@polycity/core/artifacts/build-info/a3ce3d8975341c6308ed54080a5f8b11.json

Core contracts for the PolyCityDex protocol

{
  "id": "a3ce3d8975341c6308ed54080a5f8b11",
  "_format": "hh-sol-build-info-1",
  "solcVersion": "0.6.12",
  "solcLongVersion": "0.6.12+commit.27d51765",
  "input": {
    "language": "Solidity",
    "sources": {
      "contracts/governance/Timelock.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\n// COPIED FROM https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/GovernorAlpha.sol\n// Copyright 2020 Compound Labs, Inc.\n// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:\n// 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.\n// 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.\n// 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.\n// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS \"AS IS\" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\n//\n// Ctrl+f for XXX to see all the modifications.\n\n// XXX: pragma solidity ^0.5.16;\npragma solidity 0.6.12;\n\n// XXX: import \"./SafeMath.sol\";\nimport \"@openzeppelin/contracts/math/SafeMath.sol\";\nimport \"@openzeppelin/contracts/access/Ownable.sol\";\n\ncontract Timelock {\n    using SafeMath for uint256;\n\n    event NewAdmin(address indexed newAdmin);\n    event NewPendingAdmin(address indexed newPendingAdmin);\n    event NewDelay(uint256 indexed newDelay);\n    event CancelTransaction(bytes32 indexed txHash, address indexed target, uint256 value, string signature, bytes data, uint256 eta);\n    event ExecuteTransaction(bytes32 indexed txHash, address indexed target, uint256 value, string signature, bytes data, uint256 eta);\n    event QueueTransaction(bytes32 indexed txHash, address indexed target, uint256 value, string signature, bytes data, uint256 eta);\n\n    uint256 public constant GRACE_PERIOD = 14 days;\n    uint256 public constant MINIMUM_DELAY = 2 days;\n    uint256 public constant MAXIMUM_DELAY = 30 days;\n\n    address public admin;\n    address public pendingAdmin;\n    uint256 public delay;\n    bool public admin_initialized;\n\n    mapping(bytes32 => bool) public queuedTransactions;\n\n    constructor(address admin_, uint256 delay_) public {\n        require(delay_ >= MINIMUM_DELAY, \"Timelock::constructor: Delay must exceed minimum delay.\");\n        require(delay_ <= MAXIMUM_DELAY, \"Timelock::constructor: Delay must not exceed maximum delay.\");\n\n        admin = admin_;\n        delay = delay_;\n        admin_initialized = false;\n    }\n\n    // XXX: function() external payable { }\n    receive() external payable {}\n\n    function setDelay(uint256 delay_) public {\n        require(msg.sender == address(this), \"Timelock::setDelay: Call must come from Timelock.\");\n        require(delay_ >= MINIMUM_DELAY, \"Timelock::setDelay: Delay must exceed minimum delay.\");\n        require(delay_ <= MAXIMUM_DELAY, \"Timelock::setDelay: Delay must not exceed maximum delay.\");\n        delay = delay_;\n\n        emit NewDelay(delay);\n    }\n\n    function acceptAdmin() public {\n        require(msg.sender == pendingAdmin, \"Timelock::acceptAdmin: Call must come from pendingAdmin.\");\n        admin = msg.sender;\n        pendingAdmin = address(0);\n\n        emit NewAdmin(admin);\n    }\n\n    function setPendingAdmin(address pendingAdmin_) public {\n        // allows one time setting of admin for deployment purposes\n        if (admin_initialized) {\n            require(msg.sender == address(this), \"Timelock::setPendingAdmin: Call must come from Timelock.\");\n        } else {\n            require(msg.sender == admin, \"Timelock::setPendingAdmin: First call must come from admin.\");\n            admin_initialized = true;\n        }\n        pendingAdmin = pendingAdmin_;\n\n        emit NewPendingAdmin(pendingAdmin);\n    }\n\n    function setDirectAdmin(address directAdmin_) public {\n        require(directAdmin_ != address(0), \"Timelock::setDirectAdmin: zero admin address\");\n        Ownable(directAdmin_).transferOwnership(admin);\n    }\n\n    function queueTransaction(\n        address target,\n        uint256 value,\n        string memory signature,\n        bytes memory data,\n        uint256 eta\n    ) public returns (bytes32) {\n        require(msg.sender == admin, \"Timelock::queueTransaction: Call must come from admin.\");\n        require(eta >= getBlockTimestamp().add(delay), \"Timelock::queueTransaction: Estimated execution block must satisfy delay.\");\n\n        bytes32 txHash = keccak256(abi.encode(target, value, signature, data, eta));\n        queuedTransactions[txHash] = true;\n\n        emit QueueTransaction(txHash, target, value, signature, data, eta);\n        return txHash;\n    }\n\n    function cancelTransaction(\n        address target,\n        uint256 value,\n        string memory signature,\n        bytes memory data,\n        uint256 eta\n    ) public {\n        require(msg.sender == admin, \"Timelock::cancelTransaction: Call must come from admin.