Collateral Manager Contract

function deposit(
    address asset,
    uint256 amount
) external

function withdraw(
    address asset,
    uint256 amount
) external

function liquidate(
    address user,
    address debtAsset,
    uint256 debtAmount,
    address collateralAsset
) external returns (uint256 collateralSeized)

function getCollateralBalance(
    address user,
    address asset
) external view returns (uint256)

function getCollateralValue(
    address user
) external view returns (uint256)

function getBorrowingPower(
    address user
) external view returns (uint256)

function getHealthFactor(
    address user
) external view returns (uint256)

function getAssetConfig(
    address asset
) external view returns (AssetConfig memory)

struct AssetConfig {
    uint256 ltv;                    // Max loan-to-value (8000 = 80%)
    uint256 liquidationThreshold;   // Liquidation point (8500 = 85%)
    uint256 liquidationPenalty;     // Penalty (500 = 5%)
    address priceFeed;              // Oracle address
    bool enabled;                   // Is collateral enabled
}

healthFactor = totalCollateralValue × weightedLiquidationThreshold
               ─────────────────────────────────────────────────────
                              totalDebtValue

// Example liquidation
function liquidate(
    address user,
    address debtAsset,
    uint256 debtAmount,
    address collateralAsset
) external {
    // 1. Verify user is liquidatable
    require(getHealthFactor(user) < 1e18, "Not liquidatable");

    // 2. Calculate collateral to seize
    uint256 debtValue = getAssetValue(debtAsset, debtAmount);
    uint256 penalty = getAssetConfig(collateralAsset).liquidationPenalty;
    uint256 collateralToSeize = debtValue * (10000 + penalty) / 10000;

    // 3. Transfer debt from liquidator
    IERC20(debtAsset).transferFrom(msg.sender, address(this), debtAmount);

    // 4. Reduce user's debt
    _reduceDebt(user, debtAsset, debtAmount);

    // 5. Transfer collateral to liquidator
    _transferCollateral(user, msg.sender, collateralAsset, collateralToSeize);
}

event CollateralDeposited(
    address indexed user,
    address indexed asset,
    uint256 amount
);

event CollateralWithdrawn(
    address indexed user,
    address indexed asset,
    uint256 amount
);

event Liquidation(
    address indexed user,
    address indexed liquidator,
    address debtAsset,
    uint256 debtCovered,
    address collateralAsset,
    uint256 collateralSeized
);

const collateralManager = new ethers.Contract(
    COLLATERAL_MANAGER_ADDRESS,
    COLLATERAL_MANAGER_ABI,
    signer
);

// Deposit ETH as collateral
const weth = new ethers.Contract(WETH_ADDRESS, ERC20_ABI, signer);
await weth.approve(COLLATERAL_MANAGER_ADDRESS, amount);
await collateralManager.deposit(WETH_ADDRESS, amount);

// Check borrowing power
const power = await collateralManager.getBorrowingPower(userAddress);
console.log(`Can borrow up to: ${ethers.formatUnits(power, 6)} USDC`);

// Check health factor
const hf = await collateralManager.getHealthFactor(userAddress);
console.log(`Health factor: ${ethers.formatUnits(hf, 18)}`);