<?php
/**
 * Nextcloud - moodle
 *
 * This file is licensed under the Affero General Public License version 3 or
 * later. See the COPYING file.
 *
 * @author Julien Veyssier
 * @copyright Julien Veyssier 2020
 */

namespace OCA\Moodle\Service;

use OCP\IL10N;
use OCP\ILogger;
use OCP\Http\Client\IClientService;

use OCA\Moodle\AppInfo\Application;

class MoodleAPIService {

    private $l10n;
    private $logger;

    /**
     * Service to make requests to Moodle v1 API
     */
    public function __construct (
        string $appName,
        ILogger $logger,
        IL10N $l10n,
        IClientService $clientService
    ) {
        $this->appName = $appName;
        $this->l10n = $l10n;
        $this->logger = $logger;
        $this->clientService = $clientService;
        $this->client = $clientService->newClient();
    }

    public function getNotifications(string $url, string $accessToken, ?int $since): array {
        $params = [
            'wstoken' => $accessToken,
            'wsfunction' => 'block_recentlyaccesseditems_get_recent_items',
            'moodlewsrestformat' => 'json',
        ];
        $recentItems = $this->request($url, 'webservice/rest/server.php', $params);

        if (isset($recentItems['error'])) {
            return $recentItems;
        }
        $courseIds = [];
        foreach ($recentItems as $recentItem) {
            if (isset($recentItem['courseid']) && !in_array($recentItem['courseid'], $courseIds)) {
                array_push($courseIds, $recentItem['courseid']);
            }
        }

        //$upcomingEvents = [];
        //foreach ($courseIds as $courseId) {
        //    $params['wsfunction'] = 'core_calendar_get_calendar_upcoming_view';
        //    $params['courseid'] = $courseId;
        //    $upcomingEvents = array_merge($upcomingEvents, $this->request($url, 'webservice/rest/server.php', $params));
        //}

        $results = $recentItems;

        // filter by date
        if (!is_null($since)) {
            $results = array_filter($results, function($elem) use ($since) {
                $ts = intval($elem['timeaccess']);
                return $ts > $since;
            });
        }

        // sort results by date
        $a = usort($results, function($a, $b) {
            $ta = $a['timeaccess'];
            $tb = $b['timeaccess'];
            return ($ta > $tb) ? -1 : 1;
        });

        return $results;
    }

    public function getMoodleAvatar($url) {
        return $this->client->get($url)->getBody();
    }

    public function request(string $url, string $endPoint, array $params = [], string $method = 'GET'): array {
        try {
            $url = $url . '/' . $endPoint;
            $options = [
                'headers' => [
                    'User-Agent' => 'Nextcloud Moodle integration',
                ]
            ];

            if (count($params) > 0) {
                if ($method === 'GET') {
                    // manage array parameters
                    $paramsContent = '';
                    foreach ($params as $key => $value) {
                        if (is_array($value)) {
                            foreach ($value as $oneArrayValue) {
                                $paramsContent .= $key . '[]=' . urlencode($oneArrayValue) . '&';
                            }
                            unset($params[$key]);
                        }
                    }
                    $paramsContent .= http_build_query($params);
                    $url .= '?' . $paramsContent;
                } else {
                    $options['body'] = $params;
                }
            }

            if ($method === 'GET') {
                $response = $this->client->get($url, $options);
            } else if ($method === 'POST') {
                $response = $this->client->post($url, $options);
            } else if ($method === 'PUT') {
                $response = $this->client->put($url, $options);
            } else if ($method === 'DELETE') {
                $response = $this->client->delete($url, $options);
            }
            $body = $response->getBody();
            $respCode = $response->getStatusCode();

            if ($respCode >= 400) {
                return ['error' => $this->l10n->t('Bad credentials')];
            } else {
                return json_decode($body, true);
            }
        } catch (\Exception $e) {
            $this->logger->warning('Moodle API error : '.$e, array('app' => $this->appName));
            return ['error' => $e->getMessage()];
        }
    }

    public function getToken(string $moodleUrl, string $login, string $password): array {
        $params = [
            'username' => $login,
            'password' => $password,
            'service' => 'moodle_mobile_app',
        ];
        return $this->request($moodleUrl, 'login/token.php', $params, 'POST');
    }
}