edu/app/models/token.rb

class Token < ActiveRecord::Base
  include ApplicationHelper
  belongs_to :user
  validates_uniqueness_of :value

  before_create :delete_previous_tokens, :generate_new_token

  @@validity_time = 1.day
  STATUS_LOGIN  = 0
  STATUS_LOGOUT     = 1
  STATUS_EX_LOGIN = 2
  STATUS_EX_LOGOUT     = 3
  STATUS_SELF_LOGOUT     = 4
  STATUS_EX_OUT_LOGOUT     = 5
  # status 0=正常登陆1=正常退出登陆失效2=考试期间输入考试密码登录3=考试期间被挤出登录失效4=同一个浏览器登录导致失效5考试期间进入考试导致其他登录用户失效
  def generate_new_token
    self.value = Token.generate_token_value if action != User::SESSION_ACTION
  end

  def self.get_or_create_permanent_login_token(user, type)
    token = Token.get_token_from_user(user, type)
    unless token
      token = Token.create(:user => user, :action => type)
    else
      token.update_attribute(:created_on, Time.now)
    end
    token
  end
  # 更新session的token的状态值
  def self.update_token_by_session(user_id,session_id = nil,status = self::STATUS_SELF_LOGOUT)
    if session_id.present?
      token = Token.find_by(:action => User::SESSION_ACTION, :user_id => user_id, :value => session_id)
      if token.present?
        token.status = status
        token.save!
      end
    else # 同一把所有的token记录状态修改掉并清空对应session_id的缓存
      self.delete_user_session(user_id,nil,status)
    end
  end
  # 删除用户的session记录
  def self.delete_user_session(user_id,now_session_id = nil,status = self::STATUS_SELF_LOGOUT)
    session_store = Rails.application.config.session_store.new(:cache_store, Rails.application.config.session_options)
    tokens = Token.where(:action => User::SESSION_ACTION, :user_id => user_id,status:[self::STATUS_LOGIN,self::STATUS_EX_LOGIN])
    tokens = tokens.where.not(value:now_session_id) if now_session_id.present?
    tokens.each do |token|
      token.status = status
      if token.save! # 开始清空session缓存
        rr = session_store.delete_session(ENV, token.value,Rails.application.config.session_options)
        Rails.logger.info("调试删除session===#{token.value}===#{rr}")
      end
    end
  end
  def self.get_token_from_user(user, action)
    token = Token.where(:action => action, :user_id => user).first
    unless token
      token = Token.create!(user_id: user.id, action: action)
    end
    token
  end

  # Return true if token has expired
  def expired?
    return Time.now > self.created_on + @@validity_time
  end

  # Delete all expired tokens
  def self.destroy_expired
    Token.delete_all ["action NOT IN (?) AND created_on < ?", ['feeds', 'api', 'autologin'], Time.now - @@validity_time]
  end

  # Returns the active user who owns the key for the given action
  def self.find_active_user(action, key, validity_days=nil)
    user = find_user(action, key, validity_days)
    if user && user.active?
      user
    end
  end

  # Returns the user who owns the key for the given action
  def self.find_user(action, key, validity_days=nil)
    token = find_token(action, key, validity_days)
    if token
      token.user
    end
  end

  # Returns the token for action and key with an optional
  # validity duration (in number of days)
  def self.find_token(action, key, validity_days=nil)
    action = action.to_s
    key = key.to_s
    return nil unless action.present? && key =~ /\A[a-z0-9]+\z/i
    # if action == User::SESSION_ACTION # 如果是session的则需要判断token是否有效
    #   token = Token.where(value: key, action: action).first
    # else
    #   token = Token.where(value: key, action: action).first
    # end
    token = Token.where(value: key, action: action).first
    if token && (token.action == action) && (token.value == key) && token.user
      if validity_days.nil? || (token.created_on > validity_days.days.ago)
        token
      end
    end
  end

  def self.generate_token_value
    Edu::Utils.random_hex(20)
  end

  def self.delete_user_all_tokens(user)
    Token.delete_all(user_id: user.id)
  end

  private

  # Removes obsolete tokens (same user and action)
  def delete_previous_tokens
    if user && action!='_educoder_session'
      Token.where(['user_id = ? AND action = ?', user.id, action]).delete_all
    end
  end
end