creation_sourcecode: // File: contracts/lib/InitializableOwnable.sol
  
  /*
  
      Copyright 2020 DODO ZOO.
      SPDX-License-Identifier: Apache-2.0
  
  */
  
  pragma solidity 0.6.9;
  pragma experimental ABIEncoderV2;
  
  /**
   * @title Ownable
   * @author DODO Breeder
   *
   * @notice Ownership related functions
   */
  contract InitializableOwnable {
      address public _OWNER_;
      address public _NEW_OWNER_;
      bool internal _INITIALIZED_;
  
      // ============ Events ============
  
      event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);
  
      event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
  
      // ============ Modifiers ============
  
      modifier notInitialized() {
          require(!_INITIALIZED_, "DODO_INITIALIZED");
          _;
      }
  
      modifier onlyOwner() {
          require(msg.sender == _OWNER_, "NOT_OWNER");
          _;
      }
  
      // ============ Functions ============
  
      function initOwner(address newOwner) public notInitialized {
          _INITIALIZED_ = true;
          _OWNER_ = newOwner;
      }
  
      function transferOwnership(address newOwner) public onlyOwner {
          emit OwnershipTransferPrepared(_OWNER_, newOwner);
          _NEW_OWNER_ = newOwner;
      }
  
      function claimOwnership() public {
          require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
          emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
          _OWNER_ = _NEW_OWNER_;
          _NEW_OWNER_ = address(0);
      }
  }
  
  // File: contracts/lib/FeeRateModel.sol
  
  
  interface IFeeRateImpl {
      function getFeeRate(address pool, address trader) external view returns (uint256);
  }
  
  interface IFeeRateModel {
      function getFeeRate(address trader) external view returns (uint256);
  }
  
  contract FeeRateModel is InitializableOwnable {
      address public feeRateImpl;
  
      function setFeeProxy(address _feeRateImpl) public onlyOwner {
          feeRateImpl = _feeRateImpl;
      }
      
      function getFeeRate(address trader) external view returns (uint256) {
          if(feeRateImpl == address(0))
              return 0;
          return IFeeRateImpl(feeRateImpl).getFeeRate(msg.sender,trader);
      }
  }
  
  // File: contracts/intf/IERC20.sol
  
  
  /**
   * @dev Interface of the ERC20 standard as defined in the EIP.
   */
  interface IERC20 {
      /**
       * @dev Returns the amount of tokens in existence.
       */
      function totalSupply() external view returns (uint256);
  
      function decimals() external view returns (uint8);
  
      function name() external view returns (string memory);
  
      function symbol() external view returns (string memory);
  
      /**
       * @dev Returns the amount of tokens owned by `account`.
       */
      function balanceOf(address account) external view returns (uint256);
  
      /**
       * @dev Moves `amount` tokens from the caller's account to `recipient`.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * Emits a {Transfer} event.
       */
      function transfer(address recipient, uint256 amount) external returns (bool);
  
      /**
       * @dev Returns the remaining number of tokens that `spender` will be
       * allowed to spend on behalf of `owner` through {transferFrom}. This is
       * zero by default.
       *
       * This value changes when {approve} or {transferFrom} are called.
       */
      function allowance(address owner, address spender) external view returns (uint256);
  
      /**
       * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * IMPORTANT: Beware that changing an allowance with this method brings the risk
       * that someone may use both the old and the new allowance by unfortunate
       * transaction ordering. One possible solution to mitigate this race
       * condition is to first reduce the spender's allowance to 0 and set the
       * desired value afterwards:
       * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
       *
       * Emits an {Approval} event.
       */
      function approve(address spender, uint256 amount) external returns (bool);
  
      /**
       * @dev Moves `amount` tokens from `sender` to `recipient` using the
       * allowance mechanism. `amount` is then deducted from the caller's
       * allowance.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * Emits a {Transfer} event.
       */
      function transferFrom(
          address sender,
          address recipient,
          uint256 amount
      ) external returns (bool);
  }
  
  // File: contracts/lib/SafeMath.sol
  
  /**
   * @title SafeMath
   * @author DODO Breeder
   *
   * @notice Math operations with safety checks that revert on error
   */
  library SafeMath {
      function mul(uint256 a, uint256 b) internal pure returns (uint256) {
          if (a == 0) {
              return 0;
          }
  
          uint256 c = a * b;
          require(c / a == b, "MUL_ERROR");
  
          return c;
      }
  
      function div(uint256 a, uint256 b) internal pure returns (uint256) {
          require(b > 0, "DIVIDING_ERROR");
          return a / b;
      }
  
      function divCeil(uint256 a, uint256 b) internal pure returns (uint256) {
          uint256 quotient = div(a, b);
          uint256 remainder = a - quotient * b;
          if (remainder > 0) {
              return quotient + 1;
          } else {
              return quotient;
          }
      }
  
      function sub(uint256 a, uint256 b) internal pure returns (uint256) {
          require(b <= a, "SUB_ERROR");
          return a - b;
      }
  
      function add(uint256 a, uint256 b) internal pure returns (uint256) {
          uint256 c = a + b;
          require(c >= a, "ADD_ERROR");
          return c;
      }
  
      function sqrt(uint256 x) internal pure returns (uint256 y) {
          uint256 z = x / 2 + 1;
          y = x;
          while (z < y) {
              y = z;
              z = (x / z + z) / 2;
          }
      }
  }
  
