    {-# LANGUAGE OverloadedStrings #-}
    {-
    Copyright (C) 2006-2010 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.AsciiDoc
       Copyright   : Copyright (C) 2006-2010 John MacFarlane
       License     : GNU GPL, version 2 or above

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

    Conversion of 'Pandoc' documents to asciidoc.

    Note that some information may be lost in conversion, due to
    expressive limitations of asciidoc.  Footnotes and table cells with
    paragraphs (or other block items) are not possible in asciidoc.
    If pandoc encounters one of these, it will insert a message indicating
    that it has omitted the construct.

    AsciiDoc:  <http://www.methods.co.nz/asciidoc/>
    -}
    module Text.Pandoc.Writers.AsciiDoc (writeAsciiDoc) where
    import Text.Pandoc.Definition
    import Text.Pandoc.Templates (renderTemplate')
    import Text.Pandoc.Shared
    import Text.Pandoc.Writers.Shared
    import Text.Pandoc.Options
    import Text.Pandoc.Parsing hiding (blankline, space)
    import Data.List ( isPrefixOf, intersperse, intercalate )
    import Text.Pandoc.Pretty
    import Control.Monad.State
    import qualified Data.Map as M
    import Data.Aeson (Value(String), fromJSON, toJSON, Result(..))
    import qualified Data.Text as T

    data WriterState = WriterState { defListMarker :: String
                                   , orderedListLevel :: Int
                                   , bulletListLevel  :: Int
                                   }

    -- | Convert Pandoc to AsciiDoc.
    writeAsciiDoc :: WriterOptions -> Pandoc -> String
    writeAsciiDoc opts document =
      evalState (pandocToAsciiDoc opts document) WriterState{
          defListMarker = "::"
        , orderedListLevel = 1
        , bulletListLevel = 1
        }

    -- | Return asciidoc representation of document.
    pandocToAsciiDoc :: WriterOptions -> Pandoc -> State WriterState String
    pandocToAsciiDoc opts (Pandoc meta blocks) = do
      let titleblock = not $ null (docTitle meta) && null (docAuthors meta) &&
                             null (docDate meta)
      let colwidth = if writerWrapText opts
                        then Just $ writerColumns opts
                        else Nothing
      metadata <- metaToJSON opts
                  (fmap (render colwidth) . blockListToAsciiDoc opts)
                  (fmap (render colwidth) . inlineListToAsciiDoc opts)
                  meta
      let addTitleLine (String t) = String $
             t <> "\n" <> T.replicate (T.length t) "="
          addTitleLine x = x
      let metadata' = case fromJSON metadata of
                            Success m  -> toJSON $ M.adjust addTitleLine
                                                     ("title" :: T.Text) m
                            _          -> metadata
      body <- blockListToAsciiDoc opts blocks
      let main = render colwidth body
      let context  = defField "body" main
                   $ defField "toc"
                      (writerTableOfContents opts && writerStandalone opts)
                   $ defField "titleblock" titleblock
                   $ metadata'
      if writerStandalone opts
         then return $ renderTemplate' (writerTemplate opts) context
         else return main

    -- | Escape special characters for AsciiDoc.
    escapeString :: String -> String
    escapeString = escapeStringUsing escs
      where escs = backslashEscapes "{"

    -- | Ordered list start parser for use in Para below.
    olMarker :: Parser [Char] ParserState Char
    olMarker = do (start, style', delim) <- anyOrderedListMarker
                  if delim == Period &&
                              (style' == UpperAlpha || (style' == UpperRoman &&
                              start `elem` [1, 5, 10, 50, 100, 500, 1000]))
                              then spaceChar >> spaceChar
                              else spaceChar

    -- | True if string begins with an ordered list marker
    beginsWithOrderedListMarker :: String -> Bool
    beginsWithOrderedListMarker str =
      case runParser olMarker defaultParserState "para start" (take 10 str) of
             Left  _  -> False
             Right _  -> True

