mev-beta/pkg/validation/pool_validator.go

package validation

import (
	"context"
	"encoding/hex"
	"fmt"
	"math/big"
	"strings"
	"time"

	"github.com/ethereum/go-ethereum"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/ethclient"

	"github.com/fraktal/mev-beta/internal/logger"
	"github.com/fraktal/mev-beta/pkg/pools"
	"github.com/fraktal/mev-beta/pkg/security"
	"github.com/fraktal/mev-beta/pkg/uniswap"
)

// PoolValidator provides comprehensive security validation for liquidity pools
type PoolValidator struct {
	client            *ethclient.Client
	logger            *logger.Logger
	create2Calculator *pools.CREATE2Calculator
	trustedFactories  map[common.Address]string // factory address -> name
	bannedAddresses   map[common.Address]string // banned address -> reason
	validationCache   map[common.Address]*ValidationResult
	cacheTimeout      time.Duration
}

// ValidationResult contains the result of pool validation
type ValidationResult struct {
	IsValid         bool           `json:"is_valid"`
	SecurityScore   int            `json:"security_score"` // 0-100, higher is better
	Warnings        []string       `json:"warnings"`
	Errors          []string       `json:"errors"`
	PoolType        string         `json:"pool_type"` // "uniswap_v3", "uniswap_v2", etc.
	Factory         string         `json:"factory"`
	Token0          common.Address `json:"token0"`
	Token1          common.Address `json:"token1"`
	Fee             uint32         `json:"fee,omitempty"`
	CreationBlock   uint64         `json:"creation_block,omitempty"`
	ValidatedAt     time.Time      `json:"validated_at"`
	FactoryVerified bool           `json:"factory_verified"`
	InterfaceValid  bool           `json:"interface_valid"`
	TokensValid     bool           `json:"tokens_valid"`
}

// PoolValidationConfig contains configuration for pool validation
type PoolValidationConfig struct {
	RequireFactoryVerification bool          // Whether factory verification is mandatory
	MinSecurityScore           int           // Minimum security score to accept (0-100)
	MaxValidationTime          time.Duration // Maximum time to spend on validation
	AllowUnknownFactories      bool          // Whether to allow pools from unknown factories
	RequireTokenValidation     bool          // Whether to validate token contracts
}

// NewPoolValidator creates a new pool validator
func NewPoolValidator(client *ethclient.Client, logger *logger.Logger) *PoolValidator {
	pv := &PoolValidator{
		client:            client,
		logger:            logger,
		create2Calculator: pools.NewCREATE2Calculator(logger, client),
		trustedFactories:  make(map[common.Address]string),
		bannedAddresses:   make(map[common.Address]string),
		validationCache:   make(map[common.Address]*ValidationResult),
		cacheTimeout:      5 * time.Minute,
	}

	pv.initializeTrustedFactories()
	pv.initializeBannedAddresses()

	return pv
}

// ValidatePool performs comprehensive security validation of a pool
func (pv *PoolValidator) ValidatePool(ctx context.Context, poolAddr common.Address, config *PoolValidationConfig) (*ValidationResult, error) {
	if config == nil {
		config = pv.getDefaultConfig()
	}

	// Check cache first
	if cached := pv.getCachedResult(poolAddr); cached != nil {
		return cached, nil
	}

	// Create timeout context
	timeoutCtx, cancel := context.WithTimeout(ctx, config.MaxValidationTime)
	defer cancel()

	result := &ValidationResult{
		ValidatedAt:   time.Now(),
		SecurityScore: 0,
		Warnings:      make([]string, 0),
		Errors:        make([]string, 0),
	}

	// 1. Basic existence check
	if err := pv.validateBasicExistence(timeoutCtx, poolAddr, result); err != nil {
		result.Errors = append(result.Errors, fmt.Sprintf("Basic validation failed: %v", err))
		result.IsValid = false
		pv.cacheResult(poolAddr, result)
		return result, nil
	}

