module HWProto where

import IO

import Data.List

import Data.Word

import Miscutils

import Maybe (fromMaybe, fromJust)

fromRoom :: String -> [ClientInfo] -> [ClientInfo]

fromRoom roomName clients = filter (\cl -> roomName == room cl) clients

-- 'noInfo' clients state command handlers

handleCmd_noInfo :: ClientInfo -> [ClientInfo] -> [RoomInfo] -> [String] -> (ClientInfo, [RoomInfo], [ClientInfo], [String])

handleCmd_noInfo client clients rooms ("NICK":newNick:[]) =

	if not . null $ nick client then

		(client, rooms, [client], ["ERROR", "The nick already chosen"])

	else if haveSameNick then

		(client, rooms, [client], ["WARNING", "Choose another nick"])

	else

		(client{nick = newNick}, rooms, [client], ["NICK", newNick])

	where

		haveSameNick = not . null $ filter (\cl -> newNick == nick cl) clients

handleCmd_noInfo client clients rooms ("PROTO":protoNum:[]) =

	if protocol client > 0 then

		(client, rooms, [client], ["ERROR", "Protocol number already known"])

	else if parsedProto == 0 then

		(client, rooms, [client], ["ERROR", "Bad input"])

	else

		(client{protocol = parsedProto}, rooms, [], [])

	where

		parsedProto = fromMaybe 0 (maybeRead protoNum :: Maybe Word16)

handleCmd_noInfo client _ rooms _ = (client, rooms, [client], ["ERROR", "Bad command or incorrect parameter"])

-- 'noRoom' clients state command handlers

handleCmd_noRoom :: ClientInfo -> [ClientInfo] -> [RoomInfo] -> [String] -> (ClientInfo, [RoomInfo], [ClientInfo], [String])

handleCmd_noRoom client clients rooms ("CREATE":newRoom:roomPassword:[]) =

	if haveSameRoom then

		(client, rooms, [client], ["WARNING", "There's already a room with that name"])

	else

		(client{room = newRoom, isMaster = True}, (RoomInfo newRoom roomPassword):rooms, [client], ["JOIN", newRoom, nick client])

	where

		haveSameRoom = not . null $ filter (\room -> newRoom == name room) rooms

handleCmd_noRoom client clients rooms ("CREATE":newRoom:[]) =

	handleCmd_noRoom client clients rooms ["CREATE", newRoom, ""]

handleCmd_noRoom client clients rooms ("JOIN":roomName:roomPassword:[]) =

	if noRoom then

		(client, rooms, [client], ["WARNING", "There's no room with that name"])

	else if roomPassword /= password (getRoom roomName) then

		(client, rooms, [client], ["WARNING", "Wrong password"])

	else

		(client{room = roomName}, rooms, client : fromRoom roomName clients, ["JOIN", roomName, nick client])

	where

		noRoom = null $ filter (\room -> roomName == name room) rooms

		getRoom roomName = fromJust $ find (\room -> roomName == name room) rooms

handleCmd_noRoom client clients rooms ("JOIN":roomName:[]) =

	handleCmd_noRoom client clients rooms ["JOIN", roomName, ""]

handleCmd_noRoom client _ rooms _ = (client, rooms, [client], ["ERROR", "Bad command or incorrect parameter"])

-- 'inRoom' clients state command handlers

handleCmd_inRoom :: ClientInfo -> [ClientInfo] -> [RoomInfo] -> [String] -> (ClientInfo, [RoomInfo], [ClientInfo], [String])

handleCmd_inRoom client _ rooms _ = (client, rooms, [client], ["ERROR", "Bad command or incorrect parameter"])

handleCmd :: ClientInfo -> [ClientInfo] -> [RoomInfo] -> [String] -> (ClientInfo, [RoomInfo], [ClientInfo], [String])

handleCmd client clients rooms ("QUIT":xs) =

	if null (room client) then

		(client, rooms, [client], ["QUIT"])

	else

		(client, rooms, fromRoom (room client) clients, ["QUIT", nick client])

-- check state and call state-dependent commmand handlers

handleCmd client clients rooms cmd =

	if null (nick client) || protocol client == 0 then

		handleCmd_noInfo client clients rooms cmd

	else if null (room client) then

		handleCmd_noRoom client clients rooms cmd

	else

		handleCmd_inRoom client clients rooms cmd