{-

Copyright (C) 2014-2017 Jesse Rosenthal <jrosenthal@jhu.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.Readers.Docx.Lists

   Copyright   : Copyright (C) 2014-2017 Jesse Rosenthal

   License     : GNU GPL, version 2 or above

   Maintainer  : Jesse Rosenthal <jrosenthal@jhu.edu>

   Stability   : alpha

   Portability : portable

Functions for converting flat docx paragraphs into nested lists.

-}

module Text.Pandoc.Readers.Docx.Lists ( blocksToBullets

                                      , blocksToDefinitions

                                      , listParagraphDivs

                                      ) where

import Data.List

import Data.Maybe

import Text.Pandoc.Generic (bottomUp)

import Text.Pandoc.JSON

import Text.Pandoc.Shared (trim)

isListItem :: Block -> Bool

isListItem (Div (_, classes, _) _) | "list-item" `elem` classes = True

isListItem _                       = False

getLevel :: Block -> Maybe Integer

getLevel (Div (_, _, kvs) _) =  fmap read $ lookup "level" kvs

getLevel _                   = Nothing

getLevelN :: Block -> Integer

getLevelN b = fromMaybe (-1) (getLevel b)

getNumId :: Block -> Maybe Integer

getNumId (Div (_, _, kvs) _) =  fmap read $ lookup "num-id" kvs

getNumId _                   = Nothing

getNumIdN :: Block -> Integer

getNumIdN b = fromMaybe (-1) (getNumId b)

getText :: Block -> Maybe String

getText (Div (_, _, kvs) _) = lookup "text" kvs

getText _                   = Nothing

data ListType = Itemized | Enumerated ListAttributes

listStyleMap :: [(String, ListNumberStyle)]

listStyleMap = [("upperLetter", UpperAlpha),

                ("lowerLetter", LowerAlpha),

                ("upperRoman", UpperRoman),

                ("lowerRoman", LowerRoman),

                ("decimal", Decimal)]

listDelimMap :: [(String, ListNumberDelim)]

listDelimMap = [("%1)", OneParen),

                ("(%1)", TwoParens),

                ("%1.", Period)]

getListType :: Block -> Maybe ListType

getListType b@(Div (_, _, kvs) _) | isListItem b =

  let

    start = lookup "start" kvs

    frmt = lookup "format" kvs

    txt  = lookup "text" kvs

  in

   case frmt of

     Just "bullet" -> Just Itemized

     Just f        ->

       case txt of

         Just t -> Just $ Enumerated (

                  read (fromMaybe "1" start) :: Int,

                  fromMaybe DefaultStyle (lookup f listStyleMap),

                  fromMaybe DefaultDelim (lookup t listDelimMap))

         Nothing -> Nothing

     _ -> Nothing

getListType _ = Nothing

listParagraphDivs :: [String]

listParagraphDivs = ["ListParagraph"]

-- This is a first stab at going through and attaching meaning to list

-- paragraphs, without an item marker, following a list item. We

-- assume that these are paragraphs in the same item.

handleListParagraphs :: [Block] -> [Block]

handleListParagraphs [] = []

handleListParagraphs (

  Div attr1@(_, classes1, _) blks1 :

  Div (ident2, classes2, kvs2) blks2 :

  blks

  ) | "list-item" `elem` classes1 &&

    notElem "list-item" classes2 &&

    (not . null) (listParagraphDivs `intersect` classes2) =

      -- We don't want to keep this indent.

      let newDiv2 =

            Div (ident2, classes2, filter (\kv -> fst kv /= "indent") kvs2) blks2

      in

       handleListParagraphs (Div attr1 (blks1 ++ [newDiv2]) : blks)

handleListParagraphs (blk:blks) = blk : handleListParagraphs blks

separateBlocks' :: Block -> [[Block]] -> [[Block]]

separateBlocks' blk [[]] = [[blk]]

separateBlocks' b@(BulletList _) acc = init acc ++ [last acc ++ [b]]

separateBlocks' b@(OrderedList _ _) acc = init acc ++ [last acc ++ [b]]

-- The following is for the invisible bullet lists. This is how

-- pandoc-generated ooxml does multiparagraph item lists.

