package.path = "/?;/?.lua;"..package.path

local key=assert(settings.get"krist.pkey","please set private key")

local stock=require"shop2.stock"
local items = require"shop2.items"

-- ac.kst
local OURNAME = "ac"

local sres =textutils.unserializeJSON( http.post("https://krist.dev/ws/start","privatekey="..key).readAll())
assert(sres.ok,"not ok")

local ws = assert(http.websocket(sres.url))
local nextid = 0
local our_addr = "???"

local function sendws(t)
	t.id = nextid
	nextid = nextid + 1
	return ws.send(textutils.serializeJSON(t))
end

sendws{type="me"}

local function parsemeta(m)
	local out = {}
	for s in string.gmatch(m..";","(.-);") do
		local k,v = s:match"^(.-)=(.-)$"
		if k==nil then
			out.recipient = s
		else
			out[k]=v
		end
	end
	return out
end

local function divisible(a,b)
	-- returns whether a is divisible by b
	-- because % doesn't work on nonintegers for some reason
	if b == 0 then return false end
	local x = a/b
	return x == math.floor(x)
end

local function proctrans(tr)
	if tr.to ~= our_addr then return end
	if tr.type ~= "transfer" then return end
	if tr.sent_name ~= OURNAME then return end
	local meta = parsemeta(tr.metadata)
	local function tell(msg)
		if meta.username then
			if not pcall(chatbox.tell,meta.username,msg) then
				print("chatbox error, couldn't tell "..meta.username..": "..msg)
			end
		end
	end
	local function refund() if meta['return'] then sendws { type="make_transaction", to=meta['return'], amount=tr.value } end end

	local mtn = tr.sent_metaname
	local idesc
	for _,i in ipairs(items) do
		if i.adr == mtn then idesc = i end
	end
	if not idesc then
		-- some other metaname that has nothing to do with us
		-- presumably some other service @ac.kst. so just ignore it
		print("(debug) don't know what '"..mtn.."' means, ignoring")
		-- tell("(debug) i didn't recognise that metaname so no transaction occurs")
		return
	end

	if not divisible(tr.value,idesc.price) then
		tell("i can only give you a whole number of items. make sure the amount you gave me is a multiple of "..idesc.price)
		refund()
	else
		local si = stock.take_stock()
		local in_stock = stock.amt_of(si,idesc)
		if in_stock == 0 then
			tell("we are out of stock! please yell at ubq323 about this")
			refund()
		else
			local to_give = math.floor(tr.value / idesc.price)
			if to_give > in_stock then
				tell("i don't have that many items in stock, sorry")
				refund()
			else
				stock.give(si,idesc,to_give)
				tell("thank you!")
			end
		end
	end
end

local function run_shop()
	while true do
		local msgtxt = assert(ws.receive(),"ws error")
		local msg = textutils.unserializeJSON(msgtxt)
		if msg.type == "response" and msg.responding_to_type == "me" then
			our_addr = msg.address.address
		end
		if msg.type == "event" and msg.event == "transaction" then
			proctrans(msg.transaction)
		end
	end
end

local run_disp = require"shop2.disp".run

print(pcall(parallel.waitForAny,run_shop,run_disp))
-- print("hi")
-- peripheral.call("top","clear")
-- peripheral.call("left","clear")