Transaction Operations

/**
 * Simulate transaction execution to predict results
 * @param request - Transaction to simulate
 * @param options - Simulation options
 * @returns Promise resolving to simulation results
 */
simulateExecution(
  request: TransactionRequest,
  options?: SimulateExecutionOptions
): Promise<SimulateExecutionResponse>;

/**
 * Simulate asset changes that would result from a transaction
 * @param request - Transaction to simulate
 * @param options - Simulation options
 * @returns Promise resolving to asset change predictions
 */
simulateAssetChanges(
  request: TransactionRequest,
  options?: SimulateAssetChangesOptions
): Promise<SimulateAssetChangesResponse>;

/**
 * Simulate asset changes for a bundle of transactions
 * @param requests - Array of transactions to simulate as bundle
 * @param options - Simulation options
 * @returns Promise resolving to bundle asset change predictions
 */
simulateAssetChangesBundle(
  requests: TransactionRequest[],
  options?: SimulateAssetChangesBundleOptions
): Promise<SimulateAssetChangesBundleResponse>;

interface SimulateExecutionOptions {
  blockNumber?: number | string;
  stateOverrides?: StateOverrides;
}

interface SimulateExecutionResponse {
  calls: SimulateExecutionCall[];
}

interface SimulateExecutionCall {
  type: string;
  from: string;
  to: string;
  value: string;
  gasUsed: string;
  gasLimit: string;
  input: string;
  output: string;
  error?: string;
  revertReason?: string;
  calls?: SimulateExecutionCall[];
}

interface SimulateAssetChangesOptions {
  blockNumber?: number | string;
}

interface SimulateAssetChangesResponse {
  changes: AssetChange[];
  gasUsed: string;
  error?: SimulationError;
}

interface AssetChange {
  assetType: AssetType;
  changeType: ChangeType;
  from: string;
  to: string;
  rawAmount: string;
  amount: string;
  symbol: string;
  decimals: number;
  name: string;
  logo?: string;
  contractAddress?: string;
  tokenId?: string;
}

enum AssetType {
  NATIVE = "NATIVE",
  ERC20 = "ERC20",
  ERC721 = "ERC721",
  ERC1155 = "ERC1155",
}

enum ChangeType {
  APPROVE = "APPROVE",
  TRANSFER = "TRANSFER",
}

/**
 * Send a private transaction to avoid MEV
 * @param request - Transaction to send privately
 * @param options - Private transaction options
 * @returns Promise resolving to transaction hash
 */
sendPrivateTransaction(
  request: TransactionRequest,
  options?: SendPrivateTransactionOptions
): Promise<string>;

/**
 * Cancel a pending private transaction
 * @param transactionHash - Hash of transaction to cancel
 * @returns Promise resolving to cancellation status
 */
cancelPrivateTransaction(transactionHash: string): Promise<boolean>;

interface SendPrivateTransactionOptions {
  maxBlockNumber?: number;
  preferences?: PrivateTransactionPreferences;
}

interface PrivateTransactionPreferences {
  fast?: boolean;
  privacy?: PrivacyLevel;
  validity?: number;
}

enum PrivacyLevel {
  STANDARD = "standard",
  HIGH = "high",
  MAXIMUM = "maximum",
}

/**
 * Get the recommended max priority fee per gas
 * @returns Promise resolving to optimal priority fee in wei
 */
getMaxPriorityFeePerGas(): Promise<string>;

/**
 * Get gas fee recommendations for different speed preferences
 * @returns Promise resolving to gas fee suggestions
 */
getGasFeeRecommendations(): Promise<GasFeeRecommendations>;

/**
 * Estimate gas for a transaction with advanced options
 * @param request - Transaction to estimate gas for
 * @param options - Estimation options
 * @returns Promise resolving to detailed gas estimate
 */
estimateGasAdvanced(
  request: TransactionRequest,
  options?: EstimateGasOptions
): Promise<AdvancedGasEstimate>;

interface GasFeeRecommendations {
  slow: GasFeeRecommendation;
  standard: GasFeeRecommendation;
  fast: GasFeeRecommendation;
}

interface GasFeeRecommendation {
  maxFeePerGas: string;
  maxPriorityFeePerGas: string;
  gasLimit: string;
  estimatedWaitTime: number;
}

interface EstimateGasOptions {
  blockNumber?: number | string;
  stateOverrides?: StateOverrides;
}

interface AdvancedGasEstimate {
  gasLimit: string;
  gasUsed: string;
  baseFeePerGas: string;
  priorityFeePerGas: string;
  totalFee: string;
}

