UnionVoucher.sol

//SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "./interfaces/IMarketRegistry.sol";
import "./interfaces/IUserManager.sol";
import "./BaseUnionMember.sol";


/**
 * @title UnionVoucher Contract
 * @dev This contract has all the functions of Union voucher role.
 */
abstract contract UnionVoucher is BaseUnionMember{
    /**
     *  @dev Get all the addresses the user vouched for
     *  @return List of ddresses the user vouched for
     */
    function getBorrowerAddresses() public view returns (address[] memory) {
        return userManager.getBorrowerAddresses(address(this));
    }
    
    /**
     *  @dev Get user's staking amount
     *  @return Staking amount (in wei)
     */
    function getStakerBalance() public view returns (uint256) {
        return userManager.getStakerBalance(address(this));
    }

    /**
     *  @dev Set the vouching amount for another user
     *  @param account Recipient address
     *  @param amount Amount to vouch for (in wei)
     */
    function _updateTrust(address account, uint256 amount) internal {
        userManager.updateTrust(account, amount);
    }

    /**
     *  @dev Stop vouching for another one
     *  @param staker Voucher's address
     *  @param borrower Recipient address
     */
    function _cancelVouch(address staker, address borrower) internal {
        userManager.cancelVouch(staker, borrower);
    }

    /**
     *  @dev Deposit to Union
     *  @param amount Amount to stake (in wei)
     */
    function _stake(uint256 amount) internal {
        underlyingToken.approve(address(userManager), amount);
        userManager.stake(amount);
    }

    /**
     *  @dev Withdraw from Union
     *  @param amount Amount to unstake (in wei)
     */
    function _unstake(uint256 amount) internal {
        userManager.unstake(amount);
    }

    /**
     *  @dev Claim the rewarded UNION tokens
     */
    function _withdrawRewards() internal {
        userManager.withdrawRewards();
    }
    
    /**
     *  @dev Write off voucher's bad debt
     *  @param borrower Borrower's address
     *  @param amount Amount of debt to write off (in wei)
     */
    function _debtWriteOff(address borrower, uint256 amount) internal {
        userManager.debtWriteOff(borrower, amount);
    } 
}