\");\n\n        bytes32 txHash = keccak256(abi.encode(target, value, signature, data, eta));\n        queuedTransactions[txHash] = false;\n\n        emit CancelTransaction(txHash, target, value, signature, data, eta);\n    }\n\n    function executeTransaction(\n        address target,\n        uint256 value,\n        string memory signature,\n        bytes memory data,\n        uint256 eta\n    ) public payable returns (bytes memory) {\n        require(msg.sender == admin, \"Timelock::executeTransaction: Call must come from admin.\");\n\n        bytes32 txHash = keccak256(abi.encode(target, value, signature, data, eta));\n        require(queuedTransactions[txHash], \"Timelock::executeTransaction: Transaction hasn't been queued.\");\n        require(getBlockTimestamp() >= eta, \"Timelock::executeTransaction: Transaction hasn't surpassed time lock.\");\n        require(getBlockTimestamp() <= eta.add(GRACE_PERIOD), \"Timelock::executeTransaction: Transaction is stale.\");\n\n        queuedTransactions[txHash] = false;\n\n        bytes memory callData;\n\n        if (bytes(signature).length == 0) {\n            callData = data;\n        } else {\n            callData = abi.encodePacked(bytes4(keccak256(bytes(signature))), data);\n        }\n\n        // solium-disable-next-line security/no-call-value\n        (bool success, bytes memory returnData) = target.call.value(value)(callData);\n        require(success, \"Timelock::executeTransaction: Transaction execution reverted.\");\n\n        emit ExecuteTransaction(txHash, target, value, signature, data, eta);\n\n        return returnData;\n    }\n\n    function getBlockTimestamp() internal view returns (uint256) {\n        // solium-disable-next-line security/no-block-members\n        return block.timestamp;\n    }\n}\n"
      },
      "@openzeppelin/contracts/math/SafeMath.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.0 <0.8.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        uint256 c = a + b;\n        if (c < a) return (false, 0);\n        return (true, c);\n    }\n\n    /**\n     * @dev Returns the substraction of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        if (b > a) return (false, 0);\n        return (true, a - b);\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) return (true, 0);\n        uint256 c = a * b;\n        if (c / a != b) return (false, 0);\n        return (true, c);\n    }\n\n    /**\n     * @dev Returns the division of two unsigned integers, with a division by zero flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        if (b == 0) return (false, 0);\n        return (true, a / b);\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        if (b == 0) return (false, 0);\n        return (true, a % b);\n    }\n\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     *\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        return a - b;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     *\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        if (a == 0) return 0;\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers, reverting on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b > 0, \"SafeMath: division by zero\");\n        return a / b;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * reverting when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b > 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n     * overflow (when the result is negative).\n     *\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\n     * message unnecessarily. For custom revert reasons use {trySub}.\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b <= a, errorMessage);\n        return a - b;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers, reverting with custom message on\n     * division by zero. The result is rounded towards zero.\n     *\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\n     * message unnecessarily. For custom revert reasons use {tryDiv}.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b > 0, errorMessage);\n        return a / b;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * reverting with custom message when dividing by zero.\n     *\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\n     * message unnecessarily. For custom revert reasons use {tryMod}.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b > 0, errorMessage);\n        return a % b;\n    }\n}\n"
      },
