# frozen_string_literal: true

require "active_support/concern"

module Decidim
  # Shared behaviour for controllers that need user impersonation logic.
  module ImpersonateUsers
    extend ActiveSupport::Concern

    included do
      before_action :check_impersonation_log_expired

      helper_method :impersonation_session_ends_at, :impersonation_session_remaining_duration_in_minutes, :current_user_impersonated?

      alias_method :real_user, :current_user

      # Returns a manager user if the real user has an active impersonation
      def current_user
        managed_user || real_user
      end

      def impersonation_session_ends_at
        @impersonation_session_ends_at ||= impersonation_log.started_at + Decidim::ImpersonationLog::SESSION_TIME_IN_MINUTES.minutes
      end

      def impersonation_session_remaining_duration_in_minutes
        ((impersonation_session_ends_at - Time.current) / 60).round
      end

      private

      def current_user_impersonated?
        current_user && impersonation_log.present?
      end

      # Returns the managed user impersonated by an admin if exists
      def managed_user
        return unless can_impersonate_users?
        impersonation_log&.user
      end

      # Check if the active impersonation session has expired or not.
      def check_impersonation_log_expired
        return unless can_impersonate_users? && expired_log

        expired_log.ended_at = Time.current
        expired_log.save!
        flash[:alert] = I18n.t("managed_users.expired_session", scope: "decidim")
        redirect_to decidim_admin.impersonatable_users_path
      end

      def can_impersonate_users?
        real_user && allowed_to?(:impersonate, :managed_user, {}, [Decidim::Admin::Permissions], real_user)
      end

      def expired_log
        @expired_log ||= Decidim::ImpersonationLog
                         .where(admin: real_user)
                         .expired
                         .first
      end

      def impersonation_log
        @impersonation_log ||= Decidim::ImpersonationLog
                               .where(admin: real_user)
                               .active
                               .first
      end
    end
  end
end