DeFi Asset Protection DECENTRALIZED VAULT & OWNERSHIP PROTOCOL

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
/*
 Decentralized Asset Protection Vault (DAP)
 - Owner-controlled vault
 - Nominee inheritance system
 - Time-lock withdrawals
 - Emergency unlock
 WARNING: Educational only, not audited
*/

interface IERC20 {
    function transfer(address to, uint256 amount) external returns (bool);
    function transferFrom(address from, address to, uint256 amount) external returns (bool);
    function balanceOf(address user) external view returns (uint256);
}

contract DAPVault {
    address public owner;
    address public nominee;
    uint256 public lastActiveTime;
    uint256 public inactivityPeriod;

    mapping(IERC20 => uint256) public tokenBalances;

    // ── EVENTS ─────────────────────────────────────
    event Deposited(address indexed from, address token, uint256 amount);
    event Withdrawn(address indexed to, address token, uint256 amount);
    event NomineeUpdated(address indexed newNominee);
    event OwnerPing(address indexed owner);
    event Inherited(address indexed nominee);
    event EmergencyWithdrawal(address indexed to, address token, uint256 amount);

    modifier onlyOwner()   { require(msg.sender == owner,   "Not owner");   _; }
    modifier onlyNominee() { require(msg.sender == nominee, "Not nominee"); _; }

    constructor(address _nominee, uint256 _inactivityPeriod) {
        owner            = msg.sender;
        nominee          = _nominee;
        inactivityPeriod = _inactivityPeriod;
        lastActiveTime   = block.timestamp;
    }

    // ── ACTIVITY PING ──────────────────────────────
    function ping() external onlyOwner {
        lastActiveTime = block.timestamp;
        emit OwnerPing(msg.sender);
    }
    function updateNominee(address newNominee) external onlyOwner {
        nominee = newNominee;
        emit NomineeUpdated(newNominee);
    }

    // ── DEPOSIT ────────────────────────────────────
    function depositToken(IERC20 token, uint256 amount) external {
        require(amount > 0, "Zero");
        token.transferFrom(msg.sender, address(this), amount);
        tokenBalances[token] += amount;
        emit Deposited(msg.sender, address(token), amount);
    }

    // ── WITHDRAW (owner only) ──────────────────────
    function withdrawToken(IERC20 token, uint256 amount) external onlyOwner {
        require(tokenBalances[token] >= amount, "Insufficient");
        tokenBalances[token] -= amount;
        token.transfer(owner, amount);
        lastActiveTime = block.timestamp;
        emit Withdrawn(owner, address(token), amount);
    }

    // ── INHERITANCE ────────────────────────────────
    function claimInheritance() external onlyNominee {
        require(block.timestamp > lastActiveTime + inactivityPeriod, "Owner active");
        owner          = nominee;
        lastActiveTime = block.timestamp;
        emit Inherited(nominee);
    }

    // ── EMERGENCY WITHDRAWAL ───────────────────────
    // Extendable to multisig / guardian system
    function emergencyWithdraw(IERC20 token, uint256 amount, address to) external onlyNominee {
        require(block.timestamp > lastActiveTime + inactivityPeriod, "Too early");
        require(tokenBalances[token] >= amount, "Low balance");
        tokenBalances[token] -= amount;
        token.transfer(to, amount);
        emit EmergencyWithdrawal(to, address(token), amount);
    }

    // ── VIEW ───────────────────────────────────────
    function isInactive() external view returns (bool) {
        return block.timestamp > lastActiveTime + inactivityPeriod;
    }
}