args = { ... }

cache = {}

allow_dynamic_lns_hosts = false

function lns_lookup(remote_hostname)
    local data = {
        ["action"] = "lookup",
        ["hostname"] = remote_hostname
    }

    local lns_server_id = 7
    if allow_dynamic_lns_hosts then
        lns_server_id = rednet.lookup("lns", lns_server)
        if lns_server_id == nil then
            io.write("LNS Server not found!\n")
            return nil
        end
    end

    rednet.send(lns_server_id, data)

    while true do
        id, msg = rednet.receive()
        if id == lns_server_id then
            if msg == nil then
                return nil
            else
                return msg
            end
        end
    end
end

local action = args[1]
if action == nil then
    io.write("Usage: lns <action>\n")
    return
end

if action == "lookup" then
    local hostname = args[2]
    if hostname == nil then
        io.write("Usage: lns lookup <hostname>\n")
        return
    end

    if cache[hostname] ~= nil then
        io.write(cache[hostname])
        return
    end

    local id = lns_lookup(hostname)
    if id ~= nil then
        io.write(id)
        cache[hostname] = id
    end

elseif action == "clear" then
    local data = {
        ["action"] = "reload"
    }

    lns_server_id = rednet.lookup("lns", lns_server)
    rednet.send(lns_server_id, data)
    print("Reloaded LNS Server")
end