local PROTOCOL = "resource-monitor"

local function pprint(...)
	local pretty = require("cc.pretty")
	pretty.pretty_print(...)
end

local function isInventory(peripheral_name)
	for _, t in ipairs{peripheral.getType(peripheral_name)} do
		if t == "inventory" then
			return true
		end
	end
	return false
end

local function isWirelessModem(peripheral_name)
	return peripheral.getType(peripheral_name) == "modem"
		 and peripheral.call(peripheral_name, "isWireless")
end

local function getInventories()
	local inventories = {}
	for _, name in ipairs(peripheral.getNames()) do
		if isInventory(name) then
			table.insert(inventories, name)
		end
	end
	return inventories
end

local function getWirelessModem()
	for _, name in ipairs(peripheral.getNames()) do
		if isWirelessModem(name) then
			return name
		end
	end
end

local function showDiagnostics(hostname, modem_name, inventories)
	term.clear()
	term.setCursorPos(1, 1)
	print("Currently running resource monitor...")

	term.setCursorPos(1, 3)
	term.write("Protocol: ")
	print(PROTOCOL)
	term.write("Hostname: ")
	print(hostname)
	term.write("Wireless modem: ")
	print(modem_name)

	term.setCursorPos(1, 7)
	if #inventories == 0 then
		term.write("Inventories: None")
	else
		print("Inventories:")
		for _, name in ipairs(inventories) do
			term.write("* ")
			print(name)
		end
	end
end

local function getItems(inventories)
	local allItems = {}
	for _, inventory in ipairs(inventories) do
		for slot, item in pairs(peripheral.call(inventory, "list")) do
			local detail = peripheral.call(inventory, "getItemDetail", slot)
			local name = detail.displayName
			allItems[name] = (allItems[name] or 0) + item.count
		end
	end
	return allItems
end

local function main(hostname)
	if not hostname then
		print("ERROR: please provide a hostname")
		return
	end

	local modem_name = getWirelessModem()
	if not modem_name then
		print("ERROR: please attach a wireless modem")
		return
	end

	rednet.open(modem_name)
	rednet.host(PROTOCOL, hostname)

	local inventories = getInventories()

	showDiagnostics(hostname, modem_name, inventories)
	while true do
		local sender = rednet.receive(PROTOCOL)
		local items = getItems(inventories)
		local payload = textutils.serialise(items, { compact = true })
		rednet.send(sender, payload, PROTOCOL)
	end
end

main(...)