-- This file and its contents are licensed under the Apache License 2.0.
-- Please see the included NOTICE for copyright information and
-- LICENSE-APACHE for a copy of the license.

-- Clone fk constraint from a hypertable
CREATE OR REPLACE FUNCTION _timescaledb_internal.hypertable_constraint_add_table_fk_constraint(
    user_ht_constraint_name NAME,
    user_ht_schema_name NAME,
    user_ht_table_name NAME,
    compress_ht_id INTEGER
)
    RETURNS VOID LANGUAGE PLPGSQL AS
$BODY$
DECLARE
    compressed_ht_row _timescaledb_catalog.hypertable;
    constraint_oid OID;
    check_sql TEXT;
    def TEXT;
BEGIN
    SELECT * INTO STRICT compressed_ht_row FROM _timescaledb_catalog.hypertable h
    WHERE h.id = compress_ht_id;
    IF user_ht_constraint_name IS NOT NULL THEN
        SELECT oid INTO STRICT constraint_oid FROM pg_constraint
        WHERE conname=user_ht_constraint_name AND contype = 'f' AND
              conrelid = format('%I.%I', user_ht_schema_name, user_ht_table_name)::regclass::oid;
        def := pg_get_constraintdef(constraint_oid);
    ELSE
        RAISE 'unknown constraint type';
    END IF;
    IF def IS NOT NULL THEN
        -- to allow for custom types with operators outside of pg_catalog
        -- we set search_path to @extschema@
        SET LOCAL search_path TO @extschema@, pg_temp;
        EXECUTE pg_catalog.format(
            $$ ALTER TABLE %I.%I ADD CONSTRAINT %I %s $$,
            compressed_ht_row.schema_name, compressed_ht_row.table_name, user_ht_constraint_name, def
        );
    END IF;

END
$BODY$ SET search_path TO pg_catalog, pg_temp;