package arbitrum

import (
	"context"
	"fmt"
	"math/big"
	"time"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/fraktal/mev-beta/internal/logger"
	"github.com/fraktal/mev-beta/pkg/oracle"
)

// IntegrationGuide provides comprehensive examples of integrating the enhanced parser
// with the existing MEV bot architecture

// 1. MARKET PIPELINE INTEGRATION
// Replace simple parsing in pkg/market/pipeline.go

// EnhancedMarketPipeline integrates the enhanced parser with existing market pipeline
type EnhancedMarketPipeline struct {
	enhancedParser     *EnhancedDEXParser
	logger             *logger.Logger
	opportunityChannel chan *ArbitrageOpportunity

	// Existing components
	priceOracle *oracle.PriceOracle
	// Note: PoolRegistry and GasEstimator would be implemented separately

	// Configuration
	minProfitUSD      float64
	maxSlippageBps    uint64
	enabledStrategies []string
}

// ArbitrageOpportunity represents a detected arbitrage opportunity
type ArbitrageOpportunity struct {
	ID                string
	Protocol          string
	TokenIn           common.Address
	TokenOut          common.Address
	AmountIn          *big.Int
	AmountOut         *big.Int
	ExpectedProfitUSD float64
	PoolAddress       common.Address
	RouterAddress     common.Address
	GasCostEstimate   *big.Int
	Timestamp         time.Time
	EventType         EventType
	MEVType           string
	Confidence        float64
	RiskScore         float64
}

// NewEnhancedMarketPipeline creates an enhanced market pipeline
func NewEnhancedMarketPipeline(
	enhancedParser *EnhancedDEXParser,
	logger *logger.Logger,
	oracle *oracle.PriceOracle,
) *EnhancedMarketPipeline {
	return &EnhancedMarketPipeline{
		enhancedParser:     enhancedParser,
		logger:             logger,
		priceOracle:        oracle,
		opportunityChannel: make(chan *ArbitrageOpportunity, 1000),
		minProfitUSD:       100.0,
		maxSlippageBps:     500, // 5%
		enabledStrategies:  []string{"arbitrage", "liquidation"},
	}
}

// ProcessTransaction replaces the existing simple transaction processing
func (p *EnhancedMarketPipeline) ProcessTransaction(tx *types.Transaction, receipt *types.Receipt) error {
	// Use enhanced parser instead of simple parser
	result, err := p.enhancedParser.ParseTransaction(tx, receipt)
	if err != nil {
		p.logger.Debug(fmt.Sprintf("Enhanced parsing failed for tx %s: %v", tx.Hash().Hex(), err))
		return nil // Continue processing other transactions
	}

	// Process each detected DEX event
	for _, event := range result.Events {
		// Convert to arbitrage opportunity
		if opportunity := p.convertToOpportunity(event); opportunity != nil {
			// Apply filtering and validation
			if p.isValidOpportunity(opportunity) {
				select {
				case p.opportunityChannel <- opportunity:
					p.logger.Info(fmt.Sprintf("Opportunity detected: %s on %s, profit: $%.2f",
						opportunity.MEVType, opportunity.Protocol, opportunity.ExpectedProfitUSD))
				default:
					p.logger.Warn("Opportunity channel full, dropping opportunity")
				}
			}
		}
	}

	// Update pool cache with new pools
	for _, pool := range result.NewPools {
		// Pool registry integration would be implemented here
		_ = pool // Placeholder to avoid unused variable error
	}

	return nil
}

// convertToOpportunity converts a DEX event to an arbitrage opportunity
func (p *EnhancedMarketPipeline) convertToOpportunity(event *EnhancedDEXEvent) *ArbitrageOpportunity {
	// Only process events with sufficient liquidity
	if event.AmountInUSD < p.minProfitUSD {
		return nil
	}

	opportunity := &ArbitrageOpportunity{
		ID:                fmt.Sprintf("%s-%d", event.TxHash.Hex(), event.LogIndex),
		Protocol:          string(event.Protocol),
		TokenIn:           event.TokenIn,
		TokenOut:          event.TokenOut,
		AmountIn:          event.AmountIn,
		AmountOut:         event.AmountOut,
		PoolAddress:       event.PoolAddress,
		Timestamp:         event.Timestamp,
		EventType:         event.EventType,
		ExpectedProfitUSD: event.ProfitUSD,
		MEVType:           event.MEVType,
		Confidence:        p.calculateConfidence(event),
		RiskScore:         p.calculateRiskScore(event),
	}

