nexusSushi.sol

struct Minter {
  uint256 pairedETH;
  uint256 pairedUSDC;
  uint256 pairedShares;

  uint256 unpairedETH;
  uint256 unpairedShares;
}

uint256 totalSushiLP;

uint256 totalPairedETH;
uint256 totalPairedUSDC;
uint256 totalPairedShares;

function _deposit(uint256 amountETH) returns (uint256 addedUSDC, uint256 addedETH, uint256 shares) {
  Minter minter = minters[beneficiary];
  
  uint256 sushiLP;
  (addedUSDC, addedETH, sushiLP) = _poolAddLiquidityAndStake(amountETH);
  
  if (totalPairedShares == 0) {
    shares = sushiLP;
  } else {
    shares = sushiLP.mul(totalPairedShares).div(totalSushiLP);
  }

  minter.pairedUSDC = minter.pairedUSDC.add(addedUSDC);
  minter.pairedETH = minter.pairedETH.add(addedETH);
  minter.pairedShares = minter.pairedShares.add(shares);

  totalPairedUSDC = totalPairedUSDC.add(addedUSDC);
  totalPairedETH = totalPairedETH.add(addedETH);
  totalPairedShares = totalPairedShares.add(shares);
  totalSushiLP = totalSushiLP.add(sushiLP);
  
  _mint(beneficiary, shares);
}

function _withdraw(uint shares) returns (uint exitETH) {
  Minter minter = minters[sender];
  shares = Math.min(shares, minter.pairedShares + minter.unpairedShares);
  require(shares > 0, "sender not in minters");
  
  if (shares > minter.unpairedShares) {
    _unpair(shares - minter.unpairedShares);
  }
  
  exitETH = minter.unpairedETH.mul(shares).div(minter.unpairedShares);
  minter.unpairedShares = minter.unpairedShares.sub(shares);
  
  _burn(sender, shares);
}

function _unpair(uint shares) {
  uint256 sushiLP = shares.mul(totalSushiLP).div(totalPairedShares);
  (uint256 removedETH, uint256 removedUSDC) = _poolUnstakeAndRemoveLiquidity(sushiLP);

  uint256 pairedUSDC = minter.pairedUSDC.mul(shares).div(minter.pairedShares);
  uint256 pairedETH = minter.pairedETH.mul(shares).div(minter.pairedShares);
  uint256 exitUSDC;
  (exitUSDC, exitETH) = applyRebalance(removedUSDC, removedETH, pairedUSDC, pairedETH);

  minter.pairedUSDC = minter.pairedUSDC.sub(pairedUSDC);
  minter.pairedETH = minter.pairedETH.sub(pairedETH);
  minter.pairedShares = minter.pairedShares.sub(shares);

  minter.unpairedETH = minter.unpairedETH.add(exitETH);
  minter.unpairedShares = minter.unpairedShares.add(shares);

  totalPairedUSDC = totalPairedUSDC.sub(pairedUSDC);
  totalPairedETH = totalPairedETH.sub(pairedETH);
  totalPairedShares = totalPairedShares.sub(shares);
  totalSushiLP = totalSushiLP.sub(sushiLP);
}

function emergencyExit(address[] minterAddresses) {
  if (!paused()) _pause();

  for (uint256 i = 0; i < minterAddresses.length; i++) {
    address minterAddress = minterAddresses[i];
    Minter minter = minters[minterAddress];
    uint256 shares = minter.pairedShares;
    if (shares > 0) {
      _unpair(shares);
    }
  }
  
  withdrawFreeCapital();
}