-- Thanks to Drex from Dynamic DCS for all the help on sockets, go check his server out

package.path = package.path .. ";.\\LuaSocket\\?.lua;"
package.cpath = package.cpath .. ";.\\LuaSocket\\?.dll;"

local socket = require("socket")
local JSON = loadfile("Scripts\\JSON.lua")()
niod = {}

local triggers = {}
local groupsSet = SET_GROUP:New():FilterStart()

local triggerScheduler =
	SCHEDULER:New(
	nil,
	function()
		checkTriggers()
		--niod.send(formGroupInfoPayload(getGroupsInfo()))
		niod.checkTimeout()
	end,
	{},
	5,
	30
)

niod.scope = "127.0.0.1"
niod.port = 15487
niod.DATA_TIMEOUT_SEC = 0.2

niod.JSON = JSON
niod.isDev = true

niod.eventHandler = {
	handleEvents = true
}

niod.tcp = socket.tcp()
niod.tcp:settimeout(0)

-- Util functions

function niod.log(message)
	if message then
		env.info(message)
	end
end

function niod.setDevEnv(isDev)
	env.setErrorMessageBoxEnabled(niod.isDev)
end

-- NIOD functions wrappers
niod.functions = {}
niod.trigger = {}

-- This is an example trigger
--niod.trigger["GroupPartlyOrCompletelyInZone"] = function(trigger)
--	local group = GROUP:FindByName(trigger.data.groupName)
--	local zone = ZONE:FindByName(trigger.data.zoneName)
--	if not group or not zone then
--		return
--	end
--	if group:IsPartlyOrCompletelyInZone(zone) then
--		niod.sendTrigger(
--			{
--				type = "trigger",
--				callbackId = trigger.callbackId,
--				data = {}
--			}
--		)
--		if trigger.data.frequency == "once" then
--			removeTrigger(trigger.callbackId)
--		end
--	end
--end

-- Triggers

function addTrigger(args)
	table.insert(triggers, args)
end

function checkTriggers()
	for i = 1, #triggers do
		checkTrigger(triggers[i])
	end
end

function checkTrigger(t)
	if t then
		niod.trigger[t.data.type](t)
	else
		niod.log("Tried to check trigger but it wasn't defined")
	end
end

function removeTrigger(id)
	for i = 1, #triggers do
		if triggers[i].callbackId == id then
			table.remove(triggers, i)
		end
	end
end


function getGroupsInfo()
	local groups = {}
	groupsSet:ForEach(
		function(group)
			local groupInfo = {}
			groupInfo.coalitionName = group:GetCoalitionName()
			groupInfo.categoryName = group:GetCategoryName()
			groupInfo.country = group:GetCountry()
			groupInfo.units = {}
			for UnitId, UnitData in pairs(group:GetUnits()) do
				local unit = {}
				unit.fuel = UnitData:GetFuel()
				unit.callsign = UnitData:GetCallsign()
				unit.inAir = UnitData:InAir()
				unit.isActive = UnitData:IsActive()
				unit.isAlive = UnitData:IsAlive()
				unit.name = UnitData:Name()
				unit.pitch = UnitData:GetPitch()
				unit.roll = UnitData:GetRoll()
				unit.yaw = UnitData:GetYaw()
				unit.position = UnitData:GetPosition()
				table.insert(groupInfo.units, unit)
			end
			table.insert(groups, groupInfo)
		end
	)
	return groups
end

function formGroupInfoPayload(groups)
	return {
		type = "groupInfo",
		callbackId = "groupInfo",
		data = groups
	}
end

-- NIOD functions

function niod.bind()
	local bound, error = niod.tcp:bind(niod.scope, niod.port)
	if not bound then
		niod.log("Could not bind: " .. error)
		return
	end
	niod.log("Port " .. niod.port .. " bound")
	local serverStarted, error = niod.tcp:listen(1)
	if not serverStarted then
		niod.log("Could not start server: " .. error)
		return
	end
	niod.log("Server started")
end
function niod.checkJSON(jsonstring, code)
	if code == "encode" then
		if type(niod.JSON:encode(jsonstring)) ~= "string" then
			error("encode expects a string after function")
		end
	end
	if code == "decode" then
		if type(jsonstring) ~= "string" then
			error("decode expects string")
		end
	end
end

function niod.eventHandler.onEvent(event)
	niod.log("event")
	niod.log(event)
end

function niod.processRequest(request)
	local response = {}
	if request and request.type and request.callbackId then
		response.type = request.type
		response.callbackId = request.callbackId
		if request.data then
			veaf.logTrace(string.format("NIOD - niod.processRequest(%s)",veaf.p(request)))
			if request.type == "function" and request.data.name then
				response.data = niod.functions[request.data.name](request.data.args)
			elseif request.type == "trigger" and request.data then
				addTrigger(request)
				response.type = "triggerInit"
				response.data = {}
			elseif request.type == "noTimeout" then
				response.data = {}
			end
		end
	end
	veaf.logTrace(string.format("NIOD - response=%s", veaf.p(request), veaf.p(response)))
	return response
end

function niod.step()
	if not niod.client then
		niod.client = niod.tcp:accept()
		if niod.client then
			niod.client:settimeout(0)
			niod.log("Connection established")
		end
	end
	if niod.client then
		local line, err = niod.client:receive("*l")
		--niod.client:send('\n')
		local data = {}
		if line ~= nil then
			local success, error = pcall(niod.checkJSON, line, "decode")
			if success then
				local incMsg = niod.JSON:decode(line)
				niod.log(incMsg)
				data = niod.processRequest(incMsg)
			else
				niod.log("Error: " .. error)
			end
		end
		-- if there was no error, send it back to the niod.client
		if not err and data then
			local dataPayload = data --getDataMessage()
			niod.send(dataPayload)
		end
	end
end

function niod.sendTrigger(data)
	local dataPayload = data
	niod.send(dataPayload)
end

function niod.checkTimeout()
	local dataPayload = {
		type = "noTimeout",
		callbackId = "noTimeout",
		data = {}
	}
	niod.send(dataPayload)
end

function niod.send(dataPayload)
	if not niod.client then
		niod.log("Error: Connection lost")
		return
	end
	local success, error = pcall(niod.checkJSON, dataPayload, "encode")
	if success then
		local outMsg = niod.JSON:encode(dataPayload)
		local bytes, status, lastbyte = niod.client:send(outMsg .. "\n")
		if not bytes then
			niod.log("Error: Connection lost")
			niod.client = nil
		end
	else
		niod.log("Error: " .. error)
	end
end

niod.setDevEnv()
niod.bind()
world.addEventHandler(niod.eventHandler)

timer.scheduleFunction(
	function(arg, time)
		local success, error = pcall(niod.step)
		if not success then
			niod.log("Error: " .. error)
		end
		return timer.getTime() + niod.DATA_TIMEOUT_SEC
	end,
	nil,
	timer.getTime() + niod.DATA_TIMEOUT_SEC
)

niod.log("Started NIOD")