// SPDX-License-Identifier: MIT

pragma solidity ^0.8.3;

/**
 * Reads the votes that an account has.
 */
interface IHasVotes {
    /**
     * @notice Gets the current votes balance for `account`
     * @param account The address to get votes balance
     * @return The number of current votes for `account`
     */
    function getCurrentVotes(address account) external view returns (uint96);

    /**
     * @notice Determine the prior number of votes for an account as of a block number
     * @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
     * @param account The address of the account to check
     * @param blockNumber The block number to get the vote balance at
     * @return The number of votes the account had as of the given block
     */
    function getPriorVotes(address account, uint256 blockNumber)
        external
        view
        returns (uint96);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.3;

/**
 * A token that cannot be transferred.
 */
interface INonTransferrableToken {
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function decimals() external view returns (uint8);

    // Views
    function totalSupply() external view returns (uint256);

    function balanceOf(address _account) external view returns (uint256);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.3;

/**
 * Interface for a contract that keeps track of voting delegates.
 */
interface IVotingDelegates {
    /// @notice An event thats emitted when an account changes its delegate
    event DelegateChanged(
        address indexed delegator,
        address indexed fromDelegate,
        address indexed toDelegate
    );

    /// @notice An event thats emitted when a delegate account's vote balance changes
    event DelegateVotesChanged(
        address indexed delegate,
        uint256 previousBalance,
        uint256 newBalance
    );

    /// @notice An event emitted when an account's voting power is transferred.
    // - If `from` is `address(0)`, power was minted.
    // - If `to` is `address(0)`, power was burned.
    event Transfer(address indexed from, address indexed to, uint256 amount);

    /// @notice Name of the contract.
    // Required for signing.
    function name() external view returns (string memory);

    /// @notice A record of each accounts delegate
    function delegates(address delegatee) external view returns (address);

    /**
     * @notice Delegate votes from `msg.sender` to `delegatee`
     * @param delegatee The address to delegate votes to
     */
    function delegate(address delegatee) external;

    /**
     * @notice Delegates votes from signatory to `delegatee`
     * @param delegatee The address to delegate votes to
     * @param nonce The contract state required to match the signature
     * @param expiry The time at which to expire the signature
     * @param v The recovery byte of the signature
     * @param r Half of the ECDSA signature pair
     * @param s Half of the ECDSA signature pair
     */
    function delegateBySig(
        address delegatee,
        uint256 nonce,
        uint256 expiry,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @notice Get the amount of voting power of an account
     * @param account The address of the account to get the balance of
     * @return The amount of voting power held
     */
    function votingPower(address account) external view returns (uint96);

    /// @notice Total voting power in existence.
    function totalVotingPower() external view returns (uint96);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.3;

import "./VotingToken.sol";

contract TransferrableVotingToken is VotingToken {
    /**
     * @dev Sets the values for `name`, `symbol`, and `decimals`. All three of
     * these values are immutable: they can only be set once during
     * construction.
     * @param initialSupply_ Initial supply of tokens
     * @param account_ The initial account to grant all the tokens
     */
    constructor(
        string memory name_,
        string memory symbol_,
        uint8 decimals_,
        uint96 initialSupply_,
        address account_
    ) VotingToken(name_, symbol_, decimals_) {
        _mintVotes(account_, initialSupply_);
    }

    ////////////////////////////////
    //
    // The below code is copied from Uniswap's Uni.sol.
    // Changes are marked with "XXX".
    //
    ////////////////////////////////

    // XXX: deleted name, symbol, decimals, totalSupply, minter, mintingAllowedAfter,
    // minimumTimeBetweenMints, mintCap

    // Allowance amounts on behalf of others
    mapping (address => mapping (address => uint96)) internal allowances;

    // XXX: balances, delegates, Checkpoint, checkpoints,
    // numCheckpoints, DOMAIN_TYPEHASH, DELEGATION_TYPEHASH
    // are inherited from VotingPower.sol

    /// @notice The EIP-712 typehash for the permit struct used by the contract
    bytes32 public constant PERMIT_TYPEHASH = keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");

