wall tunnel builder

local TUNNEL_HEIGHT = 5;
local TUNNEL_BLOCK = "minecraft:stone";
local TUNNEL_CORNER = "minecraft:stone_stairs";
local USE_CORNER = false;
local CORNER_IS_STAIR = false;

local function findItem(itemName)
  for i = 1, 16, 1 do
    local item = turtle.getItemDetail(i);

    if item.name == itemName then return i end;
  end

  return -1;
end

local function refuel()

end

local function splashScreen()
  term.clear();
  term.setCursorPos(0,0);
  term.write(string.rep("-", 39, ""));

  for i = 1, 5, 1 do
    term.setCursorPos(1, i);
    term.setCursorPos(38, i);
  end

  term.write("| |")
  term.write("| TUNNEL WALL BUILDER |")
  term.write("| |")
  term.write("| |")
  term.write("| |")


  term.write(string.rep("-", 39, ""));
end

local function getTunnelInfo()
  local done = false;

  while not done do
    term.write("What height does your tunnel wall have? (leave empty for default)");
    local input = read();

    if input == "" then
      done = true;
      goto continue;
    end

    local numberInput = tonumber(input);
    if numberInput == nil or numberInput < 3 then
      term.write("Please use a valid integer of 3 and above, i have no use for this!");
      goto continue;
    end

    TUNNEL_HEIGHT = math.floor(numberInput);
    done = true;

    ::continue::
  end
  term.write("Great! Using " .. TUNNEL_HEIGHT .. " as the tunnel height!");

  while not done do
    term.write("What block should i use for the wall?");
    local input = read();

    if input ~= "" then
      TUNNEL_BLOCK = input;
    end


    local foundItem = findItem(TUNNEL_BLOCK);
    if foundItem == -1 then
      term.write("I can't find this block, could you please insert the specified block? " .. TUNNEL_BLOCK .. ".");
      goto continue;
    else
      done = true;
      goto continue;
    end

    ::continue::
  end
  term.write("Great! Using " .. TUNNEL_BLOCK .. " as the wall block.")

  term.write("Do you want to use a corner block? (Y/n)");
  local input = read();
  if string.lower(input) == "y" or string.lower(input) == "yes" then
    USE_CORNER = true;
  else
  term.write("I'll make the tunnel as square as possible!");
    goto skip_corner;
  end

  term.write("Now i'll need some more information about the corner block.");

  while not done do
    term.write("What block should i used for the corner?");
    local input = read();

    if input ~= "" then
      TUNNEL_CORNER = input;
    end


    local foundItem = findItem(TUNNEL_CORNER);
    if foundItem == -1 then
      term.write("I can't find this block, could you please insert the specified block? " .. TUNNEL_CORNER .. ".");
      goto continue;
    else
      done = true;
      goto continue;
    end

    ::continue::
  end
  term.write("I'll place " .. TUNNEL_CORNER .. " in the corners! ");

  term.write("Is this block a stair, or should it be treated as one? (Y/n)");
  local input = read();
  if string.lower(input) == "y" or string.lower(input) == "yes" then
    CORNER_IS_STAIR = true;
    term.write("I'll treat the corner block as a stair, and turn it around!");
  else
    term.write("Less work for me!");
    goto skip_corner;
  end

  ::skip_corner::

  term.write("I have all the information i need to get started working on this wall, thanks!");
end

local function main()
  splashScreen();
end

main();