local function drawPixelInternal(xPos, yPos)
    term.setCursorPos(xPos, yPos)
    term.write(" ")
end

local tColourLookup = {}
for n = 1, 16 do
    tColourLookup[string.byte("0123456789abcdef", n, n)] = 2 ^ (n - 1)
end

function drawFilledBox(startX, startY, endX, endY, nColour)
    if type(startX) ~= "number" or type(startX) ~= "number" or type(endX) ~=
        "number" or type(endY) ~= "number" or
        (nColour ~= nil and type(nColour) ~= "number") then
        error("Expected startX, startY, endX, endY, colour", 2)
    end

    startX = math.floor(startX)
    startY = math.floor(startY)
    endX = math.floor(endX)
    endY = math.floor(endY)

    if nColour then term.setBackgroundColor(nColour) end
    if startX == endX and startY == endY then
        drawPixelInternal(startX, startY)
        return
    end

    local minX = math.min(startX, endX)
    if minX == startX then
        minY = startY
        maxX = endX
        maxY = endY
    else
        minY = endY
        maxX = startX
        maxY = startY
    end

    for x = minX, maxX do for y = minY, maxY do drawPixelInternal(x, y) end end
end

function colore(nome) term.setTextColor(nome) end

function sfondo(nome) term.setBackgroundColor(nome) end

function fineColore() term.setTextColour(colours.white) end

function fineSfondo() term.setBackgroundColour(colours.black) end

function titolo(testo)
    drawFilledBox(1, 1, maxw, 1, colors.yellow)
    term.setCursorPos((maxw - #testo) / 2, 1)
    colore(colors.black)
    term.write(testo)
    sfondo(colors.blue)
end

function clear()
    sfondo(colors.blue)
    term.clear()
    term.setCursorPos(1, 1)
end

function errore(errore)
    sfondo(colors.red)
    colore(colors.white)
    term.clear()
    term.setCursorPos(1, 1)
    titolo("Errore irreversibile")
    term.setCursorPos(1, 3)
    sfondo(colors.red)
    colore(colors.white)
    print(errore)
    print("\n\n\nAttendere qualche secondo...")
    os.sleep(5)
    os.reboot()
end


sfondo(colors.white)
term.clear()
term.setCursorPos(1, 1)
colore(colors.white)
colore(colors.black)
sfondo(colors.white)
term.setCursorPos(14, 1)
term.write("Registrazione partita IVA")
colore(colors.white)
sfondo(colors.lime)
term.setCursorPos(31, 10)
term.write("Registra una")
term.setCursorPos(31, 11)
term.write("partita")
term.setCursorPos(31, 12)
term.write("IVA")