	// Estimate gas costs
	if gasEstimate, err := p.estimateGasCost(opportunity); err == nil {
		opportunity.GasCostEstimate = gasEstimate
	}

	return opportunity
}

// isValidOpportunity validates if an opportunity is worth pursuing
func (p *EnhancedMarketPipeline) isValidOpportunity(opp *ArbitrageOpportunity) bool {
	// Check minimum profit threshold
	if opp.ExpectedProfitUSD < p.minProfitUSD {
		return false
	}

	// Check strategy is enabled
	strategyEnabled := false
	for _, strategy := range p.enabledStrategies {
		if strategy == opp.MEVType {
			strategyEnabled = true
			break
		}
	}
	if !strategyEnabled {
		return false
	}

	// Check confidence and risk thresholds
	if opp.Confidence < 0.7 || opp.RiskScore > 0.5 {
		return false
	}

	// Verify profit after gas costs
	if opp.GasCostEstimate != nil {
		gasCostUSD := p.convertToUSD(opp.GasCostEstimate)
		netProfitUSD := opp.ExpectedProfitUSD - gasCostUSD
		if netProfitUSD < p.minProfitUSD {
			return false
		}
	}

	return true
}

// calculateConfidence calculates confidence score for an opportunity
func (p *EnhancedMarketPipeline) calculateConfidence(event *EnhancedDEXEvent) float64 {
	confidence := 0.5 // Base confidence

	// Higher confidence for larger trades
	if event.AmountInUSD > 10000 {
		confidence += 0.2
	}

	// Higher confidence for known protocols
	switch event.Protocol {
	case ProtocolUniswapV2, ProtocolUniswapV3:
		confidence += 0.2
	case ProtocolSushiSwapV2, ProtocolSushiSwapV3:
		confidence += 0.15
	default:
		confidence += 0.1
	}

	// Lower confidence for high slippage
	if event.SlippageBps > 200 { // 2%
		confidence -= 0.1
	}

	// Ensure confidence is within [0, 1]
	if confidence > 1.0 {
		confidence = 1.0
	}
	if confidence < 0.0 {
		confidence = 0.0
	}

	return confidence
}

// calculateRiskScore calculates risk score for an opportunity
func (p *EnhancedMarketPipeline) calculateRiskScore(event *EnhancedDEXEvent) float64 {
	risk := 0.1 // Base risk

	// Higher risk for smaller pools
	if event.AmountInUSD < 1000 {
		risk += 0.2
	}

	// Higher risk for high slippage
	if event.SlippageBps > 500 { // 5%
		risk += 0.3
	}

	// Higher risk for unknown protocols
	switch event.Protocol {
	case ProtocolUniswapV2, ProtocolUniswapV3:
		// Low risk, no addition
	case ProtocolSushiSwapV2, ProtocolSushiSwapV3:
		risk += 0.1
	default:
		risk += 0.2
	}

	// Higher risk for sandwich attacks
	if event.IsSandwich {
		risk += 0.4
	}

	// Ensure risk is within [0, 1]
	if risk > 1.0 {
		risk = 1.0
	}
	if risk < 0.0 {
		risk = 0.0
	}

	return risk
}

// estimateGasCost estimates gas cost for executing the opportunity
func (p *EnhancedMarketPipeline) estimateGasCost(opp *ArbitrageOpportunity) (*big.Int, error) {
	// This would integrate with the existing gas estimation system
	baseGas := big.NewInt(200000) // Base gas for arbitrage

