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| 1 | +// SPDX-License-Identifier: MIT |
| 2 | +pragma solidity ^0.8.3; |
| 3 | + |
| 4 | +// Slight modifiations from base Open Zeppelin Contracts |
| 5 | +// Consult /oz/README.md for more information |
| 6 | +import "./oz/ERC20Upgradeable.sol"; |
| 7 | +import "./oz/ERC20SnapshotUpgradeable.sol"; |
| 8 | +import "./oz/ERC20PausableUpgradeable.sol"; |
| 9 | + |
| 10 | +import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol"; |
| 11 | +import "@openzeppelin/contracts/token/ERC20/IERC20.sol"; |
| 12 | + |
| 13 | +import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol"; |
| 14 | + |
| 15 | +contract ZeroDAOTokenV2 is |
| 16 | + OwnableUpgradeable, |
| 17 | + ERC20Upgradeable, |
| 18 | + ERC20PausableUpgradeable, |
| 19 | + ERC20SnapshotUpgradeable |
| 20 | +{ |
| 21 | + using SafeERC20 for IERC20; |
| 22 | + |
| 23 | + event AuthorizedSnapshotter(address account); |
| 24 | + event DeauthorizedSnapshotter(address account); |
| 25 | + event ERC20TokenWithdrawn( |
| 26 | + IERC20 indexed token, |
| 27 | + address indexed to, |
| 28 | + uint256 indexed amount |
| 29 | + ); |
| 30 | + |
| 31 | + // Mapping which stores all addresses allowed to snapshot |
| 32 | + mapping(address => bool) authorizedToSnapshot; |
| 33 | + |
| 34 | + function initialize( |
| 35 | + string memory name, |
| 36 | + string memory symbol |
| 37 | + ) public initializer { |
| 38 | + __Ownable_init(); |
| 39 | + __ERC20_init(name, symbol); |
| 40 | + __ERC20Snapshot_init(); |
| 41 | + __ERC20Pausable_init(); |
| 42 | + } |
| 43 | + |
| 44 | + // Call this on the implementation contract (not the proxy) |
| 45 | + function initializeImplementation() public initializer { |
| 46 | + __Ownable_init(); |
| 47 | + _pause(); |
| 48 | + } |
| 49 | + |
| 50 | + /** |
| 51 | + * Mints new tokens. |
| 52 | + * @param account the account to mint the tokens for |
| 53 | + * @param amount the amount of tokens to mint. |
| 54 | + */ |
| 55 | + function mint(address account, uint256 amount) external onlyOwner { |
| 56 | + _mint(account, amount); |
| 57 | + } |
| 58 | + |
| 59 | + /** |
| 60 | + * Burns tokens from an address. |
| 61 | + * @param account the account to mint the tokens for |
| 62 | + * @param amount the amount of tokens to mint. |
| 63 | + */ |
| 64 | + function burn(address account, uint256 amount) external onlyOwner { |
| 65 | + _burn(account, amount); |
| 66 | + } |
| 67 | + |
| 68 | + /** |
| 69 | + * Pauses the token contract preventing any token mint/transfer/burn operations. |
| 70 | + * Can only be called if the contract is unpaused. |
| 71 | + */ |
| 72 | + function pause() external onlyOwner { |
| 73 | + _pause(); |
| 74 | + } |
| 75 | + |
| 76 | + /** |
| 77 | + * Unpauses the token contract preventing any token mint/transfer/burn operations |
| 78 | + * Can only be called if the contract is paused. |
| 79 | + */ |
| 80 | + function unpause() external onlyOwner { |
| 81 | + _unpause(); |
| 82 | + } |
| 83 | + |
| 84 | + /** |
| 85 | + * Creates a token balance snapshot. Ideally this would be called by the |
| 86 | + * controlling DAO whenever a proposal is made. |
| 87 | + */ |
| 88 | + function snapshot() external returns (uint256) { |
| 89 | + require( |
| 90 | + authorizedToSnapshot[_msgSender()] || _msgSender() == owner(), |
| 91 | + "zDAOToken: Not authorized to snapshot" |
| 92 | + ); |
| 93 | + return _snapshot(); |
| 94 | + } |
| 95 | + |
| 96 | + /** |
| 97 | + * Authorizes an account to take snapshots |
| 98 | + * @param account The account to authorize |
| 99 | + */ |
| 100 | + function authorizeSnapshotter(address account) external onlyOwner { |
| 101 | + require( |
| 102 | + !authorizedToSnapshot[account], |
| 103 | + "zDAOToken: Account already authorized" |
| 104 | + ); |
| 105 | + |
| 106 | + authorizedToSnapshot[account] = true; |
| 107 | + emit AuthorizedSnapshotter(account); |
| 108 | + } |
| 109 | + |
| 110 | + /** |
| 111 | + * Deauthorizes an account to take snapshots |
| 112 | + * @param account The account to de-authorize |
| 113 | + */ |
| 114 | + function deauthorizeSnapshotter(address account) external onlyOwner { |
| 115 | + require(authorizedToSnapshot[account], "zDAOToken: Account not authorized"); |
| 116 | + |
| 117 | + authorizedToSnapshot[account] = false; |
| 118 | + emit DeauthorizedSnapshotter(account); |
| 119 | + } |
| 120 | + |
| 121 | + /** |
| 122 | + * Withdraws ERC20 tokens that are stuck in this contract. |
| 123 | + * @param token The ERC20 token contract address to withdraw |
| 124 | + * @param to The address to send the tokens to |
| 125 | + * @param amount The amount of tokens to withdraw (0 means withdraw all available) |
| 126 | + */ |
| 127 | + function withdrawERC20( |
| 128 | + IERC20 token, |
