--[[ 
 Lua IRC library

 Copyright (c) 2010 Jakob Ovrum

 Permission is hereby granted, free of charge, to any person
 obtaining a copy of this software and associated documentation
 files (the "Software"), to deal in the Software without
 restriction, including without limitation the rights to use,
 copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the
 Software is furnished to do so, subject to the following
 conditions:

 The above copyright notice and this permission notice shall be
 included in all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 OTHER DEALINGS IN THE SOFTWARE.]]

local socket = require "socket"

local error = error
local setmetatable = setmetatable
local rawget = rawget
local ipairs = ipairs
local print = print
local unpack = unpack
local pairs = pairs
local string = string
local tostring = tostring
local table = table
local type = type

module("irc")

local function assert(b, err, errlevel)
      if not b then
         error(err, errlevel or 3)
      end
      return b
end

debug = false

local clients = {}

local meta = {}
meta.__index = meta

local meta_preconnect = {}

local function postAuth_join(o, channel)
	o:send("JOIN %s", channel)
end

function meta_preconnect.__index(o, k)
         local v = rawget(meta_preconnect, k)
         if not v and meta[k] then
            error("field '"..k.."' is not accessible before connecting", 2)
         end
         return v
end

function new(user)
         local o = {}
         o.nick = assert(user.nick, "Field 'nick' is required")
         o.username = user.username or "lua"
         o.realname = user.realname or "Lua owns"
         o.socket = socket.tcp()
         o.hooks = {}
         o.rooms = {}
         o.connected = false

         return setmetatable(o, meta_preconnect)
end

function think()
		local think = meta.think
        for _,o in ipairs(clients) do
            think(o)
        end
end

function meta:hook(name, id, f)
		 f = f or id
		 self.hooks[name] = self.hooks[name] or {}
         self.hooks[name][id] = f
end
meta_preconnect.hook = meta.hook


function meta:unhook(name, id)
		local hooks = self.hooks[name]
		assert(hooks[id], "hook ID not found")
		hooks[id] = nil
end
meta_preconnect.unhook = meta.unhook

function meta:invoke(name, ...)
         local hooks = self.hooks[name]
         if hooks then
			for id,f in pairs(hooks) do
            	f(...)
         	end
		 end
end

function meta:connect(server, port)
         port = port or 6667

		 self.socket:settimeout(30)
         local succ, err = self.socket:connect(server, port)
         if not succ then return nil, err end

         setmetatable(self, meta)

         self:send("USER %s 0 * :%s", self.username, self.realname)
         self:send("NICK %s", self.nick)
         
         self._i = #clients + 1
         clients[self._i] = self
		
		 self.socket:settimeout(0)
         self.connected = true
         return true
end
meta_preconnect.connect = meta.connect

function meta:disconnect(message)
         local message = message or "Bye!"
         
         o:invoke("OnDisconnect", message, false)
         self:send("QUIT :%s", message)

         self:shutdown()
end

function meta:shutdown()
         self.connected = false

         self.socket:shutdown()
         self.socket:close()

         clients[self._i] = nil

         setmetatable(self, nil)
end

local function getline(self, errlevel)
	line, err = self.socket:receive("*l")
	
	if not line and err ~= "timeout" then
		o:invoke("OnDisconnect", err, true)			
		self:shutdown()
		error(err, errlevel)
	end

	return line
end

function meta:think()
		while true do
			local line = getline(self, 4)
			if line then
				self:handle(parse(line))
			else
				break
			end
		end
end

function parsePrefix(prefix)
         local user = {}
         if prefix then
            user.nick, user.username, user.host = prefix:match("(.*)!(.*)@(.*)")
         end
         return user
end

function parse(line)
         local colonsplit = line:find(":", 2)
         local last
         if colonsplit then
            last = line:sub(colonsplit+1)
            line = line:sub(1, colonsplit-2)
         end

         local prefix
         if line:sub(1,1) == ":" then
            local space = line:find(" ")
            prefix = line:sub(2, space-1)
            line = line:sub(space)
         end
         
         local params = {}
         local it, state, init = line:gmatch("(%S+)")
         local cmd = it(state, init)

         for sub in it, state, init do
             params[#params + 1] = sub
         end

         if last then params[#params + 1] = last end

         return prefix, cmd, params
end

local handlers = {}

handlers["PING"] = function(o, prefix, query)
         o:send("PONG :%s", query)
end

handlers["001"] = function(o)
		 o.join = postAuth_join
		 for k,room in ipairs(o.rooms) do
			o:join(room)
		 end
		 o.rooms = nil
		 
         o:invoke("OnConnect")
end

handlers["PRIVMSG"] = function(o, prefix, channel, message)
         o:invoke("OnChat", parsePrefix(prefix), channel, message)
end

handlers["NOTICE"] = function(o, prefix, channel, message)
         o:invoke("OnNotice", parsePrefix(prefix), channel, message)
end

handlers["JOIN"] = function(o, prefix, channel)
         o:invoke("OnJoin", parsePrefix(prefix), channel)
end

handlers["PART"] = function(o, prefix, channel, reason)
         o:invoke("OnPart", parsePrefix(prefix), channel, reason)
end

handlers["ERROR"] = function(o, prefix, message)
         o:invoke("OnDisconnect", message, true)
         o:shutdown()
         error(message)
end

function meta:handle(prefix, cmd, params)
         local handler = handlers[cmd]
         if handler then
            return handler(self, prefix, unpack(params))
         end
end

function meta:send(fmt, ...)
         self.socket:send(fmt:format(...) .. "\r\n")
end

function meta:sendChat(channel, msg)
		 toChannel = table.concat{"PRIVMSG ", channel, " :"}
		 for line in msg:gmatch("[^\r\n]+") do
		 	self.socket:send(table.concat{toChannel, line, "\r\n"})
		 end
end

--preAuth_join
function meta:join(channel)
         table.insert(self.rooms, channel)
end
meta_preconnect.join = meta.join

function meta:part(channel)
         self:send("PART %s", channel)
end

color = {
	black = 1,
	blue = 2,
	green = 3,
	red = 4,
	lightred = 5,
	purple = 6,
	brown = 7,
	yellow = 8,
	lightgreen = 9,
	navy = 10,
	cyan = 11,
	lightblue = 12,
	violet = 13,
	gray = 14,
	lightgray = 15,
	white = 16
}

local colByte = string.char(3)
setmetatable(color, {__call = function(_, text, colornum)
	colornum = type(colornum) == "string" and assert(color[colornum], "Invalid color '"..colornum.."'") or colornum
	return table.concat{colByte, tostring(colornum), text, colByte}
end})

local boldByte = string.char(2)
function bold(text)
	return boldByte..text..boldByte
end

local underlineByte = string.char(31)
function underline(text)
	return underlineByte..text..underlineByte
end

local whoisHandlers = {
	["311"] = "userinfo";
	["312"] = "node";
	["319"] = "channels";
	["330"] = "account";
}

function meta:whois(nick)
	self:send("WHOIS %s", nick)

	local result = {}
	
	while true do
		local line = getline(self, 3)
		if line then
			local prefix, cmd, args = parse(line)

			local handler = whoisHandlers[cmd]
			if handler then
				result[handler] = args
			elseif cmd == "318" then
				break
			else
				self:handle(prefix, cmd, args)
			end
		end
	end

	if result.account then
		result.account = result.account[3]
	end
	return result
end