  // File: contracts/lib/DecimalMath.sol
  
  /**
   * @title DecimalMath
   * @author DODO Breeder
   *
   * @notice Functions for fixed point number with 18 decimals
   */
  library DecimalMath {
      using SafeMath for uint256;
  
      uint256 internal constant ONE = 10**18;
      uint256 internal constant ONE2 = 10**36;
  
      function mulFloor(uint256 target, uint256 d) internal pure returns (uint256) {
          return target.mul(d) / (10**18);
      }
  
      function mulCeil(uint256 target, uint256 d) internal pure returns (uint256) {
          return target.mul(d).divCeil(10**18);
      }
  
      function divFloor(uint256 target, uint256 d) internal pure returns (uint256) {
          return target.mul(10**18).div(d);
      }
  
      function divCeil(uint256 target, uint256 d) internal pure returns (uint256) {
          return target.mul(10**18).divCeil(d);
      }
  
      function reciprocalFloor(uint256 target) internal pure returns (uint256) {
          return uint256(10**36).div(target);
      }
  
      function reciprocalCeil(uint256 target) internal pure returns (uint256) {
          return uint256(10**36).divCeil(target);
      }
  }
  
  // File: contracts/lib/SafeERC20.sol
  
  
  /**
   * @title SafeERC20
   * @dev Wrappers around ERC20 operations that throw on failure (when the token
   * contract returns false). Tokens that return no value (and instead revert or
   * throw on failure) are also supported, non-reverting calls are assumed to be
   * successful.
   * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
   * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
   */
  library SafeERC20 {
      using SafeMath for uint256;
  
      function safeTransfer(
          IERC20 token,
          address to,
          uint256 value
      ) internal {
          _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
      }
  
      function safeTransferFrom(
          IERC20 token,
          address from,
          address to,
          uint256 value
      ) internal {
          _callOptionalReturn(
              token,
              abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
          );
      }
  
      function safeApprove(
          IERC20 token,
          address spender,
          uint256 value
      ) internal {
          // safeApprove should only be called when setting an initial allowance,
          // or when resetting it to zero. To increase and decrease it, use
          // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
          // solhint-disable-next-line max-line-length
          require(
              (value == 0) || (token.allowance(address(this), spender) == 0),
              "SafeERC20: approve from non-zero to non-zero allowance"
          );
          _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
      }
  
      /**
       * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
       * on the return value: the return value is optional (but if data is returned, it must not be false).
       * @param token The token targeted by the call.
       * @param data The call data (encoded using abi.encode or one of its variants).
       */
      function _callOptionalReturn(IERC20 token, bytes memory data) private {
          // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
          // we're implementing it ourselves.
  
          // A Solidity high level call has three parts:
          //  1. The target address is checked to verify it contains contract code
          //  2. The call itself is made, and success asserted
          //  3. The return value is decoded, which in turn checks the size of the returned data.
          // solhint-disable-next-line max-line-length
  
          // solhint-disable-next-line avoid-low-level-calls
          (bool success, bytes memory returndata) = address(token).call(data);
          require(success, "SafeERC20: low-level call failed");
  
          if (returndata.length > 0) {
              // Return data is optional
              // solhint-disable-next-line max-line-length
              require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
          }
      }
  }
  
  // File: contracts/lib/ReentrancyGuard.sol
  
  
  /**
   * @title ReentrancyGuard
   * @author DODO Breeder
   *
   * @notice Protect functions from Reentrancy Attack
   */
  contract ReentrancyGuard {
      // https://solidity.readthedocs.io/en/latest/control-structures.html?highlight=zero-state#scoping-and-declarations
      // zero-state of _ENTERED_ is false
      bool private _ENTERED_;
  
      modifier preventReentrant() {
          require(!_ENTERED_, "REENTRANT");
          _ENTERED_ = true;
          _;
          _ENTERED_ = false;
      }
  }
  
  // File: contracts/lib/DODOMath.sol
  
  
  /**
   * @title DODOMath
   * @author DODO Breeder
   *
   * @notice Functions for complex calculating. Including ONE Integration and TWO Quadratic solutions
   */
  library DODOMath {
      using SafeMath for uint256;
  
      /*
          Integrate dodo curve from V1 to V2
          require V0>=V1>=V2>0
          res = (1-k)i(V1-V2)+ikV0*V0(1/V2-1/V1)
          let V1-V2=delta
          res = i*delta*(1-k+k(V0^2/V1/V2))
  
          i is the price of V-res trading pair
  
          support k=1 & k=0 case
  
          [round down]
      */
      function _GeneralIntegrate(
          uint256 V0,
          uint256 V1,
          uint256 V2,
          uint256 i,
          uint256 k
      ) internal pure returns (uint256) {
          require(V0 > 0, "TARGET_IS_ZERO");
          uint256 fairAmount = i.mul(V1.sub(V2)); // i*delta
          if (k == 0) {
              return fairAmount.div(DecimalMath.ONE);
          }
          uint256 V0V0V1V2 = DecimalMath.divFloor(V0.mul(V0).div(V1), V2);
          uint256 penalty = DecimalMath.mulFloor(k, V0V0V1V2); // k(V0^2/V1/V2)
          return DecimalMath.ONE.sub(k).add(penalty).mul(fairAmount).div(DecimalMath.ONE2);
      }
  
      /*
          Follow the integration function above
          i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
          Assume Q2=Q0, Given Q1 and deltaB, solve Q0
  
          i is the price of delta-V trading pair
          give out target of V
  
          support k=1 & k=0 case
  
          [round down]
      */
      function _SolveQuadraticFunctionForTarget(
          uint256 V1,
          uint256 delta,
          uint256 i,
          uint256 k
      ) internal pure returns (uint256) {
          if (V1 == 0) {
              return 0;
          }
          if (k == 0) {
              return V1.add(DecimalMath.mulFloor(i, delta));
          }
          // V0 = V1*(1+(sqrt-1)/2k)
          // sqrt = √(1+4kidelta/V1)
          // premium = 1+(sqrt-1)/2k
          // uint256 sqrt = (4 * k).mul(i).mul(delta).div(V1).add(DecimalMath.ONE2).sqrt();
          uint256 sqrt;
          uint256 ki = (4 * k).mul(i);
          if (ki == 0) {
              sqrt = DecimalMath.ONE;
          } else if ((ki * delta) / ki == delta) {
              sqrt = (ki * delta).div(V1).add(DecimalMath.ONE2).sqrt();
          } else {
              sqrt = ki.div(V1).mul(delta).add(DecimalMath.ONE2).sqrt();
          }
          uint256 premium =
              DecimalMath.divFloor(sqrt.sub(DecimalMath.ONE), k * 2).add(DecimalMath.ONE);
          // V0 is greater than or equal to V1 according to the solution
          return DecimalMath.mulFloor(V1, premium);
      }
  
