travelnet/add_target.lua

local S = minetest.get_translator("travelnet")


-- add a new target; meta is optional
travelnet.add_target = function(station_name, network_name, pos, player_name, meta, owner_name)

	-- if it is an elevator, determine the network name through x and z coordinates
	local this_node   = minetest.get_node(pos)
	local is_elevator = false

	if this_node.name == "travelnet:elevator" then
		--      owner_name   = "*"  -- the owner name is not relevant here
		is_elevator  = true
		network_name = tostring(pos.x) .. "," .. tostring(pos.z)
		if not station_name or station_name == "" then
			station_name = S("at @1 m", tostring(pos.y))
		end
	end

	if station_name == "" or not station_name then
		travelnet.show_message(pos, player_name, S("Error"), S("Please provide a name for this station."))
		return
	end

	if network_name == "" or not network_name then
		travelnet.show_message(pos, player_name, S("Error"),
				S("Please provide the name of the network this station ought to be connected to."))
		return
	end

	if owner_name == nil or owner_name == "" or owner_name == player_name then
		owner_name = player_name
	elseif is_elevator then -- elevator networks
		owner_name = player_name
	elseif not minetest.check_player_privs(player_name, { interact=true }) then
		travelnet.show_message(pos, player_name, S("Error"),
				S("There is no player with interact privilege named '@1'. Aborting.", tostring(player_name)))
		return
	elseif  not minetest.check_player_privs(player_name, { travelnet_attach=true })
		and not travelnet.allow_attach(player_name, owner_name, network_name)
	then
		travelnet.show_message(pos, player_name, S("Error"),
				S("You do not have the travelnet_attach priv which is required to attach your box to " ..
					"the network of someone else. Aborting."))
		return
	end

	-- first one by this player?
	if not travelnet.targets[owner_name] then
		travelnet.targets[owner_name] = {}
	end

	-- first station on this network?
	if not travelnet.targets[owner_name][network_name] then
		travelnet.targets[owner_name][network_name] = {}
	end

	-- lua doesn't allow efficient counting here
	local anz = 0
	for k in pairs(travelnet.targets[owner_name][network_name]) do
		if k == station_name then
			travelnet.show_message(pos, player_name, S("Error"),
					S("A station named '@1' already exists on this network. Please choose a different name!", station_name))
			return
		end
		anz = anz+1
	end

	-- we don't want too many stations in the same network because that would get confusing when displaying the targets
	if anz+1 > travelnet.MAX_STATIONS_PER_NETWORK then
		travelnet.show_message(pos, player_name, S("Error"),
				S("Network '@1', already contains the maximum number (@2) of allowed stations per network. " ..
					"Please choose a different/new network name.", network_name, travelnet.MAX_STATIONS_PER_NETWORK))
		return
	end

	-- add this station
	travelnet.targets[owner_name][network_name][station_name] = {
		pos = pos,
		timestamp = os.time()
	}

	-- do we have a new node to set up? (and are not just reading from a safefile?)
	if meta then
		minetest.chat_send_player(player_name,
				S("Station '@1'" .. " " ..
					"has been added to the network '@2'" ..
					", which now consists of @3 station(s).", station_name, network_name, anz+1))

		meta:set_string("station_name",    station_name)
		meta:set_string("station_network", network_name)
		meta:set_string("owner",           owner_name)
		meta:set_int   ("timestamp",       travelnet.targets[owner_name][network_name][station_name].timestamp)

		meta:set_string("formspec",
				"size[12,10]" ..
				"field[0.3,0.6;6,0.7;station_name;" .. S("Station:") .. ";" ..
				minetest.formspec_escape(meta:get_string("station_name")) .. "]" ..
				"field[0.3,3.6;6,0.7;station_network;" .. S("Network:") .. ";" ..
				minetest.formspec_escape(meta:get_string("station_network")) .. "]")

		-- display a list of all stations that can be reached from here
		travelnet.update_formspec(pos, player_name, nil)

		-- save the updated network data in a savefile over server restart
		travelnet.save_data()
	end
end