	// 2. Check against banned addresses
	if err := pv.checkBannedAddresses(poolAddr, result); err != nil {
		result.Errors = append(result.Errors, fmt.Sprintf("Banned address check failed: %v", err))
		result.IsValid = false
		result.SecurityScore = 0
		pv.cacheResult(poolAddr, result)
		return result, nil
	}

	// 3. Detect pool type and validate interface
	if err := pv.validatePoolInterface(timeoutCtx, poolAddr, result); err != nil {
		result.Errors = append(result.Errors, fmt.Sprintf("Interface validation failed: %v", err))
		if config.RequireFactoryVerification {
			result.IsValid = false
		}
		result.SecurityScore -= 30
	} else {
		result.InterfaceValid = true
		result.SecurityScore += 25
	}

	// 4. Validate factory deployment (critical security check)
	if err := pv.validateFactoryDeployment(timeoutCtx, poolAddr, result); err != nil {
		result.Errors = append(result.Errors, fmt.Sprintf("Factory validation failed: %v", err))
		if config.RequireFactoryVerification {
			result.IsValid = false
		}
		result.SecurityScore -= 40
	} else {
		result.FactoryVerified = true
		result.SecurityScore += 30
	}

	// 5. Validate token contracts
	if config.RequireTokenValidation {
		if err := pv.validateTokenContracts(timeoutCtx, result); err != nil {
			result.Warnings = append(result.Warnings, fmt.Sprintf("Token validation warning: %v", err))
			result.SecurityScore -= 10
		} else {
			result.TokensValid = true
			result.SecurityScore += 15
		}
	}

	// 6. Additional security checks
	pv.performAdditionalSecurityChecks(timeoutCtx, poolAddr, result)

	// 7. Final validation decision
	if result.SecurityScore >= config.MinSecurityScore && len(result.Errors) == 0 {
		result.IsValid = true
	} else {
		result.IsValid = false
	}

	// Ensure security score is within bounds
	if result.SecurityScore < 0 {
		result.SecurityScore = 0
	} else if result.SecurityScore > 100 {
		result.SecurityScore = 100
	}

	// Cache the result
	pv.cacheResult(poolAddr, result)

	pv.logger.Debug(fmt.Sprintf("Pool validation complete: %s, valid=%v, score=%d",
		poolAddr.Hex(), result.IsValid, result.SecurityScore))

	return result, nil
}

// validateBasicExistence checks if the pool contract exists and has code
func (pv *PoolValidator) validateBasicExistence(ctx context.Context, poolAddr common.Address, result *ValidationResult) error {
	// Check if contract has code
	code, err := pv.client.CodeAt(ctx, poolAddr, nil)
	if err != nil {
		return fmt.Errorf("failed to get contract code: %w", err)
	}

	if len(code) == 0 {
		return fmt.Errorf("no contract code at address %s", poolAddr.Hex())
	}

	// Basic code size check - legitimate pools should have substantial code
	if len(code) < 100 {
		result.Warnings = append(result.Warnings, "Contract has very small code size")
		result.SecurityScore -= 10
	}

	return nil
}

// checkBannedAddresses verifies the pool is not on the banned list
func (pv *PoolValidator) checkBannedAddresses(poolAddr common.Address, result *ValidationResult) error {
	if reason, banned := pv.bannedAddresses[poolAddr]; banned {
		return fmt.Errorf("pool %s is banned: %s", poolAddr.Hex(), reason)
	}
	return nil
}

// validatePoolInterface detects pool type and validates the interface
func (pv *PoolValidator) validatePoolInterface(ctx context.Context, poolAddr common.Address, result *ValidationResult) error {
	// Try to detect pool type by calling standard functions

	// Check for Uniswap V3 interface
	if pv.isUniswapV3Pool(ctx, poolAddr) {
		result.PoolType = "uniswap_v3"
		return pv.validateUniswapV3Interface(ctx, poolAddr, result)
	}

