technically if a layover is 12+ hours they have to provide a hotel but it depends upon luck . i always travel via turkish airlines and their ticket via Priceline is nearly half cheap as qatar airways . one time i had a transit for 13 hrs they give a hotel . another time simply they denied .
you have to take evisa in airport which is around 45 dollars and airlines refunds that later . if they give u hotel you can travel all istanbul and enjoy . most hotel provide free hop on hop off .

i always take turkish airline ticket through priceline and make layover more than 12 hrs so that i can enjoy free 5 star hotel , travel around istanbul and enjoy . i have same plane for dashain where ticket from qatar is 1500 plus 2 ways but turkish is 700 somethiing . hope they give me hotel this time .