# Copyright (C) 2012-2016 Zammad Foundation, http://zammad-foundation.org/
module Historisable
  extend ActiveSupport::Concern

  included do
    attr_accessor :history_changes_last_done

    after_create  :history_create
    after_update  :history_update
    after_destroy :history_destroy
  end

=begin

log object create history, if configured - will be executed automatically

  model = Model.find(123)
  model.history_create

=end

  def history_create
    history_log('created', created_by_id)
  end

=begin

log object update history with all updated attributes, if configured - will be executed automatically

  model = Model.find(123)
  model.history_update

=end

  def history_update
    return if !changed?

    # return if it's no update
    return if new_record?

    # new record also triggers update, so ignore new records
    changes = self.changes
    if history_changes_last_done
      history_changes_last_done.each { |key, value|
        if changes.key?(key) && changes[key] == value
          changes.delete(key)
        end
      }
    end
    self.history_changes_last_done = changes
    #logger.info 'updated ' + self.changes.inspect

    return if changes['id'] && !changes['id'][0]

    ignored_attributes  = self.class.instance_variable_get(:@history_attributes_ignored) || []
    ignored_attributes += %i(created_at updated_at created_by_id updated_by_id)

    changes.each { |key, value|

      next if ignored_attributes.include?(key.to_sym)

      # get attribute name
      attribute_name = key.to_s
      if attribute_name[-3, 3] == '_id'
        attribute_name = attribute_name[ 0, attribute_name.length - 3 ]
      end

      value_id = []
      value_str = [ value[0], value[1] ]
      if key.to_s[-3, 3] == '_id'
        value_id[0] = value[0]
        value_id[1] = value[1]

        if respond_to?(attribute_name) && send(attribute_name)
          relation_class = send(attribute_name).class
          if relation_class && value_id[0]
            relation_model = relation_class.lookup(id: value_id[0])
            if relation_model
              if relation_model['name']
                value_str[0] = relation_model['name']
              elsif relation_model.respond_to?('fullname')
                value_str[0] = relation_model.send('fullname')
              end
            end
          end
          if relation_class && value_id[1]
            relation_model = relation_class.lookup(id: value_id[1])
            if relation_model
              if relation_model['name']
                value_str[1] = relation_model['name']
              elsif relation_model.respond_to?('fullname')
                value_str[1] = relation_model.send('fullname')
              end
            end
          end
        end
      end
      data = {
        history_attribute: attribute_name,
        value_from: value_str[0].to_s,
        value_to: value_str[1].to_s,
        id_from: value_id[0],
        id_to: value_id[1],
      }
      #logger.info "HIST NEW #{self.class.to_s}.find(#{self.id}) #{data.inspect}"
      history_log('updated', updated_by_id, data)
    }
  end

=begin

delete object history, will be executed automatically

  model = Model.find(123)
  model.history_destroy

=end

  def history_destroy
    History.remove(self.class.to_s, id)
  end

  # methods defined here are going to extend the class, not the instance of it
  class_methods do
=begin

serve methode to ignore model attributes in historization

class Model < ApplicationModel
  include Historisable
  history_attributes_ignored :create_article_type_id, :preferences
end

=end

    def history_attributes_ignored(*attributes)
      @history_attributes_ignored = attributes
    end
  end
end