There are 2 main contracts to clearly separate the concepts: |Lending Pool | GiftCards Pool |
Lending Pool is the one on charge of keeping the Ethereum added by the lenders and that is available for selling as ETH Gift Cards GiftCards Pool is the one that will maintain the funds transferred from the lending pool when a purchase is made.
This separation of contracts provides:
- Some level of Security since all funds are not in the same contract.
- Possibility to update 1 without affecting the other, in order to call GiftCards Pool contract, an interface was generated so as long as the contract can use the same interface updates can be done.
- Easy comprehension for the developer on where to look for a specific implementation.
Following Design Patterns from the course:
- most of the state variables are private for restricting access
- circuit breaker to be able to stop new deposits in case an update is required.
- withdrawal pattern in order to make updates before transfers.