1 files changed, 194 insertions, 0 deletions
diff --git a/src/exchangedb/exchange_do_reserve_open.sql b/src/exchangedb/exchange_do_reserve_open.sql
new file mode 100644
index 000000000..dd7a578ee
--- /dev/null
+++ b/src/exchangedb/exchange_do_reserve_open.sql
@@ -0,0 +1,194 @@
+--
+-- 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_reserve_open(
+  IN in_reserve_pub BYTEA,
+  IN in_total_paid taler_amount,
+  IN in_reserve_payment taler_amount,
+  IN in_min_purse_limit INT4,
+  IN in_default_purse_limit INT4,
+  IN in_reserve_sig BYTEA,
+  IN in_desired_expiration INT8,
+  IN in_reserve_gc_delay INT8,
+  IN in_now INT8,
+  IN in_open_fee taler_amount,
+  OUT out_open_cost taler_amount,
+  OUT out_final_expiration INT8,
+  OUT out_no_reserve BOOLEAN,
+  OUT out_no_funds BOOLEAN,
+  OUT out_reserve_balance taler_amount)
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  my_balance taler_amount;
+  my_cost taler_amount;
+  my_cost_tmp INT8;
+  my_years_tmp INT4;
+  my_years INT4;
+  my_needs_update BOOL;
+  my_expiration_date INT8;
+  reserve RECORD;
+BEGIN
+
+SELECT current_balance
+      ,expiration_date
+      ,purses_allowed
+  INTO reserve
+  FROM reserves
+ WHERE reserve_pub=in_reserve_pub;
+
+IF NOT FOUND
+THEN
+  RAISE NOTICE 'reserve not found';
+  out_no_reserve = TRUE;
+  out_no_funds = TRUE;
+  out_reserve_balance.val = 0;
+  out_reserve_balance.frac = 0;
+  out_open_cost.val = 0;
+  out_open_cost.frac = 0;
+  out_final_expiration = 0;
+  RETURN;
+END IF;
+
+out_no_reserve = FALSE;
+out_reserve_balance = reserve.current_balance;
+
+-- Do not allow expiration time to start in the past already
+IF (reserve.expiration_date < in_now)
+THEN
+  my_expiration_date = in_now;
+ELSE
+  my_expiration_date = reserve.expiration_date;
+END IF;
+
+my_cost.val = 0;
+my_cost.frac = 0;
+my_needs_update = FALSE;
+my_years = 0;
+
+-- Compute years based on desired expiration time
+IF (my_expiration_date < in_desired_expiration)
+THEN
+  my_years = (31535999999999 + in_desired_expiration - my_expiration_date) / 31536000000000;
+  reserve.purses_allowed = in_default_purse_limit;
+  my_expiration_date = my_expiration_date + 31536000000000 * my_years;
+END IF;
+
+-- Increase years based on purses requested
+IF (reserve.purses_allowed < in_min_purse_limit)
+THEN
+  my_years = (31535999999999 + in_desired_expiration - in_now) / 31536000000000;
+  my_expiration_date = in_now + 31536000000000 * my_years;
+  my_years_tmp = (in_min_purse_limit + in_default_purse_limit - reserve.purses_allowed - 1) / in_default_purse_limit;
+  my_years = my_years + my_years_tmp;
+  reserve.purses_allowed = reserve.purses_allowed + (in_default_purse_limit * my_years_tmp);
+END IF;
+
+
+-- Compute cost based on annual fees
+IF (my_years > 0)
+THEN
+  my_cost.val = my_years * in_open_fee.val;
+  my_cost_tmp = my_years * in_open_fee.frac / 100000000;
+  IF (CAST (my_cost.val + my_cost_tmp AS INT8) < my_cost.val)
+  THEN
+    out_open_cost.val=9223372036854775807;
+    out_open_cost.frac=2147483647;
+    out_final_expiration=my_expiration_date;
+    out_no_funds=FALSE;
+    RAISE NOTICE 'arithmetic issue computing amount';
+  RETURN;
+  END IF;
+  my_cost.val = CAST (my_cost.val + my_cost_tmp AS INT8);
+  my_cost.frac = my_years * in_open_fee.frac % 100000000;
+  my_needs_update = TRUE;
+END IF;
+
+-- check if we actually have something to do
+IF NOT my_needs_update
+THEN
+  out_final_expiration = reserve.expiration_date;
+  out_open_cost.val = 0;
+  out_open_cost.frac = 0;
+  out_no_funds=FALSE;
+  RAISE NOTICE 'no change required';
+  RETURN;
+END IF;
+
+-- Check payment (coins and reserve) would be sufficient.
+IF ( (in_total_paid.val < my_cost.val) OR
+     ( (in_total_paid.val = my_cost.val) AND
+       (in_total_paid.frac < my_cost.frac) ) )
+THEN
+  out_open_cost.val = my_cost.val;
+  out_open_cost.frac = my_cost.frac;
+  out_no_funds=FALSE;
+  -- We must return a failure, which is indicated by
+  -- the expiration being below the desired expiration.
+  IF (reserve.expiration_date >= in_desired_expiration)
+  THEN
+    -- This case is relevant especially if the purse
+    -- count was to be increased and the payment was
+    -- insufficient to cover this for the full period.
+    RAISE NOTICE 'forcing low expiration time';
+    out_final_expiration = 0;
+  ELSE
+    out_final_expiration = reserve.expiration_date;
+  END IF;
+  RAISE NOTICE 'amount paid too low';
+  RETURN;
+END IF;
+
+-- Check reserve balance is sufficient.
+IF (out_reserve_balance.val > in_reserve_payment.val)
+THEN
+  IF (out_reserve_balance.frac >= in_reserve_payment.frac)
+  THEN
+    my_balance.val=out_reserve_balance.val - in_reserve_payment.val;
+    my_balance.frac=out_reserve_balance.frac - in_reserve_payment.frac;
+  ELSE
+    my_balance.val=out_reserve_balance.val - in_reserve_payment.val - 1;
+    my_balance.frac=out_reserve_balance.frac + 100000000 - in_reserve_payment.frac;
+  END IF;
+ELSE
+  IF (out_reserve_balance.val = in_reserve_payment.val) AND (out_reserve_balance.frac >= in_reserve_payment.frac)
+  THEN
+    my_balance.val=0;
+    my_balance.frac=out_reserve_balance.frac - in_reserve_payment.frac;
+  ELSE
+    out_final_expiration = reserve.expiration_date;
+    out_open_cost.val = my_cost.val;
+    out_open_cost.frac = my_cost.frac;
+    out_no_funds=TRUE;
+    RAISE NOTICE 'reserve balance too low';
+  RETURN;
+  END IF;
+END IF;
+
+UPDATE reserves SET
+  current_balance=my_balance
+ ,gc_date=reserve.expiration_date + in_reserve_gc_delay
+ ,expiration_date=my_expiration_date
+ ,purses_allowed=reserve.purses_allowed
+WHERE
+ reserve_pub=in_reserve_pub;
+
+out_final_expiration=my_expiration_date;
+out_open_cost = my_cost;
+out_no_funds=FALSE;
+RETURN;
+
+END $$;