(1)  A court that is making a drug treatment order must impose on the offender the sentence of imprisonment it would have imposed were it not making the order.

(2)  The sentence of imprisonment so imposed is the custodial part of the drug treatment order.

(3)  However, the offender is not required to serve all or any of the custodial part of the drug treatment order unless it is activated by some other order under this Part.

(4)  The court must not fix a non-parole period for the sentence of imprisonment imposed under subsection (1) .