// EVM字节码执行示例分析
pragma solidity ^0.8.0;

contract EVMAnalysis {
    // 存储变量布局分析
    uint256 private value;
    mapping(address => uint256) private balances;

    function executeOperation() public {
        // PUSH1 0x80 - 将0x80压入栈顶
        // PUSH1 0x40 - 将0x40压入栈顶
        // MSTORE - 存储操作，消耗3 Gas
        assembly {
            let free_ptr := mload(0x40)
            mstore(free_ptr, 0x80)
        }

        // SSTORE操作Gas消耗分析
        // 首次存储: 20000 Gas
        // 修改存储: 5000 Gas
        // 清零存储:  refund 15000 Gas
        value = 100;
    }
}

// 模块化合约架构示例
pragma solidity ^0.8.0;

// 基础接口定义
interface IERC20 {
    function transfer(address to, uint256 amount) external returns (bool);
    function balanceOf(address account) external view returns (uint256);
}

// 访问控制模块
abstract contract AccessControl {
    mapping(bytes32 => mapping(address => bool)) private _roles;

    modifier onlyRole(bytes32 role) {
        require(_roles[role][msg.sender], "AccessControl: access denied");
        _;
    }
}

// 业务逻辑主合约
contract DeFiProtocol is AccessControl {
    using SafeMath for uint256;

    // 状态变量分组存储
    struct ProtocolState {
        uint256 totalLiquidity;
        uint256 totalBorrowed;
        uint256 reserveFactor;
    }

    ProtocolState public state;

    // 事件定义
    event LiquidityAdded(address indexed user, uint256 amount);
    event BorrowExecuted(address indexed user, uint256 amount);
}

// 可升级合约架构
contract Proxy {
    address public implementation;

    constructor(address _implementation) {
        implementation = _implementation;
    }

    fallback() external payable {
        address impl = implementation;
        assembly {
            calldatacopy(0, 0, calldatasize())
            let result := delegatecall(gas(), impl, 0, calldatasize(), 0, 0)
            returndatacopy(0, 0, returndatasize())

            switch result
            case 0 { revert(0, returndatasize()) }
            default { return(0, returndatasize()) }
        }
    }
}

// 逻辑合约V1
contract LogicV1 {
    uint256 public value;

    function setValue(uint256 _value) public {
        value = _value;
    }
}

// 逻辑合约V2 - 升级版本
contract LogicV2 {
    uint256 public value;
    uint256 public timestamp;

    function setValue(uint256 _value) public {
        value = _value;
        timestamp = block.timestamp;
    }
}

contract TokenFactory {
    mapping(address => address[]) public userTokens;

    event TokenCreated(address indexed creator, address tokenAddress);

    function createToken(
        string memory name,
        string memory symbol,
        uint256 initialSupply
    ) public returns (address) {
        Token newToken = new Token(name, symbol, initialSupply, msg.sender);
        userTokens[msg.sender].push(address(newToken));
        emit TokenCreated(msg.sender, address(newToken));
        return address(newToken);
    }

    function getUserTokenCount(address user) public view returns (uint256) {
        return userTokens[user].length;
    }
}

// 内存优化示例：避免不必要的内存拷贝
contract MemoryOptimization {
    // 不优化的实现
    function processArray(uint256[] memory data) public pure returns (uint256) {
        uint256 sum = 0;
        for (uint256 i = 0; i < data.length; i++) {
            sum += data[i]; // 每次访问都从内存加载
        }
        return sum;
    }

    // 优化后的实现
    function processArrayOptimized(uint256[] memory data) public pure returns (uint256) {
        uint256 sum = 0;
        uint256 length = data.length;
        for (uint256 i = 0; i < length; i++) {
            // 使用局部变量减少内存访问
            uint256 element = data[i];
            sum += element;
        }
        return sum;
    }
}

// 恒定乘积做市商核心算法
library Math {
    function calculateOutputAmount(
        uint256 inputAmount,
        uint256 inputReserve,
        uint256 outputReserve
    ) internal pure returns (uint256) {
        require(inputReserve > 0 && outputReserve > 0, "INSUFFICIENT_LIQUIDITY");

        uint256 inputAmountWithFee = inputAmount * 997;
        uint256 numerator = inputAmountWithFee * outputReserve;
        uint256 denominator = (inputReserve * 1000) + inputAmountWithFee;

        return numerator / denominator;
    }

    // 平方根计算优化
    function sqrt(uint256 x) internal pure returns (uint256 y) {
        uint256 z = (x + 1) / 2;
        y = x;
        while (z < y) {
            y = z;
            z = (x / z + z) / 2;
        }
    }
}

