module CacheableMethod
  extend ActiveSupport::Concern

  DEFAULT_CACHE_EXPIRATION = 1.hour.to_i.freeze

  module ClassMethods
    unless const_defined?(:CACHE_EXPIRATION)
      const_set :CACHE_EXPIRATION, CacheableMethod::DEFAULT_CACHE_EXPIRATION
    end

    def cache_methods(*methods)
      methods.each do |method|
        cache_method(method)
      end
    end

    def cache_method(method, params: nil)
      define_method("#{method}_with_cache") do |*args|
        begin
          unless args.last.is_a?(Hash) && args.last.delete(:skip_cache)
            key = cache_key(method, params, args)
            cached = REDIS.get(key).try(:force_encoding, Encoding::BINARY)
            return Marshal.load(cached) if cached.present?
          end
          result = self.__send__("#{method}_without_cache", *args)
          REDIS.setex(key, self.class.const_get(:CACHE_EXPIRATION), Marshal.dump(result))
          result
        rescue StandardError
          self.__send__("#{method}_without_cache", *args)
        end
      end
      alias_method_chain method, :cache
    end
  end

  def cache_key(method, params, args)
    [
      self.class.name,
      method.to_s,
      Digest::MD5.hexdigest(get_required_args(method, params, args).to_s)
    ].join('_')
  end

  def get_required_args(method, params, args)
    return args unless params.present?
    arguments = self.method(method.to_s + "_without_cache").parameters.collect{ |a,b| b }
    args.values_at(*params.collect{ |a| arguments.index(a) })
  end
end

rescue StandardError
          self.__send__("#{method}_without_cache", *args)