History.hs

{- This file is part of irc-fun-bot.
 -
 - Written in 2015 by fr33domlover <fr33domlover@rel4tion.org>.
 -
 - ♡ Copying is an act of love. Please copy, reuse and share.
 -
 - The author(s) have dedicated all copyright and related and neighboring
 - rights to this software to the public domain worldwide. This software is
 - distributed without any warranty.
 -
 - You should have received a copy of the CC0 Public Domain Dedication along
 - with this software. If not, see
 - <http://creativecommons.org/publicdomain/zero/1.0/>.
 -}

module Network.IRC.Fun.Bot.Internal.History
    ( rememberMsg
    , checkEvent
    )
where

import Control.Monad (liftM, when)
import Control.Monad.IO.Class (liftIO)
import Control.Monad.Trans.RWS (modify)
import Data.Sequence ((|>), Seq, ViewL (..))
import Network.IRC.Fun.Bot.Internal.State
import Network.IRC.Fun.Bot.Internal.Types

import qualified Data.HashMap.Lazy as M
import qualified Data.Sequence as Q
import qualified Data.Sequence.Util as QU
import qualified Network.IRC.Fun.Client.Events as C (Event (..))

-- | Remember someone said something, for use later when quoting.
rememberMsg :: String -- ^ Channel
            -> String -- ^ User nickname
            -> String -- ^ Message
            -> Bool   -- ^ Whether a /me action (True) or regular message (False)
            -> Session e s ()
rememberMsg chan nick msg action = do
    maxlines <- liftM (maybe 0 csHistoryLines . M.lookup chan) getChans
    when (maxlines > 0) $ do
        h <- getHistory
        t <- askTimeGetter >>= liftIO . liftM snd
        m <- getMinutes
        let hl = HistoryLine
                { hlTime    = t
                , hlNick    = nick
                , hlMessage = msg
                , hlAction  = action
                , hlMinute  = m
                }
            shorten s = if Q.length s > maxlines then QU.tail s else s
            hls' = case M.lookup chan h of
                Just hls -> shorten $ hls |> hl
                Nothing  -> Q.singleton hl
        modify $ \ s -> s { bsHistory = M.insert chan hls' h }

-- | If a client event is a message to remember, get details.
checkEvent :: C.Event -> Maybe (Msg a)
checkEvent (C.ChannelMessage chan nick msg _) =
    Just $ MsgHistoryEvent nick chan msg False
checkEvent (C.ChannelAction chan nick msg) =
    Just $ MsgHistoryEvent nick chan msg True
checkEvent _ = Nothing