mev-beta/pkg/monitor/concurrent.go

package monitor

import (
	"context"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"math/big"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"time"

	"github.com/ethereum/go-ethereum"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/ethereum/go-ethereum/ethclient"
	"github.com/ethereum/go-ethereum/rpc"
	"github.com/fraktal/mev-beta/internal/config"
	"github.com/fraktal/mev-beta/internal/logger"
	"github.com/fraktal/mev-beta/internal/ratelimit"
	"github.com/fraktal/mev-beta/pkg/arbitrum"
	parserpkg "github.com/fraktal/mev-beta/pkg/arbitrum/parser"
	"github.com/fraktal/mev-beta/pkg/calldata"
	"github.com/fraktal/mev-beta/pkg/events"
	"github.com/fraktal/mev-beta/pkg/market"
	"github.com/fraktal/mev-beta/pkg/oracle"
	"github.com/fraktal/mev-beta/pkg/pools"
	"github.com/fraktal/mev-beta/pkg/scanner"
	arbitragetypes "github.com/fraktal/mev-beta/pkg/types"
	"github.com/fraktal/mev-beta/pkg/uniswap"
	"golang.org/x/time/rate"
)

// safeConvertInt64ToUint64 safely converts an int64 to uint64, ensuring no negative values
func safeConvertInt64ToUint64(v int64) uint64 {
	if v < 0 {
		return 0
	}
	return uint64(v)
}

// ArbitrumMonitor monitors the Arbitrum sequencer for transactions with concurrency support
type ArbitrumMonitor struct {
	config            *config.ArbitrumConfig
	botConfig         *config.BotConfig
	client            *ethclient.Client
	connectionManager *arbitrum.ConnectionManager
	l2Parser          *arbitrum.ArbitrumL2Parser
	logger            *logger.Logger
	rateLimiter       *ratelimit.LimiterManager
	marketMgr         *market.MarketManager
	scanner           *scanner.Scanner
	pipeline          *market.Pipeline
	fanManager        *market.FanManager
	eventParser       *events.EventParser  // CRITICAL FIX: Add event parser for direct receipt parsing
	// coordinator  *orchestrator.MEVCoordinator  // Removed to avoid import cycle
	limiter             *rate.Limiter
	pollInterval        time.Duration
	running             bool
	mu                  sync.RWMutex
	transactionChannel  chan interface{}
	lastHealthCheck     time.Time
	opportunityExecutor *parserpkg.Executor
}

var (
	payloadCaptureDir  string
	payloadCaptureOnce sync.Once
)

// NewArbitrumMonitor creates a new Arbitrum monitor with rate limiting
func NewArbitrumMonitor(
	arbCfg *config.ArbitrumConfig,
	botCfg *config.BotConfig,
	logger *logger.Logger,
	rateLimiter *ratelimit.LimiterManager,
	marketMgr *market.MarketManager,
	scanner *scanner.Scanner,
) (*ArbitrumMonitor, error) {
	logger.Info("🏁 STARTING NewArbitrumMonitor CREATION - Enhanced parser integration will begin")

	// Early check before any processing
	if arbCfg == nil {
		logger.Error("❌ arbCfg is nil")
		return nil, fmt.Errorf("arbCfg is nil")
	}
	if logger == nil {
		fmt.Println("❌ logger is nil - using printf")
		return nil, fmt.Errorf("logger is nil")
	}

	logger.Info("🔧 Parameters validated - proceeding with monitor creation")

	// Create Ethereum client with connection manager for retry and fallback support
	ctx := context.Background()
	connectionManager := arbitrum.NewConnectionManager(arbCfg, logger)
	rateLimitedClient, err := connectionManager.GetClientWithRetry(ctx, 3)
	if err != nil {
		return nil, fmt.Errorf("failed to connect to Arbitrum node with retries: %v", err)
	}
	client := rateLimitedClient.Client

	// Create price oracle for L2 parser
	priceOracle := oracle.NewPriceOracle(client, logger)

	// Create L2 parser for Arbitrum transaction parsing
	l2Parser, err := arbitrum.NewArbitrumL2Parser(arbCfg.RPCEndpoint, logger, priceOracle)
	if err != nil {
		return nil, fmt.Errorf("failed to create L2 parser: %v", err)
	}

	// Create rate limiter based on config
	limiter := rate.NewLimiter(
		rate.Limit(arbCfg.RateLimit.RequestsPerSecond),
		arbCfg.RateLimit.Burst,
	)

	// Create pipeline
	pipeline := market.NewPipeline(botCfg, logger, marketMgr, scanner, client)

	// Add default stages
	pipeline.AddDefaultStages()

	// Create fan manager
	fanManager := market.NewFanManager(
		&config.Config{
			Arbitrum: *arbCfg,
			Bot:      *botCfg,
		},
		logger,
		rateLimiter,
	)

	// CRITICAL FIX: Create enhanced event parser with L2 token extraction
	logger.Info("🔧 CREATING ENHANCED EVENT PARSER WITH L2 TOKEN EXTRACTION")

	if l2Parser == nil {
		logger.Error("❌ L2 PARSER IS NULL - Cannot create enhanced event parser")
		return nil, fmt.Errorf("L2 parser is null, cannot create enhanced event parser")
	}

	logger.Info("✅ L2 PARSER AVAILABLE - Creating enhanced event parser...")
	enhancedEventParser := events.NewEventParserWithTokenExtractor(logger, l2Parser)

	if enhancedEventParser == nil {
		logger.Error("❌ ENHANCED EVENT PARSER CREATION FAILED")
		return nil, fmt.Errorf("enhanced event parser creation failed")
	}

	logger.Info("✅ ENHANCED EVENT PARSER CREATED SUCCESSFULLY")
	logger.Info("🔄 INJECTING ENHANCED PARSER INTO PIPELINE...")

