Contract Name:
EMRLDStaking
Contract Source Code:
File 1 of 1 : EMRLDStaking
// SPDX-License-Identifier: MIT
pragma solidity 0.8.20;
/// @title $EMRLD Staking
/// @author Andre Costa @ MyWeb3Startup.com
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
/**
* @dev Interface of the ERC-20 standard as defined in the ERC.
*/
interface IERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the value of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the value of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves a `value` amount of tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 value) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets a `value` amount of tokens as the allowance of `spender` over the
* caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 value) external returns (bool);
/**
* @dev Moves a `value` amount of tokens from `from` to `to` using the
* allowance mechanism. `value` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 value) external returns (bool);
}
/**
* @dev Interface for the optional metadata functions from the ERC-20 standard.
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
/**
* @dev Standard ERC-20 Errors
* Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-20 tokens.
*/
interface IERC20Errors {
/**
* @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
* @param balance Current balance for the interacting account.
* @param needed Minimum amount required to perform a transfer.
*/
error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);
/**
* @dev Indicates a failure with the token `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
*/
error ERC20InvalidSender(address sender);
/**
* @dev Indicates a failure with the token `receiver`. Used in transfers.
* @param receiver Address to which tokens are being transferred.
*/
error ERC20InvalidReceiver(address receiver);
/**
* @dev Indicates a failure with the `spender`’s `allowance`. Used in transfers.
* @param spender Address that may be allowed to operate on tokens without being their owner.
* @param allowance Amount of tokens a `spender` is allowed to operate with.
* @param needed Minimum amount required to perform a transfer.
*/
error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);
/**
* @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
* @param approver Address initiating an approval operation.
*/
error ERC20InvalidApprover(address approver);
/**
* @dev Indicates a failure with the `spender` to be approved. Used in approvals.
* @param spender Address that may be allowed to operate on tokens without being their owner.
*/
error ERC20InvalidSpender(address spender);
}
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
*
* TIP: For a detailed writeup see our guide
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* The default value of {decimals} is 18. To change this, you should override
* this function so it returns a different value.
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC-20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the ERC may not emit
* these events, as it isn't required by the specification.
*/
abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
mapping(address account => uint256) private _balances;
mapping(address account => mapping(address spender => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the default value returned by this function, unless
* it's overridden.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `value`.
*/
function transfer(address to, uint256 value) public virtual returns (bool) {
address owner = _msgSender();
_transfer(owner, to, value);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* NOTE: If `value` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 value) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, value);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the ERC. See the note at the beginning of {ERC20}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `value`.
* - the caller must have allowance for ``from``'s tokens of at least
* `value`.
*/
function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, value);
_transfer(from, to, value);
return true;
}
/**
* @dev Moves a `value` amount of tokens from `from` to `to`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* NOTE: This function is not virtual, {_update} should be overridden instead.
*/
function _transfer(address from, address to, uint256 value) internal virtual {
if (from == address(0)) {
revert ERC20InvalidSender(address(0));
}
if (to == address(0)) {
revert ERC20InvalidReceiver(address(0));
}
_update(from, to, value);
}
/**
* @dev Transfers a `value` amount of tokens from `from` to `to`, or alternatively mints (or burns) if `from`
* (or `to`) is the zero address. All customizations to transfers, mints, and burns should be done by overriding
* this function.
*
* Emits a {Transfer} event.
*/
function _update(address from, address to, uint256 value) internal virtual {
if (from == address(0)) {
// Overflow check required: The rest of the code assumes that totalSupply never overflows
_totalSupply += value;
} else {
uint256 fromBalance = _balances[from];
if (fromBalance < value) {
revert ERC20InsufficientBalance(from, fromBalance, value);
}
unchecked {
// Overflow not possible: value <= fromBalance <= totalSupply.
_balances[from] = fromBalance - value;
}
}
if (to == address(0)) {
unchecked {
// Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
_totalSupply -= value;
}
} else {
unchecked {
// Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
_balances[to] += value;
}
}
emit Transfer(from, to, value);
}
/**
* @dev Creates a `value` amount of tokens and assigns them to `account`, by transferring it from address(0).
* Relies on the `_update` mechanism
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* NOTE: This function is not virtual, {_update} should be overridden instead.
*/
function _mint(address account, uint256 value) internal {
if (account == address(0)) {
revert ERC20InvalidReceiver(address(0));
}
_update(address(0), account, value);
}
/**
* @dev Destroys a `value` amount of tokens from `account`, lowering the total supply.