      /*
          Follow the integration expression above, we have:
          i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
          Given Q1 and deltaB, solve Q2
          This is a quadratic function and the standard version is
          aQ2^2 + bQ2 + c = 0, where
          a=1-k
          -b=(1-k)Q1-kQ0^2/Q1+i*deltaB
          c=-kQ0^2 
          and Q2=(-b+sqrt(b^2+4(1-k)kQ0^2))/2(1-k)
          note: another root is negative, abondan
  
          if deltaBSig=true, then Q2>Q1, user sell Q and receive B
          if deltaBSig=false, then Q2<Q1, user sell B and receive Q
          return |Q1-Q2|
  
          as we only support sell amount as delta, the deltaB is always negative
          the input ideltaB is actually -ideltaB in the equation
  
          i is the price of delta-V trading pair
  
          support k=1 & k=0 case
  
          [round down]
      */
      function _SolveQuadraticFunctionForTrade(
          uint256 V0,
          uint256 V1,
          uint256 delta,
          uint256 i,
          uint256 k
      ) internal pure returns (uint256) {
          require(V0 > 0, "TARGET_IS_ZERO");
          if (delta == 0) {
              return 0;
          }
  
          if (k == 0) {
              return DecimalMath.mulFloor(i, delta) > V1 ? V1 : DecimalMath.mulFloor(i, delta);
          }
  
          if (k == DecimalMath.ONE) {
              // if k==1
              // Q2=Q1/(1+ideltaBQ1/Q0/Q0)
              // temp = ideltaBQ1/Q0/Q0
              // Q2 = Q1/(1+temp)
              // Q1-Q2 = Q1*(1-1/(1+temp)) = Q1*(temp/(1+temp))
              // uint256 temp = i.mul(delta).mul(V1).div(V0.mul(V0));
              uint256 temp;
              uint256 idelta = i.mul(delta);
              if (idelta == 0) {
                  temp = 0;
              } else if ((idelta * V1) / idelta == V1) {
                  temp = (idelta * V1).div(V0.mul(V0));
              } else {
                  temp = delta.mul(V1).div(V0).mul(i).div(V0);
              }
              return V1.mul(temp).div(temp.add(DecimalMath.ONE));
          }
  
          // calculate -b value and sig
          // b = kQ0^2/Q1-i*deltaB-(1-k)Q1
          // part1 = (1-k)Q1 >=0
          // part2 = kQ0^2/Q1-i*deltaB >=0
          // bAbs = abs(part1-part2)
          // if part1>part2 => b is negative => bSig is false
          // if part2>part1 => b is positive => bSig is true
          uint256 part2 = k.mul(V0).div(V1).mul(V0).add(i.mul(delta)); // kQ0^2/Q1-i*deltaB
          uint256 bAbs = DecimalMath.ONE.sub(k).mul(V1); // (1-k)Q1
  
          bool bSig;
          if (bAbs >= part2) {
              bAbs = bAbs - part2;
              bSig = false;
          } else {
              bAbs = part2 - bAbs;
              bSig = true;
          }
          bAbs = bAbs.div(DecimalMath.ONE);
  
          // calculate sqrt
          uint256 squareRoot =
              DecimalMath.mulFloor(
                  DecimalMath.ONE.sub(k).mul(4),
                  DecimalMath.mulFloor(k, V0).mul(V0)
              ); // 4(1-k)kQ0^2
          squareRoot = bAbs.mul(bAbs).add(squareRoot).sqrt(); // sqrt(b*b+4(1-k)kQ0*Q0)
  
          // final res
          uint256 denominator = DecimalMath.ONE.sub(k).mul(2); // 2(1-k)
          uint256 numerator;
          if (bSig) {
              numerator = squareRoot.sub(bAbs);
          } else {
              numerator = bAbs.add(squareRoot);
          }
  
          uint256 V2 = DecimalMath.divCeil(numerator, denominator);
          if (V2 > V1) {
              return 0;
          } else {
              return V1 - V2;
          }
      }
  }
  
  // File: contracts/lib/PMMPricing.sol
  
  
  /**
   * @title Pricing
   * @author DODO Breeder
   *
   * @notice DODO Pricing model
   */
  
  library PMMPricing {
      using SafeMath for uint256;
  
      enum RState {ONE, ABOVE_ONE, BELOW_ONE}
  
      struct PMMState {
          uint256 i;
          uint256 K;
          uint256 B;
          uint256 Q;
          uint256 B0;
          uint256 Q0;
          RState R;
      }
  
