Integration

Oracle prices are stored within the pair contracts. To integrate the current oracle price into a smart contract, simply call getOraclePrice0() and getOraclePrice1() functions. These functions return the oracle price of the pair at the current time as a U(112,112)-fixed-point number and the timestamp of the latest block that the reserves of the pair contract have been updated.

Example

pragma solidity >=0.7.0 <0.9.0;

import './interfaces/INostraSwapPair.sol';
import './interfaces/IERC20.sol';

contract ETHUSDCOracle {
    address public ETHUSDCPair;
    address public WETH;
    address public USDC;
    
    constructor(address _ETHUSDCPair, address _WETH, address _USDC) {
        address token0 = INostraSwapPair(_ETHUSDCPair).token0();
        address token1 = INostraSwapPair(_ETHUSDCPair).token1();
        require((token0 == _WETH && token1 == _USDC) || (token0 == _USDC && token1 == _WETH), "Invalid Addresses");
        ETHUSDCPair = _ETHUSDCPair;
        WETH = _WETH;
        USDC = _USDC;
    }
    
    function ETHAbove3000() external view returns (string memory) {
        uint256 ETHPrice;
        uint8 decimalWETH = IERC20(WETH).decimals();
        uint8 decimalUSDC = IERC20(USDC).decimals();
        if (INostraSwapPair(ETHUSDCPair).token0() == WETH) {
            (ETHPrice, ) = INostraSwapPair(ETHUSDCPair).getOraclePrice0();
        } else {
            (ETHPrice, ) = INostraSwapPair(ETHUSDCPair).getOraclePrice1();
        }
        ETHPrice = ETHPrice * (10 ** decimalWETH) / (10 ** decimalUSDC)
        if (ETHPrice > encodeFP(3000)) {
            return "BullBullBull";
        } else {
            return "BearBearBear";
        }
    }
    
    function encodeFP(uint input) internal pure returns (uint224 retVal) {
        require(input < 2 ** 112, "Input too large!");
        return uint224(input * (2 ** 112));
    }
}