#!/usr/bin/lua
--! Minimalistic CRDT-like shared state structure suitable for mesh networks
--! which handles conflicts in the same entry using last modified timestamp.
--!
--! Copyright (C) 2019  Gioacchino Mazzurco <gio@altermundi.net>
--!
--! This program is free software: you can redistribute it and/or modify
--! it under the terms of the GNU Affero General Public License version 3 as
--! published by the Free Software Foundation.
--!
--! This program is distributed in the hope that it will be useful,
--! but WITHOUT ANY WARRANTY; without even the implied warranty of
--! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--! GNU Affero General Public License for more details.
--!
--! You should have received a copy of the GNU Affero General Public License
--! along with this program.  If not, see <http://www.gnu.org/licenses/>.

if type(arg[2]) ~= "string" or arg[2]:len() < 1 then
	print (arg[0], "needs CRDT name to be specified as second argument")
	os.exit(-22)
end

local JSON = require("luci.jsonc")
local shared_state = require("shared-state")
require("nixio.util")

nixio.openlog("shared-state")
local logmask = "info"
if os.getenv("DEBUG") then
	logmask = "debug"
end
nixio.setlogmask(logmask)

local sharedState = shared_state.SharedStateMultiWriter:new(arg[2], nixio.syslog)

if arg[1] == "insert" then
	local inputTable = JSON.parse(io.stdin:read("*all")) or {}
	sharedState:insert(inputTable)
elseif arg[1] == "get" then
	local resultTable = sharedState:get()
	print(JSON.stringify(resultTable))
elseif arg[1] == "sync" then
	local urls = {}
	if arg[3] ~= nil then for i=3,#arg do table.insert(urls, arg[i]) end end
	sharedState:sync(urls)
elseif arg[1] == "reqsync" then
	local inputJson = JSON.parse(io.stdin:read("*all"))
	sharedState:merge(inputJson)
	print(sharedState:toJsonString())
else
	print(arg[0], "needs an operation name to be specified as first argument")
	nixio.closelog()
	os.exit(-22)
end

nixio.closelog()