      // ============ buy & sell ============
  
      function sellBaseToken(PMMState memory state, uint256 payBaseAmount)
          internal
          pure
          returns (uint256 receiveQuoteAmount, RState newR)
      {
          if (state.R == RState.ONE) {
              // case 1: R=1
              // R falls below one
              receiveQuoteAmount = _ROneSellBaseToken(state, payBaseAmount);
              newR = RState.BELOW_ONE;
          } else if (state.R == RState.ABOVE_ONE) {
              uint256 backToOnePayBase = state.B0.sub(state.B);
              uint256 backToOneReceiveQuote = state.Q.sub(state.Q0);
              // case 2: R>1
              // complex case, R status depends on trading amount
              if (payBaseAmount < backToOnePayBase) {
                  // case 2.1: R status do not change
                  receiveQuoteAmount = _RAboveSellBaseToken(state, payBaseAmount);
                  newR = RState.ABOVE_ONE;
                  if (receiveQuoteAmount > backToOneReceiveQuote) {
                      // [Important corner case!] may enter this branch when some precision problem happens. And consequently contribute to negative spare quote amount
                      // to make sure spare quote>=0, mannually set receiveQuote=backToOneReceiveQuote
                      receiveQuoteAmount = backToOneReceiveQuote;
                  }
              } else if (payBaseAmount == backToOnePayBase) {
                  // case 2.2: R status changes to ONE
                  receiveQuoteAmount = backToOneReceiveQuote;
                  newR = RState.ONE;
              } else {
                  // case 2.3: R status changes to BELOW_ONE
                  receiveQuoteAmount = backToOneReceiveQuote.add(
                      _ROneSellBaseToken(state, payBaseAmount.sub(backToOnePayBase))
                  );
                  newR = RState.BELOW_ONE;
              }
          } else {
              // state.R == RState.BELOW_ONE
              // case 3: R<1
              receiveQuoteAmount = _RBelowSellBaseToken(state, payBaseAmount);
              newR = RState.BELOW_ONE;
          }
      }
  
      function sellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
          internal
          pure
          returns (uint256 receiveBaseAmount, RState newR)
      {
          if (state.R == RState.ONE) {
              receiveBaseAmount = _ROneSellQuoteToken(state, payQuoteAmount);
              newR = RState.ABOVE_ONE;
          } else if (state.R == RState.ABOVE_ONE) {
              receiveBaseAmount = _RAboveSellQuoteToken(state, payQuoteAmount);
              newR = RState.ABOVE_ONE;
          } else {
              uint256 backToOnePayQuote = state.Q0.sub(state.Q);
              uint256 backToOneReceiveBase = state.B.sub(state.B0);
              if (payQuoteAmount < backToOnePayQuote) {
                  receiveBaseAmount = _RBelowSellQuoteToken(state, payQuoteAmount);
                  newR = RState.BELOW_ONE;
                  if (receiveBaseAmount > backToOneReceiveBase) {
                      receiveBaseAmount = backToOneReceiveBase;
                  }
              } else if (payQuoteAmount == backToOnePayQuote) {
                  receiveBaseAmount = backToOneReceiveBase;
                  newR = RState.ONE;
              } else {
                  receiveBaseAmount = backToOneReceiveBase.add(
                      _ROneSellQuoteToken(state, payQuoteAmount.sub(backToOnePayQuote))
                  );
                  newR = RState.ABOVE_ONE;
              }
          }
      }
  
      // ============ R = 1 cases ============
  
      function _ROneSellBaseToken(PMMState memory state, uint256 payBaseAmount)
          internal
          pure
          returns (
              uint256 // receiveQuoteToken
          )
      {
          // in theory Q2 <= targetQuoteTokenAmount
          // however when amount is close to 0, precision problems may cause Q2 > targetQuoteTokenAmount
          return
              DODOMath._SolveQuadraticFunctionForTrade(
                  state.Q0,
                  state.Q0,
                  payBaseAmount,
                  state.i,
                  state.K
              );
      }
  
      function _ROneSellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
          internal
          pure
          returns (
              uint256 // receiveBaseToken
          )
      {
          return
              DODOMath._SolveQuadraticFunctionForTrade(
                  state.B0,
                  state.B0,
                  payQuoteAmount,
                  DecimalMath.reciprocalFloor(state.i),
                  state.K
              );
      }
  
      // ============ R < 1 cases ============
  
      function _RBelowSellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
          internal
          pure
          returns (
              uint256 // receiveBaseToken
          )
      {
          return
              DODOMath._GeneralIntegrate(
                  state.Q0,
                  state.Q.add(payQuoteAmount),
                  state.Q,
                  DecimalMath.reciprocalFloor(state.i),
                  state.K
              );
      }
  
      function _RBelowSellBaseToken(PMMState memory state, uint256 payBaseAmount)
          internal
          pure
          returns (
              uint256 // receiveQuoteToken
          )
      {
          return
              DODOMath._SolveQuadraticFunctionForTrade(
                  state.Q0,
                  state.Q,
                  payBaseAmount,
                  state.i,
                  state.K
              );
      }
  
      // ============ R > 1 cases ============
  
      function _RAboveSellBaseToken(PMMState memory state, uint256 payBaseAmount)
          internal
          pure
          returns (
              uint256 // receiveQuoteToken
          )
      {
          return
              DODOMath._GeneralIntegrate(
                  state.B0,
                  state.B.add(payBaseAmount),
                  state.B,
                  state.i,
                  state.K
              );
      }
  
      function _RAboveSellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
          internal
          pure
          returns (
              uint256 // receiveBaseToken
          )
      {
          return
              DODOMath._SolveQuadraticFunctionForTrade(
                  state.B0,
                  state.B,
                  payQuoteAmount,
                  DecimalMath.reciprocalFloor(state.i),
                  state.K
              );
      }
  
