Show error messages (permission error + path not found + invalid command error)

4 files changed, 36 insertions, 9 deletions

diff --git a/lib/Daffm/Action/Commands.hs b/lib/Daffm/Action/Commands.hs
index 5538eec..a963191 100644
--- a/lib/Daffm/Action/Commands.hs
+++ b/lib/Daffm/Action/Commands.hs
@@ -62,6 +62,7 @@ parseCommand cmd = mkCmd . splitCmdArgs $ trimStart cmd
       ("move", Text.stripPrefix "+" -> Just inc) -> Just . CmdMove . MoveDown . read $ Text.unpack inc
       ("move", Text.stripPrefix "-" -> Just inc) -> Just . CmdMove . MoveUp . read $ Text.unpack inc
       ("move", readMaybe . Text.unpack -> Just pos) -> Just . CmdMove . MoveTo $ pos
+      ("", _) -> Nothing
       (cmd', args) -> Just $ CmdCustom cmd' args
 
 readCommandLines :: Text.Text -> IO [Text.Text]
@@ -93,7 +94,8 @@ processCommand (CmdCommandShell cmd) args = do
       processCommand (fromMaybe CmdNoop (parseCommand cmd')) args
     runIfCmd _ = pure ()
 processCommand CmdQuit _args = M.halt
-processCommand (CmdSetCmdline txt) args = enterCmdline >> cmdSubstitutions (argSubst args txt) >>= setCmdlineText
+processCommand (CmdSetCmdline txt) args =
+  enterCmdline >> cmdSubstitutions (argSubst args txt) >>= setCmdlineText
 processCommand CmdEnterCmdline _args = enterCmdline
 processCommand CmdLeaveCmdline _args = leaveCmdline
 processCommand CmdOpenSelection _args = openSelectedFile
@@ -121,11 +123,12 @@ processCommand (CmdCustom cmd args) _ = do
   myCmd <- gets $ Map.lookup cmd . stateCustomCommands
   case myCmd of
     Just command -> processCommand command args
-    Nothing -> pure ()
+    Nothing -> modify (\st -> st { stateMessage = Just $ "Invalid command " <> cmd })
 processCommand CmdNoop _ = pure ()
 
 evaluateCommand :: Text.Text -> AppEvent ()
-evaluateCommand cmdtxt =
+evaluateCommand cmdtxt = do
+  modify (\st -> st { stateMessage = Nothing })
   case parseCommand cmdtxt of
     Just cmd -> processCommand cmd ""
     Nothing -> pure ()
diff --git a/lib/Daffm/State.hs b/lib/Daffm/State.hs
index 040d244..902b6c6 100644
--- a/lib/Daffm/State.hs
+++ b/lib/Daffm/State.hs
@@ -17,7 +17,7 @@ import qualified Data.Set as Set
 import qualified Data.Text as Text
 import qualified Data.Text.Zipper.Generic as Zipper
 import qualified Data.Vector as Vec
-import System.Directory (doesDirectoryExist, doesPathExist, getCurrentDirectory, getHomeDirectory, getSymbolicLinkTarget, listDirectory, makeAbsolute, setCurrentDirectory)
+import System.Directory (doesDirectoryExist, doesPathExist, getCurrentDirectory, getHomeDirectory, getPermissions, getSymbolicLinkTarget, listDirectory, makeAbsolute, readable, setCurrentDirectory)
 import System.FilePath (joinPath, takeDirectory)
 import System.PosixCompat (fileExist)
 import qualified System.PosixCompat as Posix
@@ -29,6 +29,7 @@ mkEmptyAppState :: Configuration -> AppState
 mkEmptyAppState config =
   AppState
     { stateFiles = L.list FocusMain (Vec.fromList []) 1,
+      stateMessage = Nothing,
       stateCmdlineEditor = mkEditor "",
       stateFocusTarget = FocusMain,
       stateListPositionHistory = Map.empty,
@@ -84,17 +85,34 @@ loadDirToState dir' appState@(AppState {stateCwd, stateListPositionHistory}) = d
         if Posix.isDirectory stat
           then (normalizedDir, Nothing)
           else (textAsString takeDirectory normalizedDir, Just normalizedDir)
-  doesDirectoryExist (Text.unpack dir) >>= \case
-    True -> do
+  isReadable <- readable <$> getPermissions (Text.unpack dir)
+  if isReadable
+    then do
       setCurrentDirectory $ Text.unpack dir
+      newState <- dirToAppState dir targetFilePath
+      doesPathExist (Text.unpack dir') >>= \case
+        True -> pure newState
+        _ -> pure newState {stateMessage = Just $ "No such file or directory: " <> dir'}
+    else do
+      let list = L.list FocusMain (Vec.fromList []) 1
+      pure $ (withNewDir dir list appState) {stateMessage = Just "Unable to read directory"}
+  where
+    withNewDir dir fileList st =
+      st
+        { stateCwd = dir,
+          stateFiles = fileList,
+          stateMessage = Nothing,
+          stateSearchIndex = 0,
+          stateSearchMatches = Vec.empty
+        }
+    dirToAppState dir targetFilePath = do
       files <- listFilesInDir dir
       let prevDirPos = findIndex ((== stateCwd) . filePath) files
       let cachedPos = Map.lookup dir stateListPositionHistory
       let targetFilePos = targetFilePath >>= \target -> findIndex ((== target) . filePath) files
       let pos = fromMaybe 0 (targetFilePos <|> cachedPos <|> prevDirPos)
       let list = L.listMoveTo pos $ L.list FocusMain (Vec.fromList files) 1
-      pure $ appState {stateFiles = list, stateCwd = dir, stateSearchIndex = 0, stateSearchMatches = Vec.empty}
-    False -> pure appState
+      pure $ withNewDir dir list appState
 
