<?php /** @noinspection PhpUndefinedClassInspection */

use Facebook\Exceptions\FacebookThrottleException;
use Facebook\Facebook as FacebookSDK;

/**
 * @return FacebookSDK
 */
function facebook()
{
    /** @noinspection PhpUndefinedClassInspection */
    return new FacebookSDK([
        'app_id' => MKBH_FACEBOOK_APP_ID,
        'app_secret' => MKBH_FACEBOOK_APP_SECRET,
        'default_graph_version' => 'v3.0',
        'default_access_token' => MKBH_FACEBOOK_APP_STATIC_ACCESS_TOKEN
    ]);
}

/**
 * Instantiate, run API request and return decoded body.
 *
 * @param $method
 * @param $endpoint
 * @param array $params
 * @param null $accessToken
 * @param null $eTag
 * @param null $graphVersion
 * @return array|null
 */
function facebookRequestSend($method, $endpoint, array $params = [], $accessToken = null, $eTag = null, $graphVersion = null)
{
    try {
        $response = facebook()->sendRequest($method, $endpoint, $params, $accessToken, $eTag, $graphVersion);

        if ($response instanceof \Facebook\FacebookResponse && !$response->isError()) {
            $appUsage = json_decode(
                $response->getHeaders()['x-app-usage']
            );

            $maxMetric = max(
                $appUsage->call_count,
                $appUsage->total_cputime,
                $appUsage->total_time
            );

            if ($maxMetric >= 75) {
                throw new FacebookThrottleException;
            }

            return $response->getDecodedBody();
        } else {
            throw $response->getThrownException();
        }
    } catch (FacebookThrottleException $e) {
        watchdog('facebookSDK', "Facebook API request [{$method} {$endpoint}] has been throttled!", [], WATCHDOG_ERROR);
        return NULL;
    } catch (\Exception $e) {
        watchdog('facebookSDK', $e->getMessage() . ' in ' . $e->getFile() . ' at ' . $e->getLine() . 'line', [], WATCHDOG_ERROR);
        return NULL;
    }
}