put command into scansess & rework

3 files changed, 65 insertions, 21 deletions

diff --git a/Main.hs b/Main.hs
index 8838823..d7ac33a 100644
--- a/Main.hs
+++ b/Main.hs
@@ -23,18 +23,18 @@ along with sscan.  If not, see <http://www.gnu.org/licenses/>.
 
 {-# LANGUAGE OverloadedStrings #-}
 
-import           Control.Concurrent (forkFinally)
+import           Control.Concurrent (forkIO)
 import           Control.Monad      (void)
 import           Lens.Micro         ((&), (.~), (^.))
 import           System.Directory   (getHomeDirectory, removeDirectoryRecursive)
 import           System.FilePath    ((</>))
-import           System.IO.Temp     (createTempDirectory)
+import           System.IO.Temp     (withSystemTempDirectory)
 
 import           Types.State
 import           UI
 
--- processScanSessDir :: ScanSess -> IO ()
--- processScanSessDir ss@(ScanSess d n) =
+processScanSessDir :: St -> IO ()
+processScanSessDir = undefined
 --     -- rather than do any error handling here, we write a logfile to
 --     -- the outdir for user inspection
 --     void $ forkFinally process $ \_ -> nukeScanSessDir ss
@@ -57,14 +57,31 @@ makeInitialState = do
         , _stDPI          = 300
         , _stOutFormat    = PDF
         , _stOutdir       = home </> "tmp"
-        , _stCommand      = Quit
         }
 
-uiLoop :: St -> IO ()
-uiLoop st = runTheApp st >>= \newSt -> do
-    undefined
+scanPage :: FilePath -> IO ()
+scanPage dir = undefined
 
-main = makeInitialState >>= uiLoop
+processCommand :: St -> IO ()
+processCommand st = case st^.stScanSess of
+  Nothing -> return ()          -- quit sscan
+  Just (ScanSess command pages maybeDir) -> case maybeDir of
+    Nothing -> withSystemTempDirectory "sscan" $ \dir ->
+      processCommand (setScanSessDir dir st)
+    Just dir -> case command of
+      Abort -> newSession
+      NextPage -> scanPage dir >> presentUI (incrementPages st)
+      FinalPage -> scanPage dir
+                >> finaliseSession (incrementPages st) >> newSession
+      Finalise -> finaliseSession st >> newSession
+  where
+    newSession = presentUI $ resetScanSess st
+    finaliseSession = forkIO . processScanSessDir
+
+presentUI    :: St -> IO ()
+presentUI st = runTheApp st >>= processCommand
+
+main = makeInitialState >>= presentUI
 
 -- TODO scanning should happen in main.  We use withTempDir to setup a
 -- session, and then fire up brick again.  add additional state
diff --git a/Types/State.hs b/Types/State.hs
index 1230e31..9d11019 100644
--- a/Types/State.hs
+++ b/Types/State.hs
@@ -56,22 +56,37 @@ type DPI = Int
 data OutputFormat = PDF | PNG
     deriving (Eq, Show)
 
--- | An active multi-page scanning session
+-- | An active scanning session
 data ScanSess = ScanSess
-    FilePath                    -- ^ session's tmpdir
-    Int                         -- ^ total pages scanner thus far
+    -- | An action requested by the user, that has not yet been
+    -- fulfilled
+    Command
+    -- | The number of pages scanned so far in this scanning session
+    Int
+    -- | Temporary directory containing pages scanned in this scanning
+    -- session, if any have been scanned, and the session is multi-page
+    (Maybe FilePath)
 
 -- | An sscan operation selected by the user in the UI
 data Command
-    = NextPage                  -- ^ scan first page or another page
-    | FinalPage                 -- ^ scan final page (might be the first page)
-    | Finalise                  -- ^ make the previous scanned page the final page of the document
-    | Abort                     -- ^ abandon the current scan session
-    | Quit                      -- ^ quit sscan
+    -- | Scan an additional page, or the first page, of a multi-page
+    -- scanning session.
+    = NextPage
+    -- | Scan the final page of a multi-page scanning session, or the
+    -- first page of a single-page scanning session
+    | FinalPage
+    -- | End a multi-page scanning session without scanning anymore
+    -- pages, i.e., consider the most recently scanned page the final
+    -- page
+    | Finalise
+    -- | Abandon the current scanning session.  Delete its tmpdir.
+    | Abort
 
 -- | Application state
 data St =
-    St { _stScanSess     :: Maybe ScanSess
+    --
+    St { _stScanSess     :: Maybe ScanSess -- ^ Nothing indicates user
+                                           -- wants to quit sscan
        , _stOCR          :: Bool -- ^ whether to use OCRmyPDF
        , _stColour       :: Colour
        , _stPaper        :: Paper -- ^ currently selected paper size
@@ -79,9 +94,9 @@ data St =
        , _stDPI          :: DPI
        , _stOutFormat    :: OutputFormat
        , _stOutdir       :: FilePath -- ^ where to save final PDFs
-       , _stCommand      :: Command
        }
--- other device-specific scanimage options the old script supported: --swdespeck; --color-filter; --depth
+-- other device-specific scanimage options the old script supported:
+-- --swdespeck; --color-filter; --depth
 
 makeLenses ''St
 
@@ -96,3 +111,15 @@ updateSt st f = ifScanSess st st (f st)
 
 resetScanSess :: St -> St
 resetScanSess st = st & stScanSess .~ Nothing
+
+setScanSessDir :: FilePath -> St -> St
+setScanSessDir dir st = case st^.stScanSess of
+  Nothing -> st
+  Just (ScanSess c p _) ->
+      st & stScanSess .~ (Just $ ScanSess c p (Just dir))
+
+incrementPages :: St -> St
+incrementPages st = case st^.stScanSess of
+  Nothing -> st
+  Just (ScanSess c p d) ->
+      st & stScanSess .~ (Just $ ScanSess c (p+1) d)
diff --git a/UI.hs b/UI.hs
index be75757..c10e2cf 100644
--- a/UI.hs
+++ b/UI.hs
@@ -66,7 +66,7 @@ drawUI st = [ui]
               ]
     status = str $ maybe
         "Ready to scan first page"
-        (\(ScanSess _ p) -> "Scanned " ++ show p ++ " pages")
+        (\(ScanSess _ p _) -> "Scanned " ++ show p ++ " pages")
         (st^.stScanSess)
     settingsBox = defnList AlignRight Nothing
         [ ("run OCRmyPDF", if st^.stOCR then "yes" else "no")