From 26624bed95aaa29dcea00095e167f3d9ec0a129e Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Tue, 27 Dec 2022 20:36:58 +0100
Subject: [PATCH] -purse deletion SQL logic

---
 src/exchangedb/exchange_do_delete_purse.sql | 109 ++++++++++++++++++++
 src/exchangedb/procedures.sql.in            |   1 +
 2 files changed, 110 insertions(+)
 create mode 100644 src/exchangedb/exchange_do_delete_purse.sql

diff --git a/src/exchangedb/exchange_do_delete_purse.sql b/src/exchangedb/exchange_do_delete_purse.sql
new file mode 100644
index 000000000..3d493e624
--- /dev/null
+++ b/src/exchangedb/exchange_do_delete_purse.sql
@@ -0,0 +1,109 @@
+--
+-- This file is part of TALER
+-- Copyright (C) 2014--2022 Taler Systems SA
+--
+-- TALER is free software; you can redistribute it and/or modify it under the
+-- terms of the GNU General Public License as published by the Free Software
+-- Foundation; either version 3, or (at your option) any later version.
+--
+-- TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+-- WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+-- A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License along with
+-- TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+--
+
+CREATE OR REPLACE FUNCTION exchange_do_delete_purse(
+  IN in_purse_pub BYTEA,
+  IN in_purse_sig BYTEA,
+  IN in_now INT8,
+  OUT out_decided BOOLEAN,
+  OUT out_found BOOLEAN)
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  my_deposit record;
+DECLARE
+  my_in_reserve_quota BOOLEAN;
+BEGIN
+
+SELECT COUNT(*) FROM purse_decision
+  WHERE purse_pub=in_purse_pub;
+IF FOUND
+THEN
+  out_found=TRUE;
+  out_decided=TRUE;
+  RETURN;
+END IF;
+out_decided=FALSE;
+
+SELECT in_reserve_quota
+  INTO my_in_reserve_quota
+  FROM exchange.purse_requests
+ WHERE purse_pub=in_purse_pub;
+out_found=FOUND;
+IF NOT FOUND
+THEN
+  RETURN;
+END IF;
+
+-- store reserve deletion
+INSERT INTO purse_deletion
+  (purse_pub
+  ,purse_sig)
+VALUES
+  (in_purse_pub
+  ,in_purse_sig);
+
+-- store purse decision
+INSERT INTO purse_decision
+  (purse_pub
+  ,action_timestamp
+  ,refunded)
+VALUES
+  (in_purse_pub
+  ,in_now
+  ,TRUE);
+
+-- update purse quota at reserve
+IF (my_in_reserve_quota)
+THEN
+  UPDATE reserves
+    SET purses_active=purses_active-1
+  WHERE reserve_pub IN
+    (SELECT reserve_pub
+       FROM exchange.purse_merges
+      WHERE purse_pub=in_purse_pub
+     LIMIT 1);
+END IF;
+
+-- restore balance to each coin deposited into the purse
+FOR my_deposit IN
+  SELECT coin_pub
+        ,amount_with_fee_val
+        ,amount_with_fee_frac
+    FROM exchange.purse_deposits
+  WHERE purse_pub = in_purse_pub
+LOOP
+  UPDATE exchange.known_coins SET
+    remaining_frac=remaining_frac+my_deposit.amount_with_fee_frac
+     - CASE
+       WHEN remaining_frac+my_deposit.amount_with_fee_frac >= 100000000
+       THEN 100000000
+       ELSE 0
+       END,
+    remaining_val=remaining_val+my_deposit.amount_with_fee_val
+     + CASE
+       WHEN remaining_frac+my_deposit.amount_with_fee_frac >= 100000000
+       THEN 1
+       ELSE 0
+       END
+    WHERE coin_pub = my_deposit.coin_pub;
+END LOOP;
+
+
+END $$;
+
+COMMENT ON FUNCTION exchange_do_delete_purse(BYTEA,BYTEA,INT8)
+  IS 'Delete a previously undecided purse and refund the coins (if any).';
diff --git a/src/exchangedb/procedures.sql.in b/src/exchangedb/procedures.sql.in
index b775639bf..fb12fbae5 100644
--- a/src/exchangedb/procedures.sql.in
+++ b/src/exchangedb/procedures.sql.in
@@ -31,6 +31,7 @@ SET search_path TO exchange;
 #include "exchange_do_purse_deposit.sql"
 #include "exchange_do_reserve_purse.sql"
 #include "exchange_do_expire_purse.sql"
+#include "exchange_do_delete_purse.sql"
 #include "exchange_do_history_request.sql"
 #include "exchange_do_reserve_open_deposit.sql"
 #include "exchange_do_reserve_open.sql"