discourse/app/models/user_history.rb

# UserHistory stores information about actions that users have taken,
# like deleting users, changing site settings, dimissing notifications, etc.
# Use other classes, like StaffActionLogger, to log records to this table.
class UserHistory < ActiveRecord::Base
  belongs_to :acting_user, class_name: 'User'
  belongs_to :target_user, class_name: 'User'

  belongs_to :post
  belongs_to :topic
  belongs_to :category

  validates_presence_of :action

  scope :only_staff_actions, -> { where("action IN (?)", UserHistory.staff_action_ids) }

  before_save :set_admin_only

  def self.actions
    @actions ||= Enum.new(
      delete_user: 1,
      change_trust_level: 2,
      change_site_setting: 3,
      change_theme: 4,
      delete_theme: 5,
      checked_for_custom_avatar: 6, # not used anymore
      notified_about_avatar: 7,
      notified_about_sequential_replies: 8,
      notified_about_dominating_topic: 9,
      suspend_user: 10,
      unsuspend_user: 11,
      facebook_no_email: 12,
      grant_badge: 13,
      revoke_badge: 14,
      auto_trust_level_change: 15,
      check_email: 16,
      delete_post: 17,
      delete_topic: 18,
      impersonate: 19,
      roll_up: 20,
      change_username: 21,
      custom: 22,
      custom_staff: 23,
      anonymize_user: 24,
      reviewed_post: 25,
      change_category_settings: 26,
      delete_category: 27,
      create_category: 28,
      change_site_text: 29,
      silence_user: 30,
      unsilence_user: 31,
      grant_admin: 32,
      revoke_admin: 33,
      grant_moderation: 34,
      revoke_moderation: 35,
      backup_create: 36,
      rate_limited_like: 37, # not used anymore
      revoke_email: 38,
      deactivate_user: 39,
      wizard_step: 40,
      lock_trust_level: 41,
      unlock_trust_level: 42,
      activate_user: 43,
      change_readonly_mode: 44,
      backup_download: 45,
      backup_destroy: 46,
      notified_about_get_a_room: 47,
      change_name: 48,
      post_locked: 49,
      post_unlocked: 50,
      check_personal_message: 51,
      disabled_second_factor: 52,
      post_edit: 53,
      topic_published: 54,
      recover_topic: 55,
      post_approved: 56,
      create_badge: 57,
      change_badge: 58,
      delete_badge: 59,
    )
  end

  # Staff actions is a subset of all actions, used to audit actions taken by staff users.
  def self.staff_actions
    @staff_actions ||= [
      :delete_user,
      :change_trust_level,
      :change_site_setting,
      :change_theme,
      :delete_theme,
      :change_site_text,
      :suspend_user,
      :unsuspend_user,
      :grant_badge,
      :revoke_badge,
      :check_email,
      :delete_post,
      :delete_topic,
      :impersonate,
      :roll_up,
      :change_username,
      :custom_staff,
      :anonymize_user,
      :reviewed_post,
      :change_category_settings,
      :delete_category,
      :create_category,
      :silence_user,
      :unsilence_user,
      :grant_admin,
      :revoke_admin,
      :grant_moderation,
      :revoke_moderation,
      :backup_create,
      :revoke_email,
      :deactivate_user,
      :lock_trust_level,
      :unlock_trust_level,
      :activate_user,
      :change_readonly_mode,
      :backup_download,
      :backup_destroy,
      :post_locked,
      :post_unlocked,
      :check_personal_message,
      :disabled_second_factor,
      :post_edit,
      :topic_published,
      :recover_topic,
      :post_approved,
      :create_badge,
      :change_badge,
      :delete_badge,
    ]
  end

  def self.staff_action_ids
    @staff_action_ids ||= staff_actions.map { |a| actions[a] }
  end

  def self.admin_only_action_ids
    @admin_only_action_ids ||= [actions[:change_site_setting]]
  end

  def self.with_filters(filters)
    query = self
    query = query.where(action: filters[:action_id]) if filters[:action_id].present?
    query = query.where(custom_type: filters[:custom_type]) if filters[:custom_type].present?

    [:acting_user, :target_user].each do |key|
      if filters[key] && (obj_id = User.where(username_lower: filters[key].downcase).pluck(:id))
        query = query.where("#{key}_id = ?", obj_id)
      end
    end
    query = query.where("subject = ?", filters[:subject]) if filters[:subject]
    query
  end

  def self.for(user, action_type)
    self.where(target_user_id: user.id, action: UserHistory.actions[action_type])
  end

  def self.exists_for_user?(user, action_type, opts = nil)
    opts = opts || {}
    result = self.where(target_user_id: user.id, action: UserHistory.actions[action_type])
    result = result.where(topic_id: opts[:topic_id]) if opts[:topic_id]
    result.exists?
  end

  def self.staff_filters
    [:action_id, :custom_type, :acting_user, :target_user, :subject]
  end

  def self.staff_action_records(viewer, opts = nil)
    opts ||= {}
    query = self.with_filters(opts.slice(*staff_filters)).only_staff_actions.limit(200).order('id DESC').includes(:acting_user, :target_user)
    query = query.where(admin_only: false) unless viewer && viewer.admin?
    query
  end

  def set_admin_only
    self.admin_only = UserHistory.admin_only_action_ids.include?(self.action)
    self
  end

  def new_value_is_json?
    [UserHistory.actions[:change_theme], UserHistory.actions[:delete_theme]].include?(action)
  end

  def previous_value_is_json?
    new_value_is_json?
  end
end

# == Schema Information
#
# Table name: user_histories
#
#  id             :integer          not null, primary key
#  action         :integer          not null
#  acting_user_id :integer
#  target_user_id :integer
#  details        :text
#  created_at     :datetime         not null
#  updated_at     :datetime         not null
#  context        :string
#  ip_address     :string
#  email          :string
#  subject        :text
#  previous_value :text
#  new_value      :text
#  topic_id       :integer
#  admin_only     :boolean          default(FALSE)
#  post_id        :integer
#  custom_type    :string
#  category_id    :integer
#
# Indexes
#
#  index_user_histories_on_acting_user_id_and_action_and_id  (acting_user_id,action,id)
#  index_user_histories_on_action_and_id                     (action,id)
#  index_user_histories_on_category_id                       (category_id)
#  index_user_histories_on_subject_and_id                    (subject,id)
#  index_user_histories_on_target_user_id_and_id             (target_user_id,id)
#