	// Add extra gas for complex operations
	switch opp.MEVType {
	case "arbitrage":
		baseGas.Add(baseGas, big.NewInt(100000)) // Flash loan gas
	case "liquidation":
		baseGas.Add(baseGas, big.NewInt(150000)) // Liquidation gas
	case "sandwich":
		baseGas.Add(baseGas, big.NewInt(300000)) // Two transactions
	}

	return baseGas, nil
}

// convertToUSD converts wei amount to USD (placeholder)
func (p *EnhancedMarketPipeline) convertToUSD(amount *big.Int) float64 {
	// This would use the price oracle to convert
	ethPriceUSD := 2000.0 // Placeholder
	amountEth := new(big.Float).Quo(new(big.Float).SetInt(amount), big.NewFloat(1e18))
	amountEthFloat, _ := amountEth.Float64()
	return amountEthFloat * ethPriceUSD
}

// 2. MONITOR INTEGRATION
// Replace simple monitoring in pkg/monitor/concurrent.go

// EnhancedArbitrumMonitor integrates enhanced parsing with monitoring
type EnhancedArbitrumMonitor struct {
	enhancedParser *EnhancedDEXParser
	marketPipeline *EnhancedMarketPipeline
	logger         *logger.Logger

	// Monitoring configuration
	enableRealTime bool
	batchSize      int
	maxWorkers     int

	// Channels
	blockChan chan uint64
	stopChan  chan struct{}

	// Metrics
	blocksProcessed    uint64
	eventsDetected     uint64
	opportunitiesFound uint64
}

// NewEnhancedArbitrumMonitor creates an enhanced monitor
func NewEnhancedArbitrumMonitor(
	enhancedParser *EnhancedDEXParser,
	marketPipeline *EnhancedMarketPipeline,
	logger *logger.Logger,
) *EnhancedArbitrumMonitor {
	return &EnhancedArbitrumMonitor{
		enhancedParser: enhancedParser,
		marketPipeline: marketPipeline,
		logger:         logger,
		enableRealTime: true,
		batchSize:      100,
		maxWorkers:     10,
		blockChan:      make(chan uint64, 1000),
		stopChan:       make(chan struct{}),
	}
}

// StartMonitoring begins real-time monitoring
func (m *EnhancedArbitrumMonitor) StartMonitoring(ctx context.Context) error {
	m.logger.Info("Starting enhanced Arbitrum monitoring")

	// Start block subscription
	go m.subscribeToBlocks(ctx)

	// Start block processing workers
	for i := 0; i < m.maxWorkers; i++ {
		go m.blockProcessor(ctx)
	}

	// Start metrics collection
	go m.metricsCollector(ctx)

	return nil
}

// subscribeToBlocks subscribes to new blocks
func (m *EnhancedArbitrumMonitor) subscribeToBlocks(ctx context.Context) {
	// This would implement real block subscription
	ticker := time.NewTicker(1 * time.Second) // Placeholder
	defer ticker.Stop()

	blockNumber := uint64(200000000) // Starting block

	for {
		select {
		case <-ticker.C:
			blockNumber++
			select {
			case m.blockChan <- blockNumber:
			default:
				m.logger.Warn("Block channel full, dropping block")
			}
		case <-ctx.Done():
			return
		case <-m.stopChan:
			return
		}
	}
}

// blockProcessor processes blocks from the queue
func (m *EnhancedArbitrumMonitor) blockProcessor(ctx context.Context) {
	for {
		select {
		case blockNumber := <-m.blockChan:
			if err := m.processBlock(blockNumber); err != nil {
				m.logger.Error(fmt.Sprintf("Failed to process block %d: %v", blockNumber, err))
			}
		case <-ctx.Done():
			return
		case <-m.stopChan:
			return
		}
	}
}

// processBlock processes a single block
func (m *EnhancedArbitrumMonitor) processBlock(blockNumber uint64) error {
	startTime := time.Now()

	// Parse block with enhanced parser
	result, err := m.enhancedParser.ParseBlock(blockNumber)
	if err != nil {
		return fmt.Errorf("failed to parse block: %w", err)
	}

	// Update metrics
	m.blocksProcessed++
	m.eventsDetected += uint64(len(result.Events))