      "@openzeppelin/contracts/access/Ownable.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.0 <0.8.0;\n\nimport \"../utils/Context.sol\";\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\nabstract contract Ownable is Context {\n    address private _owner;\n\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n    /**\n     * @dev Initializes the contract setting the deployer as the initial owner.\n     */\n    constructor () internal {\n        address msgSender = _msgSender();\n        _owner = msgSender;\n        emit OwnershipTransferred(address(0), msgSender);\n    }\n\n    /**\n     * @dev Returns the address of the current owner.\n     */\n    function owner() public view virtual returns (address) {\n        return _owner;\n    }\n\n    /**\n     * @dev Throws if called by any account other than the owner.\n     */\n    modifier onlyOwner() {\n        require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\n        _;\n    }\n\n    /**\n     * @dev Leaves the contract without owner. It will not be possible to call\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\n     *\n     * NOTE: Renouncing ownership will leave the contract without an owner,\n     * thereby removing any functionality that is only available to the owner.\n     */\n    function renounceOwnership() public virtual onlyOwner {\n        emit OwnershipTransferred(_owner, address(0));\n        _owner = address(0);\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Can only be called by the current owner.\n     */\n    function transferOwnership(address newOwner) public virtual onlyOwner {\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n        emit OwnershipTransferred(_owner, newOwner);\n        _owner = newOwner;\n    }\n}\n"
      },
      "@openzeppelin/contracts/utils/Context.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.0 <0.8.0;\n\n/*\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with GSN meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n    function _msgSender() internal view virtual returns (address payable) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes memory) {\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\n        return msg.data;\n    }\n}\n"
      },
      "contracts/PolyCityDexToken.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity 0.6.12;\n\nimport \"@openzeppelin/contracts/token/ERC20/ERC20.sol\";\nimport \"@openzeppelin/contracts/access/Ownable.sol\";\n\n// WARNING: There is a known vuln contained within this contract related to vote delegation, \n// it's NOT recommmended to use this in production.  \n\n// PolyCityDexToken with Governance.\ncontract PolyCityDexToken is ERC20(\"PolyCityDexToken\", \"PICHI\"), Ownable {\n    /// @dev Creates `_amount` token to `_to`. Must only be called by the owner (MasterChef).\n    function mint(address _to, uint256 _amount) public onlyOwner {\n        _mint(_to, _amount);\n        _moveDelegates(address(0), _delegates[_to], _amount);\n    }\n\n    // Copied and modified from YAM code:\n    // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernanceStorage.sol\n    // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernance.sol\n    // Which is copied and modified from COMPOUND:\n    // https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/Comp.sol\n\n    /// @dev A record of each accounts delegate\n    mapping (address => address) internal _delegates;\n\n    /// @dev A checkpoint for marking number of votes from a given block\n    struct Checkpoint {\n        uint32 fromBlock;\n        uint256 votes;\n    }\n\n    /// @dev A record of votes checkpoints for each account, by index\n    mapping (address => mapping (uint32 => Checkpoint)) public checkpoints;\n\n    /// @dev The number of checkpoints for each account\n    mapping (address => uint32) public numCheckpoints;\n\n    /// @dev The EIP-712 typehash for the contract's domain\n    bytes32 public constant DOMAIN_TYPEHASH = keccak256(\"EIP712Domain(string name,uint256 chainId,address verifyingContract)\");\n\n    /// @dev The EIP-712 typehash for the delegation struct used by the contract\n    bytes32 public constant DELEGATION_TYPEHASH = keccak256(\"Delegation(address delegatee,uint256 nonce,uint256 expiry)\");\n\n    /// @dev A record of states for signing / validating signatures\n    mapping (address => uint) public nonces;\n\n      /// @dev An event thats emitted when an account changes its delegate\n    event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);\n\n    /// @dev An event thats emitted when a delegate account's vote balance changes\n    event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance);\n\n    /**\n     * @dev Delegate votes from `msg.sender` to `delegatee`\n     * @param delegator The address to get delegatee for\n     */\n    function delegates(address delegator)\n        external\n        view\n        returns (address)\n    {\n        return _delegates[delegator];\n    }\n\n   /**\n    * @dev Delegate votes from `msg.sender` to `delegatee`\n    * @param delegatee