	// Inject enhanced parser into pipeline to avoid import cycle
	pipeline.SetEnhancedEventParser(enhancedEventParser)

	logger.Info("🎯 ENHANCED PARSER INJECTION COMPLETED")

	// Create raw RPC client for pool discovery
	poolRPCClient, err := rpc.Dial(arbCfg.RPCEndpoint)
	if err != nil {
		return nil, fmt.Errorf("failed to create RPC client for pool discovery: %w", err)
	}

	_ = pools.NewPoolDiscovery(poolRPCClient, logger) // Will be used in future enhancements

	// Create MEV coordinator - removed to avoid import cycle
	// coordinator := orchestrator.NewMEVCoordinator(
	//	&config.Config{
	//		Arbitrum: *arbCfg,
	//		Bot:      *botCfg,
	//	},
	//	logger,
	//	eventParser,
	//	poolDiscovery,
	//	marketMgr,
	//	scanner,
	// )

	return &ArbitrumMonitor{
		config:            arbCfg,
		botConfig:         botCfg,
		client:            client,
		connectionManager: connectionManager,
		l2Parser:          l2Parser,
		logger:            logger,
		rateLimiter:       rateLimiter,
		marketMgr:         marketMgr,
		scanner:           scanner,
		pipeline:          pipeline,
		fanManager:        fanManager,
		eventParser:       enhancedEventParser, // CRITICAL FIX: Store event parser for direct receipt parsing
		// coordinator:  coordinator,  // Removed to avoid import cycle
		limiter:            limiter,
		pollInterval:       time.Duration(botCfg.PollingInterval) * time.Second,
		running:            false,
		transactionChannel: make(chan interface{}, 50000), // Initialize with large buffer for Arbitrum's high TX volume
		lastHealthCheck:    time.Now(),
	}, nil
}

// SetOpportunityExecutor wires an arbitrage executor that receives detected opportunities.
func (m *ArbitrumMonitor) SetOpportunityExecutor(executor *parserpkg.Executor) {
	m.mu.Lock()
	defer m.mu.Unlock()
	m.opportunityExecutor = executor
}

// Start begins monitoring the Arbitrum sequencer
func (m *ArbitrumMonitor) Start(ctx context.Context) error {
	m.mu.Lock()
	m.running = true
	m.mu.Unlock()

	m.logger.Info("Starting Arbitrum sequencer monitoring...")

	// Start the MEV coordinator pipeline - removed to avoid import cycle
	// if err := m.coordinator.Start(); err != nil {
	//	return fmt.Errorf("failed to start MEV coordinator: %w", err)
	// }

	// Get the latest block to start from
	if err := m.rateLimiter.WaitForLimit(ctx, m.config.RPCEndpoint); err != nil {
		return fmt.Errorf("rate limit error: %v", err)
	}

	header, err := m.client.HeaderByNumber(ctx, nil)
	if err != nil {
		return fmt.Errorf("failed to get latest block header: %v", err)
	}

	lastBlock := header.Number.Uint64()
	m.logger.Info(fmt.Sprintf("Starting from block: %d", lastBlock))

	// Subscribe to DEX events for real-time monitoring
	if err := m.subscribeToDEXEvents(ctx); err != nil {
		m.logger.Warn(fmt.Sprintf("Failed to subscribe to DEX events: %v", err))
	} else {
		m.logger.Info("Subscribed to DEX events")
	}

	// Start transaction processor goroutine
	go m.processTransactionChannel(ctx)

	// Start connection health checker
	go m.checkConnectionHealth(ctx)

	for {
		m.mu.RLock()
		running := m.running
		m.mu.RUnlock()

		if !running {
			break
		}

		select {
		case <-ctx.Done():
			m.Stop()
			return nil
		case <-time.After(m.pollInterval):
			// Get the latest block
			if err := m.rateLimiter.WaitForLimit(ctx, m.config.RPCEndpoint); err != nil {
				m.logger.Error(fmt.Sprintf("Rate limit error: %v", err))
				continue
			}

			header, err := m.client.HeaderByNumber(ctx, nil)
			if err != nil {
				m.logger.Error(fmt.Sprintf("Failed to get latest block header: %v", err))
				continue
			}

			currentBlock := header.Number.Uint64()

			// Process blocks from lastBlock+1 to currentBlock
			for blockNum := lastBlock + 1; blockNum <= currentBlock; blockNum++ {
				if err := m.processBlock(ctx, blockNum); err != nil {
					m.logger.Error(fmt.Sprintf("Failed to process block %d: %v", blockNum, err))
				}
			}

			lastBlock = currentBlock
		}
	}

	return nil
}

// Stop stops the monitor
func (m *ArbitrumMonitor) Stop() {
	m.mu.Lock()
	defer m.mu.Unlock()
	m.running = false
	m.logger.Info("Stopping Arbitrum monitor...")
}

// processBlock processes a single block for potential swap transactions with enhanced L2 parsing
func (m *ArbitrumMonitor) processBlock(ctx context.Context, blockNumber uint64) error {
	startTime := time.Now()
	m.logger.Debug(fmt.Sprintf("Processing block %d", blockNumber))

	// Wait for rate limiter
	if err := m.rateLimiter.WaitForLimit(ctx, m.config.RPCEndpoint); err != nil {
		return fmt.Errorf("rate limit error: %v", err)
	}

	// Get block using L2 parser to bypass transaction type issues
	rpcStart := time.Now()
	l2Block, err := m.l2Parser.GetBlockByNumber(ctx, blockNumber)
	rpcDuration := time.Since(rpcStart)

	// Log RPC performance
	errorMsg := ""
	if err != nil {
		errorMsg = err.Error()
	}
	m.logger.RPC(m.config.RPCEndpoint, "GetBlockByNumber", rpcDuration, err == nil, errorMsg)

	if err != nil {
		m.logger.Error(fmt.Sprintf("Failed to get L2 block %d: %v", blockNumber, err))
		return fmt.Errorf("failed to get L2 block %d: %v", blockNumber, err)
	}

	// Parse DEX transactions from the block
	parseStart := time.Now()
	dexTransactions := m.l2Parser.ParseDEXTransactions(ctx, l2Block)
	parseDuration := time.Since(parseStart)

	// Calculate proper parsing rate (transactions per second of parsing time)
	parseRateTPS := float64(len(l2Block.Transactions)) / parseDuration.Seconds()

	// Log parsing performance
	m.logger.Performance("monitor", "parse_dex_transactions", parseDuration, map[string]interface{}{
		"block_number":           blockNumber,
		"total_txs":              len(l2Block.Transactions),
		"dex_txs":                len(dexTransactions),
		"parse_rate_txs_per_sec": parseRateTPS, // This is parsing throughput, not network TPS
		"parse_duration_ms":      parseDuration.Milliseconds(),
	})

	m.logger.Info(fmt.Sprintf("Block %d: Processing %d transactions, found %d DEX transactions",
		blockNumber, len(l2Block.Transactions), len(dexTransactions)))

	// Log block processing metrics
	m.logger.BlockProcessing(blockNumber, len(l2Block.Transactions), len(dexTransactions), time.Since(startTime))

	// Process DEX transactions
	if len(dexTransactions) > 0 {
		m.logger.Info(fmt.Sprintf("Block %d contains %d DEX transactions:", blockNumber, len(dexTransactions)))
		for i, dexTx := range dexTransactions {
			m.logger.Info(fmt.Sprintf("  [%d] %s: %s -> %s (%s) calling %s (%s)",
				i+1, dexTx.Hash, dexTx.From, dexTx.To, dexTx.ContractName,
				dexTx.FunctionName, dexTx.Protocol))

