server/posts: add getting posts around id

Leave undocumented since it add almost no value for the client
applications.

1 files changed, 28 insertions, 0 deletions

diff --git a/server/szurubooru/search/executor.py b/server/szurubooru/search/executor.py
index c024d94..6df508a 100644
--- a/server/szurubooru/search/executor.py
+++ b/server/szurubooru/search/executor.py
@@ -27,6 +27,34 @@ class Executor(object):
         self.config = search_config
         self.parser = parser.Parser()
 
+    def get_around(self, query_text, entity_id):
+        search_query = self.parser.parse(query_text)
+        self.config.on_search_query_parsed(search_query)
+        filter_query = self.config \
+            .create_filter_query() \
+            .options(sqlalchemy.orm.lazyload('*'))
+        filter_query = self._prepare_db_query(filter_query, search_query, False)
+        prev_filter_query = filter_query \
+            .filter(self.config.id_column < entity_id) \
+            .order_by(None) \
+            .order_by(sqlalchemy.func.abs(self.config.id_column - entity_id).asc()) \
+            .limit(1)
+        next_filter_query = filter_query \
+            .filter(self.config.id_column > entity_id) \
+            .order_by(None) \
+            .order_by(sqlalchemy.func.abs(self.config.id_column - entity_id).asc()) \
+            .limit(1)
+        return [
+            next_filter_query.one_or_none(),
+            prev_filter_query.one_or_none()]
+
+    def get_around_and_serialize(self, ctx, entity_id, serializer):
+        entities = self.get_around(ctx.get_param_as_string('query'), entity_id)
+        return {
+            'next': serializer(entities[0]),
+            'prev': serializer(entities[1]),
+        }
+
     def execute(self, query_text, page, page_size):
         '''
         Parse input and return tuple containing total record count and filtered