Add ChhotoProxy class for URL shortening

lib/Proxy/ChhotoProxy.php

@@ -0,0 +1,92 @@
+<?php declare(strict_types=1);
+/**
+ * PrivateBin
+ *
+ * a zero-knowledge paste bin
+ *
+ * @link      https://github.com/PrivateBin/PrivateBin
+ * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
+ * @license   https://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
+ */
+
+namespace PrivateBin\Proxy;
+
+use JsonException;
+use PrivateBin\Configuration;
+use PrivateBin\Json;
+
+/**
+ * ChhotoProxy
+ *
+ * Forwards a URL for shortening to Chhoto URL (lix.sk) and stores the result.
+ */
+class ChhotoProxy extends AbstractProxy
+{
+    /**
+     * Overrides the abstract parent function to get the proxy URL.
+     *
+     * @param Configuration $conf
+     * @return string
+     */
+    protected function _getProxyUrl(Configuration $conf): string
+    {
+        return $conf->getKey('apiurl', 'chhoto');
+    }
+
+    /**
+     * Overrides the abstract parent function to get contents from Chhoto API.
+     *
+     * @access protected
+     * @param Configuration $conf
+     * @param string $link
+     * @return array
+     */
+    protected function _getProxyPayload(Configuration $conf, string $link): array
+    {
+        $apiKey = $conf->getKey('apikey', 'chhoto');
+
+        $body = [
+            'shortlink'    => '',          // empty = auto-generate
+            'longlink'     => $link,
+            'expiry_delay' => 0,           // 0 = never expire
+            'notes'        => 'PrivateBin paste',
+        ];
+
+        try {
+            return [
+                'method'  => 'POST',
+                'header'  => "Content-Type: application/json\r\n" .
+                             'X-API-Key: ' . $apiKey . "\r\n" .
+                             "Accept: application/json\r\n",
+                'content' => Json::encode($body),
+            ];
+        } catch (JsonException $e) {
+            error_log('[' . get_class($this) . '] Error encoding body: ' . $e->getMessage());
+            return [];
+        }
+    }
+
+    /**
+     * Extracts the short URL from the Chhoto API response.
+     *
+     * @access protected
+     * @param array $data
+     * @return ?string
+     */
+    protected function _extractShortUrl(array $data): ?string
+    {
+        // Chhoto usually returns "shorturl"
+        if (!empty($data['shorturl'])) {
+            return $data['shorturl'];
+        }
+
+        // Fallback for older versions that return only the slug
+        if (!empty($data['shortlink'])) {
+            $apiUrl = $this->_getProxyUrl(new Configuration()); // not ideal, but works
+            // Better: hardcode or get base from config
+            return 'https://lix.sk/' . ltrim($data['shortlink'], '/');
+        }
+
+        return null;
+    }
+}