[fix] matrixrooms add proper MRS integration

Related:

- https://github.com/searxng/searxng/issues/2918

searx/engines/mrs.py

@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# lint: pylint
+"""Matrix Rooms Search - a fully-featured, standalone, matrix rooms search service.
+
+Configuration
+=============
+
+The engine has the following mandatory settings:
+
+- :py:obj:`base_url`
+
+.. code:: yaml
+
+  - name: MRS
+    engine: mrs
+    base_url: https://mrs-host
+    ...
+
+Implementation
+==============
+"""
+
+from urllib.parse import quote_plus
+
+about = {
+    "website": 'https://matrixrooms.info',
+    "wikidata_id": None,
+    "official_api_documentation": 'https://gitlab.com/etke.cc/mrs/api/-/blob/main/openapi.yml?ref_type=heads',
+    "use_official_api": True,
+    "require_api_key": False,
+    "results": 'JSON',
+}
+paging = True
+categories = ['social media']
+
+base_url = ""
+matrix_url = "https://matrix.to"
+page_size = 20
+
+
+def init(engine_settings):  # pylint: disable=unused-argument
+    """The ``base_url`` must be set in the configuration, if ``base_url`` is not
+    set, a :py:obj:`ValueError` is raised during initialization.
+
+    """
+    if not base_url:
+        raise ValueError('engine MRS, base_url is unset')
+
+
+def request(query, params):
+    params['url'] = f"{base_url}/search/{quote_plus(query)}/{page_size}/{(params['pageno']-1)*page_size}"
+    return params
+
+
+def response(resp):
+    results = []
+
+    for result in resp.json():
+        results.append(
+            {
+                'url': matrix_url + '/#/' + result['alias'],
+                'title': result['name'],
+                'content': result['topic']
+                + f" // {result['members']} members"
+                + f" // {result['alias']}"
+                + f" // {result['server']}",
+                'thumbnail': result['avatar_url'],
+            }
+        )
+
+    return results