	// Process significant events
	for _, event := range result.Events {
		if m.isSignificantEvent(event) {
			m.processSignificantEvent(event)
		}
	}

	processingTime := time.Since(startTime)
	if processingTime > 5*time.Second {
		m.logger.Warn(fmt.Sprintf("Slow block processing: %d took %v", blockNumber, processingTime))
	}

	return nil
}

// isSignificantEvent determines if an event is significant
func (m *EnhancedArbitrumMonitor) isSignificantEvent(event *EnhancedDEXEvent) bool {
	// Large trades
	if event.AmountInUSD > 50000 {
		return true
	}

	// MEV opportunities
	if event.IsMEV && event.ProfitUSD > 100 {
		return true
	}

	// New pool creation
	if event.EventType == EventTypePoolCreated {
		return true
	}

	return false
}

// processSignificantEvent processes important events
func (m *EnhancedArbitrumMonitor) processSignificantEvent(event *EnhancedDEXEvent) {
	m.logger.Info(fmt.Sprintf("Significant event: %s on %s, value: $%.2f",
		event.EventType, event.Protocol, event.AmountInUSD))

	if event.IsMEV {
		m.opportunitiesFound++
		m.logger.Info(fmt.Sprintf("MEV opportunity: %s, profit: $%.2f",
			event.MEVType, event.ProfitUSD))
	}
}

// metricsCollector collects and reports metrics
func (m *EnhancedArbitrumMonitor) metricsCollector(ctx context.Context) {
	ticker := time.NewTicker(1 * time.Minute)
	defer ticker.Stop()

	for {
		select {
		case <-ticker.C:
			m.reportMetrics()
		case <-ctx.Done():
			return
		case <-m.stopChan:
			return
		}
	}
}

// reportMetrics reports current metrics
func (m *EnhancedArbitrumMonitor) reportMetrics() {
	parserMetrics := m.enhancedParser.GetMetrics()

	m.logger.Info(fmt.Sprintf("Monitor metrics: blocks=%d, events=%d, opportunities=%d",
		m.blocksProcessed, m.eventsDetected, m.opportunitiesFound))

	m.logger.Info(fmt.Sprintf("Parser metrics: txs=%d, avg_time=%.2fms, errors=%d",
		parserMetrics.TotalTransactionsParsed,
		parserMetrics.AvgProcessingTimeMs,
		parserMetrics.ParseErrorCount))
}

// 3. SCANNER INTEGRATION
// Replace simple scanning in pkg/scanner/concurrent.go

// EnhancedOpportunityScanner uses enhanced parsing for opportunity detection
type EnhancedOpportunityScanner struct {
	enhancedParser *EnhancedDEXParser
	logger         *logger.Logger

	// Scanning configuration
	scanInterval       time.Duration
	maxConcurrentScans int

	// Opportunity tracking
	activeOpportunities map[string]*ArbitrageOpportunity
	opportunityHistory  []*ArbitrageOpportunity

	// Performance metrics
	scansCompleted       uint64
	opportunitiesFound   uint64
	profitableExecutions uint64
}

// NewEnhancedOpportunityScanner creates an enhanced opportunity scanner
func NewEnhancedOpportunityScanner(
	enhancedParser *EnhancedDEXParser,
	logger *logger.Logger,
) *EnhancedOpportunityScanner {
	return &EnhancedOpportunityScanner{
		enhancedParser:      enhancedParser,
		logger:              logger,
		scanInterval:        100 * time.Millisecond,
		maxConcurrentScans:  20,
		activeOpportunities: make(map[string]*ArbitrageOpportunity),
		opportunityHistory:  make([]*ArbitrageOpportunity, 0, 1000),
	}
}

// ScanForOpportunities continuously scans for arbitrage opportunities
func (s *EnhancedOpportunityScanner) ScanForOpportunities(ctx context.Context) {
	ticker := time.NewTicker(s.scanInterval)
	defer ticker.Stop()

	for {
		select {
		case <-ticker.C:
			s.performScan()
		case <-ctx.Done():
			return
		}
	}
}

// performScan performs a single scan cycle
func (s *EnhancedOpportunityScanner) performScan() {
	s.scansCompleted++

	// Get recent high-value pools from cache
	recentPools := s.enhancedParser.poolCache.GetTopPools(100)