 fileTypeFromStatus :: Posix.FileStatus -> FileType
 fileTypeFromStatus s =
diff --git a/lib/Daffm/Types.hs b/lib/Daffm/Types.hs
index 15c284b..a26b0ef 100644
--- a/lib/Daffm/Types.hs
+++ b/lib/Daffm/Types.hs
@@ -43,6 +43,7 @@ data AppState = AppState
     stateCustomCommands :: Map.Map Text.Text Command,
     stateFileSelections :: Set.Set FilePathText,
     stateFiles :: L.List FocusTarget FileInfo,
+    stateMessage :: Maybe Text.Text,
     stateFocusTarget :: FocusTarget,
     stateKeyMap :: Keymap,
     stateKeySequence :: KeySequence,
diff --git a/lib/Daffm/View.hs b/lib/Daffm/View.hs
index da6a11b..0846f66 100644
--- a/lib/Daffm/View.hs
+++ b/lib/Daffm/View.hs
@@ -18,9 +18,10 @@ import Text.Printf (printf)
 appView :: AppState -> [Widget FocusTarget]
 appView appState@(AppState {stateFiles}) = [ui]
   where
-    ui = vBox [vLimit 1 header, box, vLimit 1 cmdline]
+    ui = vBox [vLimit 1 header, box, message, vLimit 1 cmdline]
     header = headerView appState
     cmdline = cmdlineView appState
+    message = messageView appState
     box = L.renderListWithIndex (fileItemView appState) True stateFiles
 
 hFixed :: Int -> Widget n -> Widget n
@@ -101,6 +102,10 @@ symTargetView _ Nothing = withAttr invalidLinkAttr $ txt "<none>"
 symTargetView Nothing (Just target) = withAttr invalidLinkAttr $ txt target
 symTargetView _ (Just target) = txt target
 
+messageView :: AppState -> Widget FocusTarget
+messageView (AppState {stateMessage = Just message}) = txt message
+messageView _ = emptyWidget
+
 cmdlineView :: AppState -> Widget FocusTarget
 cmdlineView (AppState {stateFocusTarget = FocusCmdline, stateCmdlineEditor}) =
   txt ":" <+> renderEditor (txt . Text.unlines) True stateCmdlineEditor