    -- | Convert Pandoc block element to asciidoc.
    blockToAsciiDoc :: WriterOptions -- ^ Options
                    -> Block         -- ^ Block element
                    -> State WriterState Doc
    blockToAsciiDoc _ Null = return empty
    blockToAsciiDoc opts (Plain inlines) = do
      contents <- inlineListToAsciiDoc opts inlines
      return $ contents <> cr
    blockToAsciiDoc opts (Para [Image alt (src,'f':'i':'g':':':tit)]) =
      blockToAsciiDoc opts (Para [Image alt (src,tit)])
    blockToAsciiDoc opts (Para inlines) = do
      contents <- inlineListToAsciiDoc opts inlines
      -- escape if para starts with ordered list marker
      let esc = if beginsWithOrderedListMarker (render Nothing contents)
                   then text "\\"
                   else empty
      return $ esc <> contents <> blankline
    blockToAsciiDoc _ (RawBlock f s)
      | f == "asciidoc" = return $ text s
      | otherwise       = return empty
    blockToAsciiDoc _ HorizontalRule =
      return $ blankline <> text "'''''" <> blankline
    blockToAsciiDoc opts (Header level (ident,_,_) inlines) = do
      contents <- inlineListToAsciiDoc opts inlines
      let len = offset contents
      -- ident seem to be empty most of the time and asciidoc will generate them automatically
      -- so lets make them not show up when null
      let identifier = if (null ident) then empty else ("[[" <> text ident <> "]]")
      let setext = writerSetextHeaders opts
      return $
             (if setext
                then
                  identifier $$ contents $$
                  (case level of
                   1  -> text $ replicate len '-'
                   2  -> text $ replicate len '~'
                   3  -> text $ replicate len '^'
                   4  -> text $ replicate len '+'
                   _  -> empty) <> blankline
                else
                  identifier $$ text (replicate level '=') <> space <> contents <> blankline)
    blockToAsciiDoc _ (CodeBlock (_,classes,_) str) = return $
      flush (attrs <> dashes <> space <> attrs <> cr <> text str <>
               cr <> dashes) <> blankline
         where dashes  = text $ replicate (maximum $ map length $ lines str) '-'
               attrs = if null classes
                          then empty
                          else text $ intercalate "," $ "code" : classes
    blockToAsciiDoc opts (BlockQuote blocks) = do
      contents <- blockListToAsciiDoc opts blocks
      let isBlock (BlockQuote _) = True
          isBlock _              = False
      -- if there are nested block quotes, put in an open block
      let contents' = if any isBlock blocks
                         then "--" $$ contents $$ "--"
                         else contents
      let cols = offset contents'
      let bar = text $ replicate cols '_'
      return $ bar $$ chomp contents' $$ bar <> blankline
    blockToAsciiDoc opts (Table caption aligns widths headers rows) =  do
      caption' <- inlineListToAsciiDoc opts caption
      let caption'' = if null caption
                         then empty
                         else "." <> caption' <> cr
      let isSimple = all (== 0) widths
      let relativePercentWidths = if isSimple
                                     then widths
                                     else map (/ (sum widths)) widths
      let widths'' :: [Integer]
          widths'' = map (floor . (* 100)) relativePercentWidths
      -- ensure that the widths sum to 100
      let widths' = case widths'' of
                         _ | isSimple -> widths''
                         (w:ws) | sum (w:ws) < 100
                                   -> (100 - sum ws) : ws
                         ws        -> ws
      let totalwidth :: Integer
          totalwidth = floor $ sum widths * 100
      let colspec al wi = (case al of
                             AlignLeft    -> "<"
                             AlignCenter  -> "^"
                             AlignRight   -> ">"
                             AlignDefault -> "") ++
                          if wi == 0 then "" else (show wi ++ "%")
      let headerspec = if all null headers
                          then empty
                          else text "options=\"header\","
      let widthspec = if totalwidth == 0
                         then empty
                         else text "width="
                              <> doubleQuotes (text $ show totalwidth ++ "%")
                              <> text ","
      let tablespec = text "["
             <> widthspec
             <> text "cols="
             <> doubleQuotes (text $ intercalate ","
                 $ zipWith colspec aligns widths')
             <> text ","
             <> headerspec <> text "]"
      let makeCell [Plain x] = do d <- blockListToAsciiDoc opts [Plain x]
                                  return $ text "|" <> chomp d
          makeCell [Para x]  = makeCell [Plain x]
          makeCell _         = return $ text "|" <> "[multiblock cell omitted]"
      let makeRow cells = hsep `fmap` mapM makeCell cells
      rows' <- mapM makeRow rows
      head' <- makeRow headers
      let head'' = if all null headers then empty else head'
      let colwidth = if writerWrapText opts
                        then writerColumns opts
                        else 100000
      let maxwidth = maximum $ map offset (head':rows')
      let body = if maxwidth > colwidth then vsep rows' else vcat rows'
      let border = text $ "|" ++ replicate ((min maxwidth colwidth) - 1) '='
      return $
        caption'' $$ tablespec $$ border $$ head'' $$ body $$ border $$ blankline
    blockToAsciiDoc opts (BulletList items) = do
      contents <- mapM (bulletListItemToAsciiDoc opts) items
      return $ cat contents <> blankline
    blockToAsciiDoc opts (OrderedList (_start, sty, _delim) items) = do
      let sty' = case sty of
                      UpperRoman -> UpperAlpha
                      LowerRoman -> LowerAlpha
                      x          -> x
      let markers  = orderedListMarkers (1, sty', Period)  -- start num not used
      let markers' = map (\m -> if length m < 3
                                   then m ++ replicate (3 - length m) ' '
                                   else m) markers
      contents <- mapM (\(item, num) -> orderedListItemToAsciiDoc opts item num) $
                  zip markers' items
      return $ cat contents <> blankline
    blockToAsciiDoc opts (DefinitionList items) = do
      contents <- mapM (definitionListItemToAsciiDoc opts) items
      return $ cat contents <> blankline
    blockToAsciiDoc opts (Div _ bs) = blockListToAsciiDoc opts bs

