rate_limitable.rb

# frozen_string_literal: true

# @see https://gist.github.com/commitshappen/5928740df2e01f256778c2dbd14364a5 for the RateLimiter
module RateLimitable
  def self.included(base)
    base.extend(ClassMethods)
  end

  module ClassMethods
    def rate_limiter(bucket_name, global: {}, local: {})
      @rate_limits = { bucket_name: bucket_name, global: global, local: local }
    end

    def rate_limits
      @rate_limits ||= rate_limiter(nil)
    end
  end

  def method_missing(method_name, ...)
    if method_name.start_with?("rate_limited_")
      within_rate_limit { public_send(method_name.to_s.delete_prefix("rate_limited_"), ...) }
    else
      super(method_name, ...)
    end
  end

  def within_rate_limit(&block)
    rate_limiters[:local].within_limit do
      rate_limiters[:global].within_limit(&block)
    end
  end

  private

  def generate_rate_limiter(namespace)
    rate_limit_namespace = namespace == :local ? self.object_id : nil
    rate_limit_bucket = [rate_limits[:bucket_name], rate_limit_namespace].compact.join(":")

    RateLimiter.new(rate_limit_bucket, rate_limits[namespace])
  end

  def rate_limits
    self.class.rate_limits
  end

  def rate_limiters
    @rate_limiters ||= { global: generate_rate_limiter(:global), local: generate_rate_limiter(:local) }
  end
end