    // XXX: nonces is inherited from VotingPower.sol

    // XXX: deleted MinterChanged

    // XXX: deleted DelegateChanged, DelegateVotesChanged, Transfer and moved them to IVotingPower

    /// @notice The standard EIP-20 approval event
    event Approval(address indexed owner, address indexed spender, uint256 amount);

    // XXX: deleted constructor, setMinter, mint

    /**
     * @notice Get the number of tokens `spender` is approved to spend on behalf of `account`
     * @param account The address of the account holding the funds
     * @param spender The address of the account spending the funds
     * @return The number of tokens approved
     */
    function allowance(address account, address spender) external view returns (uint) {
        return allowances[account][spender];
    }

    // XXX_ADDED: upgrade to Solidity 0.8.3, which doesn't allow use of uintn(-1)
    uint256 internal constant MAX_INT = 2**256 - 1;
    uint96 internal constant MAX_INT_96 = 2**96 - 1;

    /**
     * @notice Approve `spender` to transfer up to `amount` from `src`
     * @dev This will overwrite the approval amount for `spender`
     *  and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve)
     * @param spender The address of the account which may transfer tokens
     * @param rawAmount The number of tokens that are approved (2^256-1 means infinite)
     * @return Whether or not the approval succeeded
     */
    function approve(address spender, uint rawAmount) external returns (bool) {
        uint96 amount;
        // XXX: uint256(-1) => MAX_INT
        if (rawAmount == MAX_INT) {
            // XXX: uint96(-1) => MAX_INT_96
            amount = MAX_INT_96;
        } else {
            amount = safe96(rawAmount, "Uni::approve: amount exceeds 96 bits");
        }

        allowances[msg.sender][spender] = amount;

        emit Approval(msg.sender, spender, amount);
        return true;
    }

    /**
     * @notice Triggers an approval from owner to spends
     * @param owner The address to approve from
     * @param spender The address to be approved
     * @param rawAmount The number of tokens that are approved (2^256-1 means infinite)
     * @param deadline The time at which to expire the signature
     * @param v The recovery byte of the signature
     * @param r Half of the ECDSA signature pair
     * @param s Half of the ECDSA signature pair
     */
    function permit(address owner, address spender, uint rawAmount, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        uint96 amount;
        // XXX: uint256(-1) => MAX_INT
        if (rawAmount == MAX_INT) {
            // XXX: uint96(-1) => MAX_INT_oy
            amount = MAX_INT_96;
        } else {
            amount = safe96(rawAmount, "Uni::permit: amount exceeds 96 bits");
        }

        // XXX_CHANGED: name => name()
        bytes32 domainSeparator = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name())), getChainId(), address(this)));
        bytes32 structHash = keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, rawAmount, nonces[owner]++, deadline));
        bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
        address signatory = ecrecover(digest, v, r, s);
        require(signatory != address(0), "Uni::permit: invalid signature");
        require(signatory == owner, "Uni::permit: unauthorized");
        // XXX: added linter disable
        // solhint-disable-next-line not-rely-on-time
        require(block.timestamp <= deadline, "Uni::permit: signature expired");

        allowances[owner][spender] = amount;

        emit Approval(owner, spender, amount);
    }

    // XXX: deleted balanceOf

    /**
     * @notice Transfer `amount` tokens from `msg.sender` to `dst`
     * @param dst The address of the destination account
     * @param rawAmount The number of tokens to transfer
     * @return Whether or not the transfer succeeded
     */
    function transfer(address dst, uint rawAmount) external returns (bool) {
        // XXX_ADDED
        require(
            dst != address(this),
            "TransferrableVotingToken::transfer: cannot send tokens to contract"
        );
        uint96 amount = safe96(rawAmount, "Uni::transfer: amount exceeds 96 bits");
        _transferTokens(msg.sender, dst, amount);
        return true;
    }

    /**
     * @notice Transfer `amount` tokens from `src` to `dst`
     * @param src The address of the source account
     * @param dst The address of the destination account
     * @param rawAmount The number of tokens to transfer
     * @return Whether or not the transfer succeeded
     */
    function transferFrom(address src, address dst, uint rawAmount) external returns (bool) {
        // XXX_ADDED
        require(
            dst != address(this),
            "TransferrableVotingToken::transferFrom: cannot send tokens to contract"
        );
        address spender = msg.sender;
        uint96 spenderAllowance = allowances[src][spender];
        uint96 amount = safe96(rawAmount, "Uni::approve: amount exceeds 96 bits");

