-- |
-- = Notification server plugin for [XMobar](https://codeberg.org/xmobar/xmobar)
--
-- This module only exposes the 'XNobar' data type, along with the homonym ctor
-- to be used for instantiating a plugin for [XMobar](https://codeberg.org/xmobar/xmobar).
--
-- That plugin will start a notification server, and show the notifications in a marquee
-- as they come, with a default text if there's no notification to show.
--
-- A single click on the marquee will dismiss the notification on which the click happened.
--
{-# LANGUAGE LambdaCase #-}
module XNobar (XNobar (..)) where

import Control.Monad (when)
import Xmobar (Exec (..))

import XNobar.Server (startServer)
import XNobar.Scroller (scroller)


-- |XNobar plugin ctor.  You would use it like this in your @xmobar.hs@
-- (__note__: the non-library usage of
-- [XMobar](https://codeberg.org/xmobar/xmobar) is not supported, or at least I
-- haven't tried using xnobar in that context):
--
-- @
-- main :: IO ()
-- main = xmobar defaultConfig {
--        , commands = [
--             Run $ 'XNobar' "hello" 20 1
--        -- ...
-- @
data XNobar = XNobar !String -- ^ Default string (to be shown steady) when no notification is left.
                     !Int -- ^ Width (in number of characters) of the scrolling marquee (this is unrelated ot the length of the first argument).
                     !Int -- ^ Scrolling rate (in tenths of seconds per character).
                     deriving (Read, -- ^ For integration with [XMobar](https://codeberg.org/xmobar/xmobar).
                               Show) -- ^ For integration with [XMobar](https://codeberg.org/xmobar/xmobar).


-- |For integration with [XMobar](https://codeberg.org/xmobar/xmobar).
instance Exec XNobar where
  alias (XNobar {}) = "XNobar"
  start (XNobar def len rate) cb
    = startServer >>= \case Just notifs -> do scroller def rate len cb notifs
                                              error "What? scroller returned. Has it been killed?!"
                            Nothing -> cb "<fc=#FF0000>Server could not start</fc>"