	// Check for Uniswap V2 interface
	if pv.isUniswapV2Pool(ctx, poolAddr) {
		result.PoolType = "uniswap_v2"
		return pv.validateUniswapV2Interface(ctx, poolAddr, result)
	}

	// Unknown pool type
	result.PoolType = "unknown"
	result.Warnings = append(result.Warnings, "Unknown pool type")
	return fmt.Errorf("unknown pool interface")
}

// isUniswapV3Pool checks if the pool implements Uniswap V3 interface
func (pv *PoolValidator) isUniswapV3Pool(ctx context.Context, poolAddr common.Address) bool {
	// Try to call slot0() function (unique to Uniswap V3)
	slot0ABI := `[{"inputs":[],"name":"slot0","outputs":[{"internalType":"uint160","name":"sqrtPriceX96","type":"uint160"},{"internalType":"int24","name":"tick","type":"int24"},{"internalType":"uint16","name":"observationIndex","type":"uint16"},{"internalType":"uint16","name":"observationCardinality","type":"uint16"},{"internalType":"uint16","name":"observationCardinalityNext","type":"uint16"},{"internalType":"uint8","name":"feeProtocol","type":"uint8"},{"internalType":"bool","name":"unlocked","type":"bool"}],"stateMutability":"view","type":"function"}]`

	contractABI, err := uniswap.ParseABI(slot0ABI)
	if err != nil {
		return false
	}

	callData, err := contractABI.Pack("slot0")
	if err != nil {
		return false
	}

	_, err = pv.client.CallContract(ctx, ethereum.CallMsg{
		To:   &poolAddr,
		Data: callData,
	}, nil)

	return err == nil
}

// isUniswapV2Pool checks if the pool implements Uniswap V2 interface
func (pv *PoolValidator) isUniswapV2Pool(ctx context.Context, poolAddr common.Address) bool {
	// Try to call getReserves() function (standard in Uniswap V2)
	reservesABI := `[{"inputs":[],"name":"getReserves","outputs":[{"internalType":"uint112","name":"_reserve0","type":"uint112"},{"internalType":"uint112","name":"_reserve1","type":"uint112"},{"internalType":"uint32","name":"_blockTimestampLast","type":"uint32"}],"stateMutability":"view","type":"function"}]`

	contractABI, err := uniswap.ParseABI(reservesABI)
	if err != nil {
		return false
	}

	callData, err := contractABI.Pack("getReserves")
	if err != nil {
		return false
	}

	_, err = pv.client.CallContract(ctx, ethereum.CallMsg{
		To:   &poolAddr,
		Data: callData,
	}, nil)

	return err == nil
}

// validateUniswapV3Interface validates Uniswap V3 specific functions
func (pv *PoolValidator) validateUniswapV3Interface(ctx context.Context, poolAddr common.Address, result *ValidationResult) error {
	// Get token addresses and fee
	token0, token1, fee, err := pv.getUniswapV3PoolInfo(ctx, poolAddr)
	if err != nil {
		return fmt.Errorf("failed to get V3 pool info: %w", err)
	}

	result.Token0 = token0
	result.Token1 = token1
	result.Fee = fee

	// Validate token ordering (token0 < token1)
	if token0.Big().Cmp(token1.Big()) >= 0 {
		return fmt.Errorf("invalid token ordering: token0 must be < token1")
	}

	// Validate fee tier
	validFees := []uint32{500, 3000, 10000, 100} // 0.05%, 0.3%, 1%, 0.01%
	feeValid := false
	for _, validFee := range validFees {
		if fee == validFee {
			feeValid = true
			break
		}
	}
	if !feeValid {
		result.Warnings = append(result.Warnings, fmt.Sprintf("Unusual fee tier: %d", fee))
	}

	return nil
}

// validateUniswapV2Interface validates Uniswap V2 specific functions
func (pv *PoolValidator) validateUniswapV2Interface(ctx context.Context, poolAddr common.Address, result *ValidationResult) error {
	// Get token addresses
	token0, token1, err := pv.getUniswapV2PoolInfo(ctx, poolAddr)
	if err != nil {
		return fmt.Errorf("failed to get V2 pool info: %w", err)
	}

	result.Token0 = token0
	result.Token1 = token1
	result.Fee = 3000 // V2 has fixed 0.3% fee

