example.rb

post '/login' do
  redirect '/login' and return unless params[:login].present?
  login = params[:login].strip

  @new_user = User.new

  if (user = User.where(email: login).first) and User.authenticate(user, params[:password])
    if user.service.present?
      Event.blocked_email! login, user.service

      erb :"account/login", locals: {blocked: user.service}
    elsif !user.confirmed?
      flash.now[:login] = "Your account has not been confirmed."
      erb :"account/login"
    else
      log_in user
      redirect_back_or '/'
    end
  else
    flash.now[:login] = "Invalid login or password."
    erb :"account/login"
  end
end