# 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 )
    if !type
      recent_views = RecentView.where( :created_by_id => user.id ).
      order('created_at DESC, id DESC').
      limit(limit)
    else
      recent_views = 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 = self.list( user, limit )

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

    return {
      :stream => recent_viewed,
      :assets => assets,
    }
  end

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

  private

  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
end