	// Validate token ordering
	if token0.Big().Cmp(token1.Big()) >= 0 {
		return fmt.Errorf("invalid token ordering: token0 must be < token1")
	}

	return nil
}

// validateFactoryDeployment verifies the pool was deployed by a trusted factory
func (pv *PoolValidator) validateFactoryDeployment(ctx context.Context, poolAddr common.Address, result *ValidationResult) error {
	// For each known factory, try to verify if this pool could have been deployed by it
	for factoryAddr, factoryName := range pv.trustedFactories {
		if pv.verifyFactoryDeployment(factoryAddr, factoryName, poolAddr, result) {
			result.Factory = factoryName
			return nil
		}
	}

	return fmt.Errorf("pool not deployed by any trusted factory")
}

// verifyFactoryDeployment verifies a specific factory deployed the pool
func (pv *PoolValidator) verifyFactoryDeployment(factoryAddr common.Address, factoryName string, poolAddr common.Address, result *ValidationResult) bool {
	if result.Token0 == (common.Address{}) || result.Token1 == (common.Address{}) {
		return false
	}

	// Use CREATE2 calculator to verify the pool address
	return pv.create2Calculator.ValidatePoolAddress(factoryName, result.Token0, result.Token1, result.Fee, poolAddr)
}

// validateTokenContracts validates the token contracts in the pool
func (pv *PoolValidator) validateTokenContracts(ctx context.Context, result *ValidationResult) error {
	if result.Token0 == (common.Address{}) || result.Token1 == (common.Address{}) {
		return fmt.Errorf("token addresses not available")
	}

	// Validate token0
	if err := pv.validateTokenContract(ctx, result.Token0); err != nil {
		return fmt.Errorf("token0 validation failed: %w", err)
	}

	// Validate token1
	if err := pv.validateTokenContract(ctx, result.Token1); err != nil {
		return fmt.Errorf("token1 validation failed: %w", err)
	}

	return nil
}

// validateTokenContract validates a single token contract
func (pv *PoolValidator) validateTokenContract(ctx context.Context, tokenAddr common.Address) error {
	// Check if contract exists
	code, err := pv.client.CodeAt(ctx, tokenAddr, nil)
	if err != nil {
		return fmt.Errorf("failed to get token contract code: %w", err)
	}

	if len(code) == 0 {
		return fmt.Errorf("no contract code at token address %s", tokenAddr.Hex())
	}

	// Try to call standard ERC20 functions
	return pv.validateERC20Interface(ctx, tokenAddr)
}

// validateERC20Interface validates ERC20 token interface
func (pv *PoolValidator) validateERC20Interface(ctx context.Context, tokenAddr common.Address) error {
	// Try to call totalSupply() function
	erc20ABI := `[{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"}]`

	contractABI, err := uniswap.ParseABI(erc20ABI)
	if err != nil {
		return fmt.Errorf("failed to parse ERC20 ABI: %w", err)
	}

	callData, err := contractABI.Pack("totalSupply")
	if err != nil {
		return fmt.Errorf("failed to pack totalSupply call: %w", err)
	}

	_, err = pv.client.CallContract(ctx, ethereum.CallMsg{
		To:   &tokenAddr,
		Data: callData,
	}, nil)

	if err != nil {
		return fmt.Errorf("totalSupply call failed: %w", err)
	}

	return nil
}

// performAdditionalSecurityChecks performs various security checks
func (pv *PoolValidator) performAdditionalSecurityChecks(ctx context.Context, poolAddr common.Address, result *ValidationResult) {
	// Check contract creation time
	if creationBlock := pv.getContractCreationBlock(ctx, poolAddr); creationBlock > 0 {
		result.CreationBlock = creationBlock

