include/sql/0002-recoup.sql

@@ -0,0 +1,268 @@
+--
+-- This file is part of TALER
+-- Copyright (C) 2025 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 FUNCTION create_table_recoup(
+  IN partition_suffix TEXT DEFAULT NULL
+)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  table_name TEXT DEFAULT 'recoup';
+BEGIN
+
+  PERFORM create_partitioned_table(
+    'CREATE TABLE %I'
+      '(recoup_uuid BIGINT GENERATED BY DEFAULT AS IDENTITY'
+      ',coin_pub BYTEA NOT NULL CHECK (LENGTH(coin_pub)=32)'
+      ',coin_sig BYTEA NOT NULL CHECK(LENGTH(coin_sig)=64)'
+      ',coin_blind BYTEA NOT NULL CHECK(LENGTH(coin_blind)=32)'
+      ',amount taler_amount NOT NULL'
+      ',recoup_timestamp INT8 NOT NULL'
+      ',withdraw_id INT8 NOT NULL'
+    ') %s ;'
+    ,table_name
+    ,'PARTITION BY HASH (coin_pub);'
+    ,partition_suffix
+  );
+  PERFORM comment_partitioned_table(
+     'Information about recoups that were executed between a coin and a reserve. In this type of recoup, the amount is credited back to the reserve from which the coin originated.'
+    ,table_name
+    ,partition_suffix
+  );
+  PERFORM comment_partitioned_column(
+     'Coin that is being debited in the recoup. Do not CASCADE ON DROP on the coin_pub, as we may keep the coin alive!'
+    ,'coin_pub'
+    ,table_name
+    ,partition_suffix
+  );
+  PERFORM comment_partitioned_column(
+     'Identifies the h_commitment of the recouped coin and provides the link to the credited reserve.'
+    ,'withdraw_id'
+    ,table_name
+    ,partition_suffix
+  );
+  PERFORM comment_partitioned_column(
+     'Signature by the coin affirming the recoup, of type TALER_SIGNATURE_WALLET_COIN_RECOUP'
+    ,'coin_sig'
+    ,table_name
+    ,partition_suffix
+  );
+  PERFORM comment_partitioned_column(
+     'Denomination blinding key used when creating the blinded coin from the planchet. Secret revealed during the recoup to provide the linkage between the coin and the withdraw operation.'
+    ,'coin_blind'
+    ,table_name
+    ,partition_suffix
+  );
+END
+$$;
+
+
+CREATE FUNCTION constrain_table_recoup(
+  IN partition_suffix TEXT
+)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  table_name TEXT DEFAULT 'recoup';
+BEGIN
+  table_name = concat_ws('_', table_name, partition_suffix);
+  EXECUTE FORMAT (
+    'CREATE INDEX ' || table_name || '_by_coin_pub_index '
+    'ON ' || table_name || ' '
+    '(coin_pub);'
+  );
+  EXECUTE FORMAT (
+    'ALTER TABLE ' || table_name ||
+    ' ADD CONSTRAINT ' || table_name || '_recoup_uuid_key'
+    ' UNIQUE (recoup_uuid) '
+  );
+END
+$$;
+
+
+CREATE OR REPLACE FUNCTION foreign_table_recoup()
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  table_name TEXT DEFAULT 'recoup';
+BEGIN
+  EXECUTE FORMAT (
+    'ALTER TABLE ' || table_name ||
+    ' ADD CONSTRAINT ' || table_name || '_foreign_withdraw'
+    ' FOREIGN KEY (withdraw_id) '
+    ' REFERENCES withdraw (withdraw_id) ON DELETE CASCADE'
+    ',ADD CONSTRAINT ' || table_name || '_foreign_coin_pub'
+    ' FOREIGN KEY (coin_pub) '
+    ' REFERENCES known_coins (coin_pub)'
+  );
+END
+$$;
+
+
+CREATE FUNCTION create_table_recoup_by_reserve(
+  IN partition_suffix TEXT DEFAULT NULL
+)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  table_name TEXT DEFAULT 'recoup_by_reserve';
+BEGIN
+  PERFORM create_partitioned_table(
+  'CREATE TABLE %I'
+    '(withdraw_id INT8 NOT NULL' -- REFERENCES withdraw (withdraw_id) ON DELETE CASCADE
+    ',coin_pub BYTEA CHECK (LENGTH(coin_pub)=32)' -- REFERENCES known_coins (coin_pub)
+    ') %s ;'
+    ,table_name
+    ,'PARTITION BY HASH (withdraw_id)'
+    ,partition_suffix
+  );
+  PERFORM comment_partitioned_table(
+     'Information in this table is strictly redundant with that of recoup, but saved by a different primary key for fast lookups by withdraw_id.'
