I'm currently working on developing a smart contract that allows users to approve a certain amount of ERC20 tokens, and the contract owner can fetch these approved tokens from each user individually. The contract should keep track of approved amounts separately for each user and ensure that the contract owner can only fetch tokens up to the approved amount for each user.
Here's a brief overview of the contract functionality:
- Users can approve a certain amount of ERC20 tokens to the contract.
- The contract maintains a mapping to track the approved amounts for each user.
- The contract owner should be able to fetch tokens from each user's approved balance individually, up to the approved amount.
I'm seeking guidance on how to implement this functionality securely and efficiently. Specifically, I'd like assistance with:
- Designing the contract structure to manage approved token balances for each user.
- Implementing the approval mechanism to ensure that the contract accurately tracks approved amounts for each user.
- Developing the fetching function to allow the contract owner to retrieve tokens from each user's approved balance without exceeding the approved amount.
- Addressing any potential security concerns or best practices to follow when developing this type of contract.
Any insights, code examples, or resources that can help me achieve these goals would be greatly appreciated. Thank you!