-- ## CONFIG ## --

local SERVER_BASE_URL:string = "http://localhost:7000/"
local REQUESTS_PER_MINUTE:number = 500 -- roblox 500 requests per minute limit
local ALLOW_CLIENT:boolean = true;

-- ## MODULE ## --

local exposed = {}

local isServer = game:GetService("RunService"):IsServer()

shared.BatchHttpModule = shared.BatchHttpModule or {}
shared.BatchHttpModule.queue = shared.BatchHttpModule.queue or {}
shared.BatchHttpModule.signal = shared.BatchHttpModule.signal or Instance.new("BindableEvent")
shared.BatchHttpModule.lastSent = shared.BatchHttpModule.lastSent or 0;
shared.BatchHttpModule.waitingForResponse = shared.BatchHttpModule.waitingForResponse or {}

shared.BatchHttpModule.clientRemote = shared.BatchHttpModule.clientRemote or (function()
	local funcName = "_BatchHTTP"
	local funcLocation = workspace
	if (isServer) then
		local remoteFunction = Instance.new("RemoteFunction")
		remoteFunction.Name = funcName
		remoteFunction.Parent = funcLocation
		remoteFunction.OnServerInvoke = function(plr,options)
			if not ALLOW_CLIENT then return end
			return exposed:RequestAsync(options)
		end
		return remoteFunction
	else
		return funcLocation:WaitForChild(funcName)
	end
end)()	

local signal:BindableEvent = shared.BatchHttpModule.signal
local THREAD_INTERVAL:number = (60/REQUESTS_PER_MINUTE)

local RealHttpService = game:GetService("HttpService")
local InstanceSecret = (RealHttpService:GenerateGUID(false).."--"..game.JobId) -- not only using jobid so that random people cant just spam the api to get a response

function ProcessQueue()
	--print("processing queue")
	local requests = {}
	local waiting = shared.BatchHttpModule.waitingForResponse
	for _,queueObj in shared.BatchHttpModule.queue do
		table.insert(requests, queueObj)
		table.insert(shared.BatchHttpModule.waitingForResponse,queueObj.id)
	end
	
	local body = {}
	if (#requests ~= 0) then body.requests = requests end
	if (#waiting ~= 0) then body.waiting = waiting end
	
	if not (body.waiting or body.requests) then return end
	
	shared.BatchHttpModule.lastSent = tick()
	
	local jsonBody = RealHttpService:JSONEncode(body)
	shared.BatchHttpModule.queue = {}
	local response = RealHttpService:PostAsync(SERVER_BASE_URL..InstanceSecret, jsonBody, Enum.HttpContentType.ApplicationJson, true, {
		["X-BatchHttp-Api-Key"] = "silly!" -- i know this exposes the key to client but its just temporary (permanent)
	})
	local data = RealHttpService:JSONDecode(response)
	
	signal:Fire(data.responses or {})
end

function AddToQueue(queueObj)
	table.insert(shared.BatchHttpModule.queue, queueObj)
end

function DoRequest(request)
	local id = RealHttpService:GenerateGUID(false);
	print("[BatchHTTP] sending request",id)
	AddToQueue({
		id = id,
		request = request,
	})
	local response = nil;
	while not response do
		local receivedData = signal.Event:Wait()
		for _,obj in receivedData do
			if obj.id == id then
				response = obj
				local tableIndex = table.find(shared.BatchHttpModule.waitingForResponse,id)
				if tableIndex then
					table.remove(shared.BatchHttpModule.waitingForResponse,tableIndex)
				end
			end
		end	
	end
	
	if response.error then
		warn('[BatchHTTP] request '..id..' errored "'..response.error.message..'"')
	else
		print("[BatchHTTP] got response "+response.status,id)
	end
	
	return response.data
end

shared.BatchHttpModule.thread = shared.BatchHttpModule.thread or coroutine.wrap(function()
	while true do 
		if (tick() - shared.BatchHttpModule.lastSent) > THREAD_INTERVAL then
			task.spawn(ProcessQueue)
		end
		task.wait()
	end
end)()

exposed.HttpEnabled = RealHttpService.HttpEnabled

exposed.GenerateGUID = RealHttpService.GenerateGUID
exposed.GetSecret = RealHttpService.GetSecret

exposed.JSONDecode = RealHttpService.JSONDecode
exposed.JSONEncode = RealHttpService.JSONEncode
exposed.UrlEncode = RealHttpService.UrlEncode

function exposed:RequestAsync(options) 
	if (isServer) then
		return DoRequest(options)
	else
		return shared.BatchHttpModule.clientRemote:InvokeServer(options)
	end
end 

function exposed:PostAsync(url, body, contentType, compress, headers) 
	return exposed:RequestAsync({
		Method = "post";
		Url = url;
		Body = body;
		Headers = headers;
	})
end 

function exposed:GetAsync(url)
	return exposed:RequestAsync({
		Method = "get";
		Url = url;
	})
end

return exposed;