// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COBALT_CONFIG_CLIENT_CONFIG_H_
#define COBALT_CONFIG_CLIENT_CONFIG_H_

#include <memory>
#include <string>
#include <utility>

#include "config/cobalt_config.pb.h"
#include "config/encoding_config.h"
#include "config/encodings.pb.h"
#include "config/metric_config.h"
#include "config/metrics.pb.h"

namespace cobalt {
namespace config {

// ClientConfig provides a convenient interface to the Cobalt configuration
// system that is intended to be used by the Encoder client.
class ClientConfig {
 public:
  // Constructs and returns an instance of ClientConfig by first parsing
  // a CobaltConfig proto message from |cobalt_config_base64|, which should
  // contain the Base64 encoding of the bytes of the binary serialization of
  // such a message, and then extracting the Metrics and EncodingConfigs from
  // that.
  static std::unique_ptr<ClientConfig> CreateFromCobaltConfigBase64(
      const std::string& cobalt_config_base64);

  // Constructs and returns an instance of ClientConfig by first parsing
  // a CobaltConfig proto message from |cobalt_config_bytes|, which should
  // contain the bytes of the binary serialization of such a message, and then
  // extracting the Metrics and EncodingConfigs from that.
  static std::unique_ptr<ClientConfig> CreateFromCobaltConfigBytes(
      const std::string& cobalt_config_bytes);

  // Checks list of Metrics or EncodingConfigs to  make sure that |customer_id|
  // is the only customer_id referenced and |project_id| is the only project_id
  // referenced.
  template <class Config>
  static bool ValidateSingleProjectConfig(
      const ::google::protobuf::RepeatedPtrField<Config>& configs,
      uint32_t customer_id, uint32_t project_id);

  // Constructs and returns an instance of ClientConfig by first parsing
  // a CobaltConfig proto message with configuration only for a single project
  // from |cobalt_config_bytes|. This should contain the bytes of the binary
  // serialization of such a message. Then extracts the Metrics and
  // EncodingConfigs from that. Also validates that the CobaltConfig only
  // contains a single customer_id and project_id and returns the project_id
  // as the second value in the pair.
  static std::pair<std::unique_ptr<ClientConfig>, uint32_t>
  CreateFromCobaltProjectConfigBytes(const std::string& cobalt_config_bytes);

  // Constructs and returns an instance of ClientConfig by swapping all of
  // the Metrics and EncodingConfigs from the given |cobalt_config|.
  static std::unique_ptr<ClientConfig> CreateFromCobaltConfig(
      CobaltConfig* cobalt_config);

  // Returns the EncodingConfig with the given ID triple, or nullptr if there is
  // no such EncodingConfig. The caller does not take ownership of the returned
  // pointer.
  const EncodingConfig* EncodingConfig(uint32_t customer_id,
                                       uint32_t project_id,
                                       uint32_t encoding_config_id);

  // Returns the Metric with the given ID triple, or nullptr if there is
  // no such Metric. The caller does not take ownership of the returned
  // pointer.
  const class Metric* Metric(uint32_t customer_id, uint32_t project_id,
                             uint32_t metric_id);

  // Returns the Metric with the given triple, or nullptr if there is no
  // such Metric. The caller does not take ownership of the returned pointer.
  const class Metric* Metric(uint32_t customer_id, uint32_t project_id,
                             const std::string& metric_name);

 private:
  // Constructs an ClientConfig that wraps the given registries.
  ClientConfig(std::shared_ptr<config::EncodingRegistry> encoding_configs,
               std::shared_ptr<config::MetricRegistry> metrics);

  std::shared_ptr<config::EncodingRegistry> encoding_configs_;
  std::shared_ptr<config::MetricRegistry> metrics_;
};

}  // namespace config
}  // namespace cobalt

#endif  // COBALT_CONFIG_CLIENT_CONFIG_H_