--
-- 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/>
--

-------------------- Tables ----------------------------

CREATE OR REPLACE FUNCTION create_table_wire_targets(
  IN shard_suffix VARCHAR DEFAULT NULL
)
RETURNS VOID
LANGUAGE plpgsql
AS $$
BEGIN

  PERFORM create_partitioned_table(
    'CREATE TABLE IF NOT EXISTS %I'
      '(wire_target_serial_id BIGINT GENERATED BY DEFAULT AS IDENTITY' -- UNIQUE'
      ',wire_target_h_payto BYTEA PRIMARY KEY CHECK (LENGTH(wire_target_h_payto)=32)'
      ',payto_uri VARCHAR NOT NULL'
    ') %s ;'
    ,'wire_targets'
    ,'PARTITION BY HASH (wire_target_h_payto)'
    ,shard_suffix
  );

END
$$;

-- We need a separate function for this, as we call create_table only once but need to add
-- those constraints to each partition which gets created
CREATE OR REPLACE FUNCTION add_constraints_to_wire_targets_partition(
  IN partition_suffix VARCHAR
)
RETURNS void
LANGUAGE plpgsql
AS $$
BEGIN

  EXECUTE FORMAT (
    'ALTER TABLE wire_targets_' || partition_suffix || ' '
      'ADD CONSTRAINT wire_targets_' || partition_suffix || '_wire_target_serial_id_key '
        'UNIQUE (wire_target_serial_id)'
  );
END
$$;


CREATE OR REPLACE FUNCTION detach_default_partitions2()
  RETURNS VOID
  LANGUAGE plpgsql
AS $$
BEGIN

  RAISE NOTICE 'Detaching all default table partitions';

  ALTER TABLE IF EXISTS wire_targets
    DETACH PARTITION wire_targets_default;

END
$$;

COMMENT ON FUNCTION detach_default_partitions2
  IS 'We need to drop default and create new one before deleting the default partitions
      otherwise constraints get lost too. Might be needed in sharding too';


CREATE OR REPLACE FUNCTION drop_default_partitions2()
  RETURNS VOID
  LANGUAGE plpgsql
AS $$
BEGIN

  RAISE NOTICE 'Dropping default table partitions';

  DROP TABLE IF EXISTS wire_targets_default;
END
$$;

COMMENT ON FUNCTION drop_default_partitions2
  IS 'Drop all default partitions once other partitions are attached.
      Might be needed in sharding too.';


CREATE OR REPLACE FUNCTION create_partitions2(
    num_partitions INTEGER
)
RETURNS VOID
LANGUAGE plpgsql
AS $$
DECLARE
  modulus INTEGER;
BEGIN

  modulus := num_partitions;

  PERFORM detach_default_partitions2();

  LOOP

    PERFORM create_hash_partition(
      'wire_targets'
      ,modulus
      ,num_partitions
    );
    PERFORM add_constraints_to_wire_targets_partition(num_partitions::varchar);

  END LOOP;

  PERFORM drop_default_partitions2();

END
$$;


CREATE OR REPLACE FUNCTION prepare_sharding2()
RETURNS VOID
LANGUAGE plpgsql
AS $$
BEGIN

  PERFORM detach_default_partitions2();

  ALTER TABLE IF EXISTS wire_targets
    DROP CONSTRAINT IF EXISTS wire_targets_pkey CASCADE
  ;

END
$$;


CREATE OR REPLACE FUNCTION create_shard_server2(
    shard_suffix VARCHAR
    ,total_num_shards INTEGER
    ,current_shard_num INTEGER
    ,remote_host VARCHAR
    ,remote_user VARCHAR
    ,remote_user_password VARCHAR
    ,remote_db_name VARCHAR DEFAULT 'taler-exchange'
    ,remote_port INTEGER DEFAULT '5432'
    ,local_user VARCHAR DEFAULT 'taler-exchange-httpd'
)
RETURNS VOID
LANGUAGE plpgsql
AS $$
BEGIN

  RAISE NOTICE 'Creating server %', remote_host;

  PERFORM create_foreign_hash_partition(
    'wire_targets'
    ,total_num_shards
    ,shard_suffix
    ,current_shard_num
    ,local_user
  );
END
$$;

COMMENT ON FUNCTION create_shard_server2
  IS 'Create a shard server on the master
      node with all foreign tables and user mappings';