      // ============ Helper functions ============
  
      function adjustedTarget(PMMState memory state) internal pure {
          if (state.R == RState.BELOW_ONE) {
              state.Q0 = DODOMath._SolveQuadraticFunctionForTarget(
                  state.Q,
                  state.B.sub(state.B0),
                  state.i,
                  state.K
              );
          } else if (state.R == RState.ABOVE_ONE) {
              state.B0 = DODOMath._SolveQuadraticFunctionForTarget(
                  state.B,
                  state.Q.sub(state.Q0),
                  DecimalMath.reciprocalFloor(state.i),
                  state.K
              );
          }
      }
  
      function getMidPrice(PMMState memory state) internal pure returns (uint256) {
          if (state.R == RState.BELOW_ONE) {
              uint256 R = DecimalMath.divFloor(state.Q0.mul(state.Q0).div(state.Q), state.Q);
              R = DecimalMath.ONE.sub(state.K).add(DecimalMath.mulFloor(state.K, R));
              return DecimalMath.divFloor(state.i, R);
          } else {
              uint256 R = DecimalMath.divFloor(state.B0.mul(state.B0).div(state.B), state.B);
              R = DecimalMath.ONE.sub(state.K).add(DecimalMath.mulFloor(state.K, R));
              return DecimalMath.mulFloor(state.i, R);
          }
      }
  }
  
  // File: contracts/DODOVendingMachine/impl/DVMStorage.sol
  
  
  contract DVMStorage is ReentrancyGuard {
      using SafeMath for uint256;
  
      bool public _IS_OPEN_TWAP_ = false;
  
      bool internal _DVM_INITIALIZED_;
  
      // ============ Core Address ============
  
      address public _MAINTAINER_;
  
      IERC20 public _BASE_TOKEN_;
      IERC20 public _QUOTE_TOKEN_;
  
      uint112 public _BASE_RESERVE_;
      uint112 public _QUOTE_RESERVE_;
      uint32 public _BLOCK_TIMESTAMP_LAST_;
  
      uint256 public _BASE_PRICE_CUMULATIVE_LAST_;
  
      // ============ Shares (ERC20) ============
  
      string public symbol;
      uint8 public decimals;
      string public name;
  
      uint256 public totalSupply;
      mapping(address => uint256) internal _SHARES_;
      mapping(address => mapping(address => uint256)) internal _ALLOWED_;
  
      // ================= Permit ======================
  
      bytes32 public DOMAIN_SEPARATOR;
      // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
      bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
      mapping(address => uint256) public nonces;
  
      // ============ Variables for Pricing ============
  
      uint256 public _LP_FEE_RATE_;
      IFeeRateModel public _MT_FEE_RATE_MODEL_;
      uint256 public _K_;
      uint256 public _I_;
  
  
      // ============ Helper Functions ============
  
      function getPMMState() public view returns (PMMPricing.PMMState memory state) {
          state.i = _I_;
          state.K = _K_;
          state.B = _BASE_RESERVE_;
          state.Q = _QUOTE_RESERVE_;
          state.B0 = 0; // will be calculated in adjustedTarget
          state.Q0 = 0;
          state.R = PMMPricing.RState.ABOVE_ONE;
          PMMPricing.adjustedTarget(state);
      }
  
      function getPMMStateForCall() 
          external 
          view 
          returns (
              uint256 i,
              uint256 K,
              uint256 B,
              uint256 Q,
              uint256 B0,
              uint256 Q0,
              uint256 R
          )
      {
          PMMPricing.PMMState memory state = getPMMState();
          i = state.i;
          K = state.K;
          B = state.B;
          Q = state.Q;
          B0 = state.B0;
          Q0 = state.Q0;
          R = uint256(state.R);
      }
  
      function getMidPrice() public view returns (uint256 midPrice) {
          return PMMPricing.getMidPrice(getPMMState());
      }
  }
  
  // File: contracts/DODOVendingMachine/impl/DVMVault.sol
  
  
  contract DVMVault is DVMStorage {
      using SafeMath for uint256;
      using SafeERC20 for IERC20;
  
      // ============ Events ============
  
      event Transfer(address indexed from, address indexed to, uint256 amount);
  
      event Approval(address indexed owner, address indexed spender, uint256 amount);
  
      event Mint(address indexed user, uint256 value);
  
      event Burn(address indexed user, uint256 value);
  
      // ============ View Functions ============
  
      function getVaultReserve() external view returns (uint256 baseReserve, uint256 quoteReserve) {
          baseReserve = _BASE_RESERVE_;
          quoteReserve = _QUOTE_RESERVE_;
      }
  
      function getUserFeeRate(address user) external view returns (uint256 lpFeeRate, uint256 mtFeeRate) {
          lpFeeRate = _LP_FEE_RATE_;
          mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(user);
      }
  
      // ============ Asset In ============
  
      function getBaseInput() public view returns (uint256 input) {
          return _BASE_TOKEN_.balanceOf(address(this)).sub(uint256(_BASE_RESERVE_));
      }
  
      function getQuoteInput() public view returns (uint256 input) {
          return _QUOTE_TOKEN_.balanceOf(address(this)).sub(uint256(_QUOTE_RESERVE_));
      }
  
      // ============ TWAP UPDATE ===========
      
      function _twapUpdate() internal {
          uint32 blockTimestamp = uint32(block.timestamp % 2**32);
          uint32 timeElapsed = blockTimestamp - _BLOCK_TIMESTAMP_LAST_;
          if (timeElapsed > 0 && _BASE_RESERVE_ != 0 && _QUOTE_RESERVE_ != 0) {
              _BASE_PRICE_CUMULATIVE_LAST_ += getMidPrice() * timeElapsed;
          }
          _BLOCK_TIMESTAMP_LAST_ = blockTimestamp;
      }
  
