module Bullet
  module SaveWithBulletSupport
    def save(*args)
      was_new_record = new_record?
      super(*args).tap do |result|
        Bullet::Detector::NPlusOneQuery.add_impossible_object(self) if result && was_new_record
      end
    end

    def save!(*args)
      was_new_record = new_record?
      super(*args).tap do |result|
        Bullet::Detector::NPlusOneQuery.add_impossible_object(self) if result && was_new_record
      end
    end
  end

  module ActiveRecord
    def self.enable
      require 'active_record'
      ::ActiveRecord::Base.extend(Module.new do
        def find_by_sql(sql, binds = [], preparable: nil, &block)
          result = super
          if Bullet.start?
            if result.is_a? Array
              if result.size > 1
                Bullet::Detector::NPlusOneQuery.add_possible_objects(result)
                Bullet::Detector::CounterCache.add_possible_objects(result)
              elsif result.size == 1
                Bullet::Detector::NPlusOneQuery.add_impossible_object(result.first)
                Bullet::Detector::CounterCache.add_impossible_object(result.first)
              end
            elsif result.is_a? ::ActiveRecord::Base
              Bullet::Detector::NPlusOneQuery.add_impossible_object(result)
              Bullet::Detector::CounterCache.add_impossible_object(result)
            end
          end
          result
        end
      end)

      ::ActiveRecord::Base.prepend(SaveWithBulletSupport)

      ::ActiveRecord::Relation.prepend(Module.new do
        # if select a collection of objects, then these objects have possible to cause N+1 query.
        # if select only one object, then the only one object has impossible to cause N+1 query.
        def records
          result = super
          if Bullet.start?
            if result.first.class.name !~ /^HABTM_/
              if result.size > 1
                Bullet::Detector::NPlusOneQuery.add_possible_objects(result)
                Bullet::Detector::CounterCache.add_possible_objects(result)
              elsif result.size == 1
                Bullet::Detector::NPlusOneQuery.add_impossible_object(result.first)
                Bullet::Detector::CounterCache.add_impossible_object(result.first)
              end
            end
          end
          result
        end
      end)

      ::ActiveRecord::Associations::Preloader.prepend(Module.new do
        def preloaders_for_one(association, records, scope)
          if Bullet.start?
            records.compact!
            if records.first.class.name !~ /^HABTM_/
              records.each do |record|
                Bullet::Detector::Association.add_object_associations(record, association)
              end
              Bullet::Detector::UnusedEagerLoading.add_eager_loadings(records, association)
            end
          end
          super
        end
      end)

      ::ActiveRecord::FinderMethods.prepend(Module.new do
        # add includes in scope
        def find_with_associations
          return super { |r| yield r } if block_given?
          records = super
          if Bullet.start?
            associations = (eager_load_values + includes_values).uniq
            records.each do |record|
              Bullet::Detector::Association.add_object_associations(record, associations)
            end
            Bullet::Detector::UnusedEagerLoading.add_eager_loadings(records, associations)
          end
          records
        end
      end)

      ::ActiveRecord::Associations::JoinDependency.prepend(Module.new do
        def instantiate(result_set, aliases)
          @bullet_eager_loadings = {}
          records = super

          if Bullet.start?
            @bullet_eager_loadings.each do |_klazz, eager_loadings_hash|
              objects = eager_loadings_hash.keys
              Bullet::Detector::UnusedEagerLoading.add_eager_loadings(objects, eager_loadings_hash[objects.first].to_a)
            end
          end
          records
        end

        def construct(ar_parent, parent, row, rs, seen, model_cache, aliases)
          if Bullet.start?
            unless ar_parent.nil?
              parent.children.each do |node|
                key = aliases.column_alias(node, node.primary_key)
                id = row[key]
                next unless id.nil?
                associations = node.reflection.name
                Bullet::Detector::Association.add_object_associations(ar_parent, associations)
                Bullet::Detector::NPlusOneQuery.call_association(ar_parent, associations)
                @bullet_eager_loadings[ar_parent.class] ||= {}
                @bullet_eager_loadings[ar_parent.class][ar_parent] ||= Set.new
                @bullet_eager_loadings[ar_parent.class][ar_parent] << associations
              end
            end
          end

          super
        end

        # call join associations
        def construct_model(record, node, row, model_cache, id, aliases)
          result = super

          if Bullet.start?
            associations = node.reflection.name
            Bullet::Detector::Association.add_object_associations(record, associations)
            Bullet::Detector::NPlusOneQuery.call_association(record, associations)
            @bullet_eager_loadings[record.class] ||= {}
            @bullet_eager_loadings[record.class][record] ||= Set.new
            @bullet_eager_loadings[record.class][record] << associations
          end

          result
        end
      end)

      ::ActiveRecord::Associations::CollectionAssociation.prepend(Module.new do
        def load_target
          records = super

          if Bullet.start?
            if is_a? ::ActiveRecord::Associations::ThroughAssociation
              Bullet::Detector::NPlusOneQuery.call_association(owner, through_reflection.name)
              association = owner.association through_reflection.name
              Array(association.target).each do |through_record|
                Bullet::Detector::NPlusOneQuery.call_association(through_record, source_reflection.name)
              end
            end
            Bullet::Detector::NPlusOneQuery.call_association(owner, reflection.name) unless @inversed
            if records.first.class.name !~ /^HABTM_/
              if records.size > 1
                Bullet::Detector::NPlusOneQuery.add_possible_objects(records)
                Bullet::Detector::CounterCache.add_possible_objects(records)
              elsif records.size == 1
                Bullet::Detector::NPlusOneQuery.add_impossible_object(records.first)
                Bullet::Detector::CounterCache.add_impossible_object(records.first)
              end
            end
          end
          records
        end

        def empty?
          if Bullet.start? && !reflection.has_cached_counter?
            Bullet::Detector::NPlusOneQuery.call_association(owner, reflection.name)
          end
          super
        end

        def include?(object)
          if Bullet.start?
            Bullet::Detector::NPlusOneQuery.call_association(owner, reflection.name)
          end
          super
        end
      end)

      ::ActiveRecord::Associations::SingularAssociation.prepend(Module.new do
        # call has_one and belongs_to associations
        def target
          result = super()
          if Bullet.start?
            if owner.class.name !~ /^HABTM_/ && !@inversed
              Bullet::Detector::NPlusOneQuery.call_association(owner, reflection.name)
              if Bullet::Detector::NPlusOneQuery.impossible?(owner)
                Bullet::Detector::NPlusOneQuery.add_impossible_object(result) if result
              else
                Bullet::Detector::NPlusOneQuery.add_possible_objects(result) if result
              end
            end
          end
          result
        end
      end)

      ::ActiveRecord::Associations::HasManyAssociation.prepend(Module.new do
        def empty?
          result = super
          if Bullet.start? && !reflection.has_cached_counter?
            Bullet::Detector::NPlusOneQuery.call_association(owner, reflection.name)
          end
          result
        end

        def count_records
          result = reflection.has_cached_counter?
          if Bullet.start? && !result && !is_a?(::ActiveRecord::Associations::ThroughAssociation)
            Bullet::Detector::CounterCache.add_counter_cache(owner, reflection.name)
          end
          super
        end
      end)
    end
  end
end