-- Clear the screen and set up colors
term.clear()
term.setBackgroundColor(colors.black)
term.setTextColor(colors.white)
term.clear()

-- Define the width and height of the screen
local width, height = term.getSize()

-- Helper function to center text on the screen
local function centerText(y, text, textColor)
    local x = math.floor((width - #text) / 2)
    term.setCursorPos(x, y)
    term.setTextColor(textColor)
    term.write(text)
end

-- Define the dog ASCII art with white color and @ for eyes
local dogArt = {
    "     |\\_/|                  ",
    "     | @ @                  ",
    "     |   <>              _   ",
    "     |  _/\\------____ ((| |))",
    "     |               `--' |  ",
    " _____|_       ___|   |___.  ",
    "/_/_____/____/_______|       "
}

local startLine = math.floor((height - #dogArt) / 2) - 2

-- Display the dog ASCII art with white color
term.setTextColor(colors.white)
for i, line in ipairs(dogArt) do
    centerText(startLine + i, line, colors.white)
end

-- Display the "Insert Disk" message
centerText(startLine + #dogArt + 2, "Insert disk", colors.white)

-- Wait a moment to let the user see the "Insert Disk" message
sleep(2)

-- Check if /disk2/ exists
if fs.exists("/disk2/") then
    -- Display the confirmation prompt for update
    term.setCursorPos(1, height)
    term.setTextColor(colors.yellow)
    term.write("Press 'Y' to proceed with the update, 'N' to cancel: ")

    -- Wait for user input
    local event, key = os.pullEvent("key")
    if key == keys.y then
        -- User confirmed to proceed with the update
        centerText(startLine + #dogArt + 2, "Emergency System Update...", colors.white)

        -- Simulate progress with an animated progress bar
        local progressBarWidth = 30
        local progressBarStartY = startLine + #dogArt + 4

        for i = 1, progressBarWidth do
            local progress = math.floor((i / progressBarWidth) * 100)
            local bar = string.rep("=", i) .. string.rep(" ", progressBarWidth - i)

            -- Clear previous progress bar line
            term.setCursorPos(1, progressBarStartY)
            term.write(string.rep(" ", width))

            -- Display updated progress bar
            term.setCursorPos(math.floor((width - progressBarWidth) / 2), progressBarStartY)
            term.setTextColor(colors.green)
            term.write("[" .. bar .. "] " .. progress .. "%")

            -- Wait a bit to simulate progress
            sleep(0.5)
        end

        -- Wait for additional 15 seconds to simulate finalizing the update
        sleep(15)
    elseif key == keys.n then
        -- User canceled the update
        centerText(startLine + #dogArt + 2, "Update canceled. Rebooting...", colors.red)

        -- Wait for 5 seconds to let the user see the cancellation message
        sleep(5)
    else
        -- If the input is not 'Y' or 'N', assume cancellation
        centerText(startLine + #dogArt + 2, "Invalid input. Update canceled.", colors.red)
        sleep(5)
    end
else
    -- Display an error message if /disk2/ doesn't exist
    centerText(startLine + #dogArt + 2, "Disk not found. Unable to update.", colors.red)

    -- Wait for 5 seconds to let the user see the error message
    sleep(5)
end

-- Display the "Rebooting..." message
centerText(startLine + #dogArt + 4, "Rebooting...", colors.white)

-- Wait a few seconds before rebooting
sleep(3)

-- Reboot the system
os.reboot()