    -- | Convert bullet list item (list of blocks) to asciidoc.
    bulletListItemToAsciiDoc :: WriterOptions -> [Block] -> State WriterState Doc
    bulletListItemToAsciiDoc opts blocks = do
      let addBlock :: Doc -> Block -> State WriterState Doc
          addBlock d b | isEmpty d    = chomp `fmap` blockToAsciiDoc opts b
          addBlock d b@(BulletList _) = do x <- blockToAsciiDoc opts b
                                           return $ d <> cr <> chomp x
          addBlock d b@(OrderedList _ _) = do x <- blockToAsciiDoc opts b
                                              return $ d <> cr <> chomp x
          addBlock d b = do x <- blockToAsciiDoc opts b
                            return $ d <> cr <> text "+" <> cr <> chomp x
      lev <- bulletListLevel `fmap` get
      modify $ \s -> s{ bulletListLevel = lev + 1 }
      contents <- foldM addBlock empty blocks
      modify $ \s -> s{ bulletListLevel = lev }
      let marker = text (replicate lev '*')
      return $ marker <> space <> contents <> cr

    -- | Convert ordered list item (a list of blocks) to asciidoc.
    orderedListItemToAsciiDoc :: WriterOptions -- ^ options
                              -> String        -- ^ list item marker
                              -> [Block]       -- ^ list item (list of blocks)
                              -> State WriterState Doc
    orderedListItemToAsciiDoc opts marker blocks = do
      let addBlock :: Doc -> Block -> State WriterState Doc
          addBlock d b | isEmpty d    = chomp `fmap` blockToAsciiDoc opts b
          addBlock d b@(BulletList _) = do x <- blockToAsciiDoc opts b
                                           return $ d <> cr <> chomp x
          addBlock d b@(OrderedList _ _) = do x <- blockToAsciiDoc opts b
                                              return $ d <> cr <> chomp x
          addBlock d b = do x <- blockToAsciiDoc opts b
                            return $ d <> cr <> text "+" <> cr <> chomp x
      lev <- orderedListLevel `fmap` get
      modify $ \s -> s{ orderedListLevel = lev + 1 }
      contents <- foldM addBlock empty blocks
      modify $ \s -> s{ orderedListLevel = lev }
      return $ text marker <> space <> contents <> cr

    -- | Convert definition list item (label, list of blocks) to asciidoc.
    definitionListItemToAsciiDoc :: WriterOptions
                                 -> ([Inline],[[Block]])
                                 -> State WriterState Doc
    definitionListItemToAsciiDoc opts (label, defs) = do
      labelText <- inlineListToAsciiDoc opts label
      marker <- defListMarker `fmap` get
      if marker == "::"
         then modify (\st -> st{ defListMarker = ";;"})
         else modify (\st -> st{ defListMarker = "::"})
      let divider = cr <> text "+" <> cr
      let defsToAsciiDoc :: [Block] -> State WriterState Doc
          defsToAsciiDoc ds = (vcat . intersperse divider . map chomp)
               `fmap` mapM (blockToAsciiDoc opts) ds
      defs' <- mapM defsToAsciiDoc defs
      modify (\st -> st{ defListMarker = marker })
      let contents = nest 2 $ vcat $ intersperse divider $ map chomp defs'
      return $ labelText <> text marker <> cr <> contents <> cr

    -- | Convert list of Pandoc block elements to asciidoc.
    blockListToAsciiDoc :: WriterOptions -- ^ Options
                        -> [Block]       -- ^ List of block elements
                        -> State WriterState Doc
    blockListToAsciiDoc opts blocks = cat `fmap` mapM (blockToAsciiDoc opts) blocks