The address to delegate votes to\n    */\n    function delegate(address delegatee) external {\n        return _delegate(msg.sender, delegatee);\n    }\n\n    /**\n     * @dev Delegates votes from signatory to `delegatee`\n     * @param delegatee The address to delegate votes to\n     * @param nonce The contract state required to match the signature\n     * @param expiry The time at which to expire the signature\n     * @param v The recovery byte of the signature\n     * @param r Half of the ECDSA signature pair\n     * @param s Half of the ECDSA signature pair\n     */\n    function delegateBySig(\n        address delegatee,\n        uint nonce,\n        uint expiry,\n        uint8 v,\n        bytes32 r,\n        bytes32 s\n    )\n        external\n    {\n        bytes32 domainSeparator = keccak256(\n            abi.encode(\n                DOMAIN_TYPEHASH,\n                keccak256(bytes(name())),\n                getChainId(),\n                address(this)\n            )\n        );\n\n        bytes32 structHash = keccak256(\n            abi.encode(\n                DELEGATION_TYPEHASH,\n                delegatee,\n                nonce,\n                expiry\n            )\n        );\n\n        bytes32 digest = keccak256(\n            abi.encodePacked(\n                \"\\x19\\x01\",\n                domainSeparator,\n                structHash\n            )\n        );\n\n        address signatory = ecrecover(digest, v, r, s);\n        require(signatory != address(0), \"PICHI::delegateBySig: invalid signature\");\n        require(nonce == nonces[signatory]++, \"PICHI::delegateBySig: invalid nonce\");\n        require(now <= expiry, \"PICHI::delegateBySig: signature expired\");\n        return _delegate(signatory, delegatee);\n    }\n\n    /**\n     * @dev Gets the current votes balance for `account`\n     * @param account The address to get votes balance\n     * @return The number of current votes for `account`\n     */\n    function getCurrentVotes(address account)\n        external\n        view\n        returns (uint256)\n    {\n        uint32 nCheckpoints = numCheckpoints[account];\n        return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;\n    }\n\n    /**\n     * @dev Determine the prior number of votes for an account as of a block number\n     * @dev Block number must be a finalized block or else this function will revert to prevent misinformation.\n     * @param account The address of the account to check\n     * @param blockNumber The block number to get the vote balance at\n     * @return The number of votes the account had as of the given block\n     */\n    function getPriorVotes(address account, uint blockNumber)\n        external\n        view\n        returns (uint256)\n    {\n        require(blockNumber < block.number, \"PICHI::getPriorVotes: not yet determined\");\n\n        uint32 nCheckpoints = numCheckpoints[account];\n        if (nCheckpoints == 0) {\n            return 0;\n        }\n\n        // First check most recent balance\n        if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {\n            return checkpoints[account][nCheckpoints - 1].votes;\n        }\n\n        // Next check implicit zero balance\n        if (checkpoints[account][0].fromBlock > blockNumber) {\n            return 0;\n        }\n\n        uint32 lower = 0;\n        uint32 upper = nCheckpoints - 1;\n        while (upper > lower) {\n            uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow\n            Checkpoint memory cp = checkpoints[account][center];\n            if (cp.fromBlock == blockNumber) {\n                return cp.votes;\n            } else if (cp.fromBlock < blockNumber) {\n                lower = center;\n            } else {\n                upper = center - 1;\n            }\n        }\n        return checkpoints[account][lower].votes;\n    }\n\n    function _delegate(address delegator, address delegatee)\n        internal\n    {\n        address currentDelegate = _delegates[delegator];\n        uint256 delegatorBalance = balanceOf(delegator); // balance of underlying PICHIs (not scaled);\n        _delegates[delegator] = delegatee;\n\n        emit DelegateChanged(delegator, currentDelegate, delegatee);\n\n        _moveDelegates(currentDelegate, delegatee, delegatorBalance);\n    }\n\n    function _moveDelegates(address srcRep, address dstRep, uint256 amount) internal {\n        if (srcRep != dstRep && amount > 0) {\n            if (srcRep != address(0)) {\n                // decrease old representative\n                uint32 srcRepNum = numCheckpoints[srcRep];\n                uint256 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;\n                uint256 srcRepNew = srcRepOld.sub(amount);\n                _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);\n            }\n\n            if (dstRep != address(0)) {\n                // increase new representative\n                uint32 dstRepNum = numCheckpoints[dstRep];\n                uint256 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;\n                uint256 dstRepNew = dstRepOld.add(amount);\n                _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);\n            }\n        }\n    }\n\n    function _writeCheckpoint(\n        address delegatee,\n        uint32 nCheckpoints,\n        uint256 oldVotes,\n        uint256 newVotes\n    )\n        internal\n    {\n        uint32 blockNumber = safe32(block.number, \"PICHI::_writeCheckpoint: block number exceeds 32 bits\");\n\n        if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {\n            checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;\n        } else {\n            checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);\n            numCheckpoints[delegatee] = nCheckpoints + 1;\n        }\n\n        emit DelegateVotesChanged(delegatee, oldVotes, newVotes);\n    }\n\n    function safe32(uint n, string memory errorMessage) internal pure returns (uint32) {\n        require(n < 2**32, errorMessage);\n        return uint32(n);\n    }\n\n    function getChainId() internal pure returns (uint) {\n        uint256 chainId;\n        assembly { chainId := chainid() }\n        return chainId;\n    }\n}"
      },
      "@openzeppelin/contracts/token/ERC20/ERC20.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.0 <0.8.0;\n\nimport \"../../utils/Context.sol\";\nimport \"./IERC20.sol\";\nimport \"../../math/SafeMath.sol\";\n\n/**\n * @dev Implementation of the {IERC20} interface.\n *\n * This implementation is agnostic to the way tokens are created. This means\n * that a supply mechanism has to be added in a derived contract using {_mint}.\n * For a generic mechanism see {ERC20PresetMinterPauser}.\n *\n * TIP: For a detailed writeup see our guide\n * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How\n * to implement supply mechanisms].\n *\n * We have followed general OpenZeppelin guidelines: functions revert instead\n * of returning `false` on failure. This behavior is nonetheless conventional\n * and does not conflict with the expectations of ERC20 applications.\n *\n * Additionally, an {Approval} event is emitted on calls to {transferFrom}.\n * This allows applications to reconstruct the allowance for all accounts just\n * by listening to said events. Other implementations of the EIP may not emit\n * these events, as it isn't required by the specification.\n *\n * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}\n * functions have been added to mitigate the well-known issues around setting\n * allowances. See {IERC20-approve}.\n */\ncontract ERC20 is Context, IERC20 {\n    using SafeMath for uint256;\n\n    mapping (address => uint256) private _balances;\n\n    mapping (address => mapping (address => uint256)) private _allowances;\n\n    uint256 private _totalSupply;\n\n    string private _name;\n    string private _symbol;\n    uint8 private _decimals;\n\n    /**\n     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with\n     * a default value of 18.\n     *\n     * To select a different value for {decimals}, use {_setupDecimals}.\n     *\n     * All three of these values are immutable: they can only be set once during\n     * construction.\n     */\n    constructor (string memory name_, string memory symbol_) public {\n        _name = name_;\n        _symbol = symbol_;\n        _decimals = 18;\n    }\n\n    /**\n     * @dev Returns the name of the token.\n     */\n    function name() public view virtual returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Returns the symbol of the token, usually a shorter version of the\n     * name.\n     */\n    function symbol() public view virtual returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns the number of decimals used to get its user representation.\n     * For example, if `decimals` equals `2`, a balance of `505` tokens should\n     * be displayed to a user as `5,05` (`505 / 10 ** 2`).\n     *\n     * Tokens usually opt for a value of 18, imitating the relationship between\n     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is\n     * called.\n     *\n     * NOTE: This information is only used for _display_ purposes: it in\n     * no way affects any of the arithmetic of the contract, including\n     * {IERC20-balanceOf} and {IERC20-transfer}.\n     */\n    function decimals() public view virtual returns (uint8) {\n        return _decimals;\n    }\n\n    /**\n     * @dev See {IERC20-totalSupply}.\n     */\n    function totalSupply() public view virtual override returns (uint256) {\n        return _totalSupply;\n    }\n\n    /**\n     * @dev See {IERC20-balanceOf}.