American Express DeFi: How Corporate Loyalty Tokens Could Replace Your Membership Rewards

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/AccessControl.sol";
import "@openzeppelin/contracts/security/Pausable.sol";

contract AmexRewardToken is ERC20, AccessControl, Pausable {
    bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
    bytes32 public constant PAUSER_ROLE = keccak256("PAUSER_ROLE");
    
    // Mapping for tier-based multipliers
    mapping(address => uint256) public membershipTier;
    
    // Events for tracking loyalty actions
    event RewardsEarned(address indexed user, uint256 amount, string activity);
    event TierUpdated(address indexed user, uint256 newTier);
    
    constructor() ERC20("AmexRewardToken", "ART") {
        _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);
        _grantRole(MINTER_ROLE, msg.sender);
        _grantRole(PAUSER_ROLE, msg.sender);
    }
    
    /**
     * @dev Mint rewards based on spending activity
     * @param to Address receiving rewards
     * @param amount Base reward amount
     * @param activity Type of spending activity
     */
    function mintRewards(
        address to, 
        uint256 amount, 
        string memory activity
    ) public onlyRole(MINTER_ROLE) {
        uint256 multiplier = getTierMultiplier(to);
        uint256 finalAmount = amount * multiplier;
        
        _mint(to, finalAmount);
        emit RewardsEarned(to, finalAmount, activity);
    }
    
    /**
     * @dev Calculate tier-based reward multiplier
     * @param user Address to check tier for
     * @return multiplier Reward multiplier (100 = 1x, 150 = 1.5x)
     */
    function getTierMultiplier(address user) public view returns (uint256) {
        uint256 tier = membershipTier[user];
        if (tier >= 3) return 200; // Centurion: 2x multiplier
        if (tier >= 2) return 150; // Platinum: 1.5x multiplier
        if (tier >= 1) return 125; // Gold: 1.25x multiplier
        return 100; // Basic: 1x multiplier
    }
}

contract AmexStakingPool {
    using SafeMath for uint256;
    
    IERC20 public rewardToken;
    uint256 public rewardRate = 100; // 1% daily APY
    uint256 public constant REWARD_DURATION = 86400; // 24 hours
    
    mapping(address => uint256) public stakedBalance;
    mapping(address => uint256) public lastUpdateTime;
    mapping(address => uint256) public rewards;
    
    event Staked(address indexed user, uint256 amount);
    event Withdrawn(address indexed user, uint256 amount);
    event RewardPaid(address indexed user, uint256 reward);
    
    /**
     * @dev Stake loyalty tokens to earn yield
     * @param amount Number of tokens to stake
     */
    function stake(uint256 amount) external updateReward(msg.sender) {
        require(amount > 0, "Cannot stake 0");
        
        stakedBalance[msg.sender] = stakedBalance[msg.sender].add(amount);
        rewardToken.transferFrom(msg.sender, address(this), amount);
        
        emit Staked(msg.sender, amount);
    }
    
    /**
     * @dev Calculate pending rewards for user
     * @param account Address to calculate rewards for
     * @return Pending reward amount
     */
    function earned(address account) public view returns (uint256) {
        uint256 timeElapsed = block.timestamp.sub(lastUpdateTime[account]);
        uint256 stakingReward = stakedBalance[account]
            .mul(rewardRate)
            .mul(timeElapsed)
            .div(REWARD_DURATION)
            .div(10000);
            
        return rewards[account].add(stakingReward);
    }
    
    modifier updateReward(address account) {
        rewards[account] = earned(account);
        lastUpdateTime[account] = block.timestamp;
        _;
    }
}

// Node.js service for bridging traditional points to tokens
const Web3 = require('web3');
const { AmexRewardToken } = require('./contracts');

class LoyaltyBridge {
    constructor(web3Provider, contractAddress) {
        this.web3 = new Web3(web3Provider);
        this.contract = new this.web3.eth.Contract(
            AmexRewardToken.abi, 
            contractAddress
        );
    }
    
    /**
     * Convert traditional points to blockchain tokens
     * @param {string} userId - Customer identifier
     * @param {number} pointsBalance - Traditional points balance
     * @param {string} activity - Earning activity type
     */
    async convertPointsToTokens(userId, pointsBalance, activity) {
        try {
            // Verify points balance from traditional database
            const verified = await this.verifyPointsBalance(userId, pointsBalance);
            if (!verified) throw new Error('Points balance verification failed');
            
