InCompounder

[
  {
    "inputs": [
      {
        "internalType": "contract IERC20",
        "name": "inToken",
        "type": "address"
      },
      {
        "internalType": "contract IStakingRewards",
        "name": "poolA",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "owner_",
        "type": "address"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "constructor"
  },
  {
    "inputs": [],
    "name": "AssetRescueForbidden",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "allowance",
        "type": "uint256"
      },
      {
        "internalType": "uint256",
        "name": "needed",
        "type": "uint256"
      }
    ],
    "name": "ERC20InsufficientAllowance",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "sender",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "balance",
        "type": "uint256"
      },
      {
        "internalType": "uint256",
        "name": "needed",
        "type": "uint256"
      }
    ],
    "name": "ERC20InsufficientBalance",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "approver",
        "type": "address"
      }
    ],
    "name": "ERC20InvalidApprover",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "receiver",
        "type": "address"
      }
    ],
    "name": "ERC20InvalidReceiver",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "sender",
        "type": "address"
      }
    ],
    "name": "ERC20InvalidSender",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      }
    ],
    "name": "ERC20InvalidSpender",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "receiver",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "assets",
        "type": "uint256"
      },
      {
        "internalType": "uint256",
        "name": "max",
        "type": "uint256"
      }
    ],
    "name": "ERC4626ExceededMaxDeposit",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "receiver",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "shares",
        "type": "uint256"
      },
      {
        "internalType": "uint256",
        "name": "max",
        "type": "uint256"
      }
    ],
    "name": "ERC4626ExceededMaxMint",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "shares",
        "type": "uint256"
      },
      {
        "internalType": "uint256",
        "name": "max",
        "type": "uint256"
      }
    ],
    "name": "ERC4626ExceededMaxRedeem",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "assets",
        "type": "uint256"
      },
      {
        "internalType": "uint256",
        "name": "max",
        "type": "uint256"
      }
    ],
    "name": "ERC4626ExceededMaxWithdraw",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "EnforcedPause",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "ExpectedPause",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      }
    ],
    "name": "OwnableInvalidOwner",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "account",
        "type": "address"
      }
    ],
    "name": "OwnableUnauthorizedAccount",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "PoolAssetMismatch",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "ReentrancyGuardReentrantCall",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "token",
        "type": "address"
      }
    ],
    "name": "SafeERC20FailedOperation",
    "type": "error"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "Approval",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "sender",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "assets",
        "type": "uint256"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "shares",
        "type": "uint256"
      }
    ],
    "name": "Deposit",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "caller",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "rewardsClaimed",
        "type": "uint256"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "totalStakedAfter",
        "type": "uint256"
      }
    ],
    "name": "Harvest",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "previousOwner",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "newOwner",
        "type": "address"
      }
    ],
    "name": "OwnershipTransferred",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "internalType": "address",
        "name": "account",
        "type": "address"
      }
    ],
    "name": "Paused",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "from",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "Transfer",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "internalType": "address",
        "name": "account",
        "type": "address"
      }
    ],
    "name": "Unpaused",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "sender",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "receiver",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "assets",
        "type": "uint256"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "shares",
        "type": "uint256"
      }
    ],
    "name": "Withdraw",
    "type": "event"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      }
    ],
    "name": "allowance",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "approve",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "asset",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "account",
        "type": "address"
      }
    ],
    "name": "balanceOf",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "shares",
        "type": "uint256"
      }
    ],
    "name": "convertToAssets",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "assets",
        "type": "uint256"
      }
    ],
    "name": "convertToShares",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "decimals",
    "outputs": [
      {
        "internalType": "uint8",
        "name": "",
        "type": "uint8"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "assets",
        "type": "uint256"
      },
      {
        "internalType": "address",
        "name": "receiver",
        "type": "address"
      }
    ],
    "name": "deposit",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "harvest",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "name": "maxDeposit",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "name": "maxMint",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      }
    ],
    "name": "maxRedeem",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      }
    ],
    "name": "maxWithdraw",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "shares",
        "type": "uint256"
      },
      {
        "internalType": "address",
        "name": "receiver",
        "type": "address"
      }
    ],
    "name": "mint",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "name",
    "outputs": [
      {
        "internalType": "string",
        "name": "",
        "type": "string"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "owner",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "pause",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "paused",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "pool",
    "outputs": [
      {
        "internalType": "contract IStakingRewards",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "assets",
        "type": "uint256"
      }
    ],
    "name": "previewDeposit",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "shares",
        "type": "uint256"
      }
    ],
    "name": "previewMint",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "shares",
        "type": "uint256"
      }
    ],
    "name": "previewRedeem",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "assets",
        "type": "uint256"
      }
    ],
    "name": "previewWithdraw",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "shares",
        "type": "uint256"
      },
      {
        "internalType": "address",
        "name": "receiver",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      }
    ],
    "name": "redeem",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "renounceOwnership",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "contract IERC20",
        "name": "token",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "rescueToken",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "symbol",
    "outputs": [
      {
        "internalType": "string",
        "name": "",
        "type": "string"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "totalAssets",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "totalSupply",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "transfer",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "from",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "transferFrom",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "newOwner",
        "type": "address"
      }
    ],
    "name": "transferOwnership",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "unpause",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "assets",
        "type": "uint256"
      },
      {
        "internalType": "address",
        "name": "receiver",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      }
    ],
    "name": "withdraw",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  }
]

