os.loadAPI("h2touchpanel")

local num1 = 0
local num2 = 0
local a = 0
local answer = 0
local count = 0

function input(num)
if count == 0 then
num1 = num1 * 10 + num
print(num1)
else
num2 = num2 * 10 + num
print(num2)
end
end

function add()
a = 1
count = count + 1
print("+")
end

function sub()
a = 2
count = count + 1
print("-")
end

function multi()
a = 3
count = count + 1
print("*")
end

function div()
a = 4
count = count + 1
print("/")
end

function enter()
if a == 1 then
answer = num1 + num2

elseif a == 2 then
answer = num1 - num2

elseif a == 3 then
answer = num1 * num2

else
answer = num1 / num2

end
print("answer is ", answer)

num1 = 0
num2 = 0
a = 0
answer = 0
count = 0

end

local buttons = {}

buttons[1] = { name = "1", cmd = function() input(1) end }
buttons[2] = { name = "2", cmd = function() input(2) end }
buttons[3] = { name = "3", cmd = function() input(3) end }
buttons[4] = { name = "4", cmd = function() input(4) end }
buttons[5] = { name = "5", cmd = function() input(5) end }
buttons[6] = { name = "6", cmd = function() input(6) end }
buttons[7] = { name = "7", cmd = function() input(7) end }
buttons[8] = { name = "8", cmd = function() input(8) end }
buttons[9] = { name = "9", cmd = function() input(9) end }
buttons[10] = { name = "0", cmd = function() input(0) end }
buttons[11] = { name = "+", cmd = function() add() end }
buttons[12] = { name = "-", cmd = function() sub() end }
buttons[13] = { name = "*", cmd = function() multi() end }
buttons[14] = { name = "/", cmd = function() div() end }
buttons[15] = { name = "=", cmd = function() enter() end }

local monitor = peripheral.wrap("top")
local option = { topPos = 1, bottomPos = 9}
local panel = h2touchpanel.makePanel(buttons, 3, 5, monitor, option)
panel:draw()
while true do
local event, btn = panel:pullButtonPushEvent()
btn:run()
panel:drawPushedButtonEffect(btn, 0.5)
end