			// CRITICAL FIX: Parse swap events from transaction receipt
			txHashBytes := common.HexToHash(dexTx.Hash)
			receipt, err := m.client.TransactionReceipt(ctx, txHashBytes)
			if err != nil {
				m.logger.Debug(fmt.Sprintf("Failed to fetch receipt for DEX tx %s: %v", dexTx.Hash, err))
			} else if receipt != nil {
				// Parse events from receipt using event parser
				timestamp := safeConvertInt64ToUint64(time.Now().Unix())
				parsedEvents, err := m.eventParser.ParseTransactionReceipt(receipt, blockNumber, timestamp)
				if err != nil {
					m.logger.Debug(fmt.Sprintf("Failed to parse events from receipt %s: %v", dexTx.Hash, err))
				} else if len(parsedEvents) > 0 {
					m.logger.Info(fmt.Sprintf("✅ Parsed %d events from DEX tx %s", len(parsedEvents), dexTx.Hash))

					// Submit each parsed event directly to the scanner
					for _, event := range parsedEvents {
						if event != nil {
							// Log submission (will be enriched by scanner before processing)
							m.logger.Info(fmt.Sprintf("📤 Submitting event: Type=%s, Pool=%s, Tokens=%s↔%s",
								event.Type.String(), event.PoolAddress.Hex()[:10],
								event.Token0.Hex()[:10], event.Token1.Hex()[:10]))

							// Submit to scanner for arbitrage analysis
							// Note: Scanner will enrich event with token addresses from cache if missing
							m.scanner.SubmitEvent(*event)
						}
					}
				}
			}

			// Also send to pipeline for compatibility
			standardizedTx := m.convertToStandardFormat(&dexTx)
			if standardizedTx != nil {
				// Send to pipeline for arbitrage analysis
				select {
				case m.transactionChannel <- standardizedTx:
					// Successfully sent to pipeline
				default:
					// Channel full, log warning
					m.logger.Warn(fmt.Sprintf("Transaction pipeline full, dropping tx %s", dexTx.Hash))
				}
			}
		}
	}

	// If no DEX transactions found, report empty block
	if len(dexTransactions) == 0 {
		if len(l2Block.Transactions) == 0 {
			m.logger.Info(fmt.Sprintf("Block %d: Empty block", blockNumber))
		} else {
			m.logger.Info(fmt.Sprintf("Block %d: No DEX transactions found in %d total transactions",
				blockNumber, len(l2Block.Transactions)))
		}
	}

	return nil
}

// checkConnectionHealth periodically checks and maintains connection health
func (m *ArbitrumMonitor) checkConnectionHealth(ctx context.Context) {
	defer func() {
		if r := recover(); r != nil {
			m.logger.Error(fmt.Sprintf("Panic in connection health checker: %v", r))
		}
	}()

	healthCheckInterval := 30 * time.Second
	ticker := time.NewTicker(healthCheckInterval)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			m.logger.Info("Connection health checker shutting down")
			return
		case <-ticker.C:
			m.performHealthCheck(ctx)
		}
	}
}

// performHealthCheck checks connection health and reconnects if necessary
func (m *ArbitrumMonitor) performHealthCheck(ctx context.Context) {
	m.mu.Lock()
	defer m.mu.Unlock()

	// Skip health check if too recent
	if time.Since(m.lastHealthCheck) < 10*time.Second {
		return
	}

	// Test connection by trying to get latest block
	testCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
	defer cancel()

	_, err := m.client.HeaderByNumber(testCtx, nil)
	if err != nil {
		m.logger.Warn(fmt.Sprintf("Connection health check failed: %v, attempting reconnection", err))

		// Attempt to get a new healthy client
		rateLimitedClient, reconnectErr := m.connectionManager.GetClientWithRetry(ctx, 3)
		if reconnectErr != nil {
			m.logger.Error(fmt.Sprintf("Failed to reconnect: %v", reconnectErr))
		} else {
			// Close old client and update to new one
			m.client.Close()
			m.client = rateLimitedClient.Client
			m.logger.Info("Successfully reconnected to Arbitrum RPC")
		}
	}

	m.lastHealthCheck = time.Now()
}

// processTransactionChannel processes transactions from the transaction channel
func (m *ArbitrumMonitor) processTransactionChannel(ctx context.Context) {
	defer func() {
		if r := recover(); r != nil {
			m.logger.Error(fmt.Sprintf("Panic in transaction processor: %v", r))
		}
	}()

	for {
		select {
		case <-ctx.Done():
			m.logger.Info("Transaction processor shutting down")
			return
		case tx := <-m.transactionChannel:
			if tx != nil {
				if err := m.processChannelTransaction(ctx, tx); err != nil {
					m.logger.Debug(fmt.Sprintf("Error processing transaction from channel: %v", err))
				}
			}
		}
	}
}

// processChannelTransaction processes a single transaction from the channel
func (m *ArbitrumMonitor) processChannelTransaction(ctx context.Context, tx interface{}) error {
	// Convert transaction to the expected format and process through pipeline
	if txMap, ok := tx.(map[string]interface{}); ok {
		// Log transaction processing
		if hash, exists := txMap["hash"]; exists {
			m.logger.Debug(fmt.Sprintf("Processing transaction from pipeline: %s", hash))
		}

		// Process transaction through the scanner for arbitrage analysis
		// This bypasses the full pipeline since we already have the parsed DEX data
		if err := m.processTransactionMap(ctx, txMap); err != nil {
			return fmt.Errorf("transaction processing error: %w", err)
		}
	}

	return nil
}

// processTransactionMap processes a transaction map for arbitrage opportunities
func (m *ArbitrumMonitor) processTransactionMap(ctx context.Context, txMap map[string]interface{}) error {
	// Extract basic transaction info
	hash, _ := txMap["hash"].(string)
	protocol, _ := txMap["protocol"].(string)
	functionName, _ := txMap["function"].(string)

	m.logger.Debug(fmt.Sprintf("Analyzing transaction %s: %s.%s", hash, protocol, functionName))

	// DISABLED: This legacy code creates incomplete events with zero addresses
	// Events should only be created from DEXTransaction objects with valid SwapDetails
	// The L2 parser (processTransaction) handles event creation properly
	//
	// Leaving this as a no-op to avoid breaking the transaction channel flow
	// but preventing submission of incomplete events

	m.logger.Debug(fmt.Sprintf("Skipping legacy event creation for %s - events created by L2 parser instead", hash))

	return nil
}

// getUint64 safely extracts a uint64 from a map
func getUint64(m map[string]interface{}, key string) uint64 {
	if val, ok := m[key]; ok {
		switch v := val.(type) {
		case uint64:
			return v
		case int64:
			if v < 0 {
				return 0
			}
			return uint64(v)
		case int:
			if v < 0 {
				return 0
			}
			return uint64(v)
		case float64:
			if v < 0 {
				return 0
			}
			return uint64(v)
		}
	}
	return 0
}