\n     */\n    function balanceOf(address account) public view virtual override returns (uint256) {\n        return _balances[account];\n    }\n\n    /**\n     * @dev See {IERC20-transfer}.\n     *\n     * Requirements:\n     *\n     * - `recipient` cannot be the zero address.\n     * - the caller must have a balance of at least `amount`.\n     */\n    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {\n        _transfer(_msgSender(), recipient, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-allowance}.\n     */\n    function allowance(address owner, address spender) public view virtual override returns (uint256) {\n        return _allowances[owner][spender];\n    }\n\n    /**\n     * @dev See {IERC20-approve}.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function approve(address spender, uint256 amount) public virtual override returns (bool) {\n        _approve(_msgSender(), spender, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-transferFrom}.\n     *\n     * Emits an {Approval} event indicating the updated allowance. This is not\n     * required by the EIP. See the note at the beginning of {ERC20}.\n     *\n     * Requirements:\n     *\n     * - `sender` and `recipient` cannot be the zero address.\n     * - `sender` must have a balance of at least `amount`.\n     * - the caller must have allowance for ``sender``'s tokens of at least\n     * `amount`.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {\n        _transfer(sender, recipient, amount);\n        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, \"ERC20: transfer amount exceeds allowance\"));\n        return true;\n    }\n\n    /**\n     * @dev Atomically increases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));\n        return true;\n    }\n\n    /**\n     * @dev Atomically decreases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     * - `spender` must have allowance for the caller of at least\n     * `subtractedValue`.\n     */\n    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, \"ERC20: decreased allowance below zero\"));\n        return true;\n    }\n\n    /**\n     * @dev Moves tokens `amount` from `sender` to `recipient`.\n     *\n     * This is internal function is equivalent to {transfer}, and can be used to\n     * e.g. implement automatic token fees, slashing mechanisms, etc.\n     *\n     * Emits a {Transfer} event.\n     *\n     * Requirements:\n     *\n     * - `sender` cannot be the zero address.\n     * - `recipient` cannot be the zero address.\n     * - `sender` must have a balance of at least `amount`.\n     */\n    function _transfer(address sender, address recipient, uint256 amount) internal virtual {\n        require(sender != address(0), \"ERC20: transfer from the zero address\");\n        require(recipient != address(0), \"ERC20: transfer to the zero address\");\n\n        _beforeTokenTransfer(sender, recipient, amount);\n\n        _balances[sender] = _balances[sender].sub(amount, \"ERC20: transfer amount exceeds balance\");\n        _balances[recipient] = _balances[recipient].add(amount);\n        emit Transfer(sender, recipient, amount);\n    }\n\n    /** @dev Creates `amount` tokens and assigns them to `account`, increasing\n     * the total supply.\n     *\n     * Emits a {Transfer} event with `from` set to the zero address.\n     *\n     * Requirements:\n     *\n     * - `to` cannot be the zero address.\n     */\n    function _mint(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"ERC20: mint to the zero address\");\n\n        _beforeTokenTransfer(address(0), account, amount);\n\n        _totalSupply = _totalSupply.add(amount);\n        _balances[account] = _balances[account].add(amount);\n        emit Transfer(address(0), account, amount);\n    }\n\n    /**\n     * @dev Destroys `amount` tokens from `account`, reducing the\n     * total supply.\n     *\n     * Emits a {Transfer} event with `to` set to the zero address.\n     *\n     * Requirements:\n     *\n     * - `account` cannot be the zero address.\n     * - `account` must have at least `amount` tokens.\n     */\n    function _burn(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"ERC20: burn from the zero address\");\n\n        _beforeTokenTransfer(account, address(0), amount);\n\n        _balances[account] = _balances[account].sub(amount, \"ERC20: burn amount exceeds balance\");\n        _totalSupply = _totalSupply.sub(amount);\n        emit Transfer(account, address(0), amount);\n    }\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.\n     *\n     * This internal function is equivalent to `approve`, and can be used to\n     * e.g. set automatic allowances for certain subsystems, etc.\n     *\n     * Emits an {Approval} event.\n     *\n     * Requirements:\n     *\n     * - `owner` cannot be the zero address.\n     * - `spender` cannot be the zero address.