* Relies on the `_update` mechanism.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* NOTE: This function is not virtual, {_update} should be overridden instead
*/
function _burn(address account, uint256 value) internal {
if (account == address(0)) {
revert ERC20InvalidSender(address(0));
}
_update(account, address(0), value);
}
/**
* @dev Sets `value` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*
* Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
*/
function _approve(address owner, address spender, uint256 value) internal {
_approve(owner, spender, value, true);
}
/**
* @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
*
* By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
* `_spendAllowance` during the `transferFrom` operation set the flag to false. This saves gas by not emitting any
* `Approval` event during `transferFrom` operations.
*
* Anyone who wishes to continue emitting `Approval` events on the`transferFrom` operation can force the flag to
* true using the following override:
* ```
* function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
* super._approve(owner, spender, value, true);
* }
* ```
*
* Requirements are the same as {_approve}.
*/
function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
if (owner == address(0)) {
revert ERC20InvalidApprover(address(0));
}
if (spender == address(0)) {
revert ERC20InvalidSpender(address(0));
}
_allowances[owner][spender] = value;
if (emitEvent) {
emit Approval(owner, spender, value);
}
}
/**
* @dev Updates `owner` s allowance for `spender` based on spent `value`.
*
* Does not update the allowance value in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Does not emit an {Approval} event.
*/
function _spendAllowance(address owner, address spender, uint256 value) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
if (currentAllowance < value) {
revert ERC20InsufficientAllowance(spender, currentAllowance, value);
}
unchecked {
_approve(owner, spender, currentAllowance - value, false);
}
}
}
}
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)
pragma solidity ^0.8.0;
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes calldata data
) external;
/**
* @dev Returns the total amount of tokens stored by the contract.
*/
function totalSupply() external view returns (uint256);
}
contract EMRLDStaking is Ownable, ERC20 {
/**
* @dev Struct to represent a staking pool with specific parameters.
*/
struct StakingPool {
uint256 apr; // Annual Percentage Rate for the staking pool.
uint256 minStake; // Minimum staking amount allowed.
uint256 maxStake; // Maximum staking amount allowed.
uint256 totalMaxStakeAmount; // Total maximum amount that can be staked in this pool.
uint256 totalStaked; // Total amount currently staked in this pool.
uint256 totalStakers; // Total number of stakers in this pool.
bool active; // Boolean to indicate if the pool is active.
}
mapping(uint256 => StakingPool) public stakingPools; // Mapping of staking pool IDs to their respective pools.
/**
* @dev Struct to represent a stake made by a user.
*/
struct Stake {
uint256 totalStaked; // Total amount of ETH staked by the user.
uint256 stakeTimestamp; // Last timestamp the user's staking data was updated.
bool isActive; // Boolean to indicate if the stake is currently active.
}
mapping(address => mapping(uint256 => Stake)) public stakes; // Maps user addresses to their staking information.
mapping(address => uint256) public tokensClaimed; // Mapping of user addresses to the total amount of tokens claimed.
IERC20Metadata public EMRLD; // ERC20 token for EMRLD.
/**
* @dev Enum to represent the state of the contract.
*/
enum ContractState { OFF, OPEN } // States of contract: OFF for not accepting stakes, OPEN for accepting stakes.
ContractState public contractState = ContractState.OPEN; // Initial state of the contract.
/**
* @dev Event emitted when a new staking pool is created.
* @param lock The lock period for the staking pool.
* @param apr The APR for the staking pool.
* @param minStake The minimum stake amount for the staking pool.
* @param maxStake The maximum stake amount for the staking pool.
* @param totalMaxStakeAmount The total maximum stake amount for the staking pool.
* @param active Whether the staking pool is active.
*/
event StakingPoolCreated(uint256 lock, uint256 apr, uint256 minStake, uint256 maxStake, uint256 totalMaxStakeAmount, bool active);
/**
* @dev Event emitted when a user stakes tokens.
* @param user The address of the user.
* @param lock The ID of the staking pool.
* @param amount The amount of tokens staked.
*/
event Staked(address indexed user, uint256 indexed lock, uint256 amount);
/**
* @dev Event emitted when a user unstakes tokens.
* @param user The address of the user.
* @param lock The ID of the staking pool.
* @param amount The amount of tokens unstaked.
