require 'sidekiq/circuit_breaker/manager'
require 'sidekiq/circuit_breaker/middleware'
require 'sidekiq/client'

module Sidekiq
  module CircuitBreaker
    module Middleware
      class Client
        def call(worker_class, msg, queue, redis_pool)
          worker = constantize(worker_class)
          circuit_breaker = worker.respond_to?(:sidekiq_circuit_breaker_enabled?)
          return yield unless circuit_breaker

          options = worker.sidekiq_circuit_breaker_options
          scope = extract_scope(options, msg) || worker_class

          mgr = CircuitBreaker::Manager.new(scope, options)
          if mgr.open? && msg['at'].nil?
            msg['at'] = (Time.now + mgr.time_to_open + rand(10)).to_f
          end

          yield
        end

        private

        def extract_scope(options, msg)
          scope = options.scope
          return scope if scope.is_a?(String)

          options.scope.call(*msg['args'])
        end

        def constantize(str)
          names = str.split('::')
          names.shift if names.empty? || names.first.empty?

          names.inject(Object) do |constant, name|
            constant.const_defined?(name, false) ? constant.const_get(name, false) : constant.const_missing(name)
          end
        end
      end

      class Server
        def call(worker, msg, queue)
          circuit_breaker_enabled = worker.class.respond_to?(:sidekiq_circuit_breaker_enabled?)
          return yield unless circuit_breaker_enabled

          def worker.perform(*args)
            manager = sidekiq_circuit_breaker_manager(args)

            if manager.open?
              begin
                Sidekiq::Client.push(
                  'class' => self.class,
                  'args'  => args
                )
                return
              end
            end

            super(*args)
          end

          manager = worker.sidekiq_circuit_breaker_manager(msg['args'])

          begin
            yield
          rescue => e
            manager.evaluate_failure
            raise e
          end

          manager.register_success
        end
      end
    end
  end
end

Sidekiq.configure_client do |config|
  config.client_middleware do |chain|
    chain.add Sidekiq::CircuitBreaker::Middleware::Client
  end
end

Sidekiq.configure_server do |config|
  config.client_middleware do |chain|
    chain.add Sidekiq::CircuitBreaker::Middleware::Client
  end
  config.server_middleware do |chain|
    chain.add Sidekiq::CircuitBreaker::Middleware::Server
  end
end