--[[

Network protocol file for HaxServ.

Written by: Test_User <hax@andrewyu.org>

This is free and unencumbered software released into the public
domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of
relinquishment in perpetuity of all present and future rights to this
software under copyright law.

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 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 function mode_snomask(current, mode, dir, arg)
	if dir == "+" then
		current[mode] = current[mode] or {}
		parse_modes(arg, {}, {}, current[mode])
		if not next(current[mode]) then
			current[mode] = nil
		end
		return true
	else
		current[mode] = nil
	end
end

local function mode_replace(current, mode, dir, arg)
	if dir == "+" then
		current[mode] = arg
		return true
	else
		current[mode] = nil
	end
end

local function mode_multi(current, mode, dir, arg)
	if dir == "+" then
		current[mode] = current[mode] or {}
		current[mode][arg] = true
	else
		if current[mode] == nil then
			print("Invalid mode change attempt!\n")
			current[mode] = {}
		end
		current[mode][arg] = nil
		if next(current[mode]) == nil then
			current[mode] = nil
		end
	end
	return true
end

local usermodes = {
	["s"] = mode_snomask,
}

local chanmodes = {
	["l"] = mode_replace,
	["L"] = mode_replace,
	["v"] = mode_multi,
	["o"] = mode_multi,
	["h"] = mode_multi,
	["a"] = mode_multi,
	["q"] = mode_multi,
	["Y"] = mode_multi,
	["d"] = mode_replace,
	["f"] = mode_replace,
	["g"] = mode_multi,
	["b"] = mode_multi,
	["e"] = mode_multi,
	["I"] = mode_multi,
	["k"] = mode_replace,
	["w"] = mode_multi,
	["E"] = mode_replace,
	["F"] = mode_replace,
	["H"] = mode_replace,
	["J"] = mode_replace,
	["X"] = mode_multi,
}

local function parse_modes(modes, args, has_args, current)
	local dir = "-"
	for i = 1, #modes do
		local mode = modes:sub(i, i)

		if mode == "+" or mode == "-" then
			dir = mode
		elseif has_args[mode] and has_args[mode][dir] then
			if not args[1] then return false end

			if dir == "+" then
				current[mode] = (type(current[mode]) == "table" and current[mode] or {})
				current[mode][args[1]] = true
			else
				if current[mode] then
					current[mode][args[1]] = nil
				end
			end
			table.remove(args, 1)
		else
			current[mode] = (dir == "+" and true or nil)
		end
	end
	return true
end

local function mode_to_string(modes)
	local res = "+"
	local args = {}
	for mode, arg in pairs(modes) do
		if arg == true then
			res = res..mode
		elseif type(arg) == "string" then
			res = res..mode
			table.insert(args, arg)
		elseif type(arg) == "table" then
			for _, a in pairs(arg) do
				res = res..mode
				table.insert(args, a)
			end
		end
	end

	res = res.." "..table.concat(args, " ")

	return res
end

message_handler = {
	["PING"] = function(con, source, args, original)
		con:send(":"..args[2].." PONG "..args[2].." "..source.."\n")
	end,

	["SERVER"] = function(con, source, args, original)
		if source then
			servlist[args[4]] = {address = args[1], distance = args[3] + 1 + servlist[source].distance, name = args[5], metadata = {}}
		else
			servlist[args[4]] = {address = args[1], distance = args[3], name = args[5], metadata = {}}
		end
	end,

	["METADATA"] = function(con, source, args, original)
		if args[1] == "*" then
			if servlist[source] then
				servlist[source].metadata[args[2]] = args[3]
			else
				print("Got metadata command from an unknown server!\n")
			end
		elseif args[1]:sub(1, 1) == "#" then
			print(string.format("%q", original))
			print("Channels not yet handled!\n")
		else
			if userlist[args[1]] then
				userlist[args[1]].metadata[args[2]] = args[3]
			else
				print(("%q"):format(original))
				print("Got metadata for an unknown user!\n")
			end
		end
	end,

