DOGGY BOOTLOADER for opencomputers with BIOS UPDATE FEATURE

local function main()
  local ci = component.invoke
  local computer = computer or require("computer")

  local bi = function(a, m, ...)
    local r = table.pack(pcall(ci, a, m, ...))
    if not r[1] then return nil, r[2] else return table.unpack(r, 2, r.n) end
  end

  local e = component.list("eeprom")()
  computer.getBootAddress = function() return bi(e, "getData") end
  computer.setBootAddress = function(a) return bi(e, "setData", a) end

  do
    local s, g = component.list("screen")(), component.list("gpu")()
    if g and s then bi(g, "bind", s) end
  end

  local function tryLoad(a)
    local h, r = bi(a, "open", "/init.lua")
    if not h then return nil, "Failed to open /init.lua: " .. tostring(r) end
    local b = ""
    repeat
      local d, r = bi(a, "read", h, math.maxinteger or math.huge)
      if not d and r then
        bi(a, "close", h)
        return nil, "Failed to read /init.lua: " .. tostring(r)
      end
      b = b .. (d or "")
    until not d
    bi(a, "close", h)
    local i, l = load(b, "=init")
    if not i then return nil, "Failed to load /init.lua: " .. tostring(l) end
    return i
  end

  local function flashEEPROM(address)
    local h, r = bi(address, "open", "/DOGGY.ROM")
    if not h then return false, "Failed to open DOGGY.ROM: " .. tostring(r) end
    local totalSize = bi(address, "size", "/DOGGY.ROM")
    local pageSize = 64 -- Example EEPROM page size
    local chunkSize = math.min(totalSize, pageSize * 2) -- Choose a chunk size that is a multiple of page size, e.g., 128 bytes
    local data, chunk = "", ""
    local progressWidth = 20 -- Width of the progress bar
    repeat
        chunk = bi(address, "read", h, chunkSize)
        if chunk then
            bi(e, "set", data .. chunk) -- Write chunk to EEPROM
            data = data .. chunk
            local progress = #data / totalSize
            local progressBar = string.rep("=", math.floor(progress * progressWidth)) .. string.rep(" ", progressWidth - math.floor(progress * progressWidth))
            bi(component.list("gpu")(), "set", 1, 1, "Flashing: [" .. progressBar .. "] " .. math.floor(progress * 100) .. "%")
        end
        computer.pullSignal(6) -- Wait for 6 seconds
    until not chunk
    bi(address, "close", h)
    return true
  end

  local function bootloader()
    local l = {}
    for a in component.list("filesystem") do
      local b = bi(a, "getLabel") or "Unnamed Drive"
      if b ~= "tmpfs" then
        table.insert(l, { address = a, label = b })
      end
    end

    local function displayError(errorMessage)
      local g = component.list("gpu")()
      local w, h = bi(g, "getResolution")
      local boxWidth, boxHeight = 60, 4
      local boxX, boxY = math.floor((w - boxWidth) / 2), math.floor((h - boxHeight) / 2)
      bi(g, "setBackground", 0x0000FF) -- Light blue background
      bi(g, "fill", boxX, boxY, boxWidth, boxHeight, " ")
      bi(g, "setForeground", 0xFF0000) -- Red text
      bi(g, "setBackground", 0x0000FF) -- Light blue background
      local textX = math.floor((boxWidth - #errorMessage) / 2) + boxX
      local textY = math.floor((boxHeight - 1) / 2) + boxY
      bi(g, "set", textX, textY, errorMessage)

      computer.beep(800, 1) -- 1 second beep
      computer.beep(800, 0.5) -- Half-second beep
      computer.beep(800, 0.5) -- Half-second beep
    end

    local function displayMenu(sI)
      local g = component.list("gpu")()
      local w, h = bi(g, "getResolution")
      local boxWidth, boxHeight = 60, #l + 4
      local boxX, boxY = math.floor((w - boxWidth) / 2), math.floor((h - boxHeight) / 2)
      local filteredList = {}
      for _, o in ipairs(l) do
        if o.label ~= "tmpfs" then
          table.insert(filteredList, o)
        end
      end
      if #filteredList == 0 then
        displayError("No bootable medium found!")
        return
      end
      bi(g, "setBackground", 0x0000FF) -- Light blue background
      bi(g, "fill", boxX, boxY, boxWidth, boxHeight, " ")
      bi(g, "setForeground", 0xFFFFFF)
      bi(g, "setBackground", 0x0000FF) -- Light blue background
      bi(g, "set", boxX + 2, boxY + 1, "Select OS to boot:")
      for i, o in ipairs(filteredList) do
        local lN = boxY + i + 2
        local tC = i == sI and 0xFF0000 or 0xFFFFFF
        bi(g, "setForeground", tC)
        bi(g, "set", boxX + 2, lN, o.label .. " (" .. o.address .. ")")
      end
      computer.beep(800, 0.1) -- Shorter beep
    end

    local sI = math.ceil(#l / 2)
    displayMenu(sI)
    while true do
      local e = { computer.pullSignal() }
      if e[1] == "key_down" then
        if e[4] == 200 and sI > 1 then
          sI = sI - 1
          displayMenu(sI)
        elseif e[4] == 208 and sI < #l then
          sI = sI + 1
          displayMenu(sI)
        elseif e[4] == 28 then
          local o = l[sI]
          local i, r = tryLoad(o.address)
          if i then
            computer.setBootAddress(o.address)
            computer.beep(800, 0.2)
            computer.beep(800, 0.6)
            computer.beep(800, 0.2)
            return i()
          else
            displayError("Unable to boot device!")
            computer.beep(800, 0.1)
            computer.beep(800, 0.1)
            computer.beep(800, 0.1)
          end
        end
      end
    end
  end

  -- Check for DOGGY.ROM and flash it to EEPROM if found
  local hasDoggyRom = false
  for _, drive in ipairs(l) do
    hasDoggyRom, err = bi(drive.address, "exists", "/DOGGY.ROM")
    if hasDoggyRom then
      local success, flashError = flashEEPROM(drive.address)
      if success then
        computer.beep(800, 0.2)
        computer.beep(800, 0.2)
        computer.beep(800, 0.2)
        bi(component.list("gpu")(), "set", 1, 1, "Flash complete!")
        computer.beep(800, 1) -- Beep once to indicate flash completion
      else
        bi(component.list("gpu")(), "set", 1, 1, "Flash failed: " .. flashError)
        computer.beep(800, 0.1)
        computer.beep(800, 0.1)
        computer.beep(800, 0.1)
        computer.beep(800, 1) -- Beep to indicate failure
        computer.shutdown(true) -- Halt the system
      end
      break
    end
  end

  if not hasDoggyRom then
    bootloader() -- Call the bootloader function if DOGGY.ROM is not found
  end
end

main()