// subscribeToDEXEvents subscribes to DEX contract events for real-time monitoring
func (m *ArbitrumMonitor) subscribeToDEXEvents(ctx context.Context) error {
	// Define official DEX contract addresses for Arbitrum mainnet
	dexContracts := []struct {
		Address common.Address
		Name    string
	}{
		// Official Arbitrum DEX Factories
		{common.HexToAddress("0xf1D7CC64Fb4452F05c498126312eBE29f30Fbcf9"), "UniswapV2Factory"}, // Official Uniswap V2 Factory
		{common.HexToAddress("0x1F98431c8aD98523631AE4a59f267346ea31F984"), "UniswapV3Factory"}, // Official Uniswap V3 Factory
		{common.HexToAddress("0xc35DADB65012eC5796536bD9864eD8773aBc74C4"), "SushiSwapFactory"}, // Official SushiSwap V2 Factory

		// Official Arbitrum DEX Routers
		{common.HexToAddress("0x4752ba5dbc23f44d87826276bf6fd6b1c372ad24"), "UniswapV2Router02"},        // Official Uniswap V2 Router02
		{common.HexToAddress("0xE592427A0AEce92De3Edee1F18E0157C05861564"), "UniswapV3Router"},          // Official Uniswap V3 SwapRouter
		{common.HexToAddress("0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45"), "UniswapV3Router02"},        // Official Uniswap V3 SwapRouter02
		{common.HexToAddress("0x1b02dA8Cb0d097eB8D57A175b88c7D8b47997506"), "SushiSwapRouter"},          // Official SushiSwap Router
		{common.HexToAddress("0xC36442b4a4522E871399CD717aBDD847Ab11FE88"), "UniswapV3PositionManager"}, // Official Position Manager

		// Additional official routers
		{common.HexToAddress("0xa51afafe0263b40edaef0df8781ea9aa03e381a3"), "UniversalRouter"}, // Universal Router
		{common.HexToAddress("0x4C60051384bd2d3C01bfc845Cf5F4b44bcbE9de5"), "GMX Router"},      // GMX DEX Router

		// Popular Arbitrum pools (verified high volume pools)
		{common.HexToAddress("0xC6962004f452bE9203591991D15f6b388e09E8D0"), "USDC/WETH UniswapV3 0.05%"}, // High volume pool
		{common.HexToAddress("0x17c14D2c404D167802b16C450d3c99F88F2c4F4d"), "USDC/WETH UniswapV3 0.3%"},  // High volume pool
		{common.HexToAddress("0x2f5e87C9312fa29aed5c179E456625D79015299c"), "WBTC/WETH UniswapV3 0.05%"}, // High volume pool
		{common.HexToAddress("0x149e36E72726e0BceA5c59d40df2c43F60f5A22D"), "WBTC/WETH UniswapV3 0.3%"},  // High volume pool
		{common.HexToAddress("0x641C00A822e8b671738d32a431a4Fb6074E5c79d"), "USDT/WETH UniswapV3 0.05%"}, // High volume pool
		{common.HexToAddress("0xFe7D6a84287235C7b4b57C4fEb9a44d4C6Ed3BB8"), "ARB/WETH UniswapV3 0.05%"},  // ARB native token pool
	}

	// Define common DEX event signatures
	eventSignatures := []common.Hash{
		common.HexToHash("0xd78ad95fa46c994b6551d0da85fc275fe613ce37657fb8d5e3d130840159d822"), // Swap (Uniswap V2)
		common.HexToHash("0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67"), // Swap (Uniswap V3)
		common.HexToHash("0x4c209b5fc8ad50758f13e2e1088ba56a560dff690a1c6fef26394f4c03821c4f"), // Mint (Uniswap V2)
		common.HexToHash("0x7a53080ba414158be7ec69b987b5fb7d07dee101fe85488f0853ae16239d0bde"), // Burn (Uniswap V2)
		common.HexToHash("0x783cca1c0412dd0d695e784568c96da2e9c22ff989357a2e8b1d9b2b4e6b7118"), // Mint (Uniswap V3)
		common.HexToHash("0x0c396cd989a39f49a56c8a608a0409f2075c6b60e9c44533b5cf87abdbe393f1"), // Burn (Uniswap V3)
	}

	// Create filter query for DEX events
	addresses := make([]common.Address, len(dexContracts))
	for i, dex := range dexContracts {
		addresses[i] = dex.Address
	}

	topics := [][]common.Hash{{}}
	topics[0] = eventSignatures

	query := ethereum.FilterQuery{
		Addresses: addresses,
		Topics:    topics,
	}

	// Subscribe to logs
	logs := make(chan types.Log)
	sub, err := m.client.SubscribeFilterLogs(ctx, query, logs)
	if err != nil {
		return fmt.Errorf("failed to subscribe to DEX events: %v", err)
	}

	m.logger.Info("Subscribed to DEX events")

	// Process logs in a goroutine
	go func() {
		defer func() {
			if r := recover(); r != nil {
				m.logger.Error(fmt.Sprintf("Panic in DEX event processor: %v", r))
			}
		}()

		defer sub.Unsubscribe()

		for {
			select {
			case log := <-logs:
				m.processDEXEvent(ctx, log)
			case err := <-sub.Err():
				if err != nil {
					m.logger.Error(fmt.Sprintf("DEX event subscription error: %v", err))
				}
				return
			case <-ctx.Done():
				return
			}
		}
	}()

	return nil
}

// processDEXEvent processes a DEX event log
func (m *ArbitrumMonitor) processDEXEvent(ctx context.Context, log types.Log) {
	m.logger.Debug(fmt.Sprintf("Processing DEX event from contract %s, topic count: %d", log.Address.Hex(), len(log.Topics)))

	// Check if this is a swap event
	if len(log.Topics) > 0 {
		eventSig := log.Topics[0]

