How will you give NFT as reward after Staking?

Question

I'm working on a smart contract for a staking dApp. I have two ERC20 tokens S and R. Let's say S is a staking token, and R is a reward token. I also have one ERC721 token. It is called NFT Token. So the user stakes 100 S tokens for seven days, and then he claims 20 R tokens as a reward. So that you know – the scenario implemented above works just fine.

I want to implement another reward scenario for the staking. The user who stakes the tokens over seven days can claim the NFT Token after 30 days as a reward.

Do you know how I can implement it? What is the logic so the user can return and claim the NFT Token after 30 days? The user has already claimed his staking rewards in R tokens.

Where would I store NFT Token rewards pending claims? What process would you suggest for the user to claim awarded NFT Token after the waiting period completion?

Answer 1

One possible implementation is to mint the NFT token at the same time the R tokens are minted, but moving them to a vault contract with a 30 days time lock.

After the additional 30 days the NFT tokens could be withdraw from the vault contract.

Answer 2

create a NFT minting contract that handles the minting of the nft at the cost of however many R tokens would be earned in a 30 day period

I.E if the user earns 30 R tokens over staking for 30 days they would spend 30 R tokens to mint the NFT