I am trying to learn and understand how ICOs and the smart contracts used in them work and I am having a hard time understanding the following:
Take for example ParagoinCoin, you can see here that it has several phases (Early Bird at Presale, Presale, Early Bird at Crowdsale and Crowdsale) which have discounts on the token's price and a minimum purchase amount, as well as dates for these phases.
Now looking at the contract source code here, I see absolutely nothing related to those phases, discounts or minimum purchase amounts.
How does this works? Where are those values controlled? Is it done with different contracts? is it controlled via some DAPP, maybe with the Ethereum Wallet?
I'm sorry if these things are obvious for some of you, I'm completely new to this and I have to say it is all quite overwhelming. Links to good resources about this are very welcome too, it's hard to find pertinent info about this at the moment.