            // Calculate token amount (1 point = 1 token * tier multiplier)
            const userAddress = await this.getUserWalletAddress(userId);
            const tokenAmount = this.web3.utils.toWei(pointsBalance.toString(), 'ether');
            
            // Mint tokens on blockchain
            const tx = await this.contract.methods
                .mintRewards(userAddress, tokenAmount, activity)
                .send({ from: this.adminAddress, gas: 200000 });
                
            console.log(`Minted ${pointsBalance} tokens for user ${userId}`);
            return tx.transactionHash;
            
        } catch (error) {
            console.error('Token conversion failed:', error);
            throw error;
        }
    }
    
    /**
     * Handle real-time spending events
     * @param {Object} spendingEvent - Credit card transaction data
     */
    async handleSpendingEvent(spendingEvent) {
        const { userId, amount, merchant, category } = spendingEvent;
        
        // Calculate rewards based on spending category
        const rewardRate = this.getCategoryRewardRate(category);
        const rewardPoints = Math.floor(amount * rewardRate);
        
        if (rewardPoints > 0) {
            await this.convertPointsToTokens(
                userId, 
                rewardPoints, 
                `${category}_purchase`
            );
        }
    }
}

contract AmexDeFiIntegration {
    using SafeERC20 for IERC20;
    
    IERC20 public rewardToken;
    
    // Integration with popular DeFi protocols
    address public uniswapRouter;
    address public compoundPool;
    address public aavePool;
    
    mapping(address => mapping(string => uint256)) public protocolBalances;
    
    /**
     * @dev Enable users to provide liquidity on Uniswap
     * @param tokenAmount Amount of reward tokens to add
     * @param ethAmount Amount of ETH to pair
     */
    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) external {
        require(tokenAmount > 0 && ethAmount > 0, "Invalid amounts");
        
        rewardToken.safeTransferFrom(msg.sender, address(this), tokenAmount);
        
        // Add liquidity to Uniswap pool
        IUniswapV2Router02(uniswapRouter).addLiquidityETH{value: ethAmount}(
            address(rewardToken),
            tokenAmount,
            0, // Accept any amount of tokens
            0, // Accept any amount of ETH
            msg.sender,
            block.timestamp + 3600
        );
        
        protocolBalances[msg.sender]["uniswap"] += tokenAmount;
    }
    
    /**
     * @dev Stake tokens in Compound for yield
     * @param amount Amount of tokens to stake
     */
    function stakeInCompound(uint256 amount) external {
        require(amount > 0, "Cannot stake 0");
        
        rewardToken.safeTransferFrom(msg.sender, address(this), amount);
        
        // Deposit tokens into Compound
        // (Implementation depends on Compound's interface)
        
        protocolBalances[msg.sender]["compound"] += amount;
    }
}

const tokenomicsConfig = {
    // Initial supply allocation
    totalSupply: 1000000000, // 1 billion tokens
    allocation: {
        customerRewards: 0.60,    // 60% for customer rewards
        stakingRewards: 0.20,     // 20% for staking yields
        partnerships: 0.10,       // 10% for merchant partnerships
        treasury: 0.10            // 10% for corporate treasury
    },
    
    // Emission schedule
    dailyEmissionRate: 0.001,     // 0.1% daily inflation
    halvingPeriod: 730,           // Halve emissions every 2 years
    
    // Burn mechanisms
    burnEvents: [
        'transaction_fees',        // Burn tokens on redemptions
        'tier_upgrades',          // Burn for membership upgrades
        'partner_purchases'       // Burn when spent with partners
    ],
    
    // Utility mechanisms
    utilities: [
        'fee_discounts',          // Reduced transaction fees
        'exclusive_access',       // VIP events and services
        'governance_voting',      // Vote on program changes
        'yield_farming'           // Earn additional rewards
    ]
};

contract AmexTierSystem {
    struct TierBenefits {
        uint256 rewardMultiplier;
        uint256 stakingBonus;
        uint256 feeDiscount;
        bool governanceVoting;
    }
    
    mapping(uint256 => TierBenefits) public tierBenefits;
    mapping(address => uint256) public userTier;
    mapping(address => uint256) public tokenBalance;
    
    constructor() {
        // Define tier benefits
        tierBenefits[1] = TierBenefits(125, 0, 0, false);      // Gold: 1.25x rewards
        tierBenefits[2] = TierBenefits(150, 500, 10, false);   // Platinum: 1.5x rewards, 5% staking bonus
        tierBenefits[3] = TierBenefits(200, 1000, 25, true);   // Centurion: 2x rewards, 10% staking bonus
    }
    
