module CarrierWave
  module Backgrounder

    Logger = Logger.new(STDOUT)

    autoload :Delay, 'backgrounder/delay'
    autoload :DelayStorage, 'backgrounder/delay'

    module ORM
      autoload :Base, 'backgrounder/orm/base'
    end

    class << self
      def backend=(value)
        @backend = value
        self.configure_backend
      end

      def backend
        return @backend unless @backend.nil?
        if available_backends.empty?
          warn 'WARNING: No queue backends found to use for CarrierWave::Backgrounder'
        elsif available_backends.size == 1
          self.backend = available_backends.first
        elsif available_backends.size > 1
          warn 'WARNING: Multiple queue backends found for CarrierWave::Backgrounder. You need to set one explicitly.'
        end
      end

      def configure
        yield self
      end

      def available_backends
        @available_backends ||= begin
          backends = []
          backends << :girl_friday if defined? ::GirlFriday
          backends << :delayed_job if defined? ::Delayed::Job
          backends << :resque      if defined? ::Resque
          backends << :qu          if defined? ::Qu
          backends << :sidekiq     if defined? ::Sidekiq
          backends << :qc          if defined? ::QC
          backends
        end
      end

      def configure_backend
        if backend == :girl_friday
          require 'girl_friday'
          @girl_friday_queue = GirlFriday::WorkQueue.new(:carrierwave) do |msg|
            worker = msg[:worker]
            worker.perform
          end
        end
      end

      def enqueue_for_backend(worker, class_name, subject_id, mounted_as)
        case backend
        when :girl_friday
          @girl_friday_queue << { :worker => worker.new(self.class.name, subject_id, mounted_as) }
        when :delayed_job
          ::Delayed::Job.enqueue worker.new(class_name, subject_id, mounted_as)
        when :resque
          ::Resque.enqueue worker, class_name, subject_id, mounted_as
        when :qu
          ::Qu.enqueue worker, class_name, subject_id, column.mounted_as
        when :sidekiq
          ::Sidekiq::Client.enqueue worker, class_name, subject_id, mounted_as
        when :qc
          ::QC.enqueue "#{worker.name}.perform", class_name, subject_id, mounted_as.to_s
        end
      end

    end

  end
end

if defined?(Rails)
  module CarrierWave
    module Backgrounder
      class Railtie < Rails::Railtie

        initializer "carrierwave_backgrounder.active_record" do
          ActiveSupport.on_load :active_record do
            require 'backgrounder/orm/activerecord'
          end
        end

        initializer "carrierwave_backgrounder.data_mapper", :before =>"data_mapper.add_to_prepare" do
          require 'backgrounder/orm/data_mapper' if defined?(DataMapper)
        end

        initializer "carrierwave_backgrounder.mongoid" do
          require 'backgrounder/orm/mongoid' if defined?(Mongoid)
        end

      end
    end
  end
end