	["UID"] = function(con, source, args, original)
		userlist[args[1]] = {
			server = source,
			nick_ts = args[2],
			nick = args[3],
			hostname = args[4],
			vhost = args[5],
			ident = args[6],
			ip = args[7],
			user_ts = args[8],
			modes = {},
			realname = args[-1], -- last one is safer as any extra are arguments to umodes (or protocol violations, but at that point nothing is a safe option)

			metadata = {}, -- controlled by METADATA network commands
		}

		if not parse_modes(args[9], {table.unpack(args, 10, #args-1)}, {["s"] = {["+"] = true, ["-"] = false}}, userlist[args[1]].modes) then return true end
	end,

	["OPERTYPE"] = function(con, source, args, original)
		if userlist[source] then
			userlist[source].opertype = args[1]
		else
			print("Server "..source.." attempted to set OPERTYPE on a nonexistent user!\n")
		end
	end,

	["NICK"] = function(con, source, args, original)
		if userlist[source] then
			userlist[source].nick = args[1]
			userlist[source].nick_ts = args[2]
		end
	end,

	["PRIVMSG"] = function(con, source, args, original)
		if args[1] == cur_channel then
			print(("%q"):format("<"..userlist[source].nick.."> "..args[2]))
		end

		local cmd_args = {}
		for part in args[2]:gmatch("[^ ]*") do
			table.insert(cmd_args, part)
		end
		cmd = cmd_args[1]:upper()
		table.remove(cmd_args, 1)

		local resp
		if args[1]:sub(1, 1) == "#" then
			resp = args[1]

			if cmd:sub(1, 3) ~= "\x0304" then return end

			cmd = cmd:sub(4) -- remove leading '-'
		else
			resp = source
		end

		if commands[cmd] then
			if has_permission(userlist[source], commands[cmd].privs) then
				print(("%q"):format(userlist[source].nick.." executed command: "..cmd))
				return commands[cmd].func(con, source, cmd, cmd_args, resp)
			else
				con:send(":1HC000000 NOTICE "..resp.." :You are not authorized to execute that command.\n")
			end
		else
			con:send(":1HC000000 NOTICE "..resp.." :Unknown command: "..cmd.."\n")
		end
	end,

	["MODE"] = function(con, source, args, original)
		if args[1]:sub(1, 1) == "#" then
			print("Channels not handled yet!\n")
		else
			if not userlist[args[1]] then
				print("Attempted to set mode on an unknown user!\n")
			elseif not parse_modes(args[2], {table.unpack(args, 3)}, usermodes, userlist[args[1]].modes) then
				return true
			elseif not userlist[args[1]].modes.o then
				userlist[args[1]].opertype = nil
			end
		end
	end,

	["QUIT"] = function(con, source, args, original)
		userlist[source] = nil
		for name, chan in pairs(chanlist) do
			chan["users"][source] = nil
			if next(chan["users"]) == nil and not chan["modes"]["P"] then
				chanlist[name] = nil
			end
		end
	end,

	["KILL"] = function(con, source, args, original)
		if args[1]:sub(1,3) ~= "1HC" then
			print("Kill remote", original)
			userlist[source] = nil
			for name, chan in pairs(chanlist) do
				chan["users"][source] = nil
				if next(chan["users"]) == nil and not chan["modes"]["P"] then
					chanlist[name] = nil
				end
			end
		else
			print("Kill local", original)
			local user = userlist[args[1]]
			if type(user) == "table" then
				con:send("UID "..args[1].." "..user.nick_ts.." "..user.nick.." "..user.hostname.." "..user.vhost.." "..user.ident.." "..user.ip.." "..user.user_ts.." "..mode_to_string(user.modes).." :"..user.realname.."\n")

				-- temporary before I handle channels
				for channel, _ in pairs(config.channels) do
					con:send(":"..args[1].." JOIN "..channel.."\n")
					con:send("MODE "..channel.." +o "..args[1].."\n")
				end
			end
		end
	end,

	["KICK"] = function(con, soure, args, original)
		if args[2]:sub(1,3) == "1HC" then
			con:send(":"..args[2].." JOIN "..args[1].."\n")
			con:send("MODE "..args[1].." +o "..args[2].."\n")
		else
			print("Channels not yet handled: "..("%q"):format(original))
		end
	end,

--[[	["FJOIN"] = function(con, source, args, original)
		
	end]]
}