Add possibility to provide card in CLI argument

app/Main.hs

@@ -4,16 +4,25 @@ import Lib (runBrickFlashcards)
 import BrickHelpers
 import Brick
 import Brick.Widgets.Center
+import CardUI
+import Control.Exception (displayException, try)
+import Control.Monad.IO.Class
+import Data.Functor (($>))
+import Parser
 import System.Environment (getArgs)
 import System.Process (runCommand)
 
 main :: IO ()
 main = do
-  _ <- runCommand "echo \\\\e[5 q"
-  runBrickFlashcards
-
--- test :: Widget ()
--- test = hCenter $ myStrWrap "Heey, this is a very long string of text, well maybe not that long... but pretty long in any case."
-
--- main :: IO ()
--- main = simpleMain test
+  _ <- runCommand "echo -n \\\\e[5 q"
+  
+  args <- getArgs
+  if null args
+    then runBrickFlashcards
+    else do
+      strOrExc <- liftIO (try (readFile (head args)) :: IO (Either IOError String))
+      case strOrExc of
+        Left exc -> putStr (displayException exc)
+        Right str -> case parseCards str of
+          Left parseError -> print parseError
+          Right result -> runCardUI result $> ()