{- 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.Chat
    ( disconnect
    --, reconnect
    , quit
    , run
    , login
    , pong
    , joinChannel
    , joinMulti
    , joinConfig
    , partChannel
    , partMulti
    , partAll
    , sendToUser
    , sendToChannel
    , putIrc
    )
where

import Control.Exception (bracket)
import Control.Monad.IO.Class (liftIO)
import Control.Monad.Trans.RWS (runRWST)
import Network.IRC.Fun.Bot.Internal.Persist
import Network.IRC.Fun.Bot.Internal.State
import Network.IRC.Fun.Bot.Internal.Types
import Network.IRC.Fun.Client.Commands
import Network.IRC.Fun.Client.IO (ircConnect, ircDisconnect, hPutIrc)
import Network.IRC.Fun.Client.Time (currentTimeGetter)
import Network.IRC.Fun.Messages.Types (Message)

-------------------------------------------------------------------------------
-- Connection Management
-------------------------------------------------------------------------------

-- | Disconnect from IRC by closing the bot's side of the connection. This
-- function is mainly provided for completeness and cases of error. You should
-- probably use the QUIT command of IRC to quit the network in a manner
-- coordinated with the server.
--
-- After disconnection, make sure not to send more IRC commands.
disconnect :: Session e s ()
disconnect = askHandle >>= liftIO . ircDisconnect

-- Disconnect from the IRC server and connect again. This includes
-- identifying with the bot's nickname and joining IRC channels.
--
-- This operation closes the bot session. It opens a new one, and returns it.
--botReconnect :: Session s (Session e s ())
--botReconnect = do
--    disconnect

-- | Finish the IRC session, asking the server to close the connection.
quit :: Maybe String -- ^ Optional message, e.g. the reason for quitting
     -> Session e s ()
quit reason = do
    h <- askHandle
    liftIO $ ircQuit h reason

-------------------------------------------------------------------------------
-- Session Management
-------------------------------------------------------------------------------

-- Run a bot session computation
runSession :: BotEnv e s -> BotState s -> Session e s a -> IO a
runSession bot state session = do
    (a, _, _) <- runRWST session bot state
    return a

-- | Connect to an IRC server and run the bot session
run :: Config        -- ^ IRC configuration
    -> Behavior e s  -- ^ Bot behavior definition
    -> e             -- ^ Custom bot environment (read-only state)
    -> s             -- ^ Initial custom bot state
    -> Session e s a -- ^ Session definition
    -> IO a
run conf beh env state session = do
    timeGetter <- currentTimeGetter
    save <- mkSaveBotState conf
    putStrLn "Bot: Connecting to IRC server"
    bracket
        (ircConnect $ connection conf)
        ircDisconnect
        (\ h -> do
            let botEnv = BotEnv conf beh h timeGetter save env
            putStrLn "Bot: Loading state from file"
            botState <- loadBotState botEnv state
            runSession botEnv botState session
        )

-- | Log in as an IRC user and identify with the bot's nickname and password.
-- This is the first thing to do after 'botConnect'ing to the server.
login :: Session e s ()
login = do
    h <- askHandle
    conn <- askConfigS connection
    liftIO $ ircLogin h conn False False

-- | IRC servers send PING messages at regular intervals to test the presence
-- of an active client, at least if no other activity is detected on the
-- connection. The server closes the connection automatically if a PONG
-- response isn't sent from the client within a certain amount of time.
--
-- Therefore, an IRC client (both humans users and bots) usually listens to
-- these PINGs and sends back PONG messages. This function sends a PONG. The
-- parameters should simply be the ones received in the PING message.
pong :: String       -- ^ Server name
     -> Maybe String -- ^ Optional server to forward to
     -> Session e s ()
pong server1 mserver2 = do
    h <- askHandle
    liftIO $ ircPong h server1 mserver2

-------------------------------------------------------------------------------
-- Channels
-------------------------------------------------------------------------------

-- | Join an IRC channel.
joinChannel :: String       -- ^ Channel name
            -> Maybe String -- ^ Optional channel key (password)
            -> Session e s ()
joinChannel channel key = do
    h <- askHandle
    liftIO $ ircJoin h channel key

-- | Join one or more IRC channels.
joinMulti :: [(String, Maybe String)] -- ^ List of channels and optional keys
          -> Session e s ()
joinMulti channels = do
    h <- askHandle
    liftIO $ ircJoinMulti h channels

-- | Join the IRC channels listed in the configuration, without leaving any
-- other channels the bot already joined.
joinConfig :: Session e s ()
joinConfig = do
    chans <- askConfigS channels
    joinMulti $ map (flip (,) Nothing) chans --TODO avoid unnecessary JOINs?

-- | Leave an IRC channel.
partChannel :: String       -- ^ Channel name
            -> Maybe String -- ^ Optional part message, e.g. the reason for
                            --   leaving
            -> Session e s ()
partChannel channel reason = do
    h <- askHandle
    liftIO $ ircPart h channel reason

-- | Leave one or more IRC channels.
partMulti :: [String]     -- ^ List of channel names
          -> Maybe String -- ^ Optional part message, e.g. the reason for
                          --   leaving
          -> Session e s ()
partMulti chans reason = do
    h <- askHandle
    liftIO $ ircPartMulti h chans reason

-- | Leave all IRC channels the bot joined.
partAll :: Session e s ()
partAll = askHandle >>= liftIO . ircPartAll

-------------------------------------------------------------------------------
-- Sending Messages
-------------------------------------------------------------------------------

-- | Send a message to an IRC channel.
--
-- This usually requires that the bot joins the channel first, because many
-- channels have the +n flag set. This flag forbids sending a messages into
-- a channel from outside it.
sendToChannel :: String -- ^ The channel name
              -> String -- ^ The message to send. It may contain newlines, in
                        --   which case it will be split into multiple messages
                        --   and sent sequentially.
              -> Session e s ()
sendToChannel channel msg = do
    h <- askHandle
    liftIO $ mapM_ (ircSendToChannel h channel) $ lines msg

-- | Send a private message to an IRC user.
sendToUser :: String -- ^ The user's nickname
           -> String -- ^ The message to send. It may contain newlines, in
                     --   which case it will be split into multiple messages
                     --   and sent sequentially.
           -> Session e s ()
sendToUser nick msg = do
    h <- askHandle
    liftIO $ mapM_ (ircSendToUser h nick) $ lines msg

-------------------------------------------------------------------------------
-- Other Utilities
-------------------------------------------------------------------------------

-- | Send an IRC message to the server. This should only be used if the other
-- wrappers don't provide what you need. If that's the case, it may be a good
-- idea for reusability to add a new wrapper.
putIrc :: Message -> Session e s ()
putIrc msg = do
    h <- askHandle
    liftIO $ hPutIrc h msg