        // XXX: uint96(-1) => MAX_INT_96
        if (spender != src && spenderAllowance != MAX_INT_96) {
            uint96 newAllowance = sub96(spenderAllowance, amount, "Uni::transferFrom: transfer amount exceeds spender allowance");
            allowances[src][spender] = newAllowance;

            emit Approval(src, spender, newAllowance);
        }

        _transferTokens(src, dst, amount);
        return true;
    }

    // XXX: rest is in VotingPower.sol
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.3;

import "./voting/TransferrableVotingToken.sol";

/**
 * Ubeswap governance token, based on Uni.
 */
contract UbeToken is TransferrableVotingToken {
    /// @notice The maximum supply of Ube Tokens.
    uint96 public constant MAX_SUPPLY = 100_000_000e18;

    /**
     * @notice Construct a new Ube token
     * Note: this contract doesn't specify an initial minter, so there is no way new
     * tokens can get created.
     * @param _initialOwner The initial account to grant all the tokens
     */
    constructor(address _initialOwner)
        TransferrableVotingToken(
            "Ubeswap",
            "UBE",
            18,
            MAX_SUPPLY,
            _initialOwner
        )
    // solhint-disable-next-line no-empty-blocks
    {
        // Do nothing
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.3;

import "../interfaces/IHasVotes.sol";
import "../interfaces/IVotingDelegates.sol";

/**
 * Power to vote. Heavily based on Uni.
 */
contract VotingPower is IHasVotes, IVotingDelegates {
    // Name of the token. This cannot be changed after creating the token.
    string private _name;

    // Total amount of voting power available.
    uint96 private totalVotingPowerSupply;

    constructor(string memory name_) {
        _name = name_;
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @notice Mint new voting power
     * @param dst The address of the destination account
     * @param amount The amount of voting power to be minted
     */
    function _mintVotes(address dst, uint96 amount) internal {
        require(dst != address(0), "VotingPower::_mintVotes: cannot mint to the zero address");

        // transfer the amount to the recipient
        balances[dst] = add96(balances[dst], amount, "VotingPower::_mintVotes: mint amount overflows");
        totalVotingPowerSupply = add96(
            totalVotingPowerSupply, amount, "VotingPower::_mintVotes: total supply overflows"
        );
        emit Transfer(address(0), dst, amount);

        // move delegates
        _moveDelegates(address(0), delegates[dst], amount);
    }

    /**
     * @notice Burn voting power
     * @param src The address of the source account
     * @param amount The amount of voting power to be burned
     */
    function _burnVotes(address src, uint96 amount) internal {
        require(src != address(0), "VotingPower::_burnVotes: cannot burn from the zero address");

        // transfer the amount to the recipient
        balances[src] = sub96(balances[src], amount, "VotingPower::_burnVotes: burn amount underflows");
        totalVotingPowerSupply = sub96(
            totalVotingPowerSupply, amount, "VotingPower::_burnVotes: total supply underflows"
        );
        emit Transfer(src, address(0), amount);

        // move delegates
        _moveDelegates(delegates[src], address(0), amount);
    }

    /**
     * @notice Get the amount of voting power of an account
     * @param account The address of the account to get the balance of
     * @return The amount of voting power held
     */
    function votingPower(address account) public view override returns (uint96) {
        return balances[account];
    }

    function totalVotingPower() public view override returns (uint96) {
        return totalVotingPowerSupply;
    }

    ////////////////////////////////
    //
    // The below code is copied from ../uniswap-governance/contracts/Uni.sol.
    // Changes are marked with "XXX".
    //
    ////////////////////////////////

    // XXX: deleted name, symbol, decimals, totalSupply, minter, mintingAllowedAfter,
    // minimumTimeBetweenMints, mintCap, allowances

    // Official record of token balances for each account
    // XXX: internal => private visibility
    mapping (address => uint96) private balances;