		// Warn about very new contracts
		currentBlock, err := pv.client.BlockNumber(ctx)
		if err == nil && currentBlock-creationBlock < 100 {
			result.Warnings = append(result.Warnings, "Pool is very new (< 100 blocks old)")
			result.SecurityScore -= 5
		}
	}

	// Check for common attack patterns
	pv.checkForAttackPatterns(ctx, poolAddr, result)
}

// getContractCreationBlock attempts to find when the contract was created using binary search
func (pv *PoolValidator) getContractCreationBlock(ctx context.Context, addr common.Address) uint64 {
	pv.logger.Debug(fmt.Sprintf("Finding creation block for contract %s", addr.Hex()))

	// Get latest block number first
	latestBlock, err := pv.client.BlockNumber(ctx)
	if err != nil {
		pv.logger.Warn(fmt.Sprintf("Failed to get latest block number: %v", err))
		return 0
	}

	// Check if contract exists at latest block
	codeAtLatest, err := pv.client.CodeAt(ctx, addr, new(big.Int).SetUint64(latestBlock))
	if err != nil || len(codeAtLatest) == 0 {
		pv.logger.Debug(fmt.Sprintf("Contract %s does not exist at latest block", addr.Hex()))
		return 0
	}

	// Binary search to find creation block
	// Start with a reasonable range - most pools created in last 10M blocks
	searchStart := uint64(0)
	if latestBlock > 10000000 {
		searchStart = latestBlock - 10000000
	}

	creationBlock := pv.binarySearchCreationBlock(ctx, addr, searchStart, latestBlock)

	if creationBlock > 0 {
		pv.logger.Debug(fmt.Sprintf("Contract %s created at block %d", addr.Hex(), creationBlock))
	}

	return creationBlock
}

// binarySearchCreationBlock performs binary search to find the exact creation block
func (pv *PoolValidator) binarySearchCreationBlock(ctx context.Context, addr common.Address, start, end uint64) uint64 {
	// Limit search iterations to prevent infinite loops
	maxIterations := 50
	iteration := 0

	for start <= end && iteration < maxIterations {
		iteration++
		mid := (start + end) / 2

		// Check if contract exists at mid block
		code, err := pv.client.CodeAt(ctx, addr, new(big.Int).SetUint64(mid))
		if err != nil {
			pv.logger.Debug(fmt.Sprintf("Error checking code at block %d: %v", mid, err))
			break
		}

		hasCode := len(code) > 0

		if hasCode {
			// Contract exists at mid, check if it exists at mid-1
			if mid == 0 {
				return mid
			}

			prevCode, err := pv.client.CodeAt(ctx, addr, new(big.Int).SetUint64(mid-1))
			if err != nil || len(prevCode) == 0 {
				// Contract doesn't exist at mid-1 but exists at mid
				return mid
			}

			// Contract exists at both mid and mid-1, search earlier
			end = mid - 1
		} else {
			// Contract doesn't exist at mid, search later
			start = mid + 1
		}

		// Add small delay to avoid rate limiting
		if iteration%10 == 0 {
			select {
			case <-ctx.Done():
				return 0
			case <-time.After(100 * time.Millisecond):
			}
		}
	}

	// If we couldn't find exact block, return start as best estimate
	if start <= end {
		return start
	}

	return 0
}

// checkForAttackPatterns looks for common malicious patterns
func (pv *PoolValidator) checkForAttackPatterns(ctx context.Context, poolAddr common.Address, result *ValidationResult) {
	// Check if contract is a proxy (may be suspicious)
	if pv.isProxyContract(ctx, poolAddr) {
		result.Warnings = append(result.Warnings, "Contract appears to be a proxy")
		result.SecurityScore -= 10
	}

	// Check for unusual bytecode patterns
	if pv.hasUnusualBytecode(ctx, poolAddr) {
		result.Warnings = append(result.Warnings, "Unusual bytecode patterns detected")
		result.SecurityScore -= 15
	}
}

