module Semian::GRPC

def acquire_semian_resource_grpc(scope:)
  acquire_semian_resource(adapter: :grpc, scope: scope) do
    result = yield
    handle_operation(result, scope) if result.is_a?(::GRPC::ActiveCall::Operation)
    result
  end
end

def bidi_streamer(*, **)
  return super if disabled?
  acquire_semian_resource_grpc(scope: :bidi_streamer) { super }
end

def client_streamer(*, **)
  return super if disabled?
  acquire_semian_resource_grpc(scope: :client_streamer) { super }
end

def disabled?
  raw_semian_options.nil?
end

def handle_operation(operation, scope)
  execute = operation.singleton_method(:execute)
  operation.instance_variable_set(:@semian, self)
  operation.define_singleton_method(:execute) do
    @semian.send(:acquire_semian_resource, adapter: :grpc, scope: scope) { execute.call }
  end
end

def raw_semian_options
  @raw_semian_options ||= begin
    # If the host is empty, it's possible that the adapter was initialized
    # with the channel. Therefore, we look into the channel to find the host
    host = if @host.empty?
      @ch.target
    else
      @host
    end
    @raw_semian_options = Semian::GRPC.retrieve_semian_configuration(host)
    @raw_semian_options = @raw_semian_options.dup unless @raw_semian_options.nil?
  end
end

def request_response(*, **)
  return super if disabled?
  acquire_semian_resource_grpc(scope: :request_response) { super }
end

def resource_exceptions
  [
    ::GRPC::DeadlineExceeded,
    ::GRPC::ResourceExhausted,
    ::GRPC::Unavailable,
    ::GRPC::Unknown,
  ]
end

def retrieve_semian_configuration(host)
  @semian_configuration.call(host) if @semian_configuration.respond_to?(:call)
end

def semian_configuration=(configuration)
  raise Semian::GRPC::SemianConfigurationChangedError unless @semian_configuration.nil?
  @semian_configuration = configuration
end

def semian_identifier
  @semian_identifier ||= raw_semian_options[:name]
end

def server_streamer(*, **)
  return super if disabled?
  acquire_semian_resource_grpc(scope: :server_streamer) { super }
end