/*
 * Copyright 2019 IBM All Rights Reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
package org.hyperledger.fabric.metrics.impl;

import java.util.Properties;
import java.util.Timer;
import java.util.TimerTask;
import java.util.logging.Logger;

import org.hyperledger.fabric.Logging;
import org.hyperledger.fabric.metrics.MetricsProvider;
import org.hyperledger.fabric.metrics.TaskMetricsCollector;

/**
 * Simple default provider that logs to the org.hyperledger.Performance logger
 * the basic metrics.
 *
 */
public final class DefaultProvider implements MetricsProvider {
    private static Logger perflogger = Logger.getLogger(Logging.PERFLOGGER);

    private TaskMetricsCollector taskService;

    /**
     *
     */
    public DefaultProvider() {
        perflogger.info("Default Metrics Provider started");
    }

    @Override
    public void setTaskMetricsCollector(final TaskMetricsCollector taskService) {
        this.taskService = taskService;
    }

    private static final int TIME_INTERVAL = 5000;

    @Override
    public void initialize(final Properties props) {
        final Timer metricTimer = new Timer(true);
        metricTimer.scheduleAtFixedRate(new TimerTask() {
            @Override
            public void run() {
                DefaultProvider.this.logMetrics();
            }
        }, 0, TIME_INTERVAL);

    }

    protected void logMetrics() {

        perflogger.info(() -> {
            if (DefaultProvider.this.taskService == null) {
                return "No Metrics Provider service yet";
            }
            final StringBuilder sb = new StringBuilder();
            sb.append('{');
            sb.append(String.format(" \"active_count\":%d ", DefaultProvider.this.taskService.getActiveCount())).append(',');
            sb.append(String.format(" \"pool_size\":%d ", DefaultProvider.this.taskService.getPoolSize())).append(',');
            sb.append(String.format(" \"core_pool_size\":%d ", DefaultProvider.this.taskService.getCorePoolSize())).append(',');
            sb.append(String.format(" \"current_task_count\":%d ", DefaultProvider.this.taskService.getCurrentTaskCount())).append(',');
            sb.append(String.format(" \"current_queue_depth\":%d ", DefaultProvider.this.taskService.getCurrentQueueCount()));
            return sb.append('}').toString();
        });

    }

}