    /**
     * @dev Upgrade user tier based on token holdings
     * @param user Address to upgrade
     */
    function checkTierUpgrade(address user) external {
        uint256 balance = tokenBalance[user];
        uint256 newTier = calculateTier(balance);
        
        if (newTier > userTier[user]) {
            userTier[user] = newTier;
            emit TierUpgraded(user, newTier);
        }
    }
    
    function calculateTier(uint256 balance) internal pure returns (uint256) {
        if (balance >= 100000 * 1e18) return 3; // Centurion: 100K+ tokens
        if (balance >= 25000 * 1e18) return 2;  // Platinum: 25K+ tokens
        if (balance >= 5000 * 1e18) return 1;   // Gold: 5K+ tokens
        return 0; // Basic tier
    }
}

// Compliance monitoring system
class ComplianceMonitor {
    constructor(config) {
        this.kycProvider = config.kycProvider;
        this.amlService = config.amlService;
        this.regulatoryReporting = config.reportingService;
    }
    
    /**
     * Monitor token transfers for suspicious activity
     * @param {Object} transaction - Token transfer details
     */
    async monitorTransaction(transaction) {
        const { from, to, amount, timestamp } = transaction;
        
        // Check for AML red flags
        const amlResults = await this.amlService.screenTransaction({
            fromAddress: from,
            toAddress: to,
            amount: amount,
            tokenType: 'loyalty'
        });
        
        if (amlResults.riskScore > 80) {
            await this.flagSuspiciousActivity(transaction, amlResults);
        }
        
        // Report large transactions to regulators
        if (amount > 10000) { // $10K equivalent threshold
            await this.regulatoryReporting.submitReport({
                type: 'large_loyalty_transfer',
                transaction: transaction,
                compliance_status: 'monitored'
            });
        }
    }
    
    /**
     * Ensure users meet KYC requirements before token access
     * @param {string} userId - User identifier
     */
    async validateTokenAccess(userId) {
        const kycStatus = await this.kycProvider.getKycStatus(userId);
        
        if (kycStatus.level < 2) {
            throw new Error('Insufficient KYC verification for token access');
        }
        
        return kycStatus;
    }
}

// Security features for corporate loyalty tokens
contract SecureLoyaltyToken is AmexRewardToken {
    using SafeMath for uint256;
    
    // Rate limiting for minting
    mapping(address => uint256) public lastMintTime;
    mapping(address => uint256) public dailyMintAmount;
    uint256 public constant MAX_DAILY_MINT = 10000 * 1e18;
    
    // Emergency controls
    bool public emergencyPause = false;
    mapping(address => bool) public blacklistedAddresses;
    
    modifier rateLimited(address to, uint256 amount) {
        uint256 today = block.timestamp / 86400;
        uint256 lastMintDay = lastMintTime[to] / 86400;
        
        if (today > lastMintDay) {
            dailyMintAmount[to] = 0;
        }
        
        require(
            dailyMintAmount[to].add(amount) <= MAX_DAILY_MINT,
            "Daily mint limit exceeded"
        );
        
        dailyMintAmount[to] = dailyMintAmount[to].add(amount);
        lastMintTime[to] = block.timestamp;
        _;
    }
    
    modifier notBlacklisted(address account) {
        require(!blacklistedAddresses[account], "Address is blacklisted");
        _;
    }
    
    /**
     * @dev Override mint function with security controls
     */
    function mintRewards(
        address to,
        uint256 amount,
        string memory activity
    ) public 
        override 
        onlyRole(MINTER_ROLE) 
        rateLimited(to, amount)
        notBlacklisted(to)
        whenNotPaused 
    {
        super.mintRewards(to, amount, activity);
    }
    
