add, view, update and remove functions

alexmachina · Oct 2, 2017 · 65ba9a0 · 65ba9a0
commit 65ba9a0
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diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,3 @@
+*.o
+*.hi
+todo
diff --git a/Actions.hs b/Actions.hs
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+{-# LANGUAGE DeriveGeneric, DeriveAnyClass #-}
+
+module Actions
+  (
+   add
+  ,remove
+  ,view
+  ,todoDone
+  ,update
+  ) where 
+
+import System.IO
+import System.Posix.Files
+import System.Posix.Types
+import System.Directory
+import System.Environment
+import Data.List
+import Control.DeepSeq
+import GHC.IO
+import GHC.Generics
+import qualified Data.Char as Char
+data Todo = Todo
+  {
+    todoId :: Int
+  , title :: String
+  , done :: Bool
+  } deriving (Show, Read, Eq,Generic, NFData)
+
+type TodoList = [Todo]
+
+data Filter = Done | Pending deriving (Show, Read)
+
+parseContents :: String -> TodoList
+parseContents contents =
+  if contents == ""
+     then []
+     else read contents :: TodoList
+
+add :: [String] -> IO ()
+add [title] = do
+ (todoList, fileName) <- extractTodoList
+ let nextId = if todoList == []
+       then 1
+       else (todoId $ last todoList) + 1
+     todo = Todo { todoId = nextId
+                  , title = title
+                  , done = False }
+     newTodoList = todoList ++ [todo]
+     message = "\nTODO Added: \n\n" ++ (showStrTodo todo) ++ "\n"
+
+ (todoList,fileName) `deepseq` writeFile fileName $ show newTodoList
+
+ putStrLn message
+
+remove :: [String] -> IO ()
+remove [numberString] = do
+  (todoList, fileName) <- extractTodoList
+  let todoId' = read numberString :: Int
+      maybeTodo = getTodoById todoId' todoList
+  case maybeTodo of
+    Just todo -> do
+      let newTodoList = delete todo todoList
+          message = "\n\nTODO Removed:\n\n" ++ showStrTodo todo ++ "\n"
+      (todoList, fileName) `deepseq` writeFile fileName $ show newTodoList
+      putStrLn message
+    Nothing -> putStrLn "TODO not found!"
+parseList :: TodoList -> String
+parseList [] = "Oops, no todos added yet \nUse todos add 'some task'"
+parseList todoList =
+  foldl (\t1 t2 -> t1 ++ "\n" ++ (showStrTodo t2)) "" todoList
+
+filterDone :: TodoList -> TodoList
+filterDone todoList =
+  filter (\t -> done t == True) todoList
+
+capitalize :: String -> String
+capitalize str = Char.toUpper (head str) : tail str
+
+toUpper :: String -> String
+toUpper str = map (\c -> Char.toUpper c) str
+
+filterPending :: TodoList -> TodoList
+filterPending todoList =
+  filter (\t -> done t == False) todoList
+view :: [String] -> IO ()
+view [] = do
+  homeDir <- getHomeDirectory
+  let fileName = homeDir ++ "/.todos"
+  contents <- readFile fileName
+  let todoList = parseContents contents
+      header = "\n" ++ "TODO - Showing Todo List \n\n"
+  putStr $ header ++ (parseList todoList) ++ "\n\n"
+view [filterStr] = do
+  (todoList, _) <- extractTodoList
+  let todoFilter = read (capitalize filterStr) :: Filter
+      filteredTodoList = case todoFilter of
+        Done -> filterDone todoList
+        Pending -> filterPending todoList
+      header = "\nTODO - Showing " ++ (show todoFilter) ++ "\n\n"
+      contents = header ++ (parseList filteredTodoList) ++ "\n\n"
+  putStrLn contents
+
+getTodoById :: Int -> TodoList -> Maybe Todo
+getTodoById todoId' =
+  find (\t -> todoId t == todoId')
+
+updateInTodoList :: Todo -> TodoList -> TodoList
+updateInTodoList todo =
+  map (\t -> if todoId t == todoId todo
+                then todo
+                else t)
+update :: [String] -> IO ()
+update [] = do putStrLn "Tell me the todo ID and the new title"
+update [todoId'] = do putStrLn "Tell me the new title"
+update [todoIdStr, newTitle] = do
+  (todoList, fileName) <- extractTodoList
+  let maybeTodo = getTodoById (read todoIdStr :: Int) todoList
+  case maybeTodo of
+    Just todo -> do
+      let newTodo = todo { title = newTitle }
+          newTodoList = updateInTodoList newTodo todoList
+          message = "\nTodo updated:\n\n" ++ (showStrTodo newTodo) ++ "\n"
+      writeFile fileName $ show newTodoList
+      putStrLn message
+    Nothing -> do putStrLn "\nTODO Not found\n"
+
+
+
+
+
+showStrTodo :: Todo -> String
+showStrTodo todo =
+  let todoId' = show $ todoId todo
+      title' = title todo
+      done' = if done todo then "Done" else "Pending"
+  in  todoId' ++ " - " ++ title' ++ " [ " ++ done' ++ " ]"
+
+extractTodoList :: IO (TodoList, FilePath)
+extractTodoList = do
+  homeDir <- getHomeDirectory
+  let fileName = homeDir ++ "/.todos"
+  contents <- readFile fileName 
+  if contents == ""
+    then return ([], fileName)
+    else return (read contents :: TodoList, fileName)
+
+markAsDone :: Int -> TodoList -> String -> IO ()
+markAsDone todoId' todoList fileName = do
+  let newTodoList = map
+                    (\t -> if todoId' == todoId t
+                              then t { done = True }
+                              else t
+                    ) todoList
+  writeFile fileName $ show newTodoList
+
+todoDone :: [String] -> IO ()
+todoDone [] = do putStr "You need to tell me the Todo ID"
+todoDone [todoIdStr] = do
+  (todoList, fileName) <- extractTodoList
+
+  let maybeTodo = find (\t -> Just (todoId t) == Just (read todoIdStr :: Int)) todoList
+      todoId' = case maybeTodo of
+                  Just todo -> todoId todo
+                  Nothing -> 0
+  if todoId' == 0 then putStrLn "Todo not found"
+    else markAsDone todoId' todoList fileName
+
+
+
+
diff --git a/todo.hs b/todo.hs
@@ -0,0 +1,30 @@
+import System.Environment
+import Actions
+import System.IO
+import System.Directory
+
+type Todo = String
+dispatch :: [(String, [String] -> IO ())]
+dispatch = [ ("add", add)
+           , ("remove", remove)
+           , ("view", view)
+           , ("done", todoDone)
+           , ("update", update)]
+main = do
+  (command:args) <- getArgs
+  let (Just action) = lookup command dispatch
+  createTodosFileIfNotExists
+  action args
+
+createTodosFileIfNotExists :: IO ()
+createTodosFileIfNotExists = do
+  homeDir <- getHomeDirectory
+  let fileName = homeDir ++ "/.todos"
+  fileExist <- doesFileExist fileName
+  if fileExist
+    then return ()
+    else do
+      handle <- openFile fileName WriteMode
+      hPutStr handle ""
+      hClose handle
+
diff --git a/todo.txt b/todo.txt
@@ -0,0 +1,3 @@
+Brand new task
+another task
+new Task
-Original file line number
+Diff line change
@@ -0,0 +1,3 @@
+    *.o
+    *.hi
+    todo