-- Keypad Lock Program for Computercraft
-- Written by Sora the Hedgehog

-- Uncomment these line to disable Crtl-Ting
-- local oldPull = os.pullEvent;
-- os.pullEvent = os.pullEventRaw;

local locations = {
  [1] = {13, 3},
  [2] = {17, 3},
  [3] = {21, 3},
  [4] = {13, 7},
  [5] = {17, 7},
  [6] = {21, 7},
  [7] = {13, 11},
  [8] = {17, 11},
  [9] = {21, 11},
  [0] = {17, 15};
  ["clear"] = {13, 15},
  ["enter"] = {21, 15},
  ["dsply"] = {26, 9},
  ["code"] = {28, 8};
};

local numColor = colors.white;
local butBgOff = colors.blue;
local butBgOn = colors.red;
local dispBad = colors.red;
local dispGood = colors.lime;
-- Code can be any int-representable 4 digit string
local code = "";
local input = "";

function onSuccess()
  -- When the code has been entered

  -- Uncomment if you turned off Crtl-Ting above and wish to turn it back on
  -- os.pullEvent = oldPull
end

function onFail()
  -- When the code has not been entered
end

function drawBut(button, onoff)
  onoff = onoff or false;

  if onoff then
    color = butBgOn;
  else
    color = butBgOff;
  end

  local x, y = unpack(locations[button]);
  local text = "";

  if type(button) == "string" then
    if button == "enter" then
      text = "E";
    elseif button == "clear" then
      text = "C";
    end
  else
    text = button;
  end

  for a = x, x + 2 do
    for b = y, y + 2 do
      term.setCursorPos(a, b);
      term.setBackgroundColor(color);
      if a == x + 1 and b == y + 1 then
        term.setTextColor(numColor);
        write(text);
      else
        write(" ");
      end
    end
  end
end

function drawDisp(input, state)
  local x, y = unpack(locations.dsply);
  local codeLen = input;
  state = state or 0;

  local colors = {
    [0] = butBgOff,
    [1] = dispBad,
    [2] = dispGood,
  };

  term.setBackgroundColor(colors[state]);

  for a = x, x + 8 do
    for b = y, y + 2 do
      term.setCursorPos(a, b);

      local diff = a - x;

      if codeLen > 0 and (b == y + 1 and (diff % 2) == 1) then
        write("*");
        codeLen = codeLen - 1;
      else
        write(" ");
      end
    end
  end
end

function getButPress(x, y)
  for k, v in pairs(locations) do
    local bx, by = unpack(v);
    if (k ~= "code" and k ~= "dsply") and ((x >= bx and x <= bx + 2) and (y >= by and y <= by + 2)) then
      return k;
    end
  end

  return nil;
end

if term.isColor and (not term.isColor()) then
    print("This program requires an advanced computer");
    return;
  end
else
  print("This program requires a newer version of Computercraft");
  return;
end

term.clear();

for i = 0, 9 do
  drawBut(i, false);
end

drawBut("clear", false);
drawBut("enter", false);

local cx, cy = unpack(locations["code"]);
term.setCursorPos(cx, cy);
term.setBackgroundColor(colors.black);
term.setTextColor(colors.lime);
write("Input");

drawDisp(0);

while true do
  local _, _, mx, my = os.pullEvent("mouse_click");
  local button = getButPress(mx, my);

  if button ~= nil then
    drawBut(button, true);
    if type(button) == "number" then
      if string.len(input) < 4 then
        input = input..button;
      end
    else
      if button == "clear" then
        input = "";
      elseif button == "enter" then
        if input == code then
          drawDisp(string.len(input), 2);
          input = "";
          onSuccess();
        else
          drawDisp(string.len(input), 1);
          input = "";
          onFail();
        end
      end
    end
    sleep(0.1)
    drawBut(button, false);
    drawDisp(string.len(input));
  end
end