{-# LANGUAGE PatternGuards #-}

{-

Copyright (C) 2015 Martin Linnemann <theCodingMarlin@googlemail.com>

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.Reader.Odt

   Copyright   : Copyright (C) 2015 Martin Linnemann

   License     : GNU GPL, version 2 or above

   Maintainer  : Martin Linnemann <theCodingMarlin@googlemail.com>

   Stability   : alpha

   Portability : portable

Entry point to the odt reader.

-}

module Text.Pandoc.Readers.Odt ( readOdt ) where

import Codec.Archive.Zip

import qualified Text.XML.Light as XML

import qualified Data.ByteString.Lazy as B

import System.FilePath

import Control.Monad.Except (throwError)

import Text.Pandoc.Class (PandocMonad)

import qualified Text.Pandoc.Class as P

import Text.Pandoc.Definition

import Text.Pandoc.Error

import Text.Pandoc.MediaBag

import Text.Pandoc.Options

import qualified Text.Pandoc.UTF8 as UTF8

import Text.Pandoc.Readers.Odt.ContentReader

import Text.Pandoc.Readers.Odt.StyleReader

import Text.Pandoc.Readers.Odt.Generic.Fallible

import Text.Pandoc.Readers.Odt.Generic.XMLConverter

import Text.Pandoc.Shared (filteredFilesFromArchive)

readOdt :: PandocMonad m

        => ReaderOptions

        -> B.ByteString

        -> m Pandoc

readOdt opts bytes = case readOdt' opts bytes of

  Right (doc, mb) -> do

    P.setMediaBag mb

    return doc

  Left e -> throwError e

--

readOdt' :: ReaderOptions

         -> B.ByteString

         -> Either PandocError (Pandoc, MediaBag)

readOdt' _ bytes = bytesToOdt bytes-- of

--                    Right (pandoc, mediaBag) -> Right (pandoc , mediaBag)

--                    Left  err                -> Left err

--

bytesToOdt :: B.ByteString -> Either PandocError (Pandoc, MediaBag)

bytesToOdt bytes = case toArchiveOrFail bytes of

  Right archive -> archiveToOdt archive

  Left _        -> Left $ PandocParseError "Couldn't parse odt file."

--

archiveToOdt :: Archive -> Either PandocError (Pandoc, MediaBag)

archiveToOdt archive

  | Just contentEntry      <- findEntryByPath "content.xml" archive

  , Just stylesEntry       <- findEntryByPath "styles.xml"  archive

  , Just contentElem       <- entryToXmlElem contentEntry

  , Just stylesElem        <- entryToXmlElem stylesEntry

  , Right styles           <- chooseMax (readStylesAt stylesElem )

                                        (readStylesAt contentElem)

  , media                  <- filteredFilesFromArchive archive filePathIsOdtMedia

  , startState             <- readerState styles media

  , Right pandocWithMedia  <- runConverter' read_body

                                            startState

                                            contentElem

  = Right pandocWithMedia

  | otherwise

    -- Not very detailed, but I don't think more information would be helpful

  = Left $ PandocParseError "Couldn't parse odt file."

    where

      filePathIsOdtMedia :: FilePath -> Bool

      filePathIsOdtMedia fp =

        let (dir, _) = splitFileName fp

        in

         (dir == "Pictures/")

--

entryToXmlElem :: Entry -> Maybe XML.Element

entryToXmlElem = XML.parseXMLDoc . UTF8.toStringLazy . fromEntry