add

app/Main.hs

@@ -27,10 +27,11 @@ main = do
     putStrLn "1. Display tasks"
     putStrLn "2. Add task"
     putStrLn "3. Add task (Manual)"
-    putStrLn "4. Filter tasks by tag"
-    putStrLn "5. Sort tasks by priority"
-    putStrLn "6. Remove task"
-    putStrLn "7. Exit"
+    putStrLn "4. Edit task"
+    putStrLn "5. Filter tasks by tag"
+    putStrLn "6. Sort tasks by priority"
+    putStrLn "7. Remove task"
+    putStrLn "8. Exit"
     putStr "Choose an option: "
     hFlush stdout
     option <- getLine
@@ -38,12 +39,14 @@ main = do
         "1" -> displayTasks
         "2" -> addTask
         "3" -> addTaskWithManual
-        "4" -> filterTasksByTag
-        "5" -> sortTasksByPriority
-        "6" -> removeTask
-        "7" -> putStrLn "Goodbye!"
+        "4" -> editTask
+        "5" -> filterTasksByTag
+        "6" -> sortTasksByPriority
+        "7" -> removeTask
+        "8" -> putStrLn "Goodbye!"
         _   -> putStrLn "Invalid option" >> main
 
+
 displayTasks :: IO ()
 displayTasks = do
     exists <- doesFileExist todoFile
@@ -109,6 +112,55 @@ addTaskWithManual = do
         "x" -> main
         _ -> addTask
 
+
+editTask :: IO ()
+editTask = do
+    exists <- doesFileExist todoFile
+    if exists
+        then do
+            contents <- catch (TIO.readFile todoFile) handleReadError
+            let taskMap = parseTask contents
+            putStrLn "Existing tasks: "
+            mapM_ (putStrLn . showTaskId) (Map.toList taskMap)
+
+            putStr "Enter the ID of the task you wish to edit: "
+            hFlush stdout
+            taskIdStr <- getLine
+            let taskId = read taskIdStr :: Int
+
+            putStrLn ""
+
+            if Map.member taskId taskMap
+                then do
+                    putStrLn "Enter the new task description: "
+                    newTask <- getLine
+                    let newTaskMap = Map.insert taskId (pack newTask) taskMap
+                    catch (TIO.writeFile todoFile (serializeTask newTaskMap)) handleWriteError
+                    putStrLn "Task edited."
+                else do
+                    putStrLn "Task of this ID doesn't exist"
+                    putStrLn "Do you wish to try again? Press Enter if yes or x to go back to menu"
+                    option <- getLine
+                    case option of
+                        "x" -> main
+                        _ -> editTask
+
+        else putStrLn "No tasks found."
+    putStrLn " -------------- "
+    putStrLn "Press Enter"
+    option <- getLine
+    case option of
+        _ -> main
+  where
+    handleReadError :: IOException -> IO Text
+    handleReadError e = do
+        putStrLn $ "Error reading file: " ++ show e
+        return ""
+
+    handleWriteError :: IOException -> IO ()
+    handleWriteError e = putStrLn $ "Error writing file: " ++ show e
+
+
 filterTasksByTag :: IO ()
 filterTasksByTag = do
     putStr "Enter the tag to filter by (e.g., +GarageSale): "