| 129 | + address to, |
| 130 | + uint256 amount |
| 131 | + ) external onlyOwner { |
| 132 | + require( |
| 133 | + address(token) != address(0), |
| 134 | + "zDAOToken: Token address cannot be zero" |
| 135 | + ); |
| 136 | + require( |
| 137 | + address(token) != address(this), |
| 138 | + "zDAOToken: Token address cannot be this token" |
| 139 | + ); |
| 140 | + require(to != address(0), "zDAOToken: Recipient address cannot be zero"); |
| 141 | + |
| 142 | + uint256 withdrawAmount; |
| 143 | + if (amount == 0) { |
| 144 | + // If amount is 0, withdraw all available tokens |
| 145 | + withdrawAmount = token.balanceOf(address(this)); |
| 146 | + } else { |
| 147 | + // Otherwise, ensure the requested amount doesn't exceed the contract's balance |
| 148 | + withdrawAmount = amount; |
| 149 | + } |
| 150 | + |
| 151 | + token.safeTransfer(to, withdrawAmount); |
| 152 | + |
| 153 | + emit ERC20TokenWithdrawn(token, to, withdrawAmount); |
| 154 | + } |
| 155 | + |
| 156 | + /** |
| 157 | + * Utility function to transfer tokens to many addresses at once. |
| 158 | + * @param recipients The addresses to send tokens to |
| 159 | + * @param amount The amount of tokens to send |
| 160 | + * @return Boolean if the transfer was a success |
| 161 | + */ |
| 162 | + function transferBulk( |
| 163 | + address[] calldata recipients, |
| 164 | + uint256 amount |
| 165 | + ) external returns (bool) { |
| 166 | + address sender = _msgSender(); |
| 167 | + |
| 168 | + uint256 total = amount * recipients.length; |
| 169 | + require( |
| 170 | + _balances[sender] >= total, |
| 171 | + "ERC20: transfer amount exceeds balance" |
| 172 | + ); |
| 173 | + |
| 174 | + require(!paused(), "ERC20Pausable: token transfer while paused"); |
| 175 | + |
| 176 | + _balances[sender] -= total; |
| 177 | + _updateAccountSnapshot(sender); |
| 178 | + |
| 179 | + for (uint256 i = 0; i < recipients.length; ++i) { |
| 180 | + address recipient = recipients[i]; |
| 181 | + require(recipient != address(0), "ERC20: transfer to the zero address"); |
| 182 | + |
| 183 | + // Note: _beforeTokenTransfer isn't called here |
| 184 | + // This function emulates what it would do (paused and snapshot) |
| 185 | + |
| 186 | + _balances[recipient] += amount; |
| 187 | + |
| 188 | + _updateAccountSnapshot(recipient); |
| 189 | + |
| 190 | + emit Transfer(sender, recipient, amount); |
| 191 | + } |
| 192 | + |
| 193 | + return true; |
| 194 | + } |
| 195 | + |
| 196 | + /** |
| 197 | + * Utility function to transfer tokens to many addresses at once. |
| 198 | + * @param sender The address to send the tokens from |
| 199 | + * @param recipients The addresses to send tokens to |
| 200 | + * @param amount The amount of tokens to send |
| 201 | + * @return Boolean if the transfer was a success |
| 202 | + */ |
| 203 | + function transferFromBulk( |
| 204 | + address sender, |
| 205 | + address[] calldata recipients, |
| 206 | + uint256 amount |
| 207 | + ) external returns (bool) { |
| 208 | + require(!paused(), "ERC20Pausable: token transfer while paused"); |
| 209 | + |
| 210 | + uint256 total = amount * recipients.length; |
| 211 | + require( |
| 212 | + _balances[sender] >= total, |
| 213 | + "ERC20: transfer amount exceeds balance" |
| 214 | + ); |
| 215 | + |
| 216 | + // Ensure enough allowance |
| 217 | + uint256 currentAllowance = _allowances[sender][_msgSender()]; |
| 218 | + require( |
| 219 | + currentAllowance >= total, |
| 220 | + "ERC20: transfer total exceeds allowance" |
| 221 | + ); |
| 222 | + _approve(sender, _msgSender(), currentAllowance - total); |
| 223 | + |
| 224 | + _balances[sender] -= total; |
| 225 | + _updateAccountSnapshot(sender); |
| 226 | + |
| 227 | + for (uint256 i = 0; i < recipients.length; ++i) { |
| 228 | + address recipient = recipients[i]; |
| 229 | + require(recipient != address(0), "ERC20: transfer to the zero address"); |
| 230 | + |
| 231 | + // Note: _beforeTokenTransfer isn't called here |
| 232 | + // This function emulates what it would do (paused and snapshot) |
| 233 | + |
| 234 | + _balances[recipient] += amount; |
| 235 | + |
| 236 | + _updateAccountSnapshot(recipient); |
| 237 | + |
| 238 | + emit Transfer(sender, recipient, amount); |
| 239 | + } |
| 240 | + |
| 241 | + return true; |
| 242 | + } |
| 243 | + |
| 244 | + function _beforeTokenTransfer( |
| 245 | + address from, |
| 246 | + address to, |
| 247 | + uint256 amount |
| 248 | + ) |
| 249 | + internal |
| 250 | + virtual |
| 251 | + override( |
| 252 | + ERC20PausableUpgradeable, |
| 253 | + ERC20SnapshotUpgradeable, |
| 254 | + ERC20Upgradeable |
| 255 | + ) |
| 256 | + { |
| 257 | + super._beforeTokenTransfer(from, to, amount); |
| 258 | + } |
| 259 | +} |
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