Usage instrumentation + externalize chat session state to Postgres

agent/db.py

@@ -119,6 +119,37 @@ def _row(r: dict) -> dict:
     )
 """)
 
+# Append-only usage log for feature/command adoption reporting (see
+# scripts/usage_report.py) — deliberately no event payload beyond a
+# structural name/source, never message content or expense/income
+# descriptions, since this is financial household data.
+_run("""
+    CREATE TABLE IF NOT EXISTS usage_events (
+        id         SERIAL PRIMARY KEY,
+        user_id    INTEGER REFERENCES users(id),
+        event_type TEXT NOT NULL,
+        event_name TEXT NOT NULL,
+        source     TEXT,
+        created_at TIMESTAMPTZ DEFAULT NOW()
+    )
+""")
+
+_run("CREATE INDEX IF NOT EXISTS usage_events_name_idx ON usage_events (event_name)")
+
+# Chat session history, externalized from the in-process dict it used to
+# live in (agent/main.py's old _sessions) — that dict silently dropped every
+# in-progress conversation on every redeploy/restart, since nothing survived
+# process memory. One row per user; the whole message list is replaced on
+# every save rather than appended in SQL, since the caller always has the
+# full up-to-date list in hand already.
+_run("""
+    CREATE TABLE IF NOT EXISTS chat_sessions (
+        user_id    INTEGER PRIMARY KEY REFERENCES users(id),
+        messages   JSONB NOT NULL DEFAULT '[]',
+        updated_at TIMESTAMPTZ DEFAULT NOW()
+    )
+""")
+
 
 def get_user_by_username(username: str) -> dict | None:
     cur = _run("SELECT * FROM users WHERE username = %s", (username,))
@@ -898,3 +929,61 @@ def increment_api_call_count(user_id: int, date: str) -> None:
         """,
         (user_id, date),
     )
+
+
+def record_usage(user_id: int | None, event_type: str, event_name: str, source: str | None = None) -> None:
+    """Best-effort usage logging — never let a logging failure break the
+    actual request it's attached to (an edit/delete/tool-call succeeding
+    is what matters; the analytics record is secondary)."""
+    try:
+        _run(
+            "INSERT INTO usage_events (user_id, event_type, event_name, source) VALUES (%s, %s, %s, %s)",
+            (user_id, event_type, event_name, source),
+        )
+    except Exception:
+        pass
+
+
+def load_chat_session(user_id: int) -> list:
+    cur = _run("SELECT messages FROM chat_sessions WHERE user_id = %s", (user_id,))
+    row = cur.fetchone()
+    return row["messages"] if row else []
+
+
+def save_chat_session(user_id: int, messages: list) -> None:
+    _run(
+        """
+        INSERT INTO chat_sessions (user_id, messages, updated_at) VALUES (%s, %s, NOW())
+        ON CONFLICT (user_id) DO UPDATE SET messages = EXCLUDED.messages, updated_at = NOW()
+        """,
+        (user_id, psycopg2.extras.Json(messages)),
+    )
+
+
+def clear_chat_session(user_id: int) -> None:
+    _run("DELETE FROM chat_sessions WHERE user_id = %s", (user_id,))
+
+
+def get_usage_summary(since: str | None = None) -> list[dict]:
+    """Event counts grouped by type/name/source, for scripts/usage_report.py."""
+    if since:
+        cur = _run(
+            """
+            SELECT event_type, event_name, source, COUNT(*) AS count
+            FROM usage_events
+            WHERE created_at >= %s
+            GROUP BY event_type, event_name, source
+            ORDER BY count DESC
+            """,
+            (since,),
+        )
+    else:
+        cur = _run(
+            """
+            SELECT event_type, event_name, source, COUNT(*) AS count
+            FROM usage_events
+            GROUP BY event_type, event_name, source
+            ORDER BY count DESC
+            """
+        )
+    return [dict(r) for r in cur.fetchall()]