adapter.rb

# frozen_string_literal: true

require "semian"

module Semian
  module Adapter
    def semian_identifier
      raise NotImplementedError, "Semian adapters must implement a `semian_identifier` method"
    end

    def semian_resource
      return @semian_resource if @semian_resource

      case semian_options
      when false
        @semian_resource = UnprotectedResource.new(semian_identifier)
      when nil
        Semian.logger.info("Semian is not configured for #{self.class.name}: #{semian_identifier}")
        @semian_resource = UnprotectedResource.new(semian_identifier)
      else
        options = semian_options.dup
        options.delete(:name)
        options[:consumer] = self
        options[:exceptions] ||= []
        options[:exceptions] += resource_exceptions
        resource = ::Semian.retrieve_or_register(semian_identifier, **options)

        @semian_resource = resource unless options.fetch(:dynamic, false)

        resource
      end
    end

    def clear_semian_resource
      @semian_resource = nil
    end

    private

    def acquire_semian_resource(scope:, adapter:, &block)
      return yield if resource_already_acquired?

      semian_resource.acquire(scope: scope, adapter: adapter, resource: self) do
        mark_resource_as_acquired(&block)
      end
    rescue ::Semian::OpenCircuitError => error
      last_error = semian_resource.circuit_breaker.last_error
      message = "#{error.message} caused by #{last_error.message}"
      last_error = nil unless last_error.is_a?(Exception) # Net::HTTPServerError is not an exception
      raise self.class::CircuitOpenError.new(semian_identifier, message), cause: last_error
    rescue ::Semian::BaseError => error
      raise self.class::ResourceBusyError.new(semian_identifier, error.message)
    rescue *resource_exceptions => error
      error.semian_identifier = semian_identifier if error.respond_to?(:semian_identifier=)
      raise
    end

    def semian_options
      return @semian_options if defined? @semian_options

      options = raw_semian_options

      symbolized_options = options && options.transform_keys(&:to_sym) # rubocop:disable Style/SafeNavigation
      symbolized_options.tap do
        @semian_options = symbolized_options if !symbolized_options || !symbolized_options.fetch(:dynamic, false)
      end
    end

    def raw_semian_options
      raise NotImplementedError, "Semian adapters must implement a `raw_semian_options` method"
    end

    def resource_exceptions
      raise NotImplementedError, "Semian adapters must implement a `resource_exceptions` method"
    end

    def resource_already_acquired?
      @resource_acquired
    end

    def mark_resource_as_acquired
      previous = @resource_acquired
      @resource_acquired = true
      yield
    ensure
      @resource_acquired = previous
    end
  end
end