// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef __MASTER_METRICS_HPP__
#define __MASTER_METRICS_HPP__

#include <string>
#include <vector>

#include <process/metrics/counter.hpp>
#include <process/metrics/gauge.hpp>
#include <process/metrics/metrics.hpp>

#include <stout/hashmap.hpp>

#include "mesos/mesos.hpp"
#include "mesos/type_utils.hpp"

namespace mesos {
namespace internal {
namespace master {

class Master;

struct Metrics
{
  explicit Metrics(const Master& master);

  ~Metrics();

  process::metrics::Gauge uptime_secs;
  process::metrics::Gauge elected;

  process::metrics::Gauge slaves_connected;
  process::metrics::Gauge slaves_disconnected;
  process::metrics::Gauge slaves_active;
  process::metrics::Gauge slaves_inactive;
  process::metrics::Gauge slaves_unreachable;

  process::metrics::Gauge frameworks_connected;
  process::metrics::Gauge frameworks_disconnected;
  process::metrics::Gauge frameworks_active;
  process::metrics::Gauge frameworks_inactive;

  process::metrics::Gauge outstanding_offers;

  // Task state metrics.
  process::metrics::Gauge tasks_staging;
  process::metrics::Gauge tasks_starting;
  process::metrics::Gauge tasks_running;
  process::metrics::Gauge tasks_unreachable;
  process::metrics::Gauge tasks_killing;
  process::metrics::Counter tasks_finished;
  process::metrics::Counter tasks_failed;
  process::metrics::Counter tasks_killed;
  process::metrics::Counter tasks_lost;
  process::metrics::Counter tasks_error;
  process::metrics::Counter tasks_dropped;
  process::metrics::Counter tasks_gone;
  process::metrics::Counter tasks_gone_by_operator;

  typedef hashmap<TaskStatus::Reason, process::metrics::Counter> Reasons;
  typedef hashmap<TaskStatus::Source, Reasons> SourcesReasons;

  // NOTE: We only track metrics sources and reasons for terminal states.
  hashmap<TaskState, SourcesReasons> tasks_states;

  // Message counters.
  process::metrics::Counter dropped_messages;

  // Metrics specific to frameworks of a common principal.
  // These metrics have names prefixed by "frameworks/<principal>/".
  struct Frameworks
  {
    // Counters for messages from all frameworks of this principal.
    // Note: We only count messages from active scheduler
    // *instances* while they are *registered*. i.e., messages
    // prior to the completion of (re)registration
    // (AuthenticateMessage and (Re)RegisterFrameworkMessage) and
    // messages from an inactive scheduler instance (after the
    // framework has failed over) are not counted.

    // Framework messages received (before processing).
    process::metrics::Counter messages_received;

    // Framework messages processed.
    // NOTE: This doesn't include dropped messages. Processing of
    // a message may be throttled by a RateLimiter if one is
    // configured for this principal. Also due to Master's
    // asynchronous nature, this doesn't necessarily mean the work
    // requested by this message has finished.
    process::metrics::Counter messages_processed;

    explicit Frameworks(const std::string& principal)
      : messages_received("frameworks/" + principal + "/messages_received"),
        messages_processed("frameworks/" + principal + "/messages_processed")
    {
      process::metrics::add(messages_received);
      process::metrics::add(messages_processed);
    }

    ~Frameworks()
    {
      process::metrics::remove(messages_received);
      process::metrics::remove(messages_processed);
    }
  };

  // Per-framework-principal metrics keyed by the framework
  // principal.
  hashmap<std::string, process::Owned<Frameworks>> frameworks;

  // Messages from schedulers.
  process::metrics::Counter messages_register_framework;
  process::metrics::Counter messages_reregister_framework;
  process::metrics::Counter messages_unregister_framework;
  process::metrics::Counter messages_deactivate_framework;
  process::metrics::Counter messages_kill_task;
  process::metrics::Counter messages_status_update_acknowledgement;
  process::metrics::Counter messages_resource_request;
  process::metrics::Counter messages_launch_tasks;
  process::metrics::Counter messages_decline_offers;
  process::metrics::Counter messages_revive_offers;
  process::metrics::Counter messages_suppress_offers;
  process::metrics::Counter messages_reconcile_tasks;
  process::metrics::Counter messages_framework_to_executor;

  // Messages from executors.
  process::metrics::Counter messages_executor_to_framework;

  // Messages from slaves.
  process::metrics::Counter messages_register_slave;
  process::metrics::Counter messages_reregister_slave;
  process::metrics::Counter messages_unregister_slave;
  process::metrics::Counter messages_status_update;
  process::metrics::Counter messages_exited_executor;
  process::metrics::Counter messages_update_slave;

  // Messages from both schedulers and slaves.
  process::metrics::Counter messages_authenticate;

  process::metrics::Counter valid_framework_to_executor_messages;
  process::metrics::Counter invalid_framework_to_executor_messages;
  process::metrics::Counter valid_executor_to_framework_messages;
  process::metrics::Counter invalid_executor_to_framework_messages;

  process::metrics::Counter valid_status_updates;
  process::metrics::Counter invalid_status_updates;

  process::metrics::Counter valid_status_update_acknowledgements;
  process::metrics::Counter invalid_status_update_acknowledgements;

  // Recovery counters.
  process::metrics::Counter recovery_slave_removals;

  // Process metrics.
  process::metrics::Gauge event_queue_messages;
  process::metrics::Gauge event_queue_dispatches;
  process::metrics::Gauge event_queue_http_requests;

  // Successful registry operations.
  process::metrics::Counter slave_registrations;
  process::metrics::Counter slave_reregistrations;
  process::metrics::Counter slave_removals;
  process::metrics::Counter slave_removals_reason_unhealthy;
  process::metrics::Counter slave_removals_reason_unregistered;
  process::metrics::Counter slave_removals_reason_registered;

  // Slave observer metrics.
  //
  // TODO(neilc): The `slave_shutdowns_xxx` metrics are deprecated and
  // will always be zero. Remove in Mesos 2.0.
  process::metrics::Counter slave_shutdowns_scheduled;
  process::metrics::Counter slave_shutdowns_completed;
  process::metrics::Counter slave_shutdowns_canceled;

  process::metrics::Counter slave_unreachable_scheduled;
  process::metrics::Counter slave_unreachable_completed;
  process::metrics::Counter slave_unreachable_canceled;

  // Non-revocable resources.
  std::vector<process::metrics::Gauge> resources_total;
  std::vector<process::metrics::Gauge> resources_used;
  std::vector<process::metrics::Gauge> resources_percent;

  // Revocable resources.
  std::vector<process::metrics::Gauge> resources_revocable_total;
  std::vector<process::metrics::Gauge> resources_revocable_used;
  std::vector<process::metrics::Gauge> resources_revocable_percent;

  void incrementTasksStates(
      const TaskState& state,
      const TaskStatus::Source& source,
      const TaskStatus::Reason& reason);
};

} // namespace master {
} // namespace internal {
} // namespace mesos {

#endif // __MASTER_METRICS_HPP__