      // ============ Set States ============
  
      function _setReserve(uint256 baseReserve, uint256 quoteReserve) internal {
          require(baseReserve <= uint112(-1) && quoteReserve <= uint112(-1), "OVERFLOW");
          _BASE_RESERVE_ = uint112(baseReserve);
          _QUOTE_RESERVE_ = uint112(quoteReserve);
  
          if(_IS_OPEN_TWAP_) _twapUpdate();
      }
  
      function _sync() internal {
          uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
          uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
          require(baseBalance <= uint112(-1) && quoteBalance <= uint112(-1), "OVERFLOW");
          if (baseBalance != _BASE_RESERVE_) {
              _BASE_RESERVE_ = uint112(baseBalance);
          }
          if (quoteBalance != _QUOTE_RESERVE_) {
              _QUOTE_RESERVE_ = uint112(quoteBalance);
          }
  
          if(_IS_OPEN_TWAP_) _twapUpdate();
      }
  
  
      function sync() external preventReentrant {
          _sync();
      }
  
      // ============ Asset Out ============
  
      function _transferBaseOut(address to, uint256 amount) internal {
          if (amount > 0) {
              _BASE_TOKEN_.safeTransfer(to, amount);
          }
      }
  
      function _transferQuoteOut(address to, uint256 amount) internal {
          if (amount > 0) {
              _QUOTE_TOKEN_.safeTransfer(to, amount);
          }
      }
  
      // ============ Shares (ERC20) ============
  
      /**
       * @dev transfer token for a specified address
       * @param to The address to transfer to.
       * @param amount The amount to be transferred.
       */
      function transfer(address to, uint256 amount) public returns (bool) {
          require(amount <= _SHARES_[msg.sender], "BALANCE_NOT_ENOUGH");
  
          _SHARES_[msg.sender] = _SHARES_[msg.sender].sub(amount);
          _SHARES_[to] = _SHARES_[to].add(amount);
          emit Transfer(msg.sender, to, amount);
          return true;
      }
  
      /**
       * @dev Gets the balance of the specified address.
       * @param owner The address to query the the balance of.
       * @return balance An uint256 representing the amount owned by the passed address.
       */
      function balanceOf(address owner) external view returns (uint256 balance) {
          return _SHARES_[owner];
      }
  
      /**
       * @dev Transfer tokens from one address to another
       * @param from address The address which you want to send tokens from
       * @param to address The address which you want to transfer to
       * @param amount uint256 the amount of tokens to be transferred
       */
      function transferFrom(
          address from,
          address to,
          uint256 amount
      ) public returns (bool) {
          require(amount <= _SHARES_[from], "BALANCE_NOT_ENOUGH");
          require(amount <= _ALLOWED_[from][msg.sender], "ALLOWANCE_NOT_ENOUGH");
  
          _SHARES_[from] = _SHARES_[from].sub(amount);
          _SHARES_[to] = _SHARES_[to].add(amount);
          _ALLOWED_[from][msg.sender] = _ALLOWED_[from][msg.sender].sub(amount);
          emit Transfer(from, to, amount);
          return true;
      }
  
      /**
       * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
       * @param spender The address which will spend the funds.
       * @param amount The amount of tokens to be spent.
       */
      function approve(address spender, uint256 amount) public returns (bool) {
          _approve(msg.sender, spender, amount);
          return true;
      }
  
      function _approve(
          address owner,
          address spender,
          uint256 amount
      ) private {
          _ALLOWED_[owner][spender] = amount;
          emit Approval(owner, spender, amount);
      }
  
      /**
       * @dev Function to check the amount of tokens that an owner _ALLOWED_ to a spender.
       * @param owner address The address which owns the funds.
       * @param spender address The address which will spend the funds.
       * @return A uint256 specifying the amount of tokens still available for the spender.
       */
      function allowance(address owner, address spender) public view returns (uint256) {
          return _ALLOWED_[owner][spender];
      }
  
      function _mint(address user, uint256 value) internal {
          require(value > 1000, "MINT_INVALID");
          _SHARES_[user] = _SHARES_[user].add(value);
          totalSupply = totalSupply.add(value);
          emit Mint(user, value);
          emit Transfer(address(0), user, value);
      }
  
      function _burn(address user, uint256 value) internal {
          _SHARES_[user] = _SHARES_[user].sub(value);
          totalSupply = totalSupply.sub(value);
          emit Burn(user, value);
          emit Transfer(user, address(0), value);
      }
  
      // ============================ Permit ======================================
      
      function permit(
          address owner,
          address spender,
          uint256 value,
          uint256 deadline,
          uint8 v,
          bytes32 r,
          bytes32 s
      ) external {
          require(deadline >= block.timestamp, "DODO_DVM_LP: EXPIRED");
          bytes32 digest = keccak256(
              abi.encodePacked(
                  "\x19\x01",
                  DOMAIN_SEPARATOR,
                  keccak256(
                      abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline)
                  )
              )
          );
          address recoveredAddress = ecrecover(digest, v, r, s);
          require(
              recoveredAddress != address(0) && recoveredAddress == owner,
              "DODO_DVM_LP: INVALID_SIGNATURE"
          );
          _approve(owner, spender, value);
      }
  }
  
  // File: contracts/intf/IDODOCallee.sol
  
  
  interface IDODOCallee {
      function DVMSellShareCall(
          address sender,
          uint256 burnShareAmount,
          uint256 baseAmount,
          uint256 quoteAmount,
          bytes calldata data
      ) external;
  
      function DVMFlashLoanCall(
          address sender,
          uint256 baseAmount,
          uint256 quoteAmount,
          bytes calldata data
      ) external;
  
      function DPPFlashLoanCall(
          address sender,
          uint256 baseAmount,
          uint256 quoteAmount,
          bytes calldata data
      ) external;
  
      function CPCancelCall(
          address sender,
          uint256 amount,
          bytes calldata data
      ) external;
  
  	function CPClaimBidCall(
          address sender,
          uint256 baseAmount,
          uint256 quoteAmount,
          bytes calldata data
      ) external;
  }
  
  // File: contracts/DODOVendingMachine/impl/DVMTrader.sol
  
  
  
  contract DVMTrader is DVMVault {
      using SafeMath for uint256;
  
