add epub3 navigation parsing

app/Navigation.hs

@@ -6,12 +6,16 @@ module Navigation
   )
 where
 
-import Text.HTML.Scalpel (Scraper, attr, (@:), (@=), chroot, chroots, text, match)
-import Types (NavItem(..), EpubType (..), InternalPath(..))
+import Text.HTML.Scalpel (Scraper, attr, (@:), (@=), chroot, chroots, text, match, scrapeStringLike, scrape)
+import Types (NavItem(..), EpubType (..), InternalPath(..), EpubEnv(..))
 import Data.Maybe (fromMaybe)
+import qualified Data.ByteString.Lazy as B
 import Control.Applicative (optional)
 import Control.Monad (guard)
+import Codec.Archive.Zip
 import qualified Data.Text as T
+import qualified Data.Text.Encoding as TE
+import System.FilePath (normalise, takeDirectory, (</>))
 
 -- ------------------------------------------------------------
 -- EPub 3 navigation
@@ -39,3 +43,24 @@ lndmkScraper labels =
   where
     navPredicate "epub:type" xs = EpubType (T.pack xs) `elem` labels
     navPredicate _ _ = False
+
+                       --------------------------------------------------------
+                       --                     dispatching                     --
+                       --------------------------------------------------------
+
+getLandmarks :: EpubEnv -> [NavItem]
+getLandmarks env =
+  case eVersion env of
+    "2.0" -> []
+    "3.0" ->
+      case scrapeStringLike (opfXml env) navFinder of
+        Nothing -> []
+        Just relPath ->
+          let fullPath = normalise $ (baseDir env) </> relPath
+          in case findEntryByPath fullPath (archive env) of
+            Nothing -> []
+            Just entry ->
+              let content = TE.decodeUtf8 . B.toStrict $ fromEntry entry
+                  types = map EpubType ["toc", "landmarks", "bodymatter"]
+                  scrp = lndmkScraper types
+              in fromMaybe [] $ scrapeStringLike content scrp