KNC Migration Adapter

contracts/protocol/integration/wrap/KyberMigrationAdapter.sol

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+/*
+    Copyright 2021 Set Labs Inc.
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+
+    SPDX-License-Identifier: Apache License, Version 2.0
+*/
+
+pragma solidity 0.6.10;
+
+/**
+ * @title KyberMigrationAdapter
+ * @author Set Protocol
+ *
+ * Wrap adapter for one time token migration that returns data for wrapping KNC Legacy into KNC.
+ * Note: KNC can not be unwrapped into KNC Legacy, because migration can not be reversed.
+ */
+contract KyberMigrationWrapAdapter {
+
+    /* ============ State Variables ============ */
+
+    address public immutable kncLegacyToken;
+    address public immutable kncToken;
+
+    /* ============ Constructor ============ */
+
+    /**
+     * Set state variables
+     *
+     * @param _kncLegacyToken                   Address of KNC Legacy token
+     * @param _kncToken                         Address of KNC token
+     */
+    constructor(
+        address _kncLegacyToken,
+        address _kncToken
+    )
+        public
+    {
+        kncLegacyToken = _kncLegacyToken;
+        kncToken = _kncToken;
+    }
+
+    /* ============ External Getter Functions ============ */
+
+    /**
+     * Generates the calldata to migrate KNC Legacy to KNC.
+     *
+     * @param _underlyingToken      Address of the component to be wrapped
+     * @param _wrappedToken         Address of the wrapped component
+     * @param _underlyingUnits      Total quantity of underlying units to wrap
+     *
+     * @return address              Target contract address
+     * @return uint256              Total quantity of underlying units (if underlying is ETH)
+     * @return bytes                Wrap calldata
+     */
+    function getWrapCallData(
+        address _underlyingToken,
+        address _wrappedToken,
+        uint256 _underlyingUnits
+    )
+        external
+        view
+        returns (address, uint256, bytes memory)
+    {
+        require(_underlyingToken == kncLegacyToken, "Must be KNC Legacy token");
+        require(_wrappedToken == kncToken, "Must be KNC token");
+
+        // mintWithOldKnc(uint256 amount)
+        bytes memory callData = abi.encodeWithSignature("mintWithOldKnc(uint256)", _underlyingUnits);
+
+        return (kncToken, 0, callData);
+    }
+
+    /**
+     * This function will revert, since migration cannot be reversed.
+     */
+    function getUnwrapCallData(
+        address /* _underlyingToken */,
+        address /* _wrappedToken */,
+        uint256 /* _wrappedTokenUnits */
+    )
+        external
+        pure
+        returns (address, uint256, bytes memory)
+    {
+        revert("KNC migration cannot be reversed");
+    }
+
+    /**
+     * Returns the address to approve source tokens for wrapping.
+     *
+     * @return address        Address of the contract to approve tokens to
+     */
+    function getSpenderAddress(address /* _underlyingToken */, address /* _wrappedToken */) external view returns(address) {
+        return kncToken;
+    }
+}