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

class Sequencer::Unit::Import::Common::Model::Associations::Extract < Sequencer::Unit::Base
  prepend ::Sequencer::Unit::Import::Common::Model::Mixin::Skip::Action

  skip_any_action

  uses :model_class, :mapped
  provides :associations

  def process
    state.provide(:associations) do
      associations.filter_map do |association|

        logger.debug { "Checking association '#{association}'" }
        next if !mapped.key?(association)

        # remove from the mapped values if it's an association
        value = mapped.delete(association)
        logger.debug { "Extracted association '#{association}' value '#{value.inspect}'" }

        # skip if we don't track them
        next if tracked_associations.exclude?(association)

        logger.debug { "Using value of association '#{association}'" }
        [association, value]
      end.to_h
    end
  end

  private

  def associations
    @associations ||= begin
      # loop over all reflections
      model_class.reflect_on_all_associations.each_with_object([]) do |reflection, associations|

        # refection name is something like groups or organization (singular/plural)
        associations.push(reflection.name)

        # key is something like group_id or organization_id (singular)
        key = reflection.klass.name.foreign_key

        # add trailing 's' to get pluralized key
        reflection_name = reflection.name.to_s
        if reflection_name.singularize != reflection_name
          key = "#{key}s"
        end

        # store _id/_ids name
        associations.push(key.to_sym)
      end
    end
  end

  def tracked_associations
    # track all associations by default
    associations
  end
end