Add probe_detect hook

doc/Addons.md

@@ -466,6 +466,19 @@ Hook data is a `\FastRoute\RouterCollector` object that should be used to add ad
 
 **Notice**: The class whose name is provided in the route handler must be reachable via auto-loader.
 
+### probe_detect
+
+Called before trying to detect the target network of a URL.
+If any registered hook function sets the `result` key of the hook data array, it will be returned immediately.
+Hook functions should also return immediately if the hook data contains an existing result. 
+
+Hook data:
+
+- **uri** (input): the profile URI.
+- **network** (input): the target network (can be empty for auto-detection).
+- **uid** (input): the user to return the contact data for (can be empty for public contacts).
+- **result** (output): Set by the hook function to indicate a successful detection.
+
 ## Complete list of hook callbacks
 
 Here is a complete list of all hook callbacks with file locations (as of 24-Sep-2018). Please see the source for details of any hooks not documented above.

src/Network/Probe.php

@@ -24,6 +24,7 @@ namespace Friendica\Network;
 use DOMDocument;
 use DomXPath;
 use Friendica\Core\Cache\Duration;
+use Friendica\Core\Hook;
 use Friendica\Core\Logger;
 use Friendica\Core\Protocol;
 use Friendica\Core\System;
@@ -617,6 +618,19 @@ class Probe
 	{
 		$parts = parse_url($uri);
 
+		$hookData = [
+			'uri'     => $uri,
+			'network' => $network,
+			'uid'     => $uid,
+			'result'  => [],
+		];
+
+		Hook::callAll('probe_detect', $hookData);
+
+		if ($hookData['result']) {
+			return $hookData['result'];
+		}
+
 		if (!empty($parts["scheme"]) && !empty($parts["host"])) {
 			$host = $parts["host"];
 			if (!empty($parts["port"])) {