Initial commit from monorepo

geo_app/arango_client.py

@@ -0,0 +1,49 @@
+"""ArangoDB client singleton."""
+import logging
+from arango import ArangoClient
+from django.conf import settings
+
+logger = logging.getLogger(__name__)
+
+_db = None
+
+
+def get_db():
+    """Get ArangoDB database connection (singleton)."""
+    global _db
+    if _db is None:
+        hosts = settings.ARANGODB_INTERNAL_URL
+        if not hosts.startswith("http"):
+            hosts = f"http://{hosts}"
+
+        client = ArangoClient(hosts=hosts)
+        _db = client.db(
+            settings.ARANGODB_DATABASE,
+            username='root',
+            password=settings.ARANGODB_PASSWORD,
+        )
+        logger.info(
+            "Connected to ArangoDB: %s/%s",
+            hosts,
+            settings.ARANGODB_DATABASE,
+        )
+    return _db
+
+
+def ensure_graph():
+    """Ensure named graph exists for K_SHORTEST_PATHS queries."""
+    db = get_db()
+    graph_name = 'optovia_graph'
+
+    if db.has_graph(graph_name):
+        return db.graph(graph_name)
+
+    logger.info("Creating graph: %s", graph_name)
+    return db.create_graph(
+        graph_name,
+        edge_definitions=[{
+            'edge_collection': 'edges',
+            'from_vertex_collections': ['nodes'],
+            'to_vertex_collections': ['nodes'],
+        }],
+    )