class ThinkingSphinx::ActiveRecord::FilterReflection
  attr_reader :reflection, :class_name

  delegate :foreign_type, :active_record, :to => :reflection

  def self.call(reflection, name, class_name)
    filter = new(reflection, class_name)
    klass  = reflection.class
    arity  = klass.instance_method(:initialize).arity

    if defined?(ActiveRecord::Reflection::MacroReflection) && arity == 4
      klass.new name, filter.scope, filter.options, reflection.active_record
    elsif reflection.respond_to?(:scope)
      klass.new reflection.macro, name, filter.scope, filter.options,
        reflection.active_record
    else
      klass.new reflection.macro, name, filter.options,
        reflection.active_record
    end
  end

  def initialize(reflection, class_name)
    @reflection, @class_name = reflection, class_name
    @options = reflection.options.clone
  end

  def options
    @options.delete :polymorphic
    @options[:class_name]    = class_name
    @options[:foreign_key] ||= "#{reflection.name}_id"
    @options[:foreign_type]  = reflection.foreign_type

    if reflection.respond_to?(:scope)
      @options[:sphinx_internal_filtered] = true
      return @options
    end

    case @options[:conditions]
    when nil
      @options[:conditions] = condition
    when Array
      @options[:conditions] << condition
    when Hash
      @options[:conditions].merge!(reflection.foreign_type => @options[:class_name])
    else
      @options[:conditions] << " AND #{condition}"
    end

    @options
  end

  def scope
    if ::Joiner::Joins.instance_methods.include?(:join_association_class)
      return nil
    end

    lambda { |association|
      reflection = association.reflection
      klass      = reflection.class_name.constantize
      where(
        association.parent.aliased_table_name.to_sym =>
        {reflection.foreign_type => klass.base_class.name}
      )
    }
  end

  private

  def condition
    "::ts_join_alias::.#{quoted_foreign_type} = '#{class_name}'"
  end

  def quoted_foreign_type
    active_record.connection.quote_column_name foreign_type
  end
end