# OpenTelemetry is reached from ProTacts::Tracing, which installs the SDK
# and builds the request span's middleware, and from Web#span, which
# times a step of a request inside that span.
module OpenTelemetry
  def self.tracer_provider: () -> Trace::TracerProvider

  def self.propagation=: (untyped propagator) -> void

  module Trace
    class TracerProvider
      def tracer: (String name) -> Tracer
    end

    class Tracer
      def in_span: [T] (String name) { (Span span, untyped context) -> T } -> T
    end

    class Span
      def set_attribute: (String key, Integer value) -> self
    end
  end

  module SDK
    def self.configure: () { (Configurator) -> void } -> void

    class Configurator
      def service_name=: (String name) -> void

      def use: (String instrumentation_name, ?Hash[Symbol, untyped] config) -> void

      def add_span_processor: (untyped processor) -> void
    end

    module Trace
      module Export
        class BatchSpanProcessor
          def initialize: (Exporter::OTLP::Exporter exporter) -> void
        end
      end
    end
  end

  module Exporter
    module OTLP
      class Exporter
        def initialize: (endpoint: String) -> void
      end
    end
  end

  module Instrumentation
    module Rack
      class Instrumentation
        def self.instance: () -> Instrumentation

        def middleware_args: () -> Array[untyped]
      end
    end
  end
end