# frozen_string_literal: true

module Stripe
  class Instrumentation
    # Event emitted on `request_begin` callback.
    class RequestBeginEvent
      attr_reader :method
      attr_reader :path

      # Arbitrary user-provided data in the form of a Ruby hash that's passed
      # from subscribers on `request_begin` to subscribers on `request_end`.
      # `request_begin` subscribers can set keys which will then be available
      # in `request_end`.
      #
      # Note that all subscribers of `request_begin` share the same object, so
      # they must be careful to set unique keys so as to not conflict with data
      # set by other subscribers.
      attr_reader :user_data

      def initialize(method:, path:, user_data:)
        @method = method
        @path = path
        @user_data = user_data
        freeze
      end
    end

    # Event emitted on `request_end` callback.
    class RequestEndEvent
      attr_reader :duration
      attr_reader :http_status
      attr_reader :method
      attr_reader :num_retries
      attr_reader :path
      attr_reader :request_id

      # Arbitrary user-provided data in the form of a Ruby hash that's passed
      # from subscribers on `request_begin` to subscribers on `request_end`.
      # `request_begin` subscribers can set keys which will then be available
      # in `request_end`.
      attr_reader :user_data

      def initialize(duration:, http_status:, method:, num_retries:, path:,
                     request_id:, user_data: nil)
        @duration = duration
        @http_status = http_status
        @method = method
        @num_retries = num_retries
        @path = path
        @request_id = request_id
        @user_data = user_data
        freeze
      end
    end

    # This class was renamed for consistency. This alias is here for backwards
    # compatibility.
    RequestEvent = RequestEndEvent

    # Returns true if there are a non-zero number of subscribers on the given
    # topic, and false otherwise.
    def self.any_subscribers?(topic)
      !subscribers[topic].empty?
    end

    def self.subscribe(topic, name = rand, &block)
      subscribers[topic][name] = block
      name
    end

    def self.unsubscribe(topic, name)
      subscribers[topic].delete(name)
    end

    def self.notify(topic, event)
      subscribers[topic].each_value { |subscriber| subscriber.call(event) }
    end

    def self.subscribers
      @subscribers ||= Hash.new { |hash, key| hash[key] = {} }
    end
    private_class_method :subscribers
  end
end