# frozen_string_literal: true

module Bullet
  module SaveWithBulletSupport
    def _create_record(*)
      super do
        Bullet::Detector::NPlusOneQuery.update_inversed_object(self)
        Bullet::Detector::NPlusOneQuery.add_impossible_object(self)
        yield(self) if block_given?
      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 { |record| Bullet::Detector::Association.add_object_associations(record, association) }
                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 { |record| Bullet::Detector::Association.add_object_associations(record, associations) }
              Bullet::Detector::UnusedEagerLoading.add_eager_loadings(records, associations)
            end
            records
          end
        end
      )

      ::ActiveRecord::Associations::JoinDependency.prepend(
        Module.new do
          if ::ActiveRecord::Associations::JoinDependency.instance_method(:instantiate).parameters.last[0] == :block
            # ActiveRecord >= 5.1.5
            def instantiate(result_set, &block)
              @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
          else
            # ActiveRecord <= 5.1.4
            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
          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]
                  if node.reflection.through_reflection?
                    associations << node.reflection.through_reflection.name
                  end
                  associations.each do |association|
                    Bullet::Detector::Association.add_object_associations(ar_parent, association)
                    Bullet::Detector::NPlusOneQuery.call_association(ar_parent, association)
                    @bullet_eager_loadings[ar_parent.class] ||= {}
                    @bullet_eager_loadings[ar_parent.class][ar_parent] ||= Set.new
                    @bullet_eager_loadings[ar_parent.class][ar_parent] << association
                  end
                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]
              if node.reflection.through_reflection?
                associations << node.reflection.through_reflection.name
              end
              associations.each do |association|
                Bullet::Detector::Association.add_object_associations(record, association)
                Bullet::Detector::NPlusOneQuery.call_association(record, association)
                @bullet_eager_loadings[record.class] ||= {}
                @bullet_eager_loadings[record.class][record] ||= Set.new
                @bullet_eager_loadings[record.class][record] << association
              end
            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
                refl = reflection.through_reflection
                association = owner.association(refl.name)
                if association.loaded?
                  Bullet::Detector::NPlusOneQuery.call_association(owner, refl.name)
                  Array.wrap(association.target).each do |through_record|
                    Bullet::Detector::NPlusOneQuery.call_association(through_record, source_reflection.name)
                  end

                  if refl.through_reflection?
                    refl = refl.through_reflection while refl.through_reflection?

                    Bullet::Detector::NPlusOneQuery.call_association(owner, refl.name)
                  end
                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)
            Bullet::Detector::NPlusOneQuery.call_association(owner, reflection.name) if Bullet.start?
            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
      )

      ::ActiveRecord::Associations::CollectionProxy.prepend(
        Module.new do
          def count(column_name = nil)
            if Bullet.start? && !proxy_association.is_a?(::ActiveRecord::Associations::ThroughAssociation)
              Bullet::Detector::CounterCache.add_counter_cache(
                proxy_association.owner,
                proxy_association.reflection.name
              )
              Bullet::Detector::NPlusOneQuery.call_association(
                proxy_association.owner,
                proxy_association.reflection.name
              )
            end
            super(column_name)
          end
        end
      )
    end
  end
end