#pragma once

#include "envoy/common/exception.h"

#include "envoy/tracing/tracer.h"

#include "source/common/common/statusor.h"

#include "source/common/http/header_map_impl.h"

#include "source/common/tracing/trace_context_impl.h"

#include "source/extensions/tracers/opentelemetry/span_context.h"

namespace Envoy {

namespace Extensions {

namespace Tracers {

namespace OpenTelemetry {

class OpenTelemetryConstantValues {

public:

  const Tracing::TraceContextHandler TRACE_PARENT{"traceparent"};

  const Tracing::TraceContextHandler TRACE_STATE{"tracestate"};

};

using OpenTelemetryConstants = ConstSingleton<OpenTelemetryConstantValues>;

/**

 * This class is used to SpanContext extracted from the HTTP traceparent header

 * See https://www.w3.org/TR/trace-context/#traceparent-header.

 */

class SpanContextExtractor {

public:

  SpanContextExtractor(Tracing::TraceContext& trace_context);

  ~SpanContextExtractor();

  absl::StatusOr<SpanContext> extractSpanContext();

  bool propagationHeaderPresent();

private:

  const Tracing::TraceContext& trace_context_;

};

} // namespace OpenTelemetry

} // namespace Tracers

} // namespace Extensions

} // namespace Envoy