-- Creates a constraint on a chunk.
CREATE OR REPLACE FUNCTION _timescaledb_internal.chunk_constraint_add_table_constraint(
    chunk_constraint_row  _timescaledb_catalog.chunk_constraint
)
    RETURNS VOID LANGUAGE PLPGSQL AS
$BODY$
DECLARE
    chunk_row _timescaledb_catalog.chunk;
    hypertable_row _timescaledb_catalog.hypertable;
    constraint_oid OID;
    check_sql TEXT;
    def TEXT;
BEGIN
    SELECT * INTO STRICT chunk_row FROM _timescaledb_catalog.chunk c WHERE c.id = chunk_constraint_row.chunk_id;
    SELECT * INTO STRICT hypertable_row FROM _timescaledb_catalog.hypertable h WHERE h.id = chunk_row.hypertable_id;

    IF chunk_constraint_row.dimension_slice_id IS NOT NULL THEN
        check_sql = _timescaledb_internal.dimension_slice_get_constraint_sql(chunk_constraint_row.dimension_slice_id);
        IF check_sql IS NOT NULL THEN
            def := format('CHECK (%s)',  check_sql);
        ELSE
            def := NULL;
        END IF;
    ELSIF chunk_constraint_row.hypertable_constraint_name IS NOT NULL THEN
        SELECT oid INTO STRICT constraint_oid FROM pg_constraint
        WHERE conname=chunk_constraint_row.hypertable_constraint_name AND
              conrelid = format('%I.%I', hypertable_row.schema_name, hypertable_row.table_name)::regclass::oid;
        def := pg_get_constraintdef(constraint_oid);
    ELSE
        RAISE 'Unknown constraint type';
    END IF;

    IF def IS NOT NULL THEN
        EXECUTE format(
            $$ ALTER TABLE %I.%I ADD CONSTRAINT %I %s $$,
            chunk_row.schema_name, chunk_row.table_name, chunk_constraint_row.constraint_name, def
        );
    END IF;
END
$BODY$;