// 跨链桥核心合约简化版
contract CrossChainBridge {
    using ECDSA for bytes32;

    struct CrossChainTx {
        address from;
        uint256 amount;
        uint256 targetChainId;
        bytes32 txHash;
        bool executed;
    }

    mapping(bytes32 => CrossChainTx) public pendingTransactions;
    address[] public validators;
    uint256 public requiredSignatures;

    event CrossChainTransfer(
        address indexed from,
        uint256 amount,
        uint256 targetChainId,
        bytes32 txHash
    );

    function lockTokens(uint256 amount, uint256 targetChainId) external {
        // 资产锁定逻辑
        IERC20(token).transferFrom(msg.sender, address(this), amount);

        bytes32 txHash = keccak256(abi.encode(
            msg.sender,
            amount,
            targetChainId,
            block.chainid,
            block.number
        ));

        pendingTransactions[txHash] = CrossChainTx({
            from: msg.sender,
            amount: amount,
            targetChainId: targetChainId,
            txHash: txHash,
            executed: false
        });

        emit CrossChainTransfer(msg.sender, amount, targetChainId, txHash);
    }
}

// 期权定价核心算法
library OptionPricing {
    using FixedPoint for uint256;

    // Black-Scholes模型近似计算
    function calculateOptionPrice(
        uint256 spotPrice,
        uint256 strikePrice,
        uint256 timeToExpiry,
        uint256 volatility,
        uint256 riskFreeRate,
        bool isCall
    ) internal pure returns (uint256) {
        // 简化版Black-Scholes实现
        uint256 d1 = _calculateD1(spotPrice, strikePrice, timeToExpiry, volatility, riskFreeRate);
        uint256 d2 = d1 - volatility * FixedPoint.sqrt(timeToExpiry);

        uint256 nd1 = _normalDistribution(d1);
        uint256 nd2 = _normalDistribution(d2);

        if (isCall) {
            return (spotPrice * nd1 - strikePrice * FixedPoint.exp(-riskFreeRate * timeToExpiry) * nd2);
        } else {
            return (strikePrice * FixedPoint.exp(-riskFreeRate * timeToExpiry) * (1e18 - nd2) - spotPrice * (1e18 - nd1));
        }
    }

    function _calculateD1(
        uint256 spotPrice,
        uint256 strikePrice,
        uint256 timeToExpiry,
        uint256 volatility,
        uint256 riskFreeRate
    ) private pure returns (uint256) {
        uint256 variance = volatility * volatility;
        uint256 numerator = FixedPoint.ln(spotPrice / strikePrice) + (riskFreeRate + variance / 2) * timeToExpiry;
        uint256 denominator = volatility * FixedPoint.sqrt(timeToExpiry);

        return numerator / denominator;
    }
}

// 使用Specification语言定义合约行为
/*@
  predicate totalSupplyInvariant() = 
    totalSupply == sum(balances) + sum(pendingTransactions);

  predicate noOverflow() = 
    \forall address a; balances[a] <= MAX_SUPPLY;

  lemma transferPreservesTotalSupply:
    \forall address from, address to, uint amount;
      balances[from] >= amount ==> 
      totalSupply == \old(totalSupply);
*/

contract VerifiedToken {
    mapping(address => uint256) public balances;
    uint256 public totalSupply;

    function transfer(address to, uint256 amount) external {
        require(balances[msg.sender] >= amount, "Insufficient balance");

        balances[msg.sender] -= amount;
        balances[to] += amount;

        // 形式化验证确保不变量保持
        assert(balances[msg.sender] + balances[to] == 
               (balances[msg.sender] + amount) + (balances[to] - amount));
    }
}

// hardhat.config.js 高级配置
module.exports = {
  networks: {
    mainnet: {
      url: process.env.MAINNET_RPC_URL,
      accounts: [process.env.PRIVATE_KEY],
      gas: 12000000,
      gasPrice: 30000000000, // 30 Gwei
      timeout: 120000
    },
    local: {
      url: "http://localhost:8545",
      chainId: 31337,
      gas: 12000000
    }
  },

  solidity: {
    version: "0.8.19",
    settings: {
      optimizer: {
        enabled: true,
        runs: 200,
        details: {
          yul: true,
          yulDetails: {
            stackAllocation: true,
            optimizerSteps: "dhfoDgvulfnTUtnIf"
          }
        }
      },
      viaIR: true,
      metadata: {
        bytecodeHash: "ipfs"
      }
    }
  },

  gasReporter: {
    enabled: true,
    currency: "USD",
    gasPrice: 30,
    coinmarketcap: process.env.COINMARKETCAP_API_KEY
  },

  mocha: {
    timeout: 40000
  }
};