DropERC20.sol

// SPDX-License-Identifier: Apache-2.0
pragma solidity ^0.8.11;

//  ==========  External imports    ==========

import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC20BurnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC20VotesUpgradeable.sol";

import "@openzeppelin/contracts-upgradeable/access/AccessControlEnumerableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";

import "@openzeppelin/contracts-upgradeable/utils/structs/BitMapsUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/utils/MulticallUpgradeable.sol";

//  ==========  Internal imports    ==========

import "../interfaces/IThirdwebContract.sol";

//  ==========  Features    ==========

import "../extension/interface/IPlatformFee.sol";
import "../extension/interface/IPrimarySale.sol";

import { IDropERC20 } from "../interfaces/drop/IDropERC20.sol";
import { ITWFee } from "../interfaces/ITWFee.sol";

import "../openzeppelin-presets/metatx/ERC2771ContextUpgradeable.sol";

import "../lib/MerkleProof.sol";
import "../lib/CurrencyTransferLib.sol";
import "../lib/FeeType.sol";

contract DropERC20 is
    Initializable,
    IThirdwebContract,
    IPrimarySale,
    IPlatformFee,
    ReentrancyGuardUpgradeable,
    ERC2771ContextUpgradeable,
    MulticallUpgradeable,
    AccessControlEnumerableUpgradeable,
    ERC20BurnableUpgradeable,
    ERC20VotesUpgradeable,
    IDropERC20
{
    using BitMapsUpgradeable for BitMapsUpgradeable.BitMap;

    /*///////////////////////////////////////////////////////////////
                            State variables
    //////////////////////////////////////////////////////////////*/

    bytes32 private constant MODULE_TYPE = bytes32("DropERC20");
    uint128 private constant VERSION = 1;

    /// @dev Only transfers to or from TRANSFER_ROLE holders are valid, when transfers are restricted.
    bytes32 private constant TRANSFER_ROLE = keccak256("TRANSFER_ROLE");

    /// @dev Contract level metadata.
    string public contractURI;

    /// @dev Max bps in the thirdweb system.
    uint128 internal constant MAX_BPS = 10_000;

    /// @dev The % of primary sales collected as platform fees.
    uint128 internal platformFeeBps;

    /// @dev The address that receives all platform fees from all sales.
    address internal platformFeeRecipient;

    /// @dev The address that receives all primary sales value.
    address public primarySaleRecipient;

    /// @dev The max number of tokens a wallet can claim.
    uint256 public maxWalletClaimCount;

    /// @dev Global max total supply of tokens.
    uint256 public maxTotalSupply;

    /// @dev The set of all claim conditions, at any given moment.
    ClaimConditionList public claimCondition;

    /*///////////////////////////////////////////////////////////////
                                Mappings
    //////////////////////////////////////////////////////////////*/

    /// @dev Mapping from address => number of tokens a wallet has claimed.
    mapping(address => uint256) public walletClaimCount;

    /*///////////////////////////////////////////////////////////////
                    Constructor + initializer logic
    //////////////////////////////////////////////////////////////*/

    constructor() initializer {}

    /// @dev Initiliazes the contract, like a constructor.
    function initialize(
        address _defaultAdmin,
        string memory _name,
        string memory _symbol,
        string memory _contractURI,
        address[] memory _trustedForwarders,
        address _primarySaleRecipient,
        address _platformFeeRecipient,
        uint256 _platformFeeBps
    ) external initializer {
        // Initialize inherited contracts, most base-like -> most derived.
        __ERC2771Context_init_unchained(_trustedForwarders);
        __ERC20Permit_init(_name);
        __ERC20_init_unchained(_name, _symbol);

        // Initialize this contract's state.
        contractURI = _contractURI;
        primarySaleRecipient = _primarySaleRecipient;
        platformFeeRecipient = _platformFeeRecipient;
        platformFeeBps = uint128(_platformFeeBps);

        _setupRole(DEFAULT_ADMIN_ROLE, _defaultAdmin);
        _setupRole(TRANSFER_ROLE, _defaultAdmin);
        _setupRole(TRANSFER_ROLE, address(0));
    }

