local event = require("event")

local PORT = 80
local SEND_ATTEMPTS = 5
local BACKOFF_BASE = 1 --seconds

local gdp = {}

--init
math.randomseed(os.time())
--end-init


local function set_timer(callback, max_wait_time, elapsed_attempts)
    local function on_timer()
        if elapsed_attempts > SEND_ATTEMPTS then --TODO: Check off-by-1 error
            io.write("ERROR: TODO")
            return
        end
        callback()
        set_timer(callback, max_wait_time * 2, elapsed_attempts + 1)
    end
    io.write(elapsed_attempts, ":", event.timer(math.random() * max_wait_time, on_timer, 1), "\n")
end

local function backoff(callback)
    set_timer(callback, BACKOFF_BASE, 1)
end

function gdp.send(to, ...)
    local args = table.pack(...)
    local send_actual = function()
        io.write("id:", args[1], " ")
    end
    backoff(send_actual)
end