1 files changed, 78 insertions, 0 deletions
diff --git a/src/pandoc-oso2tex.hs b/src/pandoc-oso2tex.hs
new file mode 100644
index 0000000..881ee37
--- /dev/null
+++ b/src/pandoc-oso2tex.hs
@@ -0,0 +1,78 @@
+{-
+
+    oso2pdf --- Better conversion of Oxford Scholarship Online material to PDF
+
+    Copyright (C) 2015  Sean Whitton
+
+    This file is part of oso2pdf.
+
+    oso2pdf 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 3 of the License, or
+    (at your option) any later version.
+
+    oso2pdf 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 oso2pdf.  If not, see <http://www.gnu.org/licenses/>.
+
+-}
+
+import           Data.List        (isPrefixOf, isSuffixOf)
+import           Data.Monoid      ((<>))
+import           Text.Pandoc.JSON
+
+data Page = Page Int [Block]
+
+instance Monoid Page where
+    mempty                            = Page 1 []
+    (Page n xs) `mappend` (Page _ ys) = Page n (xs ++ ys)
+
+pagesToBlocks :: [Page] -> [Block]
+pagesToBlocks ps@( _ : (Page n _) : _) =
+    RawBlock (Format "tex") ("\\setcounter{page}{" ++ show (n - 1) ++ "}")
+    : (drop 1 $ foldr step [] ps) -- drop first \\pagebreak
+  where
+    step (Page n p) ps = RawBlock (Format "tex") "\\pagebreak" : p ++ ps
+
+-- TODO factor out joining Pages together and appending or just
+-- putting side by side
+
+blocksToPages :: [Block] -> [Page]
+blocksToPages = foldr step []
+  where
+    step (Para xs) [] = paraToPages xs
+    step x [] = [Page 1 [x]]
+    step (Para xs) ( y@(Page n _) : ys ) =
+        case paraToPages xs of
+            [a, b] -> if n /= 1 then a : b : y : ys else a : (b <> y) : ys
+            [a]    -> if n /= 1 then a : y : ys else (a <> y) : ys
+    step x (y:ys) = ((Page 1 [x]) <> y) : ys
+
+-- ASSUME: not more than one page break per paragraph!
+paraToPages      :: [Inline] -> [Page]
+paraToPages para = let (first, n, second) = foldr step ([], 1, []) para
+                   in if n == 1
+                      then [Page 1 [Para second]]
+                      else if null first
+                           then [Page 1 [Para first], Page n [Para second]]
+                           else [ Page 1 [Para first]
+                                , Page n [Para (RawInline (Format "tex") "\\noindent"
+                                                : second)]]
+  where
+    step chunk (xs, n, ys) =
+        if n /= 1
+        then (chunk : xs, n, ys)
+        else case chunk of
+            (Str x) -> if "(p." `isPrefixOf` x && ")" `isSuffixOf` x
+                       then let m = read . drop 3 . init $ x
+                            in (xs, m, ys) -- TODO: what about [Space, Space] left behind?
+                       else (xs, n, chunk : ys)
+            _       -> (xs, n, chunk : ys)
+
+main = toJSONFilter process
+  where
+    process (Pandoc meta blocks) = Pandoc meta (pagesToBlocks . blocksToPages $ blocks)