module ActsAsTaggableOn::Taggable::TaggedWithQuery
  class ExcludeTagsQuery < QueryBase
    def build
      taggable_model.joins(owning_to_tagger)
                    .where(tags_not_in_list)
                    .having(tags_that_matches_count)
                    .readonly(false)
    end

    private

    def tags_not_in_list
      return taggable_arel_table[:id].not_in(
            tagging_arel_table
              .project(tagging_arel_table[:taggable_id])
              .join(tag_arel_table)
              .on(
                  tagging_arel_table[:tag_id].eq(tag_arel_table[:id])
                  .and(tagging_arel_table[:taggable_type].eq(taggable_model.base_class.name))
                  .and(tags_match_type)
                )
          )

        # FIXME: missing time scope, this is also missing in the original implementation
    end


    def owning_to_tagger
      return [] unless options[:owned_by].present?

      owner = options[:owned_by]

      arel_join = taggable_arel_table
        .join(tagging_arel_table)
        .on(
            tagging_arel_table[:tagger_id].eq(owner.id)
            .and(tagging_arel_table[:tagger_type].eq(owner.class.base_class.to_s))
            .and(tagging_arel_table[:taggable_id].eq(taggable_arel_table[taggable_model.primary_key]))
            .and(tagging_arel_table[:taggable_type].eq(taggable_model.base_class.name))
          )

      if options[:match_all].present?
        arel_join = arel_join
          .join(tagging_arel_table, Arel::Nodes::OuterJoin)
          .on(
            match_all_on_conditions
          )
      end

      return arel_join.join_sources
    end

    def match_all_on_conditions
      on_condition = tagging_arel_table[:taggable_id].eq(taggable_arel_table[taggable_model.primary_key])
        .and(tagging_arel_table[:taggable_type].eq(taggable_model.base_class.name))

      if options[:start_at].present?
        on_condition = on_condition.and(tagging_arel_table[:created_at].gteq(options[:start_at]))
      end

      if options[:end_at].present?
        on_condition = on_condition.and(tagging_arel_table[:created_at].lteq(options[:end_at]))
      end

      if options[:on].present?
        on_condition = on_condition.and(tagging_arel_table[:context].lteq(options[:on]))
      end

      on_condition
    end

    def tags_that_matches_count
      return [] unless options[:match_all].present?

      taggable_model.find_by_sql(tag_arel_table.project(Arel.star.count).where(tags_match_type).to_sql)

      tagging_arel_table[:taggable_id].count.eq(
        tag_arel_table.project(Arel.star.count).where(tags_match_type)
      )
    end
  end
end
