add dppOracle

contracts/DODOPrivatePool/intf/IDPPOracle.sol

@@ -0,0 +1,52 @@
+/*
+
+    Copyright 2021 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+interface IDPPOracle {
+    function init(
+        address owner,
+        address maintainer,
+        address baseTokenAddress,
+        address quoteTokenAddress,
+        uint256 lpFeeRate,
+        address mtFeeRateModel,
+        uint256 k,
+        address i, //oracle address
+        bool isOpenTWAP
+    ) external;
+
+    function _MT_FEE_RATE_MODEL_() external returns (address);
+
+    //=========== admin ==========
+    function ratioSync() external;
+
+    function retrieve(
+        address payable to,
+        address token,
+        uint256 amount
+    ) external;
+
+    function reset(
+        address assetTo,
+        uint256 newLpFeeRate,
+        uint256 newK,
+        uint256 baseOutAmount,
+        uint256 quoteOutAmount,
+        uint256 minBaseReserve,
+        uint256 minQuoteReserve
+    ) external returns (bool);
+
+
+    function tuneParameters(
+        uint256 newLpFeeRate,
+        uint256 newK,
+        uint256 minBaseReserve,
+        uint256 minQuoteReserve
+    ) external returns (bool);
+}