Well we are FB app specialist and done too many application including bot,graphs and other thngs using FB api. We can easily manage campaigns from a certain FB account once validation. So we can indeed read the campaigns but it needs to have permission and their we need to use date_preset which we need to pass how long data we need like today, yesterday, this month, this qarter, this week etc etc. This features already offered by FB.
The next thing you asked to add one box and put a validation no eg you said 15 that logic needs to be little bit cleared. But I think you want to add some constraints over there.
Let me know when to discuss..