    -- | Convert list of Pandoc inline elements to asciidoc.
    inlineListToAsciiDoc :: WriterOptions -> [Inline] -> State WriterState Doc
    inlineListToAsciiDoc opts lst =
      mapM (inlineToAsciiDoc opts) lst >>= return . cat

    -- | Convert Pandoc inline element to asciidoc.
    inlineToAsciiDoc :: WriterOptions -> Inline -> State WriterState Doc
    inlineToAsciiDoc opts (Emph lst) = do
      contents <- inlineListToAsciiDoc opts lst
      return $ "_" <> contents <> "_"
    inlineToAsciiDoc opts (Strong lst) = do
      contents <- inlineListToAsciiDoc opts lst
      return $ "*" <> contents <> "*"
    inlineToAsciiDoc opts (Strikeout lst) = do
      contents <- inlineListToAsciiDoc opts lst
      return $ "[line-through]*" <> contents <> "*"
    inlineToAsciiDoc opts (Superscript lst) = do
      contents <- inlineListToAsciiDoc opts lst
      return $ "^" <> contents <> "^"
    inlineToAsciiDoc opts (Subscript lst) = do
      contents <- inlineListToAsciiDoc opts lst
      return $ "~" <> contents <> "~"
    inlineToAsciiDoc opts (SmallCaps lst) = inlineListToAsciiDoc opts lst
    inlineToAsciiDoc opts (Quoted SingleQuote lst) = do
      contents <- inlineListToAsciiDoc opts lst
      return $ "`" <> contents <> "'"
    inlineToAsciiDoc opts (Quoted DoubleQuote lst) = do
      contents <- inlineListToAsciiDoc opts lst
      return $ "``" <> contents <> "''"
    inlineToAsciiDoc _ (Code _ str) = return $
      text "`" <> text (escapeStringUsing (backslashEscapes "`") str) <> "`"
    inlineToAsciiDoc _ (Str str) = return $ text $ escapeString str
    inlineToAsciiDoc _ (Math InlineMath str) =
      return $ "latexmath:[$" <> text str <> "$]"
    inlineToAsciiDoc _ (Math DisplayMath str) =
      return $ "latexmath:[\\[" <> text str <> "\\]]"
    inlineToAsciiDoc _ (RawInline f s)
      | f == "asciidoc" = return $ text s
      | otherwise       = return empty
    inlineToAsciiDoc _ (LineBreak) = return $ " +" <> cr
    inlineToAsciiDoc _ Space = return space
    inlineToAsciiDoc opts (Cite _ lst) = inlineListToAsciiDoc opts lst
    inlineToAsciiDoc opts (Link txt (src, _tit)) = do
    -- relative:  link:downloads/foo.zip[download foo.zip]
    -- abs:  http://google.cod[Google]
    -- or my@email.com[email john]
      linktext <- inlineListToAsciiDoc opts txt
      let isRelative = ':' `notElem` src
      let prefix = if isRelative
                      then text "link:"
                      else empty
      let srcSuffix = if isPrefixOf "mailto:" src then drop 7 src else src
      let useAuto = case txt of
                          [Str s] | escapeURI s == srcSuffix -> True
                          _                                  -> False
      return $ if useAuto
                  then text srcSuffix
                  else prefix <> text src <> "[" <> linktext <> "]"
    inlineToAsciiDoc opts (Image alternate (src, tit)) = do
    -- image:images/logo.png[Company logo, title="blah"]
      let txt = if (null alternate) || (alternate == [Str ""])
                   then [Str "image"]
                   else alternate
      linktext <- inlineListToAsciiDoc opts txt
      let linktitle = if null tit
                         then empty
                         else text $ ",title=\"" ++ tit ++ "\""
      return $ "image:" <> text src <> "[" <> linktext <> linktitle <> "]"
    inlineToAsciiDoc opts (Note [Para inlines]) =
      inlineToAsciiDoc opts (Note [Plain inlines])
    inlineToAsciiDoc opts (Note [Plain inlines]) = do
      contents  <- inlineListToAsciiDoc opts inlines
      return $ text "footnote:[" <> contents <> "]"
    -- asciidoc can't handle blank lines in notes
    inlineToAsciiDoc _ (Note _) = return "[multiblock footnote omitted]"
    inlineToAsciiDoc opts (Span _ ils) = inlineListToAsciiDoc opts ils