		// Check for common swap event signatures
		switch eventSig.Hex() {
		case "0xd78ad95fa46c994b6551d0da85fc275fe613ce37657fb8d5e3d130840159d822": // Uniswap V2 Swap
			m.logger.Info(fmt.Sprintf("Uniswap V2 Swap event detected: Contract=%s, TxHash=%s",
				log.Address.Hex(), log.TxHash.Hex()))
		case "0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67": // Uniswap V3 Swap
			m.logger.Info(fmt.Sprintf("Uniswap V3 Swap event detected: Contract=%s, TxHash=%s",
				log.Address.Hex(), log.TxHash.Hex()))
		case "0x4c209b5fc8ad50758f13e2e1088ba56a560dff690a1c6fef26394f4c03821c4f": // Uniswap V2 Mint
			m.logger.Info(fmt.Sprintf("Uniswap V2 Mint event detected: Contract=%s, TxHash=%s",
				log.Address.Hex(), log.TxHash.Hex()))
		case "0x7a53080ba414158be7ec69b987b5fb7d07dee101fe85488f0853ae16239d0bde": // Uniswap V2 Burn
			m.logger.Info(fmt.Sprintf("Uniswap V2 Burn event detected: Contract=%s, TxHash=%s",
				log.Address.Hex(), log.TxHash.Hex()))
		case "0x783cca1c0412dd0d695e784568c96da2e9c22ff989357a2e8b1d9b2b4e6b7118": // Uniswap V3 Mint
			m.logger.Info(fmt.Sprintf("Uniswap V3 Mint event detected: Contract=%s, TxHash=%s",
				log.Address.Hex(), log.TxHash.Hex()))
		case "0x0c396cd989a39f49a56c8a608a0409f2075c6b60e9c44533b5cf87abdbe393f1": // Uniswap V3 Burn
			m.logger.Info(fmt.Sprintf("Uniswap V3 Burn event detected: Contract=%s, TxHash=%s",
				log.Address.Hex(), log.TxHash.Hex()))
		default:
			m.logger.Debug(fmt.Sprintf("Other DEX event detected: Contract=%s, EventSig=%s, TxHash=%s",
				log.Address.Hex(), eventSig.Hex(), log.TxHash.Hex()))
		}

		// Fetch transaction receipt for detailed analysis
		receipt, err := m.client.TransactionReceipt(ctx, log.TxHash)
		if err != nil {
			m.logger.Error(fmt.Sprintf("Failed to fetch receipt for transaction %s: %v", log.TxHash.Hex(), err))
			return
		}

		// Process the transaction through the pipeline
		// This will parse the DEX events and look for arbitrage opportunities
		m.processTransactionReceipt(ctx, receipt, log.BlockNumber, log.BlockHash)
	}
}

// processTransactionReceipt processes a transaction receipt for DEX events
func (m *ArbitrumMonitor) processTransactionReceipt(ctx context.Context, receipt *types.Receipt, blockNumber uint64, blockHash common.Hash) {
	if receipt == nil {
		return
	}

	m.logger.Debug(fmt.Sprintf("Processing transaction receipt %s from block %d",
		receipt.TxHash.Hex(), blockNumber))

	// Process transaction logs for DEX events
	dexEvents := 0
	for _, log := range receipt.Logs {
		if len(log.Topics) > 0 {
			eventSig := log.Topics[0]

			// Check for common DEX event signatures
			switch eventSig.Hex() {
			case "0xd78ad95fa46c994b6551d0da85fc275fe613ce37657fb8d5e3d130840159d822": // Uniswap V2 Swap
				m.logger.Info(fmt.Sprintf("DEX Swap event detected in transaction %s: Uniswap V2", receipt.TxHash.Hex()))
				dexEvents++
			case "0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67": // Uniswap V3 Swap
				m.logger.Info(fmt.Sprintf("DEX Swap event detected in transaction %s: Uniswap V3", receipt.TxHash.Hex()))
				dexEvents++
			case "0x4c209b5fc8ad50758f13e2e1088ba56a560dff690a1c6fef26394f4c03821c4f": // Uniswap V2 Mint
				m.logger.Info(fmt.Sprintf("DEX Mint event detected in transaction %s: Uniswap V2", receipt.TxHash.Hex()))
				dexEvents++
			case "0x7a53080ba414158be7ec69b987b5fb7d07dee101fe85488f0853ae16239d0bde": // Uniswap V2 Burn
				m.logger.Info(fmt.Sprintf("DEX Burn event detected in transaction %s: Uniswap V2", receipt.TxHash.Hex()))
				dexEvents++
			case "0x783cca1c0412dd0d695e784568c96da2e9c22ff989357a2e8b1d9b2b4e6b7118": // Uniswap V3 Mint
				m.logger.Info(fmt.Sprintf("DEX Mint event detected in transaction %s: Uniswap V3", receipt.TxHash.Hex()))
				dexEvents++
			case "0x0c396cd989a39f49a56c8a608a0409f2075c6b60e9c44533b5cf87abdbe393f1": // Uniswap V3 Burn
				m.logger.Info(fmt.Sprintf("DEX Burn event detected in transaction %s: Uniswap V3", receipt.TxHash.Hex()))
				dexEvents++
			}
		}
	}

	if dexEvents > 0 {
		m.logger.Info(fmt.Sprintf("Transaction %s contains %d DEX events", receipt.TxHash.Hex(), dexEvents))

		// CRITICAL FIX: Fetch full transaction to extract token addresses from calldata
		tx, err := m.client.TransactionInBlock(ctx, blockHash, receipt.TransactionIndex)
		if err != nil {
			m.logger.Warn(fmt.Sprintf("Failed to fetch transaction %s for token extraction: %v", receipt.TxHash.Hex(), err))
			tx = nil // Continue without transaction (will use zero addresses)
		}

		// Parse events from receipt with transaction for token enrichment
		m.logger.Debug(fmt.Sprintf("Parsing events from receipt %s using event parser (tx=%v)", receipt.TxHash.Hex(), tx != nil))

		timestamp := safeConvertInt64ToUint64(time.Now().Unix())
		parsedEvents, err := m.eventParser.ParseTransactionReceiptWithTx(receipt, tx, blockNumber, timestamp)
		if err != nil {
			m.logger.Error(fmt.Sprintf("Failed to parse events from receipt %s: %v", receipt.TxHash.Hex(), err))
			return
		}

		m.logger.Info(fmt.Sprintf("Successfully parsed %d events from receipt %s", len(parsedEvents), receipt.TxHash.Hex()))

		// Submit each parsed event directly to the scanner
		for _, event := range parsedEvents {
			if event != nil {
				m.logger.Debug(fmt.Sprintf("Submitting event to scanner: Type=%s, Pool=%s, Token0=%s, Token1=%s",
					event.Type.String(), event.PoolAddress.Hex(), event.Token0.Hex(), event.Token1.Hex()))

				// Submit to scanner for arbitrage analysis
				m.scanner.SubmitEvent(*event)

				m.logger.Info(fmt.Sprintf("✅ Event submitted to scanner successfully"))
			}
		}
	}
}

// processTransaction analyzes a transaction for potential swap opportunities
func (m *ArbitrumMonitor) processTransaction(ctx context.Context, tx *types.Transaction) error {
	// Check if this is a potential swap transaction
	// This is a simplified check - in practice, you would check for
	// specific function signatures of Uniswap-like contracts

	// For now, we'll just log all transactions
	from, err := m.client.TransactionSender(ctx, tx, common.Hash{}, 0)
	if err != nil {
		// This can happen for pending transactions
		from = common.HexToAddress("0x0")
	}

	m.logger.Debug(fmt.Sprintf("Transaction: %s, From: %s, To: %s, Value: %s ETH",
		tx.Hash().Hex(),
		from.Hex(),
		func() string {
			if tx.To() != nil {
				return tx.To().Hex()
			}
			return "contract creation"
		}(),
		new(big.Float).Quo(new(big.Float).SetInt(tx.Value()), big.NewFloat(1e18)).String(),
	))

