PyuTest.chatcommand_entity_selector = function(caller, param)
  local p_caller = core.get_player_by_name(caller)

  if core.get_player_by_name(param) ~= nil then
    return {param}
  end

  if param == "@self" or param == "@s" then
    return {caller}
  elseif param == "@random" or param == "@r" then
    local players = core.get_connected_players()
    return {players[math.random(#players)]:get_player_name()}
  elseif param == "@nearest" or param == "@n" then
    local players = core.get_connected_players()
    local pos = p_caller:get_pos()
    local cd = math.huge
    local nearest

    for _, v in pairs(players) do
      local dist = vector.distance(pos, v:get_pos())

      if dist < cd and v ~= p_caller then
        cd = dist
        nearest = v
      end
    end

    if nearest then
      return {nearest:get_player_name()}
    end
  elseif param == "@all" or param == "@a" then
    local list = {}

    for _, v in pairs(core.get_connected_players()) do
      list[#list+1] = v:get_player_name()
    end

    return list
  end

  return {caller}
end

PyuTest.execute_as = function(runner, command)
  local pos = command:find(" ")
  local cmd, param = command, ""
  if pos then
    cmd = command:sub(1, pos - 1)
    param = command:sub(pos + 1)
  end
  local cmddef = core.chatcommands[cmd]
  if not cmddef then
    core.chat_send_player(runner, "The command "..cmd.." does not exist")
    return
  end
  local has_privs, missing_privs = core.check_player_privs(runner, cmddef.privs)
  if not has_privs then
    core.chat_send_player(runner, "You don't have permission "
    .."to run "..cmd
    .." (missing privileges: "
    ..table.concat(missing_privs, ", ")..")")
    return
  end

  return cmddef.func(runner, param)
end

PyuTest.parse_command_functions = function(runner, param)
  local str = param

  -- embed the output of command
  str = str:gsub("embed{([%w%p]+)}", function(input)
    return PyuTest.execute_as(runner, input) or ""
  end)

  return str
end