Asalamualykum warehmatullahi barkatuhu
Quran is a complete book which indicates an answer to any question and in fact Allah has made it perfect.
Allah says in the Quran not to follow your desires numerous times ,and smoking anything which satisfies the human is fulfilling a desire ,,,,which means you cannot follow Islam if you are smoking,it is better to leave smoking as soon as possible and if someone is a chain smoker he/she should have an intention of quitting ,avoiding carrying of matches ,lighters ,packs of cigarette ,and should even try not to spend money on these type of things as on the day of judgement a question would be raised to us that:where did you earn your money and on what did you spent it on and should seek Allah's help .