// Copyright 2017 Google Inc. All Rights Reserved.
//
// This file contains the declarations for the Metric class and related
// types.
#ifndef WVCDM_METRICS_METRIC_PUBLISHER_H_
#define WVCDM_METRICS_METRIC_PUBLISHER_H_

namespace wvcdm {
namespace metrics {

// The MetricNotification is implemented by the code that instantiates
// MetricPublisher instances. The caller provides this MetricNotification
// instance to MetricPublisher::Publish. In turn, Publish will make a call to
// UpdateMetric for each value to be published. The Metric may contain zero or
// more values to be updated.
class MetricNotification {
 public:
  virtual ~MetricNotification() {};

  // The metric_id is the metric name, plus the metric part name, and the
  // metric field name/value string.  E.g.
  //   name: "drm/cdm/decrypt/duration"
  //   part: "mean"
  //   field name/value string: "{error_code:0&buffer_size:1024}"
  // becomes: "drm/cdm/decrypt/duration/mean/{error_code:0&buffer_size:1024}".
  virtual void UpdateString(const std::string& metric_id,
                            const std::string& value) = 0;
  virtual void UpdateInt32(const std::string& metric_id, int32_t value) = 0;
  virtual void UpdateInt64(const std::string& metric_id, int64_t value) = 0;
  virtual void UpdateDouble(const std::string& metric_id, double value) = 0;
};

// This abstract class merely provides the definition for publishing the value
// of the metric.
class MetricPublisher {
 public:
  virtual ~MetricPublisher() { }
  // Publish metric values to the MetricNotification. |subscriber| must
  // not be null and is owned by the caller.
  virtual void Publish(MetricNotification* subscriber) = 0;
};

}  // namespace metrics
}  // namespace wvcdm

#endif  // WVCDM_METRICS_METRIC_PUBLISHER_H_