I am relatively new to blockchain, and trying to write a staking smart contract, which could stake any ERC20 token and gives APY in the same token with the following requirements:
- Staking of ERC20 token for 30/60/90 days
- The user receives the token in the 'claim' transaction as per the principal amount and
APY defined as specific time period
- 30 days:-> 10% APY
- 60 days:-> 20% APY
- 90 days:-> 30% APY
The contract owner will also be able to change the staking period and similarly change APY rewards. I am able to design the logic for 30 days, but can't get my head around the 60 and 90 days one.
Here goes the code for the token Staking smart contract:-
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
import "@openzeppelin/contracts/access/Ownable.sol";
import "./tokenERC.sol";
contract APYStaking is Ownable{
string public name = "APY Staking";
tokenERC public APY;
//address public owner;
//declaring 30 days staking for APY (default 0.3% daily i.e. 10% APY in 30 days)
uint256 public dailyAPY = 300;
//declaring APY for 60 days staking ( default 0.3% daily i.e. 20% APY in 60 days)
uint256 public dailyAPY60 = 300;
// //declaring APY for 60 days staking ( default 0.3% daily i.e. 20% APY in 60 days)
uint256 public dailyAPY90 = 300;
//declaring total staked
uint256 public totalStaked;
uint256 public customTotalStaked;
//users staking balance
mapping(address => uint256) public stakingBalance;
mapping(address => uint256) public customStakingBalance;
//mapping list of users who ever staked
mapping(address => bool) public hasStaked;
mapping(address => bool) public customHasStaked;
//mapping list of users who are staking at the moment
mapping(address => bool) public isStakingAtm;
mapping(address => bool) public customIsStakingAtm;
//array of all stakers
address[] public stakers;
address[] public customStakers;
constructor(TechAlchemy _APY) public{
APY = _APY;
}
//stake tokens function
function stakeTokens(uint256 _amount) public {
//must be more than 0
require(_amount > 0, "amount cannot be 0");
//User adding test tokens
APY.transferFrom(msg.sender, address(this), _amount);
totalStaked = totalStaked + _amount;
//updating staking balance for user by mapping
stakingBalance[msg.sender] = stakingBalance[msg.sender] + _amount;
//checking if user staked before or not, if NOT staked adding to array of stakers
if (!hasStaked[msg.sender]) {
stakers.push(msg.sender);
}
//updating staking status
hasStaked[msg.sender] = true;
isStakingAtm[msg.sender] = true;
}
//unstake tokens function
function unstakeTokens() public {
//get staking balance for user
uint256 balance = stakingBalance[msg.sender];
//amount should be more than 0
require(balance > 0, "amount has to be more than 0");
//transfer staked tokens back to user
APY.transfer(msg.sender, balance);
totalStaked = totalStaked - balance;
//reseting users staking balance
stakingBalance[msg.sender] = 0;
//updating staking status
isStakingAtm[msg.sender] = false;
}
// APY pool for 60 days
function customStaking60(uint256 _amount) public {
require(_amount > 0, "amount cannot be 0");
APY.transferFrom(msg.sender, address(this), _amount);
customTotalStaked = customTotalStaked + _amount;
customStakingBalance[msg.sender] =
customStakingBalance[msg.sender] +
_amount;
if (!customHasStaked[msg.sender]) {
customStakers.push(msg.sender);
}
customHasStaked[msg.sender] = true;
customIsStakingAtm[msg.sender] = true;
}
function customUnstake60() public {
uint256 balance = customStakingBalance[msg.sender];
require(balance > 0, "amount has to be more than 0");
APY.transfer(msg.sender, balance);
customTotalStaked = customTotalStaked - balance;
customStakingBalance[msg.sender] = 0;
customIsStakingAtm[msg.sender] = false;
}
// APY pool for 90 days
function customStaking90(uint256 _amount) public {
require(_amount > 0, "amount cannot be 0");
APY.transferFrom(msg.sender, address(this), _amount);
customTotalStaked = customTotalStaked + _amount;
customStakingBalance[msg.sender] =
customStakingBalance[msg.sender] +
_amount;
if (!customHasStaked[msg.sender]) {
customStakers.push(msg.sender);
}
customHasStaked[msg.sender] = true;
customIsStakingAtm[msg.sender] = true;
}
function customUnstake90() public {
uint256 balance = customStakingBalance[msg.sender];
require(balance > 0, "amount has to be more than 0");
APY.transfer(msg.sender, balance);
customTotalStaked = customTotalStaked - balance;
customStakingBalance[msg.sender] = 0;
customIsStakingAtm[msg.sender] = false;
}
//airdropp tokens
function redistributeRewards() public onlyOwner{
//doing drop for all addresses
for (uint256 i = 0; i < stakers.length; i++) {
address recipient = stakers[i];
//calculating daily apy for user
uint256 balance = stakingBalance[recipient] * dailyAPY;
balance = balance / 100000;
if (balance > 0) {
APY.transfer(recipient, balance);
}
}
}
//dailyAPY60 tokens airdrop
function customRewards60() public onlyOwner{
for (uint256 i = 0; i < customStakers.length; i++) {
address recipient = customStakers[i];
uint256 balance = customStakingBalance[recipient] * dailyAPY60;
balance = balance / 100000;
if (balance > 0) {
APY.transfer(recipient, balance);
}
}
}
//dailyAPY90 tokens airdrop
function customRewards90() public onlyOwner{
for (uint256 i = 0; i < customStakers.length; i++) {
address recipient = customStakers[i];
uint256 balance = customStakingBalance[recipient] * dailyAPY90;
balance = balance / 100000;
if (balance > 0) {
APY.transfer(recipient, balance);
}
}
}
//change APY value for 60 days staking
function changeAPY60(uint256 _value) public onlyOwner {
require(
_value > 0,
"APY value has to be more than 0, try 300 for (0.3% daily) instead"
);
dailyAPY60= _value;
}
//change APY value for 90 days staking
function changeAPY90(uint256 _value) public onlyOwner {
require(
_value > 0,
"APY value has to be more than 0, try 300 for (0.3% daily) instead"
);
dailyAPY90 = _value;
}
//cliam test 1000 Tst (for testing purpose only !!)
function claimTst() public {
address recipient = msg.sender;
uint256 testingtoken = 1000000000000000000000;
uint256 balance = testingtoken;
APY.transfer(recipient, balance);
}
}