* @param rewards The amount of rewards earned.
*/
event Unstaked(address indexed user, uint256 indexed lock, uint256 amount, uint256 rewards);
/**
* @dev Event emitted when a user restakes tokens.
* @param user The address of the user.
* @param lock The ID of the staking pool.
* @param amount The amount of tokens restaked.
* @param rewards The amount of rewards earned.
*/
event Restaked(address indexed user, uint256 indexed lock, uint256 amount, uint256 rewards);
/**
* @dev Constructor to set the name and symbol for the staked tokens.
*/
constructor() ERC20("xEMRLD", "xEMRLD") {
EMRLD = IERC20Metadata(0xeBB1AFb0A4ddC9b1f84D9Aa72FF956cD1c1Eb4be);
}
/**
* @dev Modifier to check the contract's current state before proceeding.
* @param requiredState The state that the contract must be in.
*/
modifier isContractState(ContractState requiredState) {
require(contractState == requiredState, "Contract is not in the required state");
_;
}
/**
* @dev Function to stake tokens in a specific pool.
* @param lock The ID of the staking pool.
* @param amount The amount of tokens to stake.
*/
function stake(uint256 lock, uint256 amount) external isContractState(ContractState.OPEN) {
StakingPool storage pool = stakingPools[lock];
Stake storage userStake = stakes[msg.sender][lock];
require(pool.active, "Staking pool is not active");
require(amount + stakes[msg.sender][lock].totalStaked >= pool.minStake, "Amount is less than minimum stake");
require(amount + stakes[msg.sender][lock].totalStaked <= pool.maxStake, "Amount exceeds maximum stake");
require(pool.totalStaked + amount <= pool.totalMaxStakeAmount, "Exceeds total maximum stake amount");
require(!userStake.isActive, "User already has an active stake in this pool");
EMRLD.transferFrom(msg.sender, address(this), amount);
userStake.totalStaked = amount;
userStake.stakeTimestamp = block.timestamp;
userStake.isActive = true;
pool.totalStaked += amount;
pool.totalStakers++;
_mint(msg.sender, amount);
emit Staked(msg.sender, lock, amount);
}
/**
* @dev Function to unstake tokens from a specific pool.
* @param lock The ID of the staking pool.
*/
function unstake(uint256 lock) external isContractState(ContractState.OPEN) {
Stake storage userStake = stakes[msg.sender][lock];
require(userStake.isActive, "No active stake found");
StakingPool storage pool = stakingPools[lock];
require(block.timestamp >= userStake.stakeTimestamp + lock * 86400, "Lock period has not passed");
uint256 amountStaked = userStake.totalStaked;
uint256 rewards = calculateReward(msg.sender, lock);
tokensClaimed[msg.sender] += rewards;
// Transfer the staked amount and rewards back to the user
// EMRLD.transfer(msg.sender, rewards);
EMRLD.transfer(msg.sender, amountStaked);
// Update the user's stake and the pool's totals
userStake.isActive = false;
pool.totalStaked -= amountStaked;
pool.totalStakers -= 1;
_burn(msg.sender, amountStaked);
emit Unstaked(msg.sender, lock, amountStaked, rewards);
}
/**
* @dev Function to restake tokens and rewards in a specific pool.
* @param lock The ID of the staking pool.
*/
function restake(uint256 lock) external isContractState(ContractState.OPEN) {
Stake storage userStake = stakes[msg.sender][lock];
require(userStake.isActive, "No active stake found");
StakingPool storage pool = stakingPools[lock];
require(block.timestamp >= userStake.stakeTimestamp + lock * 86400, "Lock period has not passed");
uint256 amountStaked = userStake.totalStaked;
uint256 rewards = calculateReward(msg.sender, lock);
// Ensure the total amount to be restaked doesn't exceed pool's maximum limits
uint256 totalToRestake = amountStaked + rewards;
require(totalToRestake >= pool.minStake, "Restake amount is less than minimum stake");
require(totalToRestake <= pool.maxStake, "Restake amount exceeds maximum stake");
require(pool.totalStaked + rewards <= pool.totalMaxStakeAmount, "Exceeds total maximum stake amount");
// Update user's stake
userStake.totalStaked = totalToRestake;
userStake.stakeTimestamp = block.timestamp;
// Update the pool's total staked amount (adding only rewards, as the initial staked amount is already included)
pool.totalStaked += rewards;
_mint(msg.sender, rewards);
emit Restaked(msg.sender, lock, amountStaked, rewards);
}
/**
* @dev Emergency function for the owner to unstake tokens for a user.
