<?php

namespace Superbalist\LaravelPrometheusExporter;

use Prometheus\Gauge;

class ExampleCollector implements CollectorInterface
{
    /**
     * @var Gauge
     */
    protected $usersRegisteredGauge;

    /**
     * Return the name of the collector.
     *
     * @return string
     */
    public function getName()
    {
        return 'users';
    }

    /**
     * Register all metrics associated with the collector.
     *
     * The metrics needs to be registered on the exporter object.
     * eg:
     * ```php
     * $exporter->registerCounter('search_requests_total', 'The total number of search requests.');
     * ```
     *
     * @param PrometheusExporter $exporter
     */
    public function registerMetrics(PrometheusExporter $exporter)
    {
        $this->usersRegisteredGauge = $exporter->registerGauge(
            'users_registered_total',
            'The total number of registered users.',
            ['group']
        );
    }

    /**
     * Collect metrics data, if need be, before exporting.
     *
     * As an example, this may be used to perform time consuming database queries and set the value of a counter
     * or gauge.
     */
    public function collect()
    {
        // retrieve the total number of staff users registered
        // eg: $totalUsers = Users::where('group', 'staff')->count();
        $this->usersRegisteredGauge->set(36, ['staff']);

        // retrieve the total number of regular users registered
        // eg: $totalUsers = Users::where('group', 'regular')->count();
        $this->usersRegisteredGauge->set(192, ['regular']);
    }
}