	// Scan each pool for opportunities
	for _, pool := range recentPools {
		go s.scanPool(pool)
	}
}

// scanPool scans a specific pool for opportunities
func (s *EnhancedOpportunityScanner) scanPool(pool *PoolInfo) {
	// This would implement sophisticated pool scanning
	// Using the enhanced parser's pool information

	if opportunity := s.detectArbitrageOpportunity(pool); opportunity != nil {
		s.handleOpportunity(opportunity)
	}
}

// detectArbitrageOpportunity detects arbitrage opportunities in a pool
func (s *EnhancedOpportunityScanner) detectArbitrageOpportunity(pool *PoolInfo) *ArbitrageOpportunity {
	// Sophisticated arbitrage detection logic would go here
	// This is a placeholder implementation

	// Check if pool has sufficient liquidity
	if pool.TVL < 100000 { // $100k minimum
		return nil
	}

	// Look for price discrepancies with other protocols
	// This would involve cross-protocol price comparison

	return nil // Placeholder
}

// handleOpportunity handles a detected opportunity
func (s *EnhancedOpportunityScanner) handleOpportunity(opportunity *ArbitrageOpportunity) {
	s.opportunitiesFound++

	// Add to active opportunities
	s.activeOpportunities[opportunity.ID] = opportunity

	// Add to history
	s.opportunityHistory = append(s.opportunityHistory, opportunity)

	// Trim history if too long
	if len(s.opportunityHistory) > 1000 {
		s.opportunityHistory = s.opportunityHistory[100:]
	}

	s.logger.Info(fmt.Sprintf("Opportunity detected: %s, profit: $%.2f",
		opportunity.ID, opportunity.ExpectedProfitUSD))
}

// 4. EXECUTION INTEGRATION
// Integrate with pkg/arbitrage/executor.go

// EnhancedArbitrageExecutor executes opportunities detected by enhanced parser
type EnhancedArbitrageExecutor struct {
	enhancedParser *EnhancedDEXParser
	logger         *logger.Logger

	// Execution configuration
	maxGasPrice       *big.Int
	slippageTolerance float64
	minProfitUSD      float64

	// Performance tracking
	executionsAttempted  uint64
	executionsSuccessful uint64
	totalProfitUSD       float64
}

// ExecuteOpportunity executes an arbitrage opportunity
func (e *EnhancedArbitrageExecutor) ExecuteOpportunity(
	ctx context.Context,
	opportunity *ArbitrageOpportunity,
) error {
	e.executionsAttempted++

	// Validate opportunity is still profitable
	if !e.validateOpportunity(opportunity) {
		return fmt.Errorf("opportunity no longer profitable")
	}

	// Execute based on opportunity type
	switch opportunity.MEVType {
	case "arbitrage":
		return e.executeArbitrage(ctx, opportunity)
	case "liquidation":
		return e.executeLiquidation(ctx, opportunity)
	case "sandwich":
		return e.executeSandwich(ctx, opportunity)
	default:
		return fmt.Errorf("unsupported MEV type: %s", opportunity.MEVType)
	}
}

// validateOpportunity validates that an opportunity is still executable
func (e *EnhancedArbitrageExecutor) validateOpportunity(opportunity *ArbitrageOpportunity) bool {
	// Re-check profitability with current market conditions
	// This would involve real-time price checks
	return opportunity.ExpectedProfitUSD >= e.minProfitUSD
}

// executeArbitrage executes an arbitrage opportunity
func (e *EnhancedArbitrageExecutor) executeArbitrage(
	ctx context.Context,
	opportunity *ArbitrageOpportunity,
) error {
	e.logger.Info(fmt.Sprintf("Executing arbitrage: %s", opportunity.ID))

	// Implementation would:
	// 1. Get flash loan
	// 2. Execute first trade
	// 3. Execute second trade
	// 4. Repay flash loan
	// 5. Keep profit

	// Placeholder for successful execution
	e.executionsSuccessful++
	e.totalProfitUSD += opportunity.ExpectedProfitUSD

	return nil
}

// executeLiquidation executes a liquidation opportunity
func (e *EnhancedArbitrageExecutor) executeLiquidation(
	ctx context.Context,
	opportunity *ArbitrageOpportunity,
) error {
	e.logger.Info(fmt.Sprintf("Executing liquidation: %s", opportunity.ID))