    /*///////////////////////////////////////////////////////////////
                        Generic contract logic
    //////////////////////////////////////////////////////////////*/

    /// @dev Returns the type of the contract.
    function contractType() external pure returns (bytes32) {
        return MODULE_TYPE;
    }

    /// @dev Returns the version of the contract.
    function contractVersion() external pure returns (uint8) {
        return uint8(VERSION);
    }

    /*///////////////////////////////////////////////////////////////
                    ERC 165 + ERC20 transfer hooks
    //////////////////////////////////////////////////////////////*/

    /// @dev See ERC 165
    function supportsInterface(bytes4 interfaceId)
        public
        view
        virtual
        override(AccessControlEnumerableUpgradeable)
        returns (bool)
    {
        return super.supportsInterface(interfaceId);
    }

    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual override(ERC20Upgradeable, ERC20VotesUpgradeable) {
        super._afterTokenTransfer(from, to, amount);
    }

    /// @dev Runs on every transfer.
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal override(ERC20Upgradeable) {
        super._beforeTokenTransfer(from, to, amount);

        if (!hasRole(TRANSFER_ROLE, address(0)) && from != address(0) && to != address(0)) {
            require(hasRole(TRANSFER_ROLE, from) || hasRole(TRANSFER_ROLE, to), "transfers restricted.");
        }
    }

    /*///////////////////////////////////////////////////////////////
                            Claim logic
    //////////////////////////////////////////////////////////////*/

    /// @dev Lets an account claim tokens.
    function claim(
        address _receiver,
        uint256 _quantity,
        address _currency,
        uint256 _pricePerToken,
        bytes32[] calldata _proofs,
        uint256 _proofMaxQuantityPerTransaction
    ) external payable nonReentrant {
        require(isTrustedForwarder(msg.sender) || _msgSender() == tx.origin, "BOT");

        // Get the claim conditions.
        uint256 activeConditionId = getActiveClaimConditionId();

        /**
         *  We make allowlist checks (i.e. verifyClaimMerkleProof) before verifying the claim's general
         *  validity (i.e. verifyClaim) because we give precedence to the check of allow list quantity
         *  restriction over the check of the general claim condition's quantityLimitPerTransaction
         *  restriction.
         */

        // Verify inclusion in allowlist.
        (bool validMerkleProof, uint256 merkleProofIndex) = verifyClaimMerkleProof(
            activeConditionId,
            _msgSender(),
            _quantity,
            _proofs,
            _proofMaxQuantityPerTransaction
        );

        // Verify claim validity. If not valid, revert.
        // when there's allowlist present --> verifyClaimMerkleProof will verify the _proofMaxQuantityPerTransaction value with hashed leaf in the allowlist
        // when there's no allowlist, this check is true --> verifyClaim will check for _quantity being less/equal than the limit
        bool toVerifyMaxQuantityPerTransaction = _proofMaxQuantityPerTransaction == 0 ||
            claimCondition.phases[activeConditionId].merkleRoot == bytes32(0);
        verifyClaim(
            activeConditionId,
            _msgSender(),
            _quantity,
            _currency,
            _pricePerToken,
            toVerifyMaxQuantityPerTransaction
        );

        if (validMerkleProof && _proofMaxQuantityPerTransaction > 0) {
            /**
             *  Mark the claimer's use of their position in the allowlist. A spot in an allowlist
             *  can be used only once.
             */
            claimCondition.limitMerkleProofClaim[activeConditionId].set(merkleProofIndex);
        }

        // If there's a price, collect price.
        collectClaimPrice(_quantity, _currency, _pricePerToken);

        // Mint the relevant NFTs to claimer.
        transferClaimedTokens(_receiver, activeConditionId, _quantity);

        emit TokensClaimed(activeConditionId, _msgSender(), _receiver, _quantity);
    }

    /// @dev Lets a contract admin (account with `DEFAULT_ADMIN_ROLE`) set claim conditions.
    function setClaimConditions(ClaimCondition[] calldata _phases, bool _resetClaimEligibility)
        external
        onlyRole(DEFAULT_ADMIN_ROLE)
    {
        uint256 existingStartIndex = claimCondition.currentStartId;
        uint256 existingPhaseCount = claimCondition.count;

