1<?php
2
3namespace dokuwiki\plugin\doi\Resolver;
4
5use dokuwiki\HTTP\DokuHTTPClient;
6
7/**
8 * ISBN resolver using the Open Library API
9 */
10class IsbnOpenLibraryResolver extends AbstractIsbnResolver
11{
12    /** @inheritdoc */
13    public function getData($id)
14    {
15        $message = $this->fetchCachedData($id);
16        $result = $this->defaultResult;
17
18        $result['url'] = $message['info_url'];
19        $message = $message['details'];
20
21        $result['id'] = $message['isbn_13'][0] ?? $message['isbn_10'][0] ?? '';
22        $result['title'] = $message['full_title'] ?? $message['title'] ?? $id;
23        if(empty($result['title'])) $result['title'] = $id;
24
25        $result['authors'] = array_map(function ($author) {
26            return $author['name'];
27        }, $message['authors'] ?? []);
28
29        $published = $message['publish_date'] ?? '';
30        if (preg_match('/\b(\d{4})\b/', $published, $m)) {
31            $result['published'] = $m[1];
32        }
33        $result['publisher'] = $message['publishers'][0] ?? '';
34
35        return $result;
36    }
37
38    /** @inheritdoc */
39    protected function fetchData($id)
40    {
41        $http = new DokuHTTPClient();
42        $json = $http->get('https://openlibrary.org/api/books?jscmd=details&format=json&bibkeys=ISBN:' . $id);
43        if (!$json) throw new \Exception('Could not fetch data from Open Library. ' . $http->error);
44        $data = json_decode($json, true);
45        if (!count($data)) throw new \Exception('No ISBN results found at Open Library.');
46        return array_shift($data); // first entry
47    }
48}
49