-- Important: Keep this API in sync with modules/clusterio/api.lua
local compat = require("compat")
local api = {}


local initialized = false
function api.init()
	if initialized then
		return
	end
	initialized = true

	if remote.interfaces.clusterio_api then
		api.events = remote.call("clusterio_api", "get_events")
	else
		local null_event = script.generate_event_name()
		api.events = {
			on_instance_updated = null_event,
			on_server_startup = null_event,
		}
	end
end

local function call_api(fn, ...)
	if remote.interfaces.clusterio_api and remote.interfaces.clusterio_api[fn] then
		return remote.call("clusterio_api", fn, ...)
	else
		return nil
	end
end

function api.get_instance_name()
	return call_api("get_instance_name")
end

function api.get_instance_id()
	return call_api("get_instance_id")
end


local function escape_channel(channel)
	-- Escape bad characters.  The question mark is used for separating the
	-- channel name from the payload.
	return channel:gsub("([\x00-\x1f?\\])", function(match)
		return "\\x" .. string.format("%02x", match:byte())
	end)
end

function api.send_json(channel, data)
	if not remote.interfaces.clusterio_api then
		return
	end

	channel = escape_channel(channel)
	data = compat.table_to_json(data)

	-- If there's more than about 4kB of data users running with the Windows
	-- console open will start to experience stuttering, otherwise we could
	-- output about 1 MB of data at a time through stdout.
	if #data < 4000 then
		print("\f$ipc:" .. channel .. "?j" .. data)
	else
		local file_no = remote.call("clusterio_api", "get_file_no")
		local file_name = "clst_" .. file_no .. ".json"
		compat.write_file(file_name, data, false, 0)
		print("\f$ipc:" .. channel .. "?f" .. file_name)
	end
end

function api.send_udp(channel, data)
	local port = call_api("get_host_udp_port")
	if not port then
		return -- Lua UDP is not enabled for this instance
	end

	helpers.send_udp(port, escape_channel(channel) .. "?" .. data, 0)
end


return api