// isProxyContract checks if the contract is a proxy
func (pv *PoolValidator) isProxyContract(ctx context.Context, addr common.Address) bool {
	code, err := pv.client.CodeAt(ctx, addr, nil)
	if err != nil || len(code) == 0 {
		return false
	}

	// Look for common proxy patterns (delegatecall, etc.)
	codeHex := hex.EncodeToString(code)
	return strings.Contains(codeHex, "f4") // delegatecall opcode
}

// hasUnusualBytecode checks for suspicious bytecode patterns
func (pv *PoolValidator) hasUnusualBytecode(ctx context.Context, addr common.Address) bool {
	code, err := pv.client.CodeAt(ctx, addr, nil)
	if err != nil || len(code) == 0 {
		return false
	}

	// Check for unusual patterns
	if len(code) > 50000 {
		return true // Unusually large contract
	}

	// Check for high entropy (potential obfuscation)
	entropy := pv.calculateEntropy(code)
	return entropy > 7.5 // High entropy threshold
}

// calculateEntropy calculates Shannon entropy of bytecode
func (pv *PoolValidator) calculateEntropy(data []byte) float64 {
	if len(data) == 0 {
		return 0
	}

	freq := make(map[byte]int)
	for _, b := range data {
		freq[b]++
	}

	entropy := 0.0
	length := float64(len(data))

	for _, f := range freq {
		p := float64(f) / length
		if p > 0 {
			entropy -= p * (float64(f) / length)
		}
	}

	return entropy
}

// Helper functions to get pool information

func (pv *PoolValidator) getUniswapV3PoolInfo(ctx context.Context, poolAddr common.Address) (common.Address, common.Address, uint32, error) {
	poolABI := `[{"inputs":[],"name":"token0","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"token1","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"fee","outputs":[{"internalType":"uint24","name":"","type":"uint24"}],"stateMutability":"view","type":"function"}]`

	contractABI, err := uniswap.ParseABI(poolABI)
	if err != nil {
		return common.Address{}, common.Address{}, 0, err
	}

	// Get token0
	token0Data, err := contractABI.Pack("token0")
	if err != nil {
		return common.Address{}, common.Address{}, 0, err
	}

	token0Result, err := pv.client.CallContract(ctx, ethereum.CallMsg{
		To:   &poolAddr,
		Data: token0Data,
	}, nil)
	if err != nil {
		return common.Address{}, common.Address{}, 0, err
	}

	token0Unpacked, err := contractABI.Unpack("token0", token0Result)
	if err != nil {
		return common.Address{}, common.Address{}, 0, err
	}

	// Get token1
	token1Data, err := contractABI.Pack("token1")
	if err != nil {
		return common.Address{}, common.Address{}, 0, err
	}

	token1Result, err := pv.client.CallContract(ctx, ethereum.CallMsg{
		To:   &poolAddr,
		Data: token1Data,
	}, nil)
	if err != nil {
		return common.Address{}, common.Address{}, 0, err
	}

	token1Unpacked, err := contractABI.Unpack("token1", token1Result)
	if err != nil {
		return common.Address{}, common.Address{}, 0, err
	}

	// Get fee
	feeData, err := contractABI.Pack("fee")
	if err != nil {
		return common.Address{}, common.Address{}, 0, err
	}

	feeResult, err := pv.client.CallContract(ctx, ethereum.CallMsg{
		To:   &poolAddr,
		Data: feeData,
	}, nil)
	if err != nil {
		return common.Address{}, common.Address{}, 0, err
	}

	feeUnpacked, err := contractABI.Unpack("fee", feeResult)
	if err != nil {
		return common.Address{}, common.Address{}, 0, err
	}

	token0 := token0Unpacked[0].(common.Address)
	token1 := token1Unpacked[0].(common.Address)
	fee := feeUnpacked[0].(*big.Int).Uint64()

	feeUint32, err := security.SafeUint32(fee)
	if err != nil {
		return common.Address{}, common.Address{}, 0, fmt.Errorf("invalid fee conversion: %w", err)
	}
	return token0, token1, feeUint32, nil
}

func (pv *PoolValidator) getUniswapV2PoolInfo(ctx context.Context, poolAddr common.Address) (common.Address, common.Address, error) {
	poolABI := `[{"inputs":[],"name":"token0","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"token1","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"}]`

	contractABI, err := uniswap.ParseABI(poolABI)
	if err != nil {
		return common.Address{}, common.Address{}, err
	}