separateBlocks' b acc | fmap trim (getText b) == Just "" =

  init acc ++ [last acc ++ [b]]

separateBlocks' b acc = acc ++ [[b]]

separateBlocks :: [Block] -> [[Block]]

separateBlocks blks = foldr separateBlocks' [[]] (reverse blks)

flatToBullets' :: Integer -> [Block] -> [Block]

flatToBullets' _ [] = []

flatToBullets' num xs@(b : elems)

  | getLevelN b == num = b : flatToBullets' num elems

  | otherwise =

    let bNumId = getNumIdN b

        bLevel = getLevelN b

        (children, remaining) =

          span

          (\b' ->

            (getLevelN b') > bLevel ||

             ((getLevelN b') == bLevel && (getNumIdN b') == bNumId))

          xs

    in

     case getListType b of

       Just (Enumerated attr) ->

         OrderedList attr (separateBlocks $ flatToBullets' bLevel children) :

         flatToBullets' num remaining

       _ ->

         BulletList (separateBlocks $ flatToBullets' bLevel children) :

         flatToBullets' num remaining

flatToBullets :: [Block] -> [Block]

flatToBullets elems = flatToBullets' (-1) elems

singleItemHeaderToHeader :: Block -> Block

singleItemHeaderToHeader (OrderedList _ [[h@Header{}]]) = h

singleItemHeaderToHeader blk                            = blk

blocksToBullets :: [Block] -> [Block]

blocksToBullets blks =

  map singleItemHeaderToHeader $

  bottomUp removeListDivs $flatToBullets (handleListParagraphs blks)

plainParaInlines :: Block -> [Inline]

plainParaInlines (Plain ils) = ils

plainParaInlines (Para ils)  = ils

plainParaInlines _           = []

blocksToDefinitions' :: [([Inline], [[Block]])] -> [Block] -> [Block] -> [Block]

blocksToDefinitions' []     acc [] = reverse acc

blocksToDefinitions' defAcc acc [] =

  reverse $ DefinitionList (reverse defAcc) : acc

blocksToDefinitions' defAcc acc

  (Div (_, classes1, _) blks1 : Div (ident2, classes2, kvs2) blks2 : blks)

  | "DefinitionTerm" `elem` classes1 && "Definition"  `elem` classes2 =

    let remainingAttr2 = (ident2, delete "Definition" classes2, kvs2)

        pair = if remainingAttr2 == ("", [], []) then (concatMap plainParaInlines blks1, [blks2]) else (concatMap plainParaInlines blks1, [[Div remainingAttr2 blks2]])

    in

     blocksToDefinitions' (pair : defAcc) acc blks

blocksToDefinitions' defAcc acc

  (Div (ident2, classes2, kvs2) blks2 : blks)

  | (not . null) defAcc && "Definition"  `elem` classes2 =

    let remainingAttr2 = (ident2, delete "Definition" classes2, kvs2)

        defItems2 = case remainingAttr2 == ("", [], []) of

          True  -> blks2

          False -> [Div remainingAttr2 blks2]

        ((defTerm, defItems):defs) = defAcc

        defAcc' = case null defItems of

          True -> (defTerm, [defItems2]) : defs

          False -> (defTerm, init defItems ++ [last defItems ++ defItems2]) : defs

    in

     blocksToDefinitions' defAcc' acc blks

blocksToDefinitions' [] acc (b:blks) =

  blocksToDefinitions' [] (b:acc) blks

blocksToDefinitions' defAcc acc (b:blks) =

  blocksToDefinitions' [] (b : DefinitionList (reverse defAcc) : acc) blks

removeListDivs' :: Block -> [Block]

removeListDivs' (Div (ident, classes, kvs) blks)

  | "list-item" `elem` classes =

    case delete "list-item" classes of

      []       -> blks

      classes' -> [Div (ident, classes', kvs) blks]

removeListDivs' (Div (ident, classes, kvs) blks)

  | not $ null $ listParagraphDivs `intersect` classes =

    case classes \\ listParagraphDivs of

      []       -> blks

      classes' -> [Div (ident, classes', kvs) blks]

removeListDivs' blk = [blk]

removeListDivs :: [Block] -> [Block]

removeListDivs = concatMap removeListDivs'

blocksToDefinitions :: [Block] -> [Block]

blocksToDefinitions = blocksToDefinitions' [] []