<?php

namespace Superbalist\LaravelPrometheusExporter;

use Illuminate\Support\Arr;
use Illuminate\Support\ServiceProvider;
use Illuminate\Support\Arr;
use Prometheus\CollectorRegistry;
use Prometheus\Storage\Adapter;

class PrometheusServiceProvider extends ServiceProvider
{
    /**
     * Perform post-registration booting of services.
     */
    public function boot()
    {
        $this->publishes([
            __DIR__ . '/../config/prometheus.php' => config_path('prometheus.php'),
        ]);

        if (config('prometheus.metrics_route_enabled')) {
            $this->loadRoutesFrom(__DIR__ . '/routes.php');
        }

        $exporter = $this->app->make(PrometheusExporter::class); /* @var PrometheusExporter $exporter */
        foreach (config('prometheus.collectors') as $class) {
            $collector = $this->app->make($class);
            $exporter->registerCollector($collector);
        }
    }

    /**
     * Register bindings in the container.
     */
    public function register()
    {
        $this->mergeConfigFrom(__DIR__ . '/../config/prometheus.php', 'prometheus');

        $this->app->singleton(PrometheusExporter::class, function ($app) {
            $adapter = $app['prometheus.storage_adapter'];
            $prometheus = new CollectorRegistry($adapter);
            return new PrometheusExporter(config('prometheus.namespace'), $prometheus);
        });
        $this->app->alias(PrometheusExporter::class, 'prometheus');

        $this->app->bind('prometheus.storage_adapter_factory', function () {
            return new StorageAdapterFactory();
        });

        $this->app->bind(Adapter::class, function ($app) {
            $factory = $app['prometheus.storage_adapter_factory']; /** @var StorageAdapterFactory $factory */
            $driver = config('prometheus.storage_adapter');
            $configs = config('prometheus.storage_adapters');
            $config = Arr::get($configs, $driver, []);
            return $factory->make($driver, $config);
        });
        $this->app->alias(Adapter::class, 'prometheus.storage_adapter');
    }

    /**
     * Get the services provided by the provider.
     *
     * @return array
     */
    public function provides()
    {
        return [
            'prometheus',
            'prometheus.storage_adapter_factory',
            'prometheus.storage_adapter',
        ];
    }

    /**
     * https://medium.com/@koenhoeijmakers/properly-merging-configs-in-laravel-packages-a4209701746d
     * :heart:
     *
     * Merge the given configuration with the existing configuration.
     *
     * @param  string  $path
     * @param  string  $key
     * @return void
     */
    protected function mergeConfigFrom($path, $key)
    {
        $config = $this->app['config']->get($key, []);
        $this->app['config']->set($key, $this->mergeConfig(require $path, $config));
    }
    /**
     * Merges the configs together and takes multi-dimensional arrays into account.
     *
     * @param  array  $original
     * @param  array  $merging
     * @return array
     */
    protected function mergeConfig(array $original, array $merging)
    {
        $array = array_merge($original, $merging);
        foreach ($original as $key => $value) {
            if (! is_array($value)) {
                continue;
            }
            if (! Arr::exists($merging, $key)) {
                continue;
            }
            if (is_numeric($key)) {
                continue;
            }
            $array[$key] = $this->mergeConfig($value, $merging[$key]);
        }
        return $array;
    }
}