  -> IO String
blockListToCustom lua xs = do
  blocksep <- callfunc lua "Blocksep"
  bs <- mapM (blockToCustom lua) xs
  return $ mconcat $ intersperse blocksep bs

-- | Convert list of Pandoc inline elements to Custom.
inlineListToCustom :: LuaState -> [Inline] -> IO String
inlineListToCustom lua lst = do
  xs <- mapM (inlineToCustom lua) lst
  return $ concat xs

-- | Convert Pandoc inline element to Custom.
inlineToCustom :: LuaState -> Inline -> IO String

inlineToCustom lua (Str str) = callfunc lua "Str" str

inlineToCustom lua Space = callfunc lua "Space"

inlineToCustom lua SoftBreak = callfunc lua "SoftBreak"

inlineToCustom lua (Emph lst) = callfunc lua "Emph" lst

inlineToCustom lua (Strong lst) = callfunc lua "Strong" lst

inlineToCustom lua (Strikeout lst) = callfunc lua "Strikeout" lst

inlineToCustom lua (Superscript lst) = callfunc lua "Superscript" lst

inlineToCustom lua (Subscript lst) = callfunc lua "Subscript" lst

inlineToCustom lua (SmallCaps lst) = callfunc lua "SmallCaps" lst

inlineToCustom lua (Quoted SingleQuote lst) = callfunc lua "SingleQuoted" lst

inlineToCustom lua (Quoted DoubleQuote lst) = callfunc lua "DoubleQuoted" lst

inlineToCustom lua (Cite cs lst) = callfunc lua "Cite" lst cs

inlineToCustom lua (Code attr str) =
  callfunc lua "Code" str (attrToMap attr)

inlineToCustom lua (Math DisplayMath str) =
  callfunc lua "DisplayMath" str

inlineToCustom lua (Math InlineMath str) =
  callfunc lua "InlineMath" str

inlineToCustom lua (RawInline format str) =
  callfunc lua "RawInline" format str

inlineToCustom lua (LineBreak) = callfunc lua "LineBreak"

inlineToCustom lua (Link attr txt (src,tit)) =
  callfunc lua "Link" txt src tit (attrToMap attr)

inlineToCustom lua (Image attr alt (src,tit)) =
  callfunc lua "Image" alt src tit (attrToMap attr)

inlineToCustom lua (Note contents) = callfunc lua "Note" contents

inlineToCustom lua (Span attr items) =
  callfunc lua "Span" items (attrToMap attr)