Create graphdb.py

genesis/graphdb.py

@@ -0,0 +1,81 @@
+# genesis/graphdb.py
+from __future__ import annotations
+
+import os
+from typing import Dict, List
+
+from neo4j import GraphDatabase
+
+NEO4J_URI = os.getenv("NEO4J_URI")
+NEO4J_USER = os.getenv("NEO4J_USER")
+NEO4J_PASSWORD = os.getenv("NEO4J_PASSWORD")
+
+
+def _require_config():
+    if not (NEO4J_URI and NEO4J_USER and NEO4J_PASSWORD):
+        raise RuntimeError(
+            "Neo4j not configured. Set NEO4J_URI, NEO4J_USER, NEO4J_PASSWORD in Space Secrets."
+        )
+
+
+async def write_topic_and_papers(topic: str, citations: List[Dict[str, str]]) -> Dict[str, int]:
+    """
+    Create/merge a Topic node and Paper nodes, and connect them with MENTIONS edges.
+    Schema:
+      (t:Topic {id})-[:MENTIONS]->(p:Paper {url})  with p.title set/updated.
+    Returns: {"nodes": <int>, "rels": <int>}
+    """
+    _require_config()
+    driver = GraphDatabase.driver(NEO4J_URI, auth=(NEO4J_USER, NEO4J_PASSWORD))
+
+    nodes = 0
+    rels = 0
+    try:
+        with driver.session() as sess:
+            # Topic
+            sess.run(
+                "MERGE (t:Topic {id:$id}) SET t.title=$title",
+                id=(topic or "Topic")[:200],
+                title=(topic or "Topic")[:500],
+            )
+            nodes += 1
+
+            # Papers + edges
+            for c in citations or []:
+                title = (c.get("title") or "citation")[:500]
+                url = (c.get("url") or "")[:1000]
+                if not url and not title:
+                    continue
+
+                sess.run(
+                    """
+                    MERGE (p:Paper {url:$url})
+                    ON CREATE SET p.title=$title
+                    ON MATCH SET  p.title = coalesce(p.title, $title)
+                    WITH p
+                    MATCH (t:Topic {id:$topic})
+                    MERGE (t)-[:MENTIONS]->(p)
+                    """,
+                    url=url,
+                    title=title,
+                    topic=(topic or "Topic")[:200],
+                )
+                nodes += 1
+                rels += 1
+
+        return {"nodes": nodes, "rels": rels}
+    finally:
+        driver.close()
+
+
+# Optional helper for debugging connectivity in a notebook/Space shell
+def verify_connection() -> str:
+    _require_config()
+    driver = GraphDatabase.driver(NEO4J_URI, auth=(NEO4J_USER, NEO4J_PASSWORD))
+    try:
+        with driver.session() as sess:
+            res = sess.run("RETURN 1 AS ok").single()
+            assert res and res["ok"] == 1
+        return "Neo4j connection OK."
+    finally:
+        driver.close()