	// Implementation would liquidate undercollateralized position

	e.executionsSuccessful++
	e.totalProfitUSD += opportunity.ExpectedProfitUSD

	return nil
}

// executeSandwich executes a sandwich attack
func (e *EnhancedArbitrageExecutor) executeSandwich(
	ctx context.Context,
	opportunity *ArbitrageOpportunity,
) error {
	e.logger.Info(fmt.Sprintf("Executing sandwich: %s", opportunity.ID))

	// Implementation would:
	// 1. Front-run victim transaction
	// 2. Let victim transaction execute
	// 3. Back-run to extract profit

	e.executionsSuccessful++
	e.totalProfitUSD += opportunity.ExpectedProfitUSD

	return nil
}

// 5. COMPLETE INTEGRATION EXAMPLE

// IntegratedMEVBot demonstrates complete integration
type IntegratedMEVBot struct {
	enhancedParser *EnhancedDEXParser
	marketPipeline *EnhancedMarketPipeline
	monitor        *EnhancedArbitrumMonitor
	scanner        *EnhancedOpportunityScanner
	executor       *EnhancedArbitrageExecutor
	logger         *logger.Logger
}

// NewIntegratedMEVBot creates a fully integrated MEV bot
func NewIntegratedMEVBot(
	config *EnhancedParserConfig,
	logger *logger.Logger,
	oracle *oracle.PriceOracle,
) (*IntegratedMEVBot, error) {
	// Create enhanced parser
	enhancedParser, err := NewEnhancedDEXParser(config, logger, oracle)
	if err != nil {
		return nil, fmt.Errorf("failed to create enhanced parser: %w", err)
	}

	// Create integrated components
	marketPipeline := NewEnhancedMarketPipeline(enhancedParser, logger, oracle)
	monitor := NewEnhancedArbitrumMonitor(enhancedParser, marketPipeline, logger)
	scanner := NewEnhancedOpportunityScanner(enhancedParser, logger)
	executor := &EnhancedArbitrageExecutor{
		enhancedParser:    enhancedParser,
		logger:            logger,
		maxGasPrice:       big.NewInt(50e9), // 50 gwei
		slippageTolerance: 0.01,             // 1%
		minProfitUSD:      100.0,
	}

	return &IntegratedMEVBot{
		enhancedParser: enhancedParser,
		marketPipeline: marketPipeline,
		monitor:        monitor,
		scanner:        scanner,
		executor:       executor,
		logger:         logger,
	}, nil
}

// Start starts the integrated MEV bot
func (bot *IntegratedMEVBot) Start(ctx context.Context) error {
	bot.logger.Info("Starting integrated MEV bot with enhanced parsing")

	// Start monitoring
	if err := bot.monitor.StartMonitoring(ctx); err != nil {
		return fmt.Errorf("failed to start monitoring: %w", err)
	}

	// Start scanning
	go bot.scanner.ScanForOpportunities(ctx)

	// Start opportunity processing
	go bot.processOpportunities(ctx)

	return nil
}

// processOpportunities processes detected opportunities
func (bot *IntegratedMEVBot) processOpportunities(ctx context.Context) {
	for {
		select {
		case opportunity := <-bot.marketPipeline.opportunityChannel:
			go func(opp *ArbitrageOpportunity) {
				if err := bot.executor.ExecuteOpportunity(ctx, opp); err != nil {
					bot.logger.Error(fmt.Sprintf("Failed to execute opportunity %s: %v", opp.ID, err))
				}
			}(opportunity)
		case <-ctx.Done():
			return
		}
	}
}

// Stop stops the integrated MEV bot
func (bot *IntegratedMEVBot) Stop() error {
	bot.logger.Info("Stopping integrated MEV bot")
	return bot.enhancedParser.Close()
}

// GetMetrics returns comprehensive metrics
func (bot *IntegratedMEVBot) GetMetrics() map[string]interface{} {
	parserMetrics := bot.enhancedParser.GetMetrