// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

#pragma once

#include <atomic>
#include <chrono>
#include <iostream>
#include <map>
#include <mutex>
#include <string>

#include "opentelemetry/sdk/common/attribute_utils.h"
#include "opentelemetry/sdk/common/exporter_utils.h"
#include "opentelemetry/sdk/metrics/data/metric_data.h"
#include "opentelemetry/sdk/metrics/export/metric_producer.h"
#include "opentelemetry/sdk/metrics/instruments.h"
#include "opentelemetry/sdk/metrics/push_metric_exporter.h"
#include "opentelemetry/sdk/resource/resource.h"
#include "opentelemetry/version.h"

OPENTELEMETRY_BEGIN_NAMESPACE
namespace exporter
{
namespace metrics
{

/**
 * The OStreamMetricExporter exports record data through an ostream
 */
class OStreamMetricExporter final : public opentelemetry::sdk::metrics::PushMetricExporter
{
public:
  /**
   * Create an OStreamMetricExporter. This constructor takes in a reference to an ostream that the
   * export() function will send metrics data into.
   * The default ostream is set to stdout
   */
  explicit OStreamMetricExporter(std::ostream &sout = std::cout,
                                 sdk::metrics::AggregationTemporality aggregation_temporality =
                                     sdk::metrics::AggregationTemporality::kCumulative) noexcept;

  /**
   * Export
   * @param data metrics data
   */
  sdk::common::ExportResult Export(const sdk::metrics::ResourceMetrics &data) noexcept override;

  /**
   * Get the AggregationTemporality for ostream exporter
   *
   * @return AggregationTemporality
   */
  sdk::metrics::AggregationTemporality GetAggregationTemporality(
      sdk::metrics::InstrumentType instrument_type) const noexcept override;

  /**
   * Force flush the exporter.
   */
  bool ForceFlush(
      std::chrono::microseconds timeout = (std::chrono::microseconds::max)()) noexcept override;

  /**
   * Shut down the exporter.
   * @param timeout an optional timeout.
   * @return return the status of this operation
   */
  bool Shutdown(
      std::chrono::microseconds timeout = (std::chrono::microseconds::max)()) noexcept override;

private:
  std::ostream &sout_;
  std::atomic<bool> is_shutdown_{false};
  std::mutex serialize_lock_;
  sdk::metrics::AggregationTemporality aggregation_temporality_;
  bool isShutdown() const noexcept;
  void printInstrumentationInfoMetricData(const sdk::metrics::ScopeMetrics &info_metrics,
                                          const sdk::metrics::ResourceMetrics &data);
  void printPointData(const opentelemetry::sdk::metrics::PointType &point_data);
  void printPointAttributes(const opentelemetry::sdk::metrics::PointAttributes &point_attributes);
  void printAttributes(const std::map<std::string, sdk::common::OwnedAttributeValue> &map,
                       const std::string &prefix);
  void printResources(const opentelemetry::sdk::resource::Resource &resources);
};
}  // namespace metrics
}  // namespace exporter
OPENTELEMETRY_END_NAMESPACE