    /**
     * @dev Emergency function to blacklist suspicious addresses
     */
    function blacklistAddress(address account) 
        external 
        onlyRole(DEFAULT_ADMIN_ROLE) 
    {
        blacklistedAddresses[account] = true;
        emit AddressBlacklisted(account);
    }
}

// Multi-chain deployment configuration
const deploymentConfig = {
    networks: {
        mainnet: {
            purpose: 'High-value transactions and governance',
            gasLimit: 'High cost acceptable',
            contracts: ['governance', 'treasury', 'high_value_rewards']
        },
        polygon: {
            purpose: 'Daily transactions and small rewards',
            gasLimit: 'Low cost required',
            contracts: ['daily_rewards', 'staking', 'transfers']
        },
        arbitrum: {
            purpose: 'DeFi integrations and yield farming',
            gasLimit: 'Medium cost acceptable',
            contracts: ['defi_integrations', 'liquidity_pools']
        }
    },
    
    bridging: {
        protocol: 'LayerZero',
        supportedChains: ['ethereum', 'polygon', 'arbitrum'],
        bridgeFees: 'Subsidized by corporate treasury'
    }
};

// Hybrid on-chain/off-chain data architecture
class LoyaltyDataManager {
    constructor() {
        this.onChain = new Web3Provider();
        this.offChain = new DatabaseConnection();
        this.cache = new RedisCache();
    }
    
    /**
     * Store transaction metadata off-chain for cost efficiency
     * @param {Object} transaction - Transaction details
     */
    async storeTransaction(transaction) {
        // Store core data on-chain
        const onChainData = {
            from: transaction.from,
            to: transaction.to,
            amount: transaction.amount,
            timestamp: transaction.timestamp
        };
        
        // Store metadata off-chain
        const offChainData = {
            transactionHash: transaction.hash,
            merchant: transaction.merchant,
            category: transaction.category,
            location: transaction.location,
            receiptUrl: transaction.receiptUrl
        };
        
        await Promise.all([
            this.onChain.recordTransaction(onChainData),
            this.offChain.storeMetadata(offChainData),
            this.cache.updateUserBalance(transaction.to, transaction.amount)
        ]);
    }
    
    /**
     * Efficient balance queries using cached data
     * @param {string} userAddress - User's wallet address
     */
    async getUserBalance(userAddress) {
        // Try cache first
        let balance = await this.cache.getBalance(userAddress);
        
        if (!balance) {
            // Fallback to on-chain query
            balance = await this.onChain.getBalance(userAddress);
            await this.cache.setBalance(userAddress, balance, 300); // 5min cache
        }
        
        return balance;
    }
}

contract MerchantRewards {
    struct Partner {
        string name;
        uint256 rewardMultiplier;
        bool isActive;
        uint256 totalVolume;
    }
    
    mapping(address => Partner) public merchants;
    mapping(address => mapping(address => uint256)) public userMerchantSpending;
    
    event PartnershipCreated(address indexed merchant, string name, uint256 multiplier);
    event PurchaseReward(address indexed user, address indexed merchant, uint256 reward);
    
    /**
     * @dev Process purchase and mint rewards
     * @param user Customer wallet address
     * @param merchant Partner merchant address
     * @param purchaseAmount Purchase amount in USD (scaled by 1e8)
     */
    function processPurchase(
        address user,
        address merchant,
        uint256 purchaseAmount
    ) external onlyRole(PROCESSOR_ROLE) {
        Partner storage partner = merchants[merchant];
        require(partner.isActive, "Merchant not active");
        
        // Calculate base rewards (1 token per dollar)
        uint256 baseReward = purchaseAmount;
        
        // Apply merchant multiplier
        uint256 totalReward = baseReward.mul(partner.rewardMultiplier).div(100);
        
        // Apply user tier multiplier
        uint256 finalReward = totalReward.mul(getTierMultiplier(user)).div(100);
        
        // Mint rewards to user
        _mint(user, finalReward);
        
