Add support for channel-specific filtering in subtitle search (#1096)

* Add channel filter support to subtitle search queries

* Update search examples to include channel filter option

---------

Co-authored-by: Dmitry Sprozin <dysprozin@gmail.com>

backend/common/src/searching.py

@@ -113,6 +113,7 @@ class SearchParser:
                 "index": "ta_subtitle",
                 "lang": [],
                 "source": [],
+                "channel": [],
             },
         }
 
@@ -345,6 +346,22 @@ class QueryBuilder:
         """build query for fulltext search"""
         must_list = []
 
+        if (channel := self.query_map.get("channel")) is not None:
+            must_list.append(
+                {
+                    "multi_match": {
+                        "query": channel,
+                        "type": "bool_prefix",
+                        "fuzziness": self._get_fuzzy(),
+                        "operator": "and",
+                        "fields": [
+                            "subtitle_channel",
+                            "subtitle_channel.keyword",
+                        ],
+                    }
+                }
+            )
+
         if (term := self.query_map.get("term")) is not None:
             must_list.append(
                 {

frontend/src/components/SearchExampleQueries.tsx

@@ -104,6 +104,10 @@ const SearchExampleQueries = () => {
                   auto-generated subtitles only, or <i>user</i> to search through user-uploaded
                   subtitles only
                 </li>
+                <li>
+                  <span>channel:</span> — limit subtitle search to a specific channel name (for
+                  example: <code>full:javascript channel:corey schafer</code>)
+                </li>
               </ul>
             </li>
           </ul>