	// Detect and analyze swap transactions
	if m.isSwapTransaction(tx) {
		swapData := m.analyzeSwapTransaction(tx, from)
		if swapData != nil {
			m.logger.Info(fmt.Sprintf("Detected swap: %s -> %s, Amount: %s",
				swapData.TokenIn.Hex(), swapData.TokenOut.Hex(), swapData.AmountIn.String()))

			// Calculate potential arbitrage opportunity
			if opportunity := m.calculateArbitrageOpportunity(swapData); opportunity != nil {
				m.logger.Info(fmt.Sprintf("Potential arbitrage detected: %s profit",
					opportunity.NetProfit.String()))
			}
		}
	}

	return nil
}

// GetPendingTransactions retrieves pending transactions from the mempool
func (m *ArbitrumMonitor) GetPendingTransactions(ctx context.Context) ([]*types.Transaction, error) {
	// This is a simplified implementation
	// In practice, you might need to use a different approach to access pending transactions

	// Query for pending transactions
	txs := make([]*types.Transaction, 0)

	return txs, nil
}

// getTransactionReceiptWithRetry attempts to get a transaction receipt with exponential backoff retry
func (m *ArbitrumMonitor) getTransactionReceiptWithRetry(ctx context.Context, txHash common.Hash, maxRetries int) (*types.Receipt, error) {
	for attempt := 0; attempt < maxRetries; attempt++ {
		m.logger.Debug(fmt.Sprintf("Attempting to fetch receipt for transaction %s (attempt %d/%d)", txHash.Hex(), attempt+1, maxRetries))

		// Try to fetch the transaction receipt
		receipt, err := m.client.TransactionReceipt(ctx, txHash)
		if err == nil {
			m.logger.Debug(fmt.Sprintf("Successfully fetched receipt for transaction %s on attempt %d", txHash.Hex(), attempt+1))
			return receipt, nil
		}

		// Check for specific error types that shouldn't be retried
		if ctx.Err() != nil {
			return nil, ctx.Err()
		}

		// Log retry attempt for other errors
		if attempt < maxRetries-1 {
			backoffDuration := time.Duration(1<<uint(attempt)) * time.Second
			m.logger.Warn(fmt.Sprintf("Receipt fetch for transaction %s attempt %d failed: %v, retrying in %v",
				txHash.Hex(), attempt+1, err, backoffDuration))

			select {
			case <-ctx.Done():
				return nil, ctx.Err()
			case <-time.After(backoffDuration):
				// Continue to next attempt
			}
		} else {
			m.logger.Error(fmt.Sprintf("Receipt fetch for transaction %s failed after %d attempts: %v", txHash.Hex(), maxRetries, err))
		}
	}

	return nil, fmt.Errorf("failed to fetch receipt for transaction %s after %d attempts", txHash.Hex(), maxRetries)
}

func capturePayloadIfEnabled(dexTx *arbitrum.DEXTransaction) {
	if dexTx == nil || len(dexTx.InputData) == 0 {
		return
	}

	payloadCaptureOnce.Do(func() {
		dir := strings.TrimSpace(os.Getenv("PAYLOAD_CAPTURE_DIR"))
		if dir == "" {
			return
		}
		if err := os.MkdirAll(dir, 0o755); err != nil {
			return
		}
		payloadCaptureDir = dir
	})

	if payloadCaptureDir == "" {
		return
	}

	entry := map[string]interface{}{
		"hash":          dexTx.Hash,
		"from":          dexTx.From,
		"to":            dexTx.To,
		"value":         dexTx.Value.String(),
		"protocol":      dexTx.Protocol,
		"function":      dexTx.FunctionName,
		"function_sig":  dexTx.FunctionSig,
		"input_data":    fmt.Sprintf("0x%s", hex.EncodeToString(dexTx.InputData)),
		"contract_name": dexTx.ContractName,
		"block_number":  dexTx.BlockNumber,
	}

	data, err := json.MarshalIndent(entry, "", "  ")
	if err != nil {
		return
	}

	fileName := fmt.Sprintf("%s_%s.json", time.Now().UTC().Format("20060102T150405.000Z"), strings.TrimPrefix(dexTx.Hash, "0x"))
	filePath := filepath.Join(payloadCaptureDir, fileName)
	_ = os.WriteFile(filePath, data, 0o600)
}

// convertToStandardFormat converts a DEX transaction to standard format for pipeline processing
func (m *ArbitrumMonitor) convertToStandardFormat(dexTx *arbitrum.DEXTransaction) interface{} {
	capturePayloadIfEnabled(dexTx)

	// Convert DEX transaction to a standardized transaction format
	// that can be processed by the arbitrage pipeline
	return map[string]interface{}{
		"hash":         dexTx.Hash,
		"from":         dexTx.From,
		"to":           dexTx.To,
		"value":        dexTx.Value,
		"protocol":     dexTx.Protocol,
		"function":     dexTx.FunctionName,
		"function_sig": dexTx.FunctionSig,
		"contract":     dexTx.ContractName,
		"block_number": dexTx.BlockNumber,
		"input_data":   fmt.Sprintf("0x%s", hex.EncodeToString(dexTx.InputData)),
		"timestamp":    time.Now().Unix(),
		// Token and amount information would be extracted from InputData
		// during deeper analysis in the pipeline
	}
}

// SwapData represents analyzed swap transaction data
type SwapData struct {
	TokenIn   common.Address
	TokenOut  common.Address
	AmountIn  *big.Int
	AmountOut *big.Int
	Pool      common.Address
	Protocol  string
	Path      []common.Address
	Pools     []common.Address
}

// Use the canonical ArbitrageOpportunity from types package

// isSwapTransaction checks if a transaction is a DEX swap
func (m *ArbitrumMonitor) isSwapTransaction(tx *types.Transaction) bool {
	if tx.To() == nil || len(tx.Data()) < 4 {
		return false
	}

