discourse/script/import_scripts/base/lookup_container.rb

module ImportScripts
  class LookupContainer
    def initialize
      puts 'loading existing groups...'
      @groups = {}
      GroupCustomField.where(name: 'import_id').pluck(:group_id, :value).each do |group_id, import_id|
        @groups[import_id] = group_id
      end

      puts 'loading existing users...'
      @users = {}
      UserCustomField.where(name: 'import_id').pluck(:user_id, :value).each do |user_id, import_id|
        @users[import_id] = user_id
      end

      puts 'loading existing categories...'
      @categories = {}
      CategoryCustomField.where(name: 'import_id').pluck(:category_id, :value).each do |category_id, import_id|
        @categories[import_id] = category_id
      end

      puts 'loading existing posts...'
      @posts = {}
      PostCustomField.where(name: 'import_id').pluck(:post_id, :value).each do |post_id, import_id|
        @posts[import_id] = post_id
      end

      puts 'loading existing topics...'
      @topics = {}
      Post.joins(:topic).pluck('posts.id, posts.topic_id, posts.post_number, topics.slug').each do |p|
        @topics[p[0]] = {
          topic_id: p[1],
          post_number: p[2],
          url: Post.url(p[3], p[1], p[2])
        }
      end
    end

    # Get the Discourse Post id based on the id of the source record
    def post_id_from_imported_post_id(import_id)
      @posts[import_id] || @posts[import_id.to_s]
    end

    # Get the Discourse topic info (a hash) based on the id of the source record
    def topic_lookup_from_imported_post_id(import_id)
      post_id = post_id_from_imported_post_id(import_id)
      post_id ? @topics[post_id] : nil
    end

    # Get the Discourse Group id based on the id of the source group
    def group_id_from_imported_group_id(import_id)
      @groups[import_id] || @groups[import_id.to_s] || find_group_by_import_id(import_id).try(:id)
    end

    # Get the Discourse Group based on the id of the source group
    def find_group_by_import_id(import_id)
      GroupCustomField.where(name: 'import_id', value: import_id.to_s).first.try(:group)
    end

    # Get the Discourse User id based on the id of the source user
    def user_id_from_imported_user_id(import_id)
      @users[import_id] || @users[import_id.to_s] || find_user_by_import_id(import_id).try(:id)
    end

    # Get the Discourse User based on the id of the source user
    def find_user_by_import_id(import_id)
      UserCustomField.where(name: 'import_id', value: import_id.to_s).first.try(:user)
    end

    # Get the Discourse Category id based on the id of the source category
    def category_id_from_imported_category_id(import_id)
      @categories[import_id] || @categories[import_id.to_s]
    end

    def add_group(import_id, group)
      @groups[import_id] = group.id
    end

    def add_user(import_id, user)
      @users[import_id] = user.id
    end

    def add_category(import_id, category)
      @categories[import_id] = category.id
    end

    def add_post(import_id, post)
      @posts[import_id] = post.id
    end

    def add_topic(post)
      @topics[post.id] = {
        post_number: post.post_number,
        topic_id: post.topic_id,
        url: post.url,
      }
    end
  end
end