/*
    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;
pragma experimental "ABIEncoderV2";

/**
  * @title RgtMigrationWrapAdater
  * @author FlattestWhite
  *
  * Wrap adapter for one time token migration that returns data for wrapping RGT into TRIBE. 
  * Note: RGT can not be unwrapped into TRIBE, because migration can not be reversed.
 */
contract RgtMigrationWrapAdapter {

    /* ============ State Variables ============ */

    address public immutable pegExchanger;

    /* ============ Constructor ============ */

    /**
     * Set state variables
     *
     * @param _pegExchanger                       Address of PegExchanger contract
     */
    constructor(
        address _pegExchanger
    )
        public
    {
        pegExchanger = _pegExchanger;
    } 

    /* ============ External Getter Functions ============ */

    /**
     * Generates the calldata to migrate RGT tokens to TRIBE tokens.
     *
     * @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)
    {
        // exchange(uint256 amount)
        bytes memory callData = abi.encodeWithSignature("exchange(uint256)", _underlyingUnits);

        return (pegExchanger, 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("RGT 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 pegExchanger;
    }
}