package io.dropwizard.metrics;

import com.codahale.metrics.MetricRegistry;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.MoreObjects;
import com.google.common.collect.ImmutableList;
import io.dropwizard.lifecycle.setup.LifecycleEnvironment;
import io.dropwizard.util.Duration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.validation.Valid;
import javax.validation.constraints.NotNull;

A factory for configuring the metrics sub-system for the environment.
 Configures an optional list of reporters with a default frequency. 

Configuration Parameters:

    

        
Name
        
Default
        
Description
    
    

        
frequency
        
1 minute
        
The frequency to report metrics. Overridable per-reporter.
    
    

        
reporters
        
No reporters.
        
A list of reporters to report metrics.
    

/**
 * A factory for configuring the metrics sub-system for the environment.
 * <p/>
 * Configures an optional list of {@link com.codahale.metrics.ScheduledReporter reporters} with a
 * default {@link #frequency}.
 * <p/>
 * <b>Configuration Parameters:</b>
 * <table>
 *     <tr>
 *         <td>Name</td>
 *         <td>Default</td>
 *         <td>Description</td>
 *     </tr>
 *     <tr>
 *         <td>frequency</td>
 *         <td>1 minute</td>
 *         <td>The frequency to report metrics. Overridable per-reporter.</td>
 *     </tr>
 *     <tr>
 *         <td>reporters</td>
 *         <td>No reporters.</td>
 *         <td>A list of {@link ReporterFactory reporters} to report metrics.</td>
 *     </tr>
 * </table>
 */
public class MetricsFactory {
    private static final Logger LOGGER = LoggerFactory.getLogger(MetricsFactory.class);

    @Valid
    @NotNull
    private Duration frequency = Duration.minutes(1);

    @Valid
    @NotNull
    private ImmutableList<ReporterFactory> reporters = ImmutableList.of();

    @JsonProperty
    public ImmutableList<ReporterFactory> getReporters() {
        return reporters;
    }

    @JsonProperty
    public void setReporters(ImmutableList<ReporterFactory> reporters) {
        this.reporters = reporters;
    }

    @JsonProperty
    public Duration getFrequency() {
        return frequency;
    }

    @JsonProperty
    public void setFrequency(Duration frequency) {
        this.frequency = frequency;
    }

    
Configures the given lifecycle with the 
reporters configured for the given registry. 
 The reporters are tied in to the given lifecycle, such that their 
frequency for reporting metrics begins when the lifecycle starts, and stops when the lifecycle stops. 
Params:
environment – the lifecycle to manage the reporters.
registry – the metric registry to report metrics from./**
     * Configures the given lifecycle with the {@link com.codahale.metrics.ScheduledReporter
     * reporters} configured for the given registry.
     * <p />
     * The reporters are tied in to the given lifecycle, such that their {@link #getFrequency()
     * frequency} for reporting metrics begins when the lifecycle {@link
     * io.dropwizard.lifecycle.Managed#start() starts}, and stops when the lifecycle
     * {@link io.dropwizard.lifecycle.Managed#stop() stops}.
     *
     * @param environment the lifecycle to manage the reporters.
     * @param registry the metric registry to report metrics from.
     */
    public void configure(LifecycleEnvironment environment, MetricRegistry registry) {
        for (ReporterFactory reporter : reporters) {
            try {
                final ScheduledReporterManager manager =
                        new ScheduledReporterManager(reporter.build(registry),
                                                     reporter.getFrequency().orElseGet(this::getFrequency));
                environment.manage(manager);
            } catch (Exception e) {
                LOGGER.warn("Failed to create reporter, metrics may not be properly reported.", e);
            }
        }
    }

    @Override
    public String toString() {
        return MoreObjects.toStringHelper(this)
                .add("frequency", frequency)
                .add("reporters", reporters)
                .toString();
    }
}