/*

 ██████  ██████   ██████  ██   ██ ██████   ██████   ██████  ██   ██    ██████  ███████ ██    ██
██      ██    ██ ██    ██ ██  ██  ██   ██ ██    ██ ██    ██ ██  ██     ██   ██ ██      ██    ██
██      ██    ██ ██    ██ █████   ██████  ██    ██ ██    ██ █████      ██   ██ █████   ██    ██
██      ██    ██ ██    ██ ██  ██  ██   ██ ██    ██ ██    ██ ██  ██     ██   ██ ██       ██  ██
 ██████  ██████   ██████  ██   ██ ██████   ██████   ██████  ██   ██ ██ ██████  ███████   ████

Find any smart contract, and build your project faster: https://www.cookbook.dev/?utm=code
Twitter: https://twitter.com/cookbook_dev
Discord: https://discord.gg/P96rgQE2xp

Find this contract on Cookbook: https://www.cookbook.dev/contracts/0xCF205808Ed36593aa40a44F10c7f7C2F67d4A4d4-FriendtechSharesV1?utm=code
*/

// File: contracts/Context.sol


// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @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;
    }
}

// File: contracts/Ownable.sol


// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;


/**
 * @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);
    }
}

// File: contracts/FriendtechShares.sol



pragma solidity >=0.8.2 <0.9.0;


// TODO: Events, final pricing model, 

contract FriendtechSharesV1 is Ownable {
    address public protocolFeeDestination;
    uint256 public protocolFeePercent;
    uint256 public subjectFeePercent;

    event Trade(address trader, address subject, bool isBuy, uint256 shareAmount, uint256 ethAmount, uint256 protocolEthAmount, uint256 subjectEthAmount, uint256 supply);

    // SharesSubject => (Holder => Balance)
    mapping(address => mapping(address => uint256)) public sharesBalance;

    // SharesSubject => Supply
    mapping(address => uint256) public sharesSupply;

    function setFeeDestination(address _feeDestination) public onlyOwner {
        protocolFeeDestination = _feeDestination;
    }

    function setProtocolFeePercent(uint256 _feePercent) public onlyOwner {
        protocolFeePercent = _feePercent;
    }

    function setSubjectFeePercent(uint256 _feePercent) public onlyOwner {
        subjectFeePercent = _feePercent;
    }

    function getPrice(uint256 supply, uint256 amount) public pure returns (uint256) {
        uint256 sum1 = supply == 0 ? 0 : (supply - 1 )* (supply) * (2 * (supply - 1) + 1) / 6;
        uint256 sum2 = supply == 0 && amount == 1 ? 0 : (supply - 1 + amount) * (supply + amount) * (2 * (supply - 1 + amount) + 1) / 6;
        uint256 summation = sum2 - sum1;
        return summation * 1 ether / 16000;
    }

    function getBuyPrice(address sharesSubject, uint256 amount) public view returns (uint256) {
        return getPrice(sharesSupply[sharesSubject], amount);
    }

    function getSellPrice(address sharesSubject, uint256 amount) public view returns (uint256) {
        return getPrice(sharesSupply[sharesSubject] - amount, amount);
    }

    function getBuyPriceAfterFee(address sharesSubject, uint256 amount) public view returns (uint256) {
        uint256 price = getBuyPrice(sharesSubject, amount);
        uint256 protocolFee = price * protocolFeePercent / 1 ether;
        uint256 subjectFee = price * subjectFeePercent / 1 ether;
        return price + protocolFee + subjectFee;
    }

    function getSellPriceAfterFee(address sharesSubject, uint256 amount) public view returns (uint256) {
        uint256 price = getSellPrice(sharesSubject, amount);
        uint256 protocolFee = price * protocolFeePercent / 1 ether;
        uint256 subjectFee = price * subjectFeePercent / 1 ether;
        return price - protocolFee - subjectFee;
    }

    function buyShares(address sharesSubject, uint256 amount) public payable {
        uint256 supply = sharesSupply[sharesSubject];
        require(supply > 0 || sharesSubject == msg.sender, "Only the shares' subject can buy the first share");
        uint256 price = getPrice(supply, amount);
        uint256 protocolFee = price * protocolFeePercent / 1 ether;
        uint256 subjectFee = price * subjectFeePercent / 1 ether;
        require(msg.value >= price + protocolFee + subjectFee, "Insufficient payment");
        sharesBalance[sharesSubject][msg.sender] = sharesBalance[sharesSubject][msg.sender] + amount;
        sharesSupply[sharesSubject] = supply + amount;
        emit Trade(msg.sender, sharesSubject, true, amount, price, protocolFee, subjectFee, supply + amount);
        (bool success1, ) = protocolFeeDestination.call{value: protocolFee}("");
        (bool success2, ) = sharesSubject.call{value: subjectFee}("");
        require(success1 && success2, "Unable to send funds");
    }

    function sellShares(address sharesSubject, uint256 amount) public payable {
        uint256 supply = sharesSupply[sharesSubject];
        require(supply > amount, "Cannot sell the last share");
        uint256 price = getPrice(supply - amount, amount);
        uint256 protocolFee = price * protocolFeePercent / 1 ether;
        uint256 subjectFee = price * subjectFeePercent / 1 ether;
        require(sharesBalance[sharesSubject][msg.sender] >= amount, "Insufficient shares");
        sharesBalance[sharesSubject][msg.sender] = sharesBalance[sharesSubject][msg.sender] - amount;
        sharesSupply[sharesSubject] = supply - amount;
        emit Trade(msg.sender, sharesSubject, false, amount, price, protocolFee, subjectFee, supply - amount);
        (bool success1, ) = msg.sender.call{value: price - protocolFee - subjectFee}("");
        (bool success2, ) = protocolFeeDestination.call{value: protocolFee}("");
        (bool success3, ) = sharesSubject.call{value: subjectFee}("");
        require(success1 && success2 && success3, "Unable to send funds");
    }
}

The `FriendtechSharesV1` contract allows users to buy and sell shares of a subject (another user or contract). The price of shares is calculated based on the current supply using a bonding curve formula. The contract charges a protocol fee and a subject fee on transactions, which are sent to specified addresses. Users can only sell shares if they own them and cannot sell the last share.

The marketplace for your friends

TVL

6 downloads

Audit

Chains

Authors

Get Cookin'

6 downloads

Chains

Authors