* @param user The address of the user.
* @param lock The ID of the staking pool.
*/
function emergencyUnstake(address user, uint256 lock) external onlyOwner {
Stake storage userStake = stakes[user][lock];
require(userStake.isActive, "No active stake found");
StakingPool storage pool = stakingPools[lock];
uint256 amountStaked = userStake.totalStaked;
uint256 rewards;
if (block.timestamp >= userStake.stakeTimestamp + lock * 86400) {
rewards = calculateReward(msg.sender, lock);
tokensClaimed[user] += rewards;
}
// Transfer the staked amount and rewards back to the user
// EMRLD.transfer(msg.sender, rewards);
EMRLD.transfer(msg.sender, amountStaked);
// Update the user's stake and the pool's totals
userStake.isActive = false;
pool.totalStaked -= amountStaked;
pool.totalStakers -= 1;
_burn(user, amountStaked);
emit Unstaked(user, lock, amountStaked, rewards);
}
/**
* @dev Calculates the total rewards earned by a staker based on the staked amounts and time elapsed.
* @param staker The address of the staker.
* @param lock The ID of the staking pool.
* @return The total rewards earned.
*/
function calculateReward(address staker, uint256 lock) public view returns (uint256) {
uint256 timeStaked = block.timestamp - stakes[staker][lock].stakeTimestamp;
return (((stakes[staker][lock].totalStaked * stakingPools[lock].apr) / 10000) * timeStaked) / (365 days);
}
///
/// SETTERS
///
/**
* @dev Function to set up a staking pool.
* @param lock The lock period for the staking pool.
* @param apr The APR for the staking pool.
* @param minStake The minimum stake amount.
* @param maxStake The maximum stake amount.
* @param totalMaxStakeAmount The total maximum amount that can be staked in the pool.
* @param active Boolean indicating if the pool is active.
*/
function setStakingPool(
uint256 lock,
uint256 apr,
uint256 minStake,
uint256 maxStake,
uint256 totalMaxStakeAmount,
bool active
) public onlyOwner {
require(apr > 0 && apr <= 10000, "APR must be between 1 and 100");
require(minStake > 0, "Minimum stake must be greater than 0");
require(maxStake >= minStake, "Maximum stake must be greater than or equal to minimum stake");
require(totalMaxStakeAmount >= maxStake, "Total maximum stake amount must be greater than or equal to maximum stake");
StakingPool storage pool = stakingPools[lock];
pool.apr = apr;
pool.minStake = minStake;
pool.maxStake = maxStake;
pool.totalMaxStakeAmount = totalMaxStakeAmount;
pool.active = active;
emit StakingPoolCreated(lock, apr, minStake, maxStake, totalMaxStakeAmount, active);
}
/**
* @dev Sets the contract's operational state.
* @param newState The new state to set the contract to (0 for OFF, 1 for OPEN).
*/
function setContractState(uint256 newState) external onlyOwner {
require(newState < 2, "Invalid State!");
contractState = ContractState(newState);
}
/**
* @dev Sets the USDB ERC20 token contract.
* @param _EMRLD The address of the EMRLD ERC20 token contract.
*/
function setEMRLD(address _EMRLD) external onlyOwner {
EMRLD = IERC20Metadata(_EMRLD);
}
///
/// MISC
///
/**
* @notice Withdraws Ether from the contract.
* @param recipient The address to receive the Ether.
* @param amount The amount of Ether to withdraw.
*/
function withdrawEther(address recipient, uint256 amount) external onlyOwner {
require(recipient != address(0), "Invalid Address!");
require(amount > 0 && address(this).balance >= amount, "Invalid Amount!");
(bool sent, ) = recipient.call{value: amount}("");
require(sent, "Failed to send Ether");
}
/**
* @notice Withdraws ERC20 tokens from the contract.
* @param recipient The address to receive the tokens.
* @param amount The amount of tokens to withdraw.
* @param token The address of the token contract.
*/
function withdrawToken(address recipient, uint256 amount, address token) external onlyOwner {
require(recipient != address(0), "Invalid Address!");
require(amount > 0, "Invalid Amount!");
require(token != address(0), "Invalid Token!");
require(IERC20(token).transfer(recipient, amount), "Unsuccessful Transfer!");
}
}
