From a86a650e25c3728ed641d084a9027859c0947c81 Mon Sep 17 00:00:00 2001
From: Stephen Paul Weber <singpolyma@singpolyma.net>
Date: Tue, 25 Jan 2022 16:42:37 -0500
Subject: [PATCH] Allow check_and_notify_low_balance to be called outside of
 trigger

For use from, eg, jmp-pay
---
 deploy/notify_low_balance.sql | 16 ++++++++++++----
 revert/notify_low_balance.sql |  1 +
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/deploy/notify_low_balance.sql b/deploy/notify_low_balance.sql
index c80e6e9..e18905c 100644
--- a/deploy/notify_low_balance.sql
+++ b/deploy/notify_low_balance.sql
@@ -4,14 +4,22 @@
 
 BEGIN;
 
-CREATE OR REPLACE FUNCTION check_and_notify_low_balance() RETURNS TRIGGER AS $$
+CREATE OR REPLACE FUNCTION check_and_notify_low_balance(
+	customerid TEXT
+) RETURNS VOID AS $$
 	DECLARE
 		bal NUMERIC;
 	BEGIN
-		SELECT balance INTO bal FROM balances WHERE customer_id = NEW.customer_id;
+		SELECT balance INTO bal FROM balances WHERE customer_id = customerid;
 		IF bal < 5 THEN
-			SELECT pg_notify('low_balance', NEW.customer_id);
+			PERFORM pg_notify('low_balance', customerid);
 		END IF;
+	END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION check_and_notify_low_balance_trigger() RETURNS TRIGGER AS $$
+	BEGIN
+		PERFORM check_and_notify_low_balance(NEW.customer_id);
 		RETURN NEW;
 	END;
 $$ LANGUAGE plpgsql;
@@ -20,6 +28,6 @@ CREATE TRIGGER notify_low_balance
 	AFTER INSERT ON transactions
 	FOR EACH ROW
 	WHEN (NEW.amount < 0)
-	EXECUTE PROCEDURE check_and_notify_low_balance();
+	EXECUTE PROCEDURE check_and_notify_low_balance_trigger();
 
 COMMIT;
diff --git a/revert/notify_low_balance.sql b/revert/notify_low_balance.sql
index 2c6e2c0..056b0af 100644
--- a/revert/notify_low_balance.sql
+++ b/revert/notify_low_balance.sql
@@ -3,6 +3,7 @@
 BEGIN;
 
 DROP TRIGGER notify_low_balance ON transactions;
+DROP FUNCTION IF EXISTS check_and_notify_low_balance_trigger;
 DROP FUNCTION check_and_notify_low_balance;
 
 COMMIT;
-- 
2.38.5