	// Check function selector for common swap functions
	selector := fmt.Sprintf("0x%x", tx.Data()[:4])
	swapSelectors := map[string]bool{
		"0x38ed1739": true, // swapExactTokensForTokens
		"0x7ff36ab5": true, // swapExactETHForTokens
		"0x18cbafe5": true, // swapExactTokensForETH
		"0x8803dbee": true, // swapTokensForExactTokens
		"0x414bf389": true, // exactInputSingle (Uniswap V3)
		"0x09b81346": true, // exactInput (Uniswap V3)
	}

	return swapSelectors[selector]
}

// analyzeSwapTransaction extracts swap data from a transaction
func (m *ArbitrumMonitor) analyzeSwapTransaction(tx *types.Transaction, from common.Address) *SwapData {
	if len(tx.Data()) < 4 {
		return nil
	}

	swapCall, err := calldata.DecodeSwapCall(tx.Data(), nil)
	if err != nil {
		return m.parseGenericSwap(tx.To(), tx.Data())
	}

	pool := swapCall.PoolAddress
	if pool == (common.Address{}) && tx.To() != nil {
		pool = *tx.To()
	}

	amountIn := swapCall.AmountIn
	if amountIn == nil {
		amountIn = big.NewInt(0)
	}
	amountOut := swapCall.AmountOut
	if amountOut == nil || amountOut.Sign() == 0 {
		amountOut = swapCall.AmountOutMinimum
	}
	if amountOut == nil {
		amountOut = big.NewInt(0)
	}

	tokenIn := swapCall.TokenIn
	tokenOut := swapCall.TokenOut
	path := swapCall.Path
	if len(path) >= 2 {
		tokenIn = path[0]
		tokenOut = path[len(path)-1]
	} else if tokenIn != (common.Address{}) && tokenOut != (common.Address{}) {
		path = []common.Address{tokenIn, tokenOut}
	}

	pools := swapCall.Pools
	if len(pools) == 0 && pool != (common.Address{}) {
		pools = []common.Address{pool}
	}

	return &SwapData{
		TokenIn:   tokenIn,
		TokenOut:  tokenOut,
		AmountIn:  amountIn,
		AmountOut: amountOut,
		Pool:      pool,
		Protocol:  swapCall.Protocol,
		Path:      path,
		Pools:     pools,
	}
}

// parseUniswapV2Swap parses Uniswap V2 style swap data
func (m *ArbitrumMonitor) parseUniswapV2Swap(router *common.Address, data []byte) *SwapData {
	if len(data) < 68 { // 4 bytes selector + 2 * 32 bytes for amounts
		return nil
	}

	// Extract amount from first parameter (simplified)
	amountIn := new(big.Int).SetBytes(data[4:36])

	tokenIn := common.Address{}
	tokenOut := common.Address{}
	pathAddrs := make([]common.Address, 0)
	poolAddr := common.Address{}

	// Parse dynamic path parameter to extract first/last token
	pathOffset := new(big.Int).SetBytes(data[68:100]).Int64()
	if pathOffset > 0 {
		pathStart := 4 + int(pathOffset)
		if pathStart >= len(data) {
			return nil
		}
		if pathStart+32 > len(data) {
			return nil
		}
		pathLen := new(big.Int).SetBytes(data[pathStart : pathStart+32]).Int64()
		if pathLen >= 2 {
			for i := int64(0); i < pathLen; i++ {
				entryStart := pathStart + 32 + int(i*32)
				if entryStart+32 > len(data) {
					return nil
				}
				addr := common.BytesToAddress(data[entryStart+12 : entryStart+32])
				pathAddrs = append(pathAddrs, addr)
				if i == 0 {
					tokenIn = addr
				}
				if i == pathLen-1 {
					tokenOut = addr
				}
			}
		}
	}

	if router != nil {
		poolAddr = *router
	}

	pools := make([]common.Address, 0)
	if len(pathAddrs) >= 2 {
		factory := common.HexToAddress("0xf1D7CC64Fb4452F05c498126312eBE29f30Fbcf9")
		for i := 0; i+1 < len(pathAddrs); i++ {
			token0 := pathAddrs[i]
			token1 := pathAddrs[i+1]
			if token0.Big().Cmp(token1.Big()) > 0 {
				token0, token1 = token1, token0
			}
			keccakInput := append(token0.Bytes(), token1.Bytes()...)
			salt := crypto.Keccak256(keccakInput)
			initCodeHash := common.HexToHash("0x96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f")
			data := make([]byte, 0, 85)
			data = append(data, 0xff)
			data = append(data, factory.Bytes()...)
			data = append(data, salt...)
			data = append(data, initCodeHash.Bytes()...)
			hash := crypto.Keccak256(data)
			var addr common.Address
			copy(addr[:], hash[12:])
			pools = append(pools, addr)
			if poolAddr == (common.Address{}) {
				poolAddr = addr
			}
		}
	}

	return &SwapData{
		TokenIn:   tokenIn,
		TokenOut:  tokenOut,
		AmountIn:  amountIn,
		AmountOut: big.NewInt(0), // Would need full ABI decoding
		Pool:      poolAddr,
		Protocol:  "UniswapV2",
		Path:      pathAddrs,
		Pools:     pools,
	}
}

// parseUniswapV3SingleSwap parses Uniswap V3 exactInputSingle data
func (m *ArbitrumMonitor) parseUniswapV3SingleSwap(router *common.Address, data []byte) *SwapData {
	if len(data) < 196 { // Minimum size for exactInputSingle params
		return nil
	}

	amountIn := new(big.Int).SetBytes(data[4+5*32 : 4+6*32])

	tokenIn := common.BytesToAddress(data[4+12 : 4+32])
	tokenOut := common.BytesToAddress(data[4+32+12 : 4+2*32])
	poolAddr := common.Address{}
	if router != nil {
		poolAddr = *router
	}

	return &SwapData{
		TokenIn:   tokenIn,
		TokenOut:  tokenOut,
		AmountIn:  amountIn,
		AmountOut: big.NewInt(0), // Would need full ABI decoding
		Pool:      poolAddr,
		Protocol:  "UniswapV3",
		Path:      []common.Address{tokenIn, tokenOut},
		Pools:     []common.Address{poolAddr},
	}
}

// parseGenericSwap attempts to parse swap data from unknown format
func (m *ArbitrumMonitor) parseGenericSwap(router *common.Address, data []byte) *SwapData {
	if len(data) < 36 {
		return nil
	}

	// Very basic fallback - just extract first amount
	amountIn := new(big.Int).SetBytes(data[4:36])

	poolAddr := common.Address{}
	if router != nil {
		poolAddr = *router
	}

	pools := make([]common.Address, 0)
	if poolAddr != (common.Address{}) {
		pools = append(pools, poolAddr)
	}

	return &SwapData{
		Pool:      poolAddr,
		AmountIn:  amountIn,
		AmountOut: big.NewInt(0),
		Protocol:  "Unknown",
		Path:      nil,
		Pools:     pools,
	}
}

func (m *ArbitrumMonitor) estimateOutputFromPools(ctx context.Context, swapData *SwapData) (*big.Int, error) {
	if m.marketMgr == nil {
		return nil, fmt.Errorf("market manager not configured")
	}
	if len(swapData.Pools) == 0 || len(swapData.Path) < 2 {
		return nil, fmt.Errorf("insufficient path metadata")
	}

	amountFloat := new(big.Float).SetPrec(256).SetInt(swapData.AmountIn)
	one := new(big.Float).SetPrec(256).SetFloat64(1.0)