    /// @notice A record of each accounts delegate
    mapping (address => address) public override delegates;

    /// @notice A checkpoint for marking number of votes from a given block
    struct Checkpoint {
        uint32 fromBlock;
        uint96 votes;
    }

    /// @notice A record of votes checkpoints for each account, by index
    mapping (address => mapping (uint32 => Checkpoint)) public checkpoints;

    /// @notice The number of checkpoints for each account
    mapping (address => uint32) public numCheckpoints;

    /// @notice The EIP-712 typehash for the contract's domain
    bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");

    /// @notice The EIP-712 typehash for the delegation struct used by the contract
    bytes32 public constant DELEGATION_TYPEHASH = keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)");

    // XXX: deleted PERMIT_TYPEHASH

    /// @notice A record of states for signing / validating signatures
    mapping (address => uint) public nonces;

    // XXX: deleted MinterChanged

    // XXX: deleted DelegateChanged, DelegateVotesChanged, Transfer and moved them to IVotingPower

    // XXX: deleted Approval

    // XXX: deleted constructor, setMinter, mint, allowance, approve, permit, balanceOf

    // XXX: deleted transfer, transferFrom

    /**
     * @notice Delegate votes from `msg.sender` to `delegatee`
     * @param delegatee The address to delegate votes to
     */
    function delegate(address delegatee) public override {
        return _delegate(msg.sender, delegatee);
    }

    /**
     * @notice Delegates votes from signatory to `delegatee`
     * @param delegatee The address to delegate votes to
     * @param nonce The contract state required to match the signature
     * @param expiry The time at which to expire the signature
     * @param v The recovery byte of the signature
     * @param r Half of the ECDSA signature pair
     * @param s Half of the ECDSA signature pair
     */
    function delegateBySig(address delegatee, uint nonce, uint expiry, uint8 v, bytes32 r, bytes32 s) public override {
        // XXX_CHANGED: name => _name
        bytes32 domainSeparator = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(_name)), getChainId(), address(this)));
        bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry));
        bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
        address signatory = ecrecover(digest, v, r, s);
        require(signatory != address(0), "Uni::delegateBySig: invalid signature");
        require(nonce == nonces[signatory]++, "Uni::delegateBySig: invalid nonce");
        // XXX: added linter disable
        // solhint-disable-next-line not-rely-on-time
        require(block.timestamp <= expiry, "Uni::delegateBySig: signature expired");
        return _delegate(signatory, delegatee);
    }

    /**
     * @notice Gets the current votes balance for `account`
     * @param account The address to get votes balance
     * @return The number of current votes for `account`
     */
    function getCurrentVotes(address account) external view override returns (uint96) {
        uint32 nCheckpoints = numCheckpoints[account];
        return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;
    }

    /**
     * @notice Determine the prior number of votes for an account as of a block number
     * @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
     * @param account The address of the account to check
     * @param blockNumber The block number to get the vote balance at
     * @return The number of votes the account had as of the given block
     */
    function getPriorVotes(address account, uint blockNumber) public view override returns (uint96) {
        require(blockNumber < block.number, "Uni::getPriorVotes: not yet determined");

        uint32 nCheckpoints = numCheckpoints[account];
        if (nCheckpoints == 0) {
            return 0;
        }

        // First check most recent balance
        if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {
            return checkpoints[account][nCheckpoints - 1].votes;
        }

        // Next check implicit zero balance
        if (checkpoints[account][0].fromBlock > blockNumber) {
            return 0;
        }

        uint32 lower = 0;
        uint32 upper = nCheckpoints - 1;
        while (upper > lower) {
            uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
            Checkpoint memory cp = checkpoints[account][center];
            if (cp.fromBlock == blockNumber) {
                return cp.votes;
            } else if (cp.fromBlock < blockNumber) {
                lower = center;
            } else {
                upper = center - 1;
            }
        }
        return checkpoints[account][lower].votes;
    }

    function _delegate(address delegator, address delegatee) internal {
        address currentDelegate = delegates[delegator];
        uint96 delegatorBalance = balances[delegator];
        delegates[delegator] = delegatee;

        emit DelegateChanged(delegator, currentDelegate, delegatee);

