local component = require("component")
local sides = require("sides")
local os = require("os")
local srls = require("serialization")
local filesystem = require("filesystem")

local mc = component.me_controller
local rs = component.redstone
ed = component.os_entdetector

function getIAmount(item)
  local items = mc.getItemsInNetwork()
  for k,v in pairs(items) do
    if (v["name"] == item) then do
      local am = v["size"]
      return am
    end
  end
end
end

em = getIAmount("minecraft:emerald")

print("Current emeralds: " .. em)

file = io.open("bank_data")
t = srls.unserialize(file:read())
file:close()

print(srls.serialize(t, true))
print("Starting up!")

while true do
  nem = 0
  player = nil
  while (rs.getInput(sides.up)==1) do
    rs.setOutput(sides.back, 1)

    player = ed.scanPlayers(3)[1]
    nem = getIAmount("minecraft:emerald")-em
    print("Oh! Come here little " .. player.name .. ", and notice you have paid " .. nem)
    os.sleep(0.5)
  end
  os.sleep(2)
  if (nem~=0) then
    if (t[player.name]) then
      t[player.name] = t[player.name] + nem
    else
      t[player.name] = nem
    end
    em = em + nem

    file=io.open("bank_data","w")
    file:write(srls.serialize(t))
    file:close()
  end
  em = getIAmount("minecraft:emerald")
  print("Current emeralds: " .. em)
  rs.setOutput(sides.back, 0)
end