        /**
         *  `limitLastClaimTimestamp` and `limitMerkleProofClaim` are mappings that use a
         *  claim condition's UID as a key.
         *
         *  If `_resetClaimEligibility == true`, we assign completely new UIDs to the claim
         *  conditions in `_phases`, effectively resetting the restrictions on claims expressed
         *  by `limitLastClaimTimestamp` and `limitMerkleProofClaim`.
         */
        uint256 newStartIndex = existingStartIndex;
        if (_resetClaimEligibility) {
            newStartIndex = existingStartIndex + existingPhaseCount;
        }

        claimCondition.count = _phases.length;
        claimCondition.currentStartId = newStartIndex;

        uint256 lastConditionStartTimestamp;
        for (uint256 i = 0; i < _phases.length; i++) {
            require(
                i == 0 || lastConditionStartTimestamp < _phases[i].startTimestamp,
                "startTimestamp must be in ascending order."
            );

            uint256 supplyClaimedAlready = claimCondition.phases[newStartIndex + i].supplyClaimed;
            require(supplyClaimedAlready <= _phases[i].maxClaimableSupply, "max supply claimed already");

            claimCondition.phases[newStartIndex + i] = _phases[i];
            claimCondition.phases[newStartIndex + i].supplyClaimed = supplyClaimedAlready;

            lastConditionStartTimestamp = _phases[i].startTimestamp;
        }

        /**
         *  Gas refunds (as much as possible)
         *
         *  If `_resetClaimEligibility == true`, we assign completely new UIDs to the claim
         *  conditions in `_phases`. So, we delete claim conditions with UID < `newStartIndex`.
         *
         *  If `_resetClaimEligibility == false`, and there are more existing claim conditions
         *  than in `_phases`, we delete the existing claim conditions that don't get replaced
         *  by the conditions in `_phases`.
         */
        if (_resetClaimEligibility) {
            for (uint256 i = existingStartIndex; i < newStartIndex; i++) {
                delete claimCondition.phases[i];
                delete claimCondition.limitMerkleProofClaim[i];
            }
        } else {
            if (existingPhaseCount > _phases.length) {
                for (uint256 i = _phases.length; i < existingPhaseCount; i++) {
                    delete claimCondition.phases[newStartIndex + i];
                    delete claimCondition.limitMerkleProofClaim[newStartIndex + i];
                }
            }
        }

        emit ClaimConditionsUpdated(_phases);
    }

    /// @dev Collects and distributes the primary sale value of tokens being claimed.
    function collectClaimPrice(
        uint256 _quantityToClaim,
        address _currency,
        uint256 _pricePerToken
    ) internal {
        if (_pricePerToken == 0) {
            return;
        }

        // `_pricePerToken` is interpreted as price per 1 ether unit of the ERC20 tokens.
        uint256 totalPrice = (_quantityToClaim * _pricePerToken) / 1 ether;
        require(totalPrice > 0, "quantity too low");

        uint256 platformFees = (totalPrice * platformFeeBps) / MAX_BPS;

        if (_currency == CurrencyTransferLib.NATIVE_TOKEN) {
            require(msg.value == totalPrice, "must send total price.");
        }

        CurrencyTransferLib.transferCurrency(_currency, _msgSender(), platformFeeRecipient, platformFees);
        CurrencyTransferLib.transferCurrency(_currency, _msgSender(), primarySaleRecipient, totalPrice - platformFees);
    }

    /// @dev Transfers the tokens being claimed.
    function transferClaimedTokens(
        address _to,
        uint256 _conditionId,
        uint256 _quantityBeingClaimed
    ) internal {
        // Update the supply minted under mint condition.
        claimCondition.phases[_conditionId].supplyClaimed += _quantityBeingClaimed;