        _moveDelegates(currentDelegate, delegatee, delegatorBalance);
    }

    function _transferTokens(address src, address dst, uint96 amount) internal {
        require(src != address(0), "Uni::_transferTokens: cannot transfer from the zero address");
        require(dst != address(0), "Uni::_transferTokens: cannot transfer to the zero address");

        balances[src] = sub96(balances[src], amount, "Uni::_transferTokens: transfer amount exceeds balance");
        balances[dst] = add96(balances[dst], amount, "Uni::_transferTokens: transfer amount overflows");
        emit Transfer(src, dst, amount);

        _moveDelegates(delegates[src], delegates[dst], amount);
    }

    function _moveDelegates(address srcRep, address dstRep, uint96 amount) internal {
        if (srcRep != dstRep && amount > 0) {
            if (srcRep != address(0)) {
                uint32 srcRepNum = numCheckpoints[srcRep];
                uint96 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;
                uint96 srcRepNew = sub96(srcRepOld, amount, "Uni::_moveVotes: vote amount underflows");
                _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);
            }

            if (dstRep != address(0)) {
                uint32 dstRepNum = numCheckpoints[dstRep];
                uint96 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;
                uint96 dstRepNew = add96(dstRepOld, amount, "Uni::_moveVotes: vote amount overflows");
                _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);
            }
        }
    }

    function _writeCheckpoint(address delegatee, uint32 nCheckpoints, uint96 oldVotes, uint96 newVotes) internal {
      uint32 blockNumber = safe32(block.number, "Uni::_writeCheckpoint: block number exceeds 32 bits");

      if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {
          checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
      } else {
          checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);
          numCheckpoints[delegatee] = nCheckpoints + 1;
      }

      emit DelegateVotesChanged(delegatee, oldVotes, newVotes);
    }

    function safe32(uint n, string memory errorMessage) internal pure returns (uint32) {
        require(n < 2**32, errorMessage);
        return uint32(n);
    }

    function safe96(uint n, string memory errorMessage) internal pure returns (uint96) {
        require(n < 2**96, errorMessage);
        return uint96(n);
    }

    function add96(uint96 a, uint96 b, string memory errorMessage) internal pure returns (uint96) {
        uint96 c = a + b;
        require(c >= a, errorMessage);
        return c;
    }

    function sub96(uint96 a, uint96 b, string memory errorMessage) internal pure returns (uint96) {
        require(b <= a, errorMessage);
        return a - b;
    }

    function getChainId() internal view returns (uint) {
        uint256 chainId;
        // XXX: added linter disable
        // solhint-disable-next-line no-inline-assembly
        assembly { chainId := chainid() }
        return chainId;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.3;

import "../interfaces/INonTransferrableToken.sol";
import "./VotingPower.sol";

/**
 * A non-transferrable token that can vote.
 */
contract VotingToken is INonTransferrableToken, VotingPower {
    string private _symbol;
    uint8 private immutable _decimals;

    /**
     * @dev Sets the values for `name`, `symbol`, and `decimals`. All three of
     * these values are immutable: they can only be set once during
     * construction.
     */
    constructor(
        string memory name_,
        string memory symbol_,
        uint8 decimals_
    ) VotingPower(name_) {
        _symbol = symbol_;
        _decimals = decimals_;
    }

    function name()
        public
        view
        override(INonTransferrableToken, VotingPower)
        returns (string memory)
    {
        return VotingPower.name();
    }

    function symbol() public view override returns (string memory) {
        return _symbol;
    }

    function decimals() public view override returns (uint8) {
        return _decimals;
    }

    function totalSupply() public view override returns (uint256) {
        return totalVotingPower();
    }

    function balanceOf(address _account)
        public
        view
        override
        returns (uint256)
    {
        return votingPower(_account);
    }
}

{
  "compilationTarget": {
    "contracts/UbeToken.sol": "UbeToken"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs",
    "useLiteralContent": true
  },
  "optimizer": {
    "enabled": true,
    "runs": 999999
  },
  "remappings": []
}