      // ============ Events ============
  
      event DODOSwap(
          address fromToken,
          address toToken,
          uint256 fromAmount,
          uint256 toAmount,
          address trader,
          address receiver
      );
  
      event DODOFlashLoan(
          address borrower,
          address assetTo,
          uint256 baseAmount,
          uint256 quoteAmount
      );
  
      // ============ Trade Functions ============
  
      function sellBase(address to)
          external
          preventReentrant
          returns (uint256 receiveQuoteAmount)
      {
          uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
          uint256 baseInput = baseBalance.sub(uint256(_BASE_RESERVE_));
          uint256 mtFee;
          (receiveQuoteAmount, mtFee) = querySellBase(tx.origin, baseInput);
  
          _transferQuoteOut(to, receiveQuoteAmount);
          _transferQuoteOut(_MAINTAINER_, mtFee);
          _setReserve(baseBalance, _QUOTE_TOKEN_.balanceOf(address(this)));
  
          emit DODOSwap(
              address(_BASE_TOKEN_),
              address(_QUOTE_TOKEN_),
              baseInput,
              receiveQuoteAmount,
              msg.sender,
              to
          );
      }
  
      function sellQuote(address to)
          external
          preventReentrant
          returns (uint256 receiveBaseAmount)
      {
          uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
          uint256 quoteInput = quoteBalance.sub(uint256(_QUOTE_RESERVE_));
          uint256 mtFee;
          (receiveBaseAmount, mtFee) = querySellQuote(tx.origin, quoteInput);
  
          _transferBaseOut(to, receiveBaseAmount);
          _transferBaseOut(_MAINTAINER_, mtFee);
          _setReserve(_BASE_TOKEN_.balanceOf(address(this)), quoteBalance);
  
          emit DODOSwap(
              address(_QUOTE_TOKEN_),
              address(_BASE_TOKEN_),
              quoteInput,
              receiveBaseAmount,
              msg.sender,
              to
          );
      }
  
      function flashLoan(
          uint256 baseAmount,
          uint256 quoteAmount,
          address assetTo,
          bytes calldata data
      ) external preventReentrant {
          _transferBaseOut(assetTo, baseAmount);
          _transferQuoteOut(assetTo, quoteAmount);
  
          if (data.length > 0)
              IDODOCallee(assetTo).DVMFlashLoanCall(msg.sender, baseAmount, quoteAmount, data);
  
          uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
          uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
          
          // no input -> pure loss
          require(
              baseBalance >= _BASE_RESERVE_ || quoteBalance >= _QUOTE_RESERVE_,
              "FLASH_LOAN_FAILED"
          );
  
          // sell quote
          if (baseBalance < _BASE_RESERVE_) {
              uint256 quoteInput = quoteBalance.sub(uint256(_QUOTE_RESERVE_));
              (uint256 receiveBaseAmount, uint256 mtFee) = querySellQuote(tx.origin, quoteInput);
              require(uint256(_BASE_RESERVE_).sub(baseBalance) <= receiveBaseAmount, "FLASH_LOAN_FAILED");
  
              _transferBaseOut(_MAINTAINER_, mtFee);
              emit DODOSwap(
                  address(_QUOTE_TOKEN_),
                  address(_BASE_TOKEN_),
                  quoteInput,
                  receiveBaseAmount,
                  msg.sender,
                  assetTo
              );
          }
  
          // sell base
          if (quoteBalance < _QUOTE_RESERVE_) {
              uint256 baseInput = baseBalance.sub(uint256(_BASE_RESERVE_));
              (uint256 receiveQuoteAmount, uint256 mtFee) = querySellBase(tx.origin, baseInput);
              require(uint256(_QUOTE_RESERVE_).sub(quoteBalance) <= receiveQuoteAmount, "FLASH_LOAN_FAILED");
  
              _transferQuoteOut(_MAINTAINER_, mtFee);
              emit DODOSwap(
                  address(_BASE_TOKEN_),
                  address(_QUOTE_TOKEN_),
                  baseInput,
                  receiveQuoteAmount,
                  msg.sender,
                  assetTo
              );
          }
  
          _sync();
          
          emit DODOFlashLoan(msg.sender, assetTo, baseAmount, quoteAmount);
      }
  
      // ============ Query Functions ============
  
      function querySellBase(address trader, uint256 payBaseAmount)
          public
          view
          returns (uint256 receiveQuoteAmount, uint256 mtFee)
      {
          (receiveQuoteAmount, ) = PMMPricing.sellBaseToken(getPMMState(), payBaseAmount);
  
          uint256 lpFeeRate = _LP_FEE_RATE_;
          uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(trader);
          mtFee = DecimalMath.mulFloor(receiveQuoteAmount, mtFeeRate);
          receiveQuoteAmount = receiveQuoteAmount
              .sub(DecimalMath.mulFloor(receiveQuoteAmount, lpFeeRate))
              .sub(mtFee);
      }
  
      function querySellQuote(address trader, uint256 payQuoteAmount)
          public
          view
          returns (uint256 receiveBaseAmount, uint256 mtFee)
      {
          (receiveBaseAmount, ) = PMMPricing.sellQuoteToken(getPMMState(), payQuoteAmount);
  
          uint256 lpFeeRate = _LP_FEE_RATE_;
          uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(trader);
          mtFee = DecimalMath.mulFloor(receiveBaseAmount, mtFeeRate);
          receiveBaseAmount = receiveBaseAmount
              .sub(DecimalMath.mulFloor(receiveBaseAmount, lpFeeRate))
              .sub(mtFee);
      }
  }
  
  // File: contracts/DODOVendingMachine/impl/DVMFunding.sol
  
  
  contract DVMFunding is DVMVault {
      // ============ Events ============
  
      event BuyShares(address to, uint256 increaseShares, uint256 totalShares);
  
      event SellShares(address payer, address to, uint256 decreaseShares, uint256 totalShares);
  
