Modifying a Position

There are a few different ways you can modify your existing position. You can add more funds, you can decrease the amount of funds, and you can also re-purpose the funds already in your position.

Adding funds

pragma solidity >=0.8.0 <0.9.0;

import '@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol';
import '@mean-finance/dca-v2-core/contracts/interfaces/IDCAHub.sol';

contract MyContract {

    IDCAHub public immutable hub;
    
    constructor(IDCAHub _hub) {
        hub = _hub;
    }
    
    /// @notice Takes the unswapped balance, adds the new deposited funds and modifies the position so that
    /// it is executed in _newSwaps swaps
    /// @param _positionId The position's id
    /// @param _amount Amount of funds to add to the position
    /// @param _newSwaps The new amount of swaps
    function increasePosition(
        uint256 _positionId,
        uint256 _amount,
        uint32 _newSwaps
    ) external {        
        // We need to increase the allowance for the hub before calling it
        IERC20Metadata _from = hub.userPosition(_positionId).from;
        _from.approve(address(hub), _amount);
        hub.increasePosition(_positionId, _amount, _newSwaps);
    }
}

Decreasing funds

pragma solidity >=0.8.0 <0.9.0;

import '@mean-finance/dca-v2-core/contracts/interfaces/IDCAHub.sol';

contract MyContract {

    IDCAHub public immutable hub;
    
    constructor(IDCAHub _hub) {
        hub = _hub;
    }
    
    /// @notice Withdraws the specified amount from the unswapped balance and modifies the position so that
    /// it is executed in _newSwaps swaps
    /// @param _positionId The position's id
    /// @param _amount Amount of funds to withdraw from the position
    /// @param _newSwaps The new amount of swaps
    /// @param _recipient The address to send tokens to
    function reducePosition(
        uint256 _positionId,
        uint256 _amount,
        uint32 _newSwaps,
        address _recipient
    ) external {
        hub.reducePosition(_positionId, _amount, _newSwaps, _recipient);
    }
}

Re-purposing funds

This action can be used to take the current funds and re-purpose them. So for example, if there are still 100 DAI left to swap, you can set the amount of swaps to 5, therefore creating a position with a 20 DAI rate.

pragma solidity >=0.8.0 <0.9.0;

import '@mean-finance/dca-v2-core/contracts/interfaces/IDCAHub.sol';

contract MyContract {

    IDCAHub public immutable hub;
    
    constructor(IDCAHub _hub) {
        hub = _hub;
    }
    
    /// @notice Takes the unswapped balance, and modifies the position so that it is executed in _newSwaps swaps
    /// @param _positionId The position's id
    /// @param _newSwaps The new amount of swaps
    function repurposePosition(
        uint256 _positionId,
        uint32 _newSwaps
    ) external {        
        hub.increasePosition(_positionId, 0, _newSwaps);
    }
}

Helper Library

Sometimes, it's hard understand how much is needed in order to configure a certain position, so that it has a specific amount of swaps and rate. That's why we've built a library that does that math for you.

Take into account that you might still need to increase the allowance for the hub if you end up having to add more funds to your position.

pragma solidity >=0.8.0 <0.9.0;

import '@mean-finance/dca-v2-periphery/libraries/ModifyPositionWithRate.sol';

contract MyContract {

    using ModifyPositionWithRate for IDCAHub;

    IDCAHub public immutable hub;
    
    constructor(IDCAHub _hub) {
        hub = _hub;
    }
    
    /// @notice Modifies the rate of a position. Could request more funds or return deposited funds
    /// depending on whether the new rate is greater than the previous one.
    /// @param _positionId The position's id
    /// @param _newRate The new rate to set
    function modifyRate(
        uint256 _positionId,
        uint120 _newRate
    ) external {
        hub.modifyRate(_positionId, _newRate);
    }

    /// @notice Modifies the amount of swaps of a position. Could request more funds or return
    /// deposited funds depending on whether the new amount of swaps is greater than the swaps left.
    /// @param _positionId The position's id
    /// @param _newSwaps The new amount of swaps
    function modifySwaps(
        uint256 _positionId,
        uint32 _newSwaps
    ) external {
        hub.modifySwaps(_positionId, _newSwaps);
    }

    /// @notice Modifies both the rate and amount of swaps of a position. Could request more funds or return
    /// deposited funds depending on whether the new parameters require more or less than the current unswapped funds.
    /// @param _positionId The position's id
    /// @param _newRate The new rate to set
    /// @param _newSwaps The new amount of swaps
    function modifyRateAndSwaps(
        uint256 _positionId,
        uint120 _newRate,
        uint32 _newSwaps
    ) external {
        hub.modifyRateAndSwaps(_positionId, _newRate, _newSwaps);
    }
}