local createVersion = require('/apis/libversion');

local args = table.pack(...);

local FACE = {
  '0000000000000000',
  '0000000000000000',
  '0011110000111100',
  '0011110000111100',
  '0011110000111100',
  '0011110000111100',
  '0000001111000000',
  '0000001111000000',
  '0000111111110000',
  '0000111111110000',
  '0000111111110000',
  '0000111111110000',
  '0000110000110000',
  '0000110000110000',
  '0000110000110000',
  '0000000000000000',
};

local function printUsage()
  print('creeper usage:');
  print();
  print('  creeper');
  print('  creeper --version');
  print('  creeper --help');
end

local function drawRun(x, y, len, color)
  term.setBackgroundColor(color);
  term.setCursorPos(x, y);
  term.write(string.rep(' ', len));
end

local function drawCreeper()
  local width, height = term.getSize();
  local pixelW = math.max(1, math.floor(width / 20));
  local pixelH = math.max(1, math.floor(height / 18));

  if pixelW > 3 then pixelW = 3; end
  if pixelH > 2 then pixelH = 2; end

  local artW = #FACE[1] * pixelW;
  local artH = #FACE * pixelH;
  local startX = math.max(1, math.floor((width - artW) / 2) + 1);
  local startY = math.max(1, math.floor((height - artH) / 2) + 1);

  term.setBackgroundColor(colors.green);
  term.setTextColor(colors.white);
  term.clear();

  for row = 1, #FACE do
    for sy = 0, pixelH - 1 do
      local y = startY + ((row - 1) * pixelH) + sy;
      local col = 1;
      while col <= #FACE[row] do
        local bit = FACE[row]:sub(col, col);
        local run = 1;

        while col + run <= #FACE[row]
          and FACE[row]:sub(col + run, col + run) == bit do
          run = run + 1;
        end

        local color = colors.green;
        if bit == '1' then
          color = colors.black;
        end
        drawRun(startX + ((col - 1) * pixelW), y, run * pixelW, color);
        col = col + run;
      end
    end
  end

  term.setBackgroundColor(colors.green);
  term.setTextColor(colors.white);
  term.setCursorPos(1, height);
end

local command = args[1];

if command == '-help' or command == '--help' or command == 'help' then
  printUsage();
  return;
end

if command == '-version' or command == '--version' or command == 'version' then
  print('v' .. createVersion().forSelf());
  return;
end

if command ~= nil then
  printUsage();
  return;
end

drawCreeper();