      // ============ Buy & Sell Shares ============
  
      // buy shares [round down]
      function buyShares(address to)
          external
          preventReentrant
          returns (
              uint256 shares,
              uint256 baseInput,
              uint256 quoteInput
          )
      {
          uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
          uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
          uint256 baseReserve = _BASE_RESERVE_;
          uint256 quoteReserve = _QUOTE_RESERVE_;
  
          baseInput = baseBalance.sub(baseReserve);
          quoteInput = quoteBalance.sub(quoteReserve);
          require(baseInput > 0, "NO_BASE_INPUT");
  
          // Round down when withdrawing. Therefore, never be a situation occuring balance is 0 but totalsupply is not 0
          // But May Happen，reserve >0 But totalSupply = 0
          if (totalSupply == 0) {
              // case 1. initial supply
              require(baseBalance >= 10**3, "INSUFFICIENT_LIQUIDITY_MINED");
              shares = baseBalance; // 以免出现balance很大但shares很小的情况
          } else if (baseReserve > 0 && quoteReserve == 0) {
              // case 2. supply when quote reserve is 0
              shares = baseInput.mul(totalSupply).div(baseReserve);
          } else if (baseReserve > 0 && quoteReserve > 0) {
              // case 3. normal case
              uint256 baseInputRatio = DecimalMath.divFloor(baseInput, baseReserve);
              uint256 quoteInputRatio = DecimalMath.divFloor(quoteInput, quoteReserve);
              uint256 mintRatio = quoteInputRatio < baseInputRatio ? quoteInputRatio : baseInputRatio;
              shares = DecimalMath.mulFloor(totalSupply, mintRatio);
          }
          _mint(to, shares);
          _setReserve(baseBalance, quoteBalance);
          emit BuyShares(to, shares, _SHARES_[to]);
      }
  
      // sell shares [round down]
      function sellShares(
          uint256 shareAmount,
          address to,
          uint256 baseMinAmount,
          uint256 quoteMinAmount,
          bytes calldata data,
          uint256 deadline
      ) external preventReentrant returns (uint256 baseAmount, uint256 quoteAmount) {
          require(deadline >= block.timestamp, "TIME_EXPIRED");
          require(shareAmount <= _SHARES_[msg.sender], "DLP_NOT_ENOUGH");
          uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
          uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
          uint256 totalShares = totalSupply;
  
          baseAmount = baseBalance.mul(shareAmount).div(totalShares);
          quoteAmount = quoteBalance.mul(shareAmount).div(totalShares);
  
          require(
              baseAmount >= baseMinAmount && quoteAmount >= quoteMinAmount,
              "WITHDRAW_NOT_ENOUGH"
          );
  
          _burn(msg.sender, shareAmount);
          _transferBaseOut(to, baseAmount);
          _transferQuoteOut(to, quoteAmount);
          _sync();
  
          if (data.length > 0) {
              IDODOCallee(to).DVMSellShareCall(
                  msg.sender,
                  shareAmount,
                  baseAmount,
                  quoteAmount,
                  data
              );
          }
  
          emit SellShares(msg.sender, to, shareAmount, _SHARES_[msg.sender]);
      }
  }
  
  // File: contracts/DODOVendingMachine/impl/DVM.sol
  
  
  
  /**
   * @title DODO VendingMachine
   * @author DODO Breeder
   *
   * @notice DODOVendingMachine initialization
   */
  contract DVM is DVMTrader, DVMFunding {
      function init(
          address maintainer,
          address baseTokenAddress,
          address quoteTokenAddress,
          uint256 lpFeeRate,
          address mtFeeRateModel,
          uint256 i,
          uint256 k,
          bool isOpenTWAP
      ) external {
          require(!_DVM_INITIALIZED_, "DVM_INITIALIZED");
          _DVM_INITIALIZED_ = true;
          
          require(baseTokenAddress != quoteTokenAddress, "BASE_QUOTE_CAN_NOT_BE_SAME");
          _BASE_TOKEN_ = IERC20(baseTokenAddress);
          _QUOTE_TOKEN_ = IERC20(quoteTokenAddress);
  
          require(i > 0 && i <= 10**36);
          _I_ = i;
  
          require(k <= 10**18);
          _K_ = k;
  
          _LP_FEE_RATE_ = lpFeeRate;
          _MT_FEE_RATE_MODEL_ = IFeeRateModel(mtFeeRateModel);
          _MAINTAINER_ = maintainer;
  
          _IS_OPEN_TWAP_ = isOpenTWAP;
          if(isOpenTWAP) _BLOCK_TIMESTAMP_LAST_ = uint32(block.timestamp % 2**32);
  
          string memory connect = "_";
          string memory suffix = "DLP";
  
          name = string(abi.encodePacked(suffix, connect, addressToShortString(address(this))));
          symbol = "DLP";
          decimals = _BASE_TOKEN_.decimals();
  
          // ============================== Permit ====================================
          uint256 chainId;
          assembly {
              chainId := chainid()
          }
          DOMAIN_SEPARATOR = keccak256(
              abi.encode(
                  // keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                  0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                  keccak256(bytes(name)),
                  keccak256(bytes("1")),
                  chainId,
                  address(this)
              )
          );
          // ==========================================================================
      }
  
      function addressToShortString(address _addr) public pure returns (string memory) {
          bytes32 value = bytes32(uint256(_addr));
          bytes memory alphabet = "0123456789abcdef";
  
          bytes memory str = new bytes(8);
          for (uint256 i = 0; i < 4; i++) {
              str[i * 2] = alphabet[uint8(value[i + 12] >> 4)];
              str[1 + i * 2] = alphabet[uint8(value[i + 12] & 0x0f)];
          }
          return string(str);
      }
  
      // ============ Version Control ============
      
      function version() external pure returns (string memory) {
          return "DVM 1.0.2";
      }
  }