        // if transfer claimed tokens is called when to != msg.sender, it'd use msg.sender's limits.
        // behavior would be similar to msg.sender mint for itself, then transfer to `to`.
        claimCondition.limitLastClaimTimestamp[_conditionId][_msgSender()] = block.timestamp;
        walletClaimCount[_msgSender()] += _quantityBeingClaimed;

        _mint(_to, _quantityBeingClaimed);
    }

    /// @dev Checks a request to claim tokens against the active claim condition's criteria.
    function verifyClaim(
        uint256 _conditionId,
        address _claimer,
        uint256 _quantity,
        address _currency,
        uint256 _pricePerToken,
        bool verifyMaxQuantityPerTransaction
    ) public view {
        ClaimCondition memory currentClaimPhase = claimCondition.phases[_conditionId];

        require(
            _currency == currentClaimPhase.currency && _pricePerToken == currentClaimPhase.pricePerToken,
            "invalid currency or price specified."
        );
        // If we're checking for an allowlist quantity restriction, ignore the general quantity restriction.
        require(
            _quantity > 0 &&
                (!verifyMaxQuantityPerTransaction || _quantity <= currentClaimPhase.quantityLimitPerTransaction),
            "invalid quantity claimed."
        );
        require(
            currentClaimPhase.supplyClaimed + _quantity <= currentClaimPhase.maxClaimableSupply,
            "exceed max mint supply."
        );

        uint256 _maxTotalSupply = maxTotalSupply;
        uint256 _maxWalletClaimCount = maxWalletClaimCount;
        require(_maxTotalSupply == 0 || totalSupply() + _quantity <= _maxTotalSupply, "exceed max total supply.");
        require(
            _maxWalletClaimCount == 0 || walletClaimCount[_claimer] + _quantity <= _maxWalletClaimCount,
            "exceed claim limit for wallet"
        );

        (, uint256 nextValidClaimTimestamp) = getClaimTimestamp(_conditionId, _claimer);
        require(block.timestamp >= nextValidClaimTimestamp, "cannot claim yet.");
    }

    /// @dev Checks whether a claimer meets the claim condition's allowlist criteria.
    function verifyClaimMerkleProof(
        uint256 _conditionId,
        address _claimer,
        uint256 _quantity,
        bytes32[] calldata _proofs,
        uint256 _proofMaxQuantityPerTransaction
    ) public view returns (bool validMerkleProof, uint256 merkleProofIndex) {
        ClaimCondition memory currentClaimPhase = claimCondition.phases[_conditionId];

        if (currentClaimPhase.merkleRoot != bytes32(0)) {
            (validMerkleProof, merkleProofIndex) = MerkleProof.verify(
                _proofs,
                currentClaimPhase.merkleRoot,
                keccak256(abi.encodePacked(_claimer, _proofMaxQuantityPerTransaction))
            );
            require(validMerkleProof, "not in whitelist.");
            require(!claimCondition.limitMerkleProofClaim[_conditionId].get(merkleProofIndex), "proof claimed.");
            require(
                _proofMaxQuantityPerTransaction == 0 || _quantity <= _proofMaxQuantityPerTransaction,
                "invalid quantity proof."
            );
        }
    }

    /*///////////////////////////////////////////////////////////////
                        Getter functions
    //////////////////////////////////////////////////////////////*/

    /// @dev At any given moment, returns the uid for the active claim condition.
    function getActiveClaimConditionId() public view returns (uint256) {
        for (uint256 i = claimCondition.currentStartId + claimCondition.count; i > claimCondition.currentStartId; i--) {
            if (block.timestamp >= claimCondition.phases[i - 1].startTimestamp) {
                return i - 1;
            }
        }

        revert("no active mint condition.");
    }

    /// @dev Returns the timestamp for when a claimer is eligible for claiming tokens again.
    function getClaimTimestamp(uint256 _conditionId, address _claimer)
        public
        view
        returns (uint256 lastClaimTimestamp, uint256 nextValidClaimTimestamp)
    {
        lastClaimTimestamp = claimCondition.limitLastClaimTimestamp[_conditionId][_claimer];

        if(lastClaimTimestamp != 0) {
            unchecked {
                nextValidClaimTimestamp =
                    lastClaimTimestamp +
                    claimCondition.phases[_conditionId].waitTimeInSecondsBetweenClaims;

                if (nextValidClaimTimestamp < lastClaimTimestamp) {
                    nextValidClaimTimestamp = type(uint256).max;
                }
            }
        }

