-- Hot Pocket Repeater

SECONDS_UNTIL_PACKET_CLEARED = 10

-- Open network interface
rednet.open("top")

-- Packet table
-- This is to make sure we only repeat a packet once
repeated_packets = {}
memory_size = 0
repeated = 0
dropped = 0

function draw_screen()
  -- Clear Screen
  term.clear()
  term.setCursorPos(1, 1)

  print("HotPocketProtocol Repeater v1.1")
  print("-------------------------------")
  print("Memory Usage: " .. memory_size)
  print("Repeated Packets: " .. repeated)
  print("Dropped Packets: " .. dropped)
end

function memory_tick()
  memory_size = 0
  local k = next(repeated_packets)
  while k do
    memory_size = memory_size + 1
    n = next(repeated_packets, k)
    if repeated_packets[k] <= 0 then -- Packet is done being timed out
      repeated_packets[k] = nil -- Clear packet
    else -- Packet is not done being timed out
      repeated_packets[k] = repeated_packets[k] - 1 -- Decrement counter
    end
    if k ~= n then
      k = n
    else
      k = nil
    end
  end
end

while true do
  memory_tick()
  draw_screen()

  -- Listen for packets
  computer_id, info, protocol = rednet.receive("HotPocketProtocol", 1)

  if computer_id ~= nil then -- If a packet is received
    -- Unpack packet
    data = {}
    for i in string.gmatch(info, "%S+") do
      table.insert(data, i)
    end
    packet = data[1] .. tonumber(data[2])

    -- Make sure packet hasn't been repeated
    if repeated_packets[packet] == nil then
      repeated_packets[packet] = SECONDS_UNTIL_PACKET_CLEARED;
      rednet.broadcast(info, "HotPocketProtocol")
      repeated = repeated + 1
    else
      dropped = dropped + 1
    end
  end
end