# Copyright (C) 2012-2024 Zammad Foundation, https://zammad-foundation.org/

class Sequencer::Unit::Import::Common::Model::Update < Sequencer::Unit::Base
  include ::Sequencer::Unit::Import::Common::Model::Mixin::HandleFailure
  prepend ::Sequencer::Unit::Import::Common::Model::Mixin::Skip::Action

  skip_any_action

  uses :instance, :mapped
  provides :action

  def process
    # check if no instance is given - so we can't update it
    return if !instance

    # lock the current instance for write access
    instance.with_lock do
      # delete since we have an update and
      # the record is already created
      mapped.delete(:created_by_id)
      mapped.delete(:created_at)

      # assign regular attributes
      instance.assign_attributes(mapped)

      action = changed? ? :updated : :unchanged
      state.provide(:action, action)
    end
  rescue => e
    handle_failure(e)
  end

  private

  def changed?
    logger.debug { "Changed instance attributes: #{changes.inspect}" }
    changes.present?
  end

  def changes
    @changes ||= begin
      if instance.has_changes_to_save?
        # dry run
        instance.changes_to_save
      else
        # live run
        instance.previous_changes
      end
    end
  end
end