/**
 * Send transaction with enhanced error handling and retries
 * @param request - Transaction to send
 * @param options - Send options
 * @returns Promise resolving to transaction response
 */
sendTransactionAdvanced(
  request: TransactionRequest,
  options?: SendTransactionOptions
): Promise<TransactionResponse>;

/**
 * Replace a pending transaction with higher gas price
 * @param originalHash - Hash of transaction to replace
 * @param newRequest - New transaction with higher gas
 * @returns Promise resolving to new transaction response
 */
replaceTransaction(
  originalHash: string,
  newRequest: TransactionRequest
): Promise<TransactionResponse>;

/**
 * Speed up a pending transaction
 * @param transactionHash - Hash of transaction to speed up
 * @param gasPriceIncrease - Percentage increase in gas price
 * @returns Promise resolving to new transaction response
 */
speedUpTransaction(
  transactionHash: string,
  gasPriceIncrease?: number
): Promise<TransactionResponse>;

interface SendTransactionOptions {
  retries?: number;
  retryDelay?: number;
  monitorPending?: boolean;
  timeoutMs?: number;
}

/**
 * Check if a transaction is vulnerable to MEV
 * @param request - Transaction to analyze
 * @returns Promise resolving to MEV risk analysis
 */
analyzeMevRisk(request: TransactionRequest): Promise<MevRiskAnalysis>;

/**
 * Get MEV protection recommendations for a transaction
 * @param request - Transaction to protect
 * @returns Promise resolving to protection suggestions
 */
getMevProtectionRecommendations(
  request: TransactionRequest
): Promise<MevProtectionRecommendations>;

interface MevRiskAnalysis {
  riskLevel: MevRiskLevel;
  vulnerabilities: string[];
  recommendations: string[];
  estimatedMevValue: string;
}

interface MevProtectionRecommendations {
  usePrivateMempool: boolean;
  adjustSlippage: boolean;
  splitTransaction: boolean;
  delayExecution: boolean;
  alternativeRoutes: string[];
}

enum MevRiskLevel {
  LOW = "low",
  MEDIUM = "medium",
  HIGH = "high",
  CRITICAL = "critical",
}

interface StateOverrides {
  [address: string]: StateOverride;
}

interface StateOverride {
  balance?: string;
  nonce?: number;
  code?: string;
  state?: { [key: string]: string };
  stateDiff?: { [key: string]: string };
}

interface SimulationError {
  code: number;
  message: string;
  revertReason?: string;
}

import { Alchemy, Network } from "alchemy-sdk";

const alchemy = new Alchemy({
  apiKey: "your-api-key",
  network: Network.ETH_MAINNET,
});

// Simulate transaction execution
const simulation = await alchemy.transact.simulateExecution({
  to: "0x...",
  value: "1000000000000000000", // 1 ETH
  data: "0x...",
});

// Simulate asset changes before executing
const assetChanges = await alchemy.transact.simulateAssetChanges({
  to: "0x...", // DEX contract
  data: "0x...", // swap function call
});

console.log("Expected asset changes:", assetChanges.changes);

// Send private transaction to avoid MEV
const privateTxHash = await alchemy.transact.sendPrivateTransaction({
  to: "0x...",
  value: "1000000000000000000",
  gasLimit: "21000",
}, {
  preferences: {
    fast: true,
    privacy: "high",
  },
});

// Get optimal gas prices
const priorityFee = await alchemy.transact.getMaxPriorityFeePerGas();
const gasRecommendations = await alchemy.transact.getGasFeeRecommendations();

// Analyze MEV risk
const mevRisk = await alchemy.transact.analyzeMevRisk({
  to: "0x...", // AMM contract
  data: "0x...", // large swap
});

if (mevRisk.riskLevel === "HIGH") {
  const protection = await alchemy.transact.getMevProtectionRecommendations({
    to: "0x...",
    data: "0x...",
  });
  
  if (protection.usePrivateMempool) {
    // Use private transaction
    await alchemy.transact.sendPrivateTransaction(/* ... */);
  }
}

// Simulate bundle of transactions
const bundleSimulation = await alchemy.transact.simulateAssetChangesBundle([
  { to: "0x...", data: "0x..." }, // Transaction 1
  { to: "0x...", data: "0x..." }, // Transaction 2
]);