	for i := 0; i < len(swapData.Pools) && i+1 < len(swapData.Path); i++ {
		poolAddr := swapData.Pools[i]
		poolData, err := m.marketMgr.GetPool(ctx, poolAddr)
		if err != nil {
			return nil, err
		}
		if poolData.Liquidity == nil || poolData.Liquidity.IsZero() {
			return nil, fmt.Errorf("pool %s has zero liquidity", poolAddr.Hex())
		}

		liquidityFloat := new(big.Float).SetPrec(256).SetInt(poolData.Liquidity.ToBig())
		if liquidityFloat.Sign() <= 0 {
			return nil, fmt.Errorf("invalid liquidity for pool %s", poolAddr.Hex())
		}
		price := uniswap.SqrtPriceX96ToPrice(poolData.SqrtPriceX96.ToBig())
		if price.Sign() <= 0 {
			return nil, fmt.Errorf("invalid pool price for %s", poolAddr.Hex())
		}

		hopPrice := new(big.Float).SetPrec(256).Copy(price)
		tokenIn := swapData.Path[i]
		tokenOut := swapData.Path[i+1]

		switch {
		case poolData.Token0 == tokenIn && poolData.Token1 == tokenOut:
			// price already token1/token0
		case poolData.Token0 == tokenOut && poolData.Token1 == tokenIn:
			hopPrice = new(big.Float).SetPrec(256).Quo(one, price)
		default:
			return nil, fmt.Errorf("pool %s does not match hop tokens", poolAddr.Hex())
		}

		amountRelative := new(big.Float).Quo(amountFloat, liquidityFloat)
		ratio, _ := amountRelative.Float64()
		if ratio > 0.25 {
			return nil, fmt.Errorf("swap size too large for pool %s (ratio %.2f)", poolAddr.Hex(), ratio)
		}

		amountFloat.Mul(amountFloat, hopPrice)
	}

	estimatedOut := new(big.Int)
	amountFloat.Int(estimatedOut)
	if estimatedOut.Sign() <= 0 {
		return nil, fmt.Errorf("non-positive estimated output")
	}
	return estimatedOut, nil
}

func (m *ArbitrumMonitor) estimateGasCostWei(ctx context.Context) *big.Int {
	gasLimit := big.NewInt(220000)
	gasPrice, err := m.client.SuggestGasPrice(ctx)
	if err != nil || gasPrice == nil || gasPrice.Sign() == 0 {
		gasPrice = big.NewInt(1500000000) // fallback 1.5 gwei
	}
	return new(big.Int).Mul(gasLimit, gasPrice)
}

// calculateArbitrageOpportunity analyzes swap for arbitrage potential
func (m *ArbitrumMonitor) calculateArbitrageOpportunity(swapData *SwapData) *arbitragetypes.ArbitrageOpportunity {
	// Simplified arbitrage calculation
	// In production, this would compare prices across multiple DEXs

	// Only consider opportunities above a minimum threshold
	minAmount := big.NewInt(1000000000000000000) // 1 ETH worth
	if swapData.AmountIn.Cmp(minAmount) < 0 {
		return nil
	}

	if (swapData.TokenIn == common.Address{}) || (swapData.TokenOut == common.Address{}) {
		return nil
	}

	pathStrings := make([]string, 0)
	if len(swapData.Path) >= 2 {
		for _, addr := range swapData.Path {
			pathStrings = append(pathStrings, addr.Hex())
		}
	}
	if len(pathStrings) < 2 {
		pathStrings = []string{swapData.TokenIn.Hex(), swapData.TokenOut.Hex()}
	}

	pools := make([]string, 0)
	if len(swapData.Pools) > 0 {
		for _, addr := range swapData.Pools {
			pools = append(pools, addr.Hex())
		}
	}
	if len(pools) == 0 && swapData.Pool != (common.Address{}) {
		pools = append(pools, swapData.Pool.Hex())
	}

	ctx, cancel := context.WithTimeout(context.Background(), 150*time.Millisecond)
	defer cancel()

	estimatedOut, preciseErr := m.estimateOutputFromPools(ctx, swapData)
	if preciseErr != nil {
		// fallback to heuristic estimate if precise calculation fails
		estimatedOut = new(big.Int).Add(swapData.AmountIn, new(big.Int).Div(swapData.AmountIn, big.NewInt(1000)))
	}

	if estimatedOut.Cmp(swapData.AmountIn) <= 0 {
		return nil
	}

	grossProfit := new(big.Int).Sub(estimatedOut, swapData.AmountIn)
	gasCost := m.estimateGasCostWei(ctx)
	netProfit := new(big.Int).Sub(grossProfit, gasCost)
	if netProfit.Sign() <= 0 {
		return nil
	}

	if netProfit.Cmp(big.NewInt(10000000000000000)) <= 0 { // require >0.01 ETH net profit
		return nil
	}

	amountInFloat := new(big.Float).SetPrec(256).SetInt(swapData.AmountIn)
	netProfitFloat := new(big.Float).SetPrec(256).SetInt(netProfit)
	ROI := 0.0
	if amountInFloat.Sign() > 0 {
		roiFloat := new(big.Float).Quo(netProfitFloat, amountInFloat)
		ROI, _ = roiFloat.Float64()
	}

	roiPercent := ROI * 100
	confidence := 0.75
	if ROI > 0 {
		confidence = 0.75 + ROI
		if confidence > 0.98 {
			confidence = 0.98
		}
	}

	opp := &arbitragetypes.ArbitrageOpportunity{
		Path:            pathStrings,
		Pools:           pools,
		AmountIn:        new(big.Int).Set(swapData.AmountIn),
		RequiredAmount:  new(big.Int).Set(swapData.AmountIn),
		Profit:          new(big.Int).Set(grossProfit),
		NetProfit:       new(big.Int).Set(netProfit),
		GasEstimate:     new(big.Int).Set(gasCost),
		EstimatedProfit: new(big.Int).Set(grossProfit),
		ROI:             roiPercent,
		Protocol:        swapData.Protocol,
		ExecutionTime:   1200,
		Confidence:      confidence,
		PriceImpact:     0.01,
		MaxSlippage:     0.03,
		TokenIn:         swapData.TokenIn,
		TokenOut:        swapData.TokenOut,
		Timestamp:       time.Now().Unix(),
		DetectedAt:      time.Now(),
		ExpiresAt:       time.Now().Add(30 * time.Second),
		Risk:            0.3,
	}

	m.mu.RLock()
	executor := m.opportunityExecutor
	m.mu.RUnlock()

	if executor != nil {
		go func() {
			if err := executor.ExecuteArbitrage(context.Background(), opp); err != nil {
				m.logger.Warn(fmt.Sprintf("Failed to dispatch arbitrage opportunity: %v", err))
			}
		}()
	}

	return opp
}