+    ,table_name
+    ,partition_suffix
+  );
+END
+$$;
+
+
+CREATE FUNCTION constrain_table_recoup_by_reserve(
+  IN partition_suffix TEXT DEFAULT NULL
+)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  table_name TEXT DEFAULT 'recoup_by_reserve';
+BEGIN
+  table_name = concat_ws('_', table_name, partition_suffix);
+  EXECUTE FORMAT (
+    'CREATE INDEX ' || table_name || '_main_index '
+    'ON ' || table_name || ' '
+    '(withdraw_id);'
+  );
+END
+$$;
+
+
+CREATE OR REPLACE FUNCTION recoup_insert_trigger()
+  RETURNS trigger
+  LANGUAGE plpgsql
+  AS $$
+BEGIN
+  INSERT INTO recoup_by_reserve
+    (withdraw_id
+    ,coin_pub)
+  VALUES
+    (NEW.withdraw_id
+    ,NEW.coin_pub);
+  INSERT INTO coin_history
+    (coin_pub
+    ,table_name
+    ,serial_id)
+  VALUES
+    (NEW.coin_pub
+    ,'recoup'
+    ,NEW.recoup_uuid);
+  INSERT INTO reserve_history
+    (reserve_pub
+    ,table_name
+    ,serial_id)
+  SELECT
+     res.reserve_pub
+    ,'recoup'
+    ,NEW.recoup_uuid
+  FROM withdraw wd
+  JOIN reserves res
+    USING (reserve_pub)
+    WHERE wd.withdraw_id = NEW.withdraw_id;
+  RETURN NEW;
+END $$;
+COMMENT ON FUNCTION recoup_insert_trigger()
+  IS 'Replicates recoup inserts into recoup_by_reserve table and updates the coin_history table.';
+
+
+CREATE OR REPLACE FUNCTION recoup_delete_trigger()
+  RETURNS trigger
+  LANGUAGE plpgsql
+  AS $$
+BEGIN
+  DELETE FROM recoup_by_reserve
+   WHERE withdraw_id = OLD.withdraw_id
+     AND coin_pub = OLD.coin_pub;
+  RETURN OLD;
+END $$;
+COMMENT ON FUNCTION recoup_delete_trigger()
+  IS 'Replicate recoup deletions into recoup_by_reserve table.';
+
+
+CREATE FUNCTION master_table_recoup()
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  CREATE TRIGGER recoup_on_insert
+    AFTER INSERT
+     ON recoup
+     FOR EACH ROW EXECUTE FUNCTION recoup_insert_trigger();
+  CREATE TRIGGER recoup_on_delete
+    AFTER DELETE
+      ON recoup
+     FOR EACH ROW EXECUTE FUNCTION recoup_delete_trigger();
+END
+$$;
+
+
+INSERT INTO exchange_tables
+    (name
+    ,version
+    ,action
+    ,partitioned
+    ,by_range)
+  VALUES
+    ('recoup'
+    ,'exchange-0002'
+    ,'create'
+    ,TRUE
+    ,FALSE),
+    ('recoup'
+    ,'exchange-0002'
+    ,'constrain'
+    ,TRUE
+    ,FALSE),
+    ('recoup'
+    ,'exchange-0002'
+    ,'foreign'
+    ,TRUE
+    ,FALSE),
+    ('recoup_by_reserve'
+    ,'exchange-0002'
+    ,'create'
+    ,TRUE
+    ,FALSE),
+    ('recoup_by_reserve'
+    ,'exchange-0002'
+    ,'constrain'
+    ,TRUE
+    ,FALSE),
+    ('recoup'
+    ,'exchange-0002'
+    ,'master'
+    ,TRUE
+    ,FALSE);