local Util = require('opus.util')

local fs        = _G.fs
local os        = _G.os
local shell     = _ENV.shell

local programDir = fs.getDir(shell.getRunningProgram())
os.loadAPI(programDir .. '/'.. 'json')

local w   = require("w")
local r   = require("r")
local k   = require("k")
local jua = require("jua")

local await     = jua.await
local device    = _G.device
local json      = _G.json
local rs        = _G.rs
local textutils = _G.textutils

local chat = device['plethora:chat']

rs.setOutput('top', false)

r.init(jua)
w.init(jua)
k.init(jua, json, w, r)

local function Syntax()
	error('Syntax: swshop [domain] [password | privateKey] [isPrivateKey]')
end

local args = { ... }
local domain = args[1] or Syntax()
local password = args[2] or Syntax()
local privatekey = args[3] and args[2] or k.toKristWalletFormat(password)
local address = k.makev2address(privatekey)
local transactions = Util.readTable('/usr/swshop.log') or { }

jua.on("terminate", function()
	rs.setOutput('top', false)
	jua.stop()
	_G.printError("Terminated")
end)

local function getItemDetails(item)
	local f = fs.open('usr/config/shop', "r")
	if f then
		local t = f.readAll()
		f.close()
		t = textutils.unserialize(t)
		for key, v in pairs(t) do
			if v.name == item then
				return key, v.price
			end
		end
	end
end

local function logTransaction(transaction, details)
	transaction = Util.shallowCopy(transaction)
	Util.merge(transaction, details)
	table.insert(transactions, transaction)
	Util.writeTable('/usr/swshop.log', transactions)
end

local function handleTransaction(transaction)
	local from = transaction.from
	local to = transaction.to
	local value = transaction.value
	if to ~= address or not transaction.metadata then return end

	local metadata = k.parseMeta(transaction.metadata)
	if not metadata.domain or metadata.domain ~= domain then return end

	local recipient = metadata.meta and (metadata.meta["return"] or from) or from
	print("Handling transaction from ", recipient)
	print('purchase: ' .. tostring(metadata.name))
	print('value: ' .. value)

	local t = {
		to = transaction.to,
		from = transaction.from,
		value = transaction.value,
		id = metadata.name,
	}

	local function refundTransaction(amount, reason)
		print("Refunding to ", recipient)
		await(k.makeTransaction, privatekey, recipient, amount, reason)
		logTransaction(t, { refund = amount, reason = reason })
	end

	t.itemId, t.price = getItemDetails(metadata.name)
	if not t.itemId or not t.price then
		print('invalid item')
		logTransaction(t, { reason = 'invalid item' })
		--return refundTransaction(value, "error=Item specified is not valid")
		return -- there could be multiple stores...
	end

	if value < t.price then
		print('value too low')
		return refundTransaction(value, "error=Please pay the price listed on-screen.")
	end

	local count = math.floor(value / t.price)
	local uid = math.random()
	print(string.format('requesting %d of %s', count, t.itemId))
	os.queueEvent('shop_provide', t.itemId, count, uid)
	local timerId = os.startTimer(60)
	while true do
		local e, p1, p2 = os.pullEvent()
		if e == 'timer' and p1 == timerId then
			print('timed out waiting for provide')
			refundTransaction(value, "error=Timed out attempting to provide items")
			break

		elseif e == 'shop_provided' and p1 == uid then
			local extra = value - (t.price * p2)
			logTransaction(t, { purchased = p2 })
			if chat and chat.tell then
				local msg = string.format('PURCHASE: %s bought %d %s for %s',
					recipient, p2, t.itemId, t.price * p2)
				pcall(chat.tell, msg)
			end
			if extra > 0 then
				print('extra: ' .. extra)
				refundTransaction(extra, "message=Here's your change!")
			end
			break
		end
	end
end

local function connect()
	print('opening store for: ' .. domain)

	local success, ws = await(k.connect, privatekey)
	assert(success, "Failed to get websocket URL")

	print("Connected to websocket.")
	rs.setOutput('top', true)

	success = await(ws.subscribe, "ownTransactions", function(data)
		local transaction = data.transaction
		handleTransaction(transaction)
	end)
	assert(success, "Failed to subscribe to event")
end

local s, m = pcall(function()
	jua.go(function()
		print("Ready")
		connect()
	end)
end)

rs.setOutput('top', false)
if not s then
	error(m, 2)
end