{-# LANGUAGE OverloadedStrings #-}
-----------------------------------------------------------------------------
--
-- Module      :  VtyView
-- Copyright   :  GPL v3
-- License     :  AllRightsReserved
--
-- Maintainer  :  Ingolf Wagner <palipalo9@gmail.com>
-- Stability   :  experimental
-- Portability :
--
-- |
--
-----------------------------------------------------------------------------

module View (
    main
) where

import System.Exit
import Graphics.Vty.Widgets.All
import Graphics.Vty.Attributes
import Graphics.Vty
import Control.Monad
import System.IO
import System.Directory

import Task
import Data.IORef

import Context

import qualified Data.Text as T

-- | To be interpreted by the Main
data Action = Exit | OpenCreateTaskDialog | MoveInto Task | MoveOut | CreateTask Task

main = do
    let filePath = ".todo.rht"

    context <- createContext filePath

    let lList    = leftList context
        fullText = description context
        rList    = rightList context
        b        = bread context

    box <- (bordered b) <--> bordered lList <++>
        (bordered fullText <--> bordered rList)

    fg  <- newFocusGroup
    addToFocusGroup fg lList

    editor <- multiLineEditWidget
    eFg <- newFocusGroup
    addToFocusGroup eFg editor
    d <- plainText "Header" <--> return editor >>= withBoxSpacing 1

    c <- newCollection
    switchToMain <- addToCollection c box fg
    switchToDialog <- addToCollection c d eFg

    editor `onKeyPressed` \this key mod -> case key of
        KEsc -> do
            switchToMain
            return True
        _ -> return False

    editor `onKeyPressed` \_ key _ -> case key of
        KEsc -> do
            text <- getEditText editor
            case text of
                "" ->  do
                    switchToMain
                    return True
                _ -> do
                    appendTask context (Comment (T.unpack text) [])
                    setEditText editor ""
                    focus editor
                    switchToMain
                    return True
        _ -> do
            return False

    lList  `onKeyPressed` \this key whatever -> case key of
        KASCII 'q' -> do
            writeToFile filePath (tasks context)
            exitSuccess
            return True
        KASCII 'a' -> do
            switchToDialog
            return True
        KASCII 'j' -> do
            scrollDown $ leftList context
            return True
        KASCII 'k' -> do
            scrollUp $ leftList context
            return True
        KASCII 'd' -> do
            item <- getSelected $ leftList context
            case item of
                Nothing -> return True
                Just (itemNr, itemElem) -> do
                    full <- getListSize $ leftList context
                    -- unappendTask (full - 1 - itemNr) tasks leftList
                    unappendTask itemNr context
                    return True
        KRight     -> manoverRight context
        KASCII 'l' -> manoverRight context
        KASCII 'o' -> manoverLeft context
        KLeft      -> manoverLeft context

        _ -> return False

    lList  `onSelectionChange` \event -> case event of
        SelectionOff -> do
            clearList rList
        SelectionOn _ task renderedTask -> do
            clearList rList
            appendTasksToList rList (reverse (children task))
            setText fullText $ T.pack (text task)

    updateLeftList context

    runUi c defaultContext

manoverRight context = do
    item <- getSelected $ leftList context
    case item of
        Nothing -> return True
        Just (itemNr, itemElem) -> do
            moveInto (fst itemElem) context
            return True

manoverLeft context = do
    moveOut context
    return True