\n     */\n    function _approve(address owner, address spender, uint256 amount) internal virtual {\n        require(owner != address(0), \"ERC20: approve from the zero address\");\n        require(spender != address(0), \"ERC20: approve to the zero address\");\n\n        _allowances[owner][spender] = amount;\n        emit Approval(owner, spender, amount);\n    }\n\n    /**\n     * @dev Sets {decimals} to a value other than the default one of 18.\n     *\n     * WARNING: This function should only be called from the constructor. Most\n     * applications that interact with token contracts will not expect\n     * {decimals} to ever change, and may work incorrectly if it does.\n     */\n    function _setupDecimals(uint8 decimals_) internal virtual {\n        _decimals = decimals_;\n    }\n\n    /**\n     * @dev Hook that is called before any transfer of tokens. This includes\n     * minting and burning.\n     *\n     * Calling conditions:\n     *\n     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens\n     * will be to transferred to `to`.\n     * - when `from` is zero, `amount` tokens will be minted for `to`.\n     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.\n     * - `from` and `to` are never both zero.\n     *\n     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n     */\n    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }\n}\n"
      },
      "@openzeppelin/contracts/token/ERC20/IERC20.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.0 <0.8.0;\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n    /**\n     * @dev Returns the amount of tokens in existence.\n     */\n    function totalSupply() external view returns (uint256);\n\n    /**\n     * @dev Returns the amount of tokens owned by `account`.\n     */\n    function balanceOf(address account) external view returns (uint256);\n\n    /**\n     * @dev Moves `amount` tokens from the caller's account to `recipient`.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transfer(address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Returns the remaining number of tokens that `spender` will be\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\n     * zero by default.\n     *\n     * This value changes when {approve} or {transferFrom} are called.\n     */\n    function allowance(address owner, address spender) external view returns (uint256);\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\n     * that someone may use both the old and the new allowance by unfortunate\n     * transaction ordering. One possible solution to mitigate this race\n     * condition is to first reduce the spender's allowance to 0 and set the\n     * desired value afterwards:\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address spender, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Moves `amount` tokens from `sender` to `recipient` using the\n     * allowance mechanism. `amount` is then deducted from the caller's\n     * allowance.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\n     * another (`to`).\n     *\n     * Note that `value` may be zero.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 value);\n\n    /**\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n     * a call to {approve}. `value` is the new allowance.\n     */\n    event Approval(address indexed owner, address indexed spender, uint256 value);\n}\n"
      },
      "contracts/PolyCityHall.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity 0.6.12;\n\nimport \"@openzeppelin/contracts/token/ERC20/IERC20.sol\";\nimport \"@openzeppelin/contracts/token/ERC20/ERC20.sol\";\nimport \"@openzeppelin/contracts/math/SafeMath.sol\";\n\n// PolyCityHall is the coolest bar in town. You come in with some Pichi, and leave with more! The longer you stay, the more Pichi you get.\n//\n// This contract handles swapping to and from xPichi, PolyCityDex's staking token.\ncontract PolyCityHall is ERC20(\"PolyCityHall\", \"xPICHI\"){\n    using SafeMath for uint256;\n    IERC20 public pichi;\n\n    // Define the Pichi token contract\n    constructor(IERC20 _pichi) public {\n        pichi = _pichi;\n    }\n\n    // Enter the bar. Pay some PICHIs. Earn some shares.\n    // Locks Pichi and mints xPichi\n    function enter(uint256 _amount) public {\n        // Gets the amount of Pichi locked in the contract\n        uint256 totalPichi = pichi.balanceOf(address(this));\n        // Gets the amount of xPichi in existence\n        uint256 totalShares = totalSupply();\n        // If no xPichi exists, mint it 1:1 to the amount put in\n        if (totalShares == 0 || totalPichi == 0) {\n            _mint(msg.sender, _amount);\n        } \n        // Calculate and mint the amount of xPichi the Pichi is worth. The ratio will change overtime, as xPichi is burned/minted and Pichi deposited + gained from fees / withdrawn.