// SPDX-License-Identifier: MIT
pragma solidity 0.8.28;

import {ERC20} from "openzeppelin-contracts/contracts/token/ERC20/ERC20.sol";
import {ERC4626, IERC20} from "openzeppelin-contracts/contracts/token/ERC20/extensions/ERC4626.sol";
import {SafeERC20} from "openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol";
import {Ownable} from "openzeppelin-contracts/contracts/access/Ownable.sol";
import {Pausable} from "openzeppelin-contracts/contracts/utils/Pausable.sol";
import {ReentrancyGuard} from "openzeppelin-contracts/contracts/utils/ReentrancyGuard.sol";
import {IStakingRewards} from "./interfaces/IStakingRewards.sol";

/// @title InCompounder — ERC-4626 auto-compounding vault for the $IN single-sided pool
/// @notice The ONLY non-vendored contract in this repo. Deposits $IN into the
///         Synthetix StakingRewards Pool A (stakingToken == rewardsToken == IN)
///         and periodically restakes claimed IN rewards ("auto-compound").
///         Pattern follows the well-known minimal single-asset compounder shape
///         (xERC4626 / Beefy-simple) on top of stock OpenZeppelin v5 ERC4626.
///
/// Inflation-attack mitigations (defense in depth):
///  1. OZ virtual-shares decimal offset of 6 (_decimalsOffset).
///  2. The deploy script seeds a small "dead shares" deposit to 0x...dEaD
///     before the vault is announced (see script/DeployCompounder.s.sol).
///
/// Share price accounting: totalAssets() = staked + pending rewards + loose IN,
/// so harvest() does not move the share price (rewards accrue continuously);
/// it only converts pending rewards into staked principal.
///
/// No fees. No upgradability. Owner (treasury) can only pause new deposits
/// and rescue tokens that are NOT the underlying asset.
contract InCompounder is ERC4626, Ownable, Pausable, ReentrancyGuard {
    using SafeERC20 for IERC20;

    IStakingRewards public immutable pool;

    event Harvest(address indexed caller, uint256 rewardsClaimed, uint256 totalStakedAfter);

    error AssetRescueForbidden();
    error PoolAssetMismatch();

    constructor(IERC20 inToken, IStakingRewards poolA, address owner_)
        ERC4626(inToken)
        ERC20("Compounding Staked IN", "cIN")
        Ownable(owner_)
    {
        if (
            poolA.stakingToken() != address(inToken) || poolA.rewardsToken() != address(inToken)
        ) revert PoolAssetMismatch();
        pool = poolA;
        inToken.forceApprove(address(poolA), type(uint256).max);
    }

    // ---------------------------------------------------------------- views

    /// @notice Staked principal + pending (unclaimed) rewards + loose balance.
    function totalAssets() public view override returns (uint256) {
        return pool.balanceOf(address(this)) + pool.earned(address(this))
            + IERC20(asset()).balanceOf(address(this));
    }

    /// @dev OZ virtual-shares offset: makes classic donation/inflation attacks
    ///      economically infeasible (attacker loses ~1e6x what a victim could).
    function _decimalsOffset() internal pure override returns (uint8) {
        return 6;
    }

    /// @dev Pause blocks new deposits/mints (ERC4626-compliant via max* == 0).
    function maxDeposit(address) public view override returns (uint256) {
        return paused() ? 0 : type(uint256).max;
    }

    function maxMint(address) public view override returns (uint256) {
        return paused() ? 0 : type(uint256).max;
    }

    // ------------------------------------------------------------- mutative

    /// @notice Claim pending IN rewards from Pool A and restake everything.
    ///         Callable by anyone (keeper-friendly); no caller incentive fee.
    function harvest() external nonReentrant whenNotPaused {
        pool.getReward();
        uint256 staked = _stakeLoose();
        emit Harvest(msg.sender, staked, pool.balanceOf(address(this)));
    }

    // ------------------------------------------------------------- internal

    /// @dev Stake any loose IN into Pool A. Skips (keeps IN loose, still counted
    ///      by totalAssets) if the pool itself is paused, so vault deposits and
    ///      withdrawals keep working even if staking upstream is paused.
    function _stakeLoose() internal returns (uint256 staked) {
        staked = IERC20(asset()).balanceOf(address(this));
        if (staked == 0) return 0;
        if (pool.paused()) return 0;
        pool.stake(staked);
    }

    /// @dev Pull assets from caller (stock OZ), then stake them.
    function _deposit(address caller, address receiver, uint256 assets, uint256 shares)
        internal
        override
        nonReentrant
    {
        super._deposit(caller, receiver, assets, shares);
        _stakeLoose();
    }

    /// @dev Unstake exactly the shortfall (realizing rewards first), then pay out.
    ///      `assets <= totalAssets()` is guaranteed by ERC4626 share math, and
    ///      after getReward(): loose' = loose + earned, so any remaining
    ///      shortfall is <= staked principal — pool.withdraw cannot revert
    ///      for insufficient balance.
    function _withdraw(address caller, address receiver, address owner_, uint256 assets, uint256 shares)
        internal
        override
        nonReentrant
    {
        uint256 loose = IERC20(asset()).balanceOf(address(this));
        if (loose < assets) {
            pool.getReward();
            loose = IERC20(asset()).balanceOf(address(this));
            if (loose < assets) {
                pool.withdraw(assets - loose);
            }
        }
        super._withdraw(caller, receiver, owner_, assets, shares);
    }

    // ----------------------------------------------------------- restricted

    function pause() external onlyOwner {
        _pause();
    }

    function unpause() external onlyOwner {
        _unpause();
    }

    /// @notice Rescue tokens accidentally sent to the vault. The underlying
    ///         asset ($IN) can never be rescued — user funds are untouchable.
    function rescueToken(IERC20 token, address to, uint256 amount) external onlyOwner {
        if (address(token) == asset()) revert AssetRescueForbidden();
        token.safeTransfer(to, amount);
    }
}