(a) A person commits an offense if the person violates Section 366.071, Health and Safety Code.
(b) Except as provided by this subsection, an offense under this section is a Class C misdemeanor. If it is shown on the trial of the defendant that the defendant has been previously convicted of an offense under this section, the offense is punishable under Section 7.187(1)(A) or Section 7.187(2)(A) or both.