module LoginSystem
  protected
  
    def logged_in?
      current_user != :false
    end

    def current_user
      @current_user ||= (login_from_session || login_from_basic_auth || login_from_cookie || :false)
    end

    def current_user=(new_user)
      session[:user] = (new_user.nil? || new_user.is_a?(Symbol)) ? nil : new_user.id
      @current_user = new_user
    end
    
    # If the current actions are in our access rule will be verifyed
    def allowed?
      return AccessControl.allowed_controllers(current_user.profile.label, current_user.profile.modules).include?(params[:controller])
    end
    
    def authorized?
      logged_in? && allowed?
    end
    
    def login_required
      authorized? || access_denied
    end

    def access_denied
      respond_to do |accepts|
        accepts.html do
          #store_location
          session[:return_to] = request.request_uri
          if User.find(:first)
            redirect_to :controller => "accounts/login", :action => :index
          else
            redirect_to :controller => "accounts/login", :action => :new
          end
        end
        accepts.xml do
          headers["Status"]           = "Unauthorized"
          headers["WWW-Authenticate"] = %(Basic realm="Web Password")
          render :text => "Could't authenticate you", :status => '401 Unauthorized'
        end
      end
      false
    end  

    def store_location
      session[:return_to] = request.request_uri
    end

    def redirect_back_or_default(default)
      redirect_to(session[:return_to] || default)
      session[:return_to] = nil
    end

    def self.included(base)
      base.send :helper_method, :current_user, :logged_in?
    end

    def login_from_session
      self.current_user = User.find_by_id(session[:user]) if session[:user]
    end

    def login_from_basic_auth
      email, passwd = get_auth_data
      self.current_user = User.authenticate(email, passwd) if email && passwd
    end

    # Called from #current_user.  Finaly, attempt to login by an expiring token in the cookie.
    def login_from_cookie      
      user = cookies[:auth_token] && User.find_by_remember_token(cookies[:auth_token])
      if user && user.remember_token?
        user.remember_me
        cookies[:auth_token] = { :value => user.remember_token, :expires => user.remember_token_expires_at }
        self.current_user = user
      end
    end

  private
    @@http_auth_headers = %w(X-HTTP_AUTHORIZATION HTTP_AUTHORIZATION Authorization)
    # gets BASIC auth info
    def get_auth_data
      auth_key  = @@http_auth_headers.detect { |h| request.env.has_key?(h) }
      auth_data = request.env[auth_key].to_s.split unless auth_key.blank?
      return auth_data && auth_data[0] == 'Basic' ? Base64.decode64(auth_data[1]).split(':')[0..1] : [nil, nil] 
    end
end