    }

    /// @dev Returns the claim condition at the given uid.
    function getClaimConditionById(uint256 _conditionId) external view returns (ClaimCondition memory condition) {
        condition = claimCondition.phases[_conditionId];
    }

    /// @dev Returns the platform fee recipient and bps.
    function getPlatformFeeInfo() external view returns (address, uint16) {
        return (platformFeeRecipient, uint16(platformFeeBps));
    }

    /*///////////////////////////////////////////////////////////////
                        Setter functions
    //////////////////////////////////////////////////////////////*/

    /// @dev Lets a contract admin set a claim count for a wallet.
    function setWalletClaimCount(address _claimer, uint256 _count) external onlyRole(DEFAULT_ADMIN_ROLE) {
        walletClaimCount[_claimer] = _count;
        emit WalletClaimCountUpdated(_claimer, _count);
    }

    /// @dev Lets a contract admin set a maximum number of tokens that can be claimed by any wallet.
    function setMaxWalletClaimCount(uint256 _count) external onlyRole(DEFAULT_ADMIN_ROLE) {
        maxWalletClaimCount = _count;
        emit MaxWalletClaimCountUpdated(_count);
    }

    /// @dev Lets a contract admin set the global maximum supply of tokens.
    function setMaxTotalSupply(uint256 _maxTotalSupply) external onlyRole(DEFAULT_ADMIN_ROLE) {
        maxTotalSupply = _maxTotalSupply;
        emit MaxTotalSupplyUpdated(_maxTotalSupply);
    }

    /// @dev Lets a contract admin set the recipient for all primary sales.
    function setPrimarySaleRecipient(address _saleRecipient) external onlyRole(DEFAULT_ADMIN_ROLE) {
        primarySaleRecipient = _saleRecipient;
        emit PrimarySaleRecipientUpdated(_saleRecipient);
    }

    /// @dev Lets a contract admin update the platform fee recipient and bps
    function setPlatformFeeInfo(address _platformFeeRecipient, uint256 _platformFeeBps)
        external
        onlyRole(DEFAULT_ADMIN_ROLE)
    {
        require(_platformFeeBps <= MAX_BPS, "bps <= 10000.");

        platformFeeBps = uint64(_platformFeeBps);
        platformFeeRecipient = _platformFeeRecipient;

        emit PlatformFeeInfoUpdated(_platformFeeRecipient, _platformFeeBps);
    }

    /// @dev Lets a contract admin set the URI for contract-level metadata.
    function setContractURI(string calldata _uri) external onlyRole(DEFAULT_ADMIN_ROLE) {
        string memory prevURI = contractURI;
        contractURI = _uri;

        emit ContractURIUpdated(prevURI, _uri);
    }

    /*///////////////////////////////////////////////////////////////
                            Miscellaneous
    //////////////////////////////////////////////////////////////*/

    function _mint(address account, uint256 amount) internal virtual override(ERC20Upgradeable, ERC20VotesUpgradeable) {
        super._mint(account, amount);
    }

    function _burn(address account, uint256 amount) internal virtual override(ERC20Upgradeable, ERC20VotesUpgradeable) {
        super._burn(account, amount);
    }

    function _msgSender()
        internal
        view
        virtual
        override(ContextUpgradeable, ERC2771ContextUpgradeable)
        returns (address sender)
    {
        return ERC2771ContextUpgradeable._msgSender();
    }

    function _msgData()
        internal
        view
        virtual
        override(ContextUpgradeable, ERC2771ContextUpgradeable)
        returns (bytes calldata)
    {
        return ERC2771ContextUpgradeable._msgData();
    }
}