# Copyright (C) 2012-2014 Zammad Foundation, http://zammad-foundation.org/

class RecentView < ApplicationModel
  belongs_to :object_lookup,           class_name: 'ObjectLookup'

  after_create    :notify_clients
  after_update    :notify_clients
  after_destroy   :notify_clients

  def self.log( object, o_id, user )

    # access check
    return if !access( object, o_id, user )

    # lookups
    object_lookup_id = ObjectLookup.by_name( object )

    # create entry
    record = {
      o_id: o_id,
      recent_view_object_id: object_lookup_id.to_i,
      created_by_id: user.id,
    }
    RecentView.create(record)
  end

  def self.log_destroy( requested_object, requested_object_id )
    return if requested_object == 'RecentView'
    RecentView.where( recent_view_object_id: ObjectLookup.by_name( requested_object ) )
              .where( o_id: requested_object_id )
              .destroy_all
  end

  def self.user_log_destroy( user )
    RecentView.where( created_by_id: user.id ).destroy_all
  end

  def self.list( user, limit = 10, type = nil )
    recent_views = if !type
                     RecentView.where( created_by_id: user.id )
                               .order('created_at DESC, id DESC')
                               .limit(limit)
                   else
                     RecentView.select('DISTINCT(o_id), recent_view_object_id').where( created_by_id: user.id, recent_view_object_id: ObjectLookup.by_name(type) )
                               .order('created_at DESC, id DESC')
                               .limit(limit)
                   end

    list = []
    recent_views.each { |item|
      data           = item.attributes
      data['object'] = ObjectLookup.by_id( data['recent_view_object_id'] )
      data.delete( 'recent_view_object_id' )

      # access check
      next if !access( data['object'], data['o_id'], user )

      # add to result list
      list.push data
    }
    list
  end

  def self.list_full( user, limit = 10 )
    recent_viewed = list( user, limit )

    # get related object
    assets = ApplicationModel.assets_of_object_list(recent_viewed)

    {
      stream: recent_viewed,
      assets: assets,
    }
  end

  def notify_clients
    Sessions.send_to(
      created_by_id,
      {
        event: 'RecentView::changed',
        data: {}
      }
    )
  end

  def self.access(object, o_id, user)

    # check if object exists
    begin
      return if !Kernel.const_get( object )
      record = Kernel.const_get( object ).lookup( id: o_id )
      return if !record
    rescue
      return
    end

    # check permission
    return if !record.respond_to?(:permission)
    record.permission( current_user: user )
  end

=begin

cleanup old entries

  RecentView.cleanup

optional you can parse the max oldest entries

  RecentView.cleanup(1.month)

=end

  def self.cleanup(diff = 1.month)
    RecentView.where('created_at < ?', Time.zone.now - diff).delete_all
    true
  end

end