	// Get token0
	token0Data, err := contractABI.Pack("token0")
	if err != nil {
		return common.Address{}, common.Address{}, err
	}

	token0Result, err := pv.client.CallContract(ctx, ethereum.CallMsg{
		To:   &poolAddr,
		Data: token0Data,
	}, nil)
	if err != nil {
		return common.Address{}, common.Address{}, err
	}

	token0Unpacked, err := contractABI.Unpack("token0", token0Result)
	if err != nil {
		return common.Address{}, common.Address{}, err
	}

	// Get token1
	token1Data, err := contractABI.Pack("token1")
	if err != nil {
		return common.Address{}, common.Address{}, err
	}

	token1Result, err := pv.client.CallContract(ctx, ethereum.CallMsg{
		To:   &poolAddr,
		Data: token1Data,
	}, nil)
	if err != nil {
		return common.Address{}, common.Address{}, err
	}

	token1Unpacked, err := contractABI.Unpack("token1", token1Result)
	if err != nil {
		return common.Address{}, common.Address{}, err
	}

	token0 := token0Unpacked[0].(common.Address)
	token1 := token1Unpacked[0].(common.Address)

	return token0, token1, nil
}

// Configuration and caching methods

func (pv *PoolValidator) getDefaultConfig() *PoolValidationConfig {
	return &PoolValidationConfig{
		RequireFactoryVerification: true,
		MinSecurityScore:           70,
		MaxValidationTime:          10 * time.Second,
		AllowUnknownFactories:      false,
		RequireTokenValidation:     true,
	}
}

func (pv *PoolValidator) getCachedResult(addr common.Address) *ValidationResult {
	if result, exists := pv.validationCache[addr]; exists {
		if time.Since(result.ValidatedAt) < pv.cacheTimeout {
			return result
		}
		delete(pv.validationCache, addr)
	}
	return nil
}

func (pv *PoolValidator) cacheResult(addr common.Address, result *ValidationResult) {
	pv.validationCache[addr] = result
}

// Initialization methods

func (pv *PoolValidator) initializeTrustedFactories() {
	// Uniswap V3
	pv.trustedFactories[common.HexToAddress("0x1F98431c8aD98523631AE4a59f267346ea31F984")] = "uniswap_v3"
	// Uniswap V2
	pv.trustedFactories[common.HexToAddress("0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f")] = "uniswap_v2"
	// SushiSwap
	pv.trustedFactories[common.HexToAddress("0xC0AEe478e3658e2610c5F7A4A2E1777cE9e4f2Ac")] = "sushiswap"
	// Camelot V3 (Arbitrum)
	pv.trustedFactories[common.HexToAddress("0x1a3c9B1d2F0529D97f2afC5136Cc23e58f1FD35B")] = "camelot_v3"
}

func (pv *PoolValidator) initializeBannedAddresses() {
	// Add known malicious or problematic pool addresses
	// This would be populated with real banned addresses in production
}

// AddTrustedFactory adds a new trusted factory
func (pv *PoolValidator) AddTrustedFactory(factoryAddr common.Address, name string) {
	pv.trustedFactories[factoryAddr] = name
	pv.logger.Info(fmt.Sprintf("Added trusted factory: %s (%s)", name, factoryAddr.Hex()))
}

// BanAddress adds an address to the banned list
func (pv *PoolValidator) BanAddress(addr common.Address, reason string) {
	pv.bannedAddresses[addr] = reason
	// Clear from cache if present
	delete(pv.validationCache, addr)
	pv.logger.Warn(fmt.Sprintf("Banned address: %s (reason: %s)", addr.Hex(), reason))
}