        // Update tracking data
        userMerchantSpending[user][merchant] += purchaseAmount;
        partner.totalVolume += purchaseAmount;
        
        emit PurchaseReward(user, merchant, finalReward);
    }
    
    /**
     * @dev Add new merchant partner
     * @param merchantAddress Merchant's wallet address
     * @param name Merchant name
     * @param multiplier Reward multiplier (150 = 1.5x rewards)
     */
    function addMerchant(
        address merchantAddress,
        string memory name,
        uint256 multiplier
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        merchants[merchantAddress] = Partner({
            name: name,
            rewardMultiplier: multiplier,
            isActive: true,
            totalVolume: 0
        });
        
        emit PartnershipCreated(merchantAddress, name, multiplier);
    }
}

# Python service for AI-powered reward prediction
import numpy as np
from sklearn.ensemble import RandomForestRegressor
from web3 import Web3

class SmartRewardEngine:
    def __init__(self, web3_provider, contract_address):
        self.web3 = Web3(web3_provider)
        self.model = RandomForestRegressor(n_estimators=100)
        self.contract_address = contract_address
        
    def predict_optimal_rewards(self, user_data):
        """
        Predict optimal reward amounts to maximize user engagement
        
        Args:
            user_data (dict): User spending patterns and preferences
            
        Returns:
            dict: Optimized reward recommendations
        """
        features = self.extract_features(user_data)
        
        # Predict engagement probability for different reward levels
        reward_levels = np.linspace(1.0, 3.0, 21)  # 1x to 3x multipliers
        engagement_scores = []
        
        for multiplier in reward_levels:
            test_features = features.copy()
            test_features['reward_multiplier'] = multiplier
            
            score = self.model.predict([list(test_features.values())])[0]
            engagement_scores.append(score)
        
        # Find optimal reward level
        optimal_idx = np.argmax(engagement_scores)
        optimal_multiplier = reward_levels[optimal_idx]
        
        return {
            'recommended_multiplier': optimal_multiplier,
            'predicted_engagement': engagement_scores[optimal_idx],
            'confidence': self.calculate_confidence(features)
        }
    
    def extract_features(self, user_data):
        """Extract ML features from user spending data"""
        return {
            'avg_monthly_spend': user_data.get('monthly_spend', 0),
            'spending_categories': len(user_data.get('categories', [])),
            'days_since_last_purchase': user_data.get('days_since_last', 30),
            'tier_level': user_data.get('tier', 0),
            'total_rewards_earned': user_data.get('total_rewards', 0),
            'redemption_frequency': user_data.get('redemptions_per_month', 0)
        }

// LayerZero integration for cross-chain loyalty tokens
contract CrossChainLoyalty is AmexRewardToken {
    using SafeERC20 for IERC20;
    
    address public layerZeroEndpoint;
    mapping(uint16 => bytes) public trustedRemoteLookup;
    
    event SendToChain(uint16 indexed dstChainId, address indexed from, uint256 amount);
    event ReceiveFromChain(uint16 indexed srcChainId, address indexed to, uint256 amount);
    
    /**
     * @dev Send tokens to another chain
     * @param dstChainId Destination chain ID
     * @param to Recipient address on destination chain
     * @param amount Amount of tokens to send
     */
    function sendCrossChain(
        uint16 dstChainId,
        address to,
        uint256 amount
    ) external payable {
        require(amount > 0, "Amount must be greater than 0");
        require(balanceOf(msg.sender) >= amount, "Insufficient balance");
        
        // Burn tokens on source chain
        _burn(msg.sender, amount);
        
        // Encode payload for destination chain
        bytes memory payload = abi.encode(to, amount);
        
        // Send LayerZero message
        ILayerZeroEndpoint(layerZeroEndpoint).send{value: msg.value}(
            dstChainId,
            trustedRemoteLookup[dstChainId],
            payload,
            payable(msg.sender),
            address(0x0),
            bytes("")
        );
        
        emit SendToChain(dstChainId, msg.sender, amount);
    }
    
    /**
     * @dev Receive tokens from another chain (called by LayerZero)
     */
    function lzReceive(
        uint16 srcChainId,
        bytes memory srcAddress,
        uint64 nonce,
        bytes memory payload
    ) external {
        require(msg.sender == layerZeroEndpoint, "Only LayerZero endpoint");
        require(
            keccak256(srcAddress) == keccak256(trustedRemoteLookup[srcChainId]),
            "Invalid source address"
        );
        
        // Decode payload and mint tokens
        (address to, uint256 amount) = abi.decode(payload, (address, uint256));
        _mint(to, amount);
        
        emit ReceiveFromChain(srcChainId, to, amount);
    }
}