\n        else {\n            uint256 what = _amount.mul(totalShares).div(totalPichi);\n            _mint(msg.sender, what);\n        }\n        // Lock the Pichi in the contract\n        pichi.transferFrom(msg.sender, address(this), _amount);\n    }\n\n    // Leave the bar. Claim back your PICHIs.\n    // Unlocks the staked + gained Pichi and burns xPichi\n    function leave(uint256 _share) public {\n        // Gets the amount of xPichi in existence\n        uint256 totalShares = totalSupply();\n        // Calculates the amount of Pichi the xPichi is worth\n        uint256 what = _share.mul(pichi.balanceOf(address(this))).div(totalShares);\n        _burn(msg.sender, _share);\n        pichi.transfer(msg.sender, what);\n    }\n}\n"
      },
      "@openzeppelin/contracts/token/ERC20/SafeERC20.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.0 <0.8.0;\n\nimport \"./IERC20.sol\";\nimport \"../../math/SafeMath.sol\";\nimport \"../../utils/Address.sol\";\n\n/**\n * @title SafeERC20\n * @dev Wrappers around ERC20 operations that throw on failure (when the token\n * contract returns false). Tokens that return no value (and instead revert or\n * throw on failure) are also supported, non-reverting calls are assumed to be\n * successful.\n * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,\n * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.\n */\nlibrary SafeERC20 {\n    using SafeMath for uint256;\n    using Address for address;\n\n    function safeTransfer(IERC20 token, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));\n    }\n\n    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));\n    }\n\n    /**\n     * @dev Deprecated. This function has issues similar to the ones found in\n     * {IERC20-approve}, and its usage is discouraged.\n     *\n     * Whenever possible, use {safeIncreaseAllowance} and\n     * {safeDecreaseAllowance} instead.\n     */\n    function safeApprove(IERC20 token, address spender, uint256 value) internal {\n        // safeApprove should only be called when setting an initial allowance,\n        // or when resetting it to zero. To increase and decrease it, use\n        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'\n        // solhint-disable-next-line max-line-length\n        require((value == 0) || (token.allowance(address(this), spender) == 0),\n            \"SafeERC20: approve from non-zero to non-zero allowance\"\n        );\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));\n    }\n\n    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 newAllowance = token.allowance(address(this), spender).add(value);\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 newAllowance = token.allowance(address(this), spender).sub(value, \"SafeERC20: decreased allowance below zero\");\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    /**\n     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement\n     * on the return value: the return value is optional (but if data is returned, it must not be false).\n     * @param token The token targeted by the call.\n     * @param data The call data (encoded using abi.encode or one of its variants).\n     */\n    function _callOptionalReturn(IERC20 token, bytes memory data) private {\n        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since\n        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that\n        // the target address contains contract code and also asserts for success in the low-level call.\n\n        bytes memory returndata = address(token).functionCall(data, \"SafeERC20: low-level call failed\");\n        if (returndata.length > 0) { // Return data is optional\n            // solhint-disable-next-line max-line-length\n            require(abi.decode(returndata, (bool)), \"SafeERC20: ERC20 operation did not succeed\");\n        }\n    }\n}\n"
      },
      "@openzeppelin/contracts/utils/Address.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.2 <0.8.0;\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * [IMPORTANT]\n     * ====\n     * It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     *\n     * Among others, `isContract` will return false for the following\n     * types of addresses:\n     *\n     *  - an externally-owned account\n     *  - a contract in construction\n     *  - an address where a contract will be created\n     *  - an address where a contract lived, but was destroyed\n     * ====\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies on extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n\n    /**\n     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to\n     * `recipient`, forwarding all available gas and reverting on errors.\n     *\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\n     * imposed by `transfer`, making them unable