question_tags_manager.rb

class QuestionTagsManager < Draper::Decorator
  include Draper::LazyHelpers
  extend Forwardable

  def_delegator :project, :id, :project_id
  def_delegator :project, :title, :project_title

  def_delegator :task, :id, :task_id
  def_delegator :task, :type, :task_type
  def_delegator :task, :title, :task_title
  def_delegator :task, :description, :task_description

  def_delegator :new_tag, :save, :save_tag
  def_delegator :tag, :destroy_or_merge, :destroy_tag
  def_delegator :tag, :update_attributes, :update_tag

  def_delegator :question, :id, :question_id
  def_delegator :question, :alias, :question_alias
  def_delegator :question, :summary, :question_summary

  def_delegator :policy, :update?, :can_update?
  def_delegator :policy, :destroy?, :can_destroy?
  def_delegator :policy, :create_tags?, :can_create_tags?

  def initialize(params)
    @params = params
  end

  def render_management_header
    return unless can_create_tags?
    render("question_tags/management_header")
  end

  def render_management_links_for(tag)
    return unless can_create_tags?
    render("question_tags/management_links", question: question, tag: tag)
  end

  def listing
    tags.any? ? QuestionTagListing.new : NullQuestionTagListing.new
  end

  def tags
    @_tags ||= question.tags.map { |tag| QuestionTag.new(tag.to_h) }
  end

  def tag
    @_tag ||= find_tag
  end

  def new_tag
    attributes = @params.fetch(:tag, {}).merge(question: question)
    @_new_tag ||= QuestionTag.new(attributes)
  end

  def question
    @_question ||= find_question
  end

  def task_icon
    task.icon_tag(project_id)
  end

  private

  def policy
    @_policy ||= QuestionPolicy.new(question)
  end

  def find_tag
    QuestionTag.find(@params[:id])
  end

  def find_question
    Question.find_with_tags(@params[:question_id])
  end

  def task
    @_task ||= TaskDecorator.decorate(Task.find(question.task.id))
  end

  def project
    @_project ||= task_list.project
  end

  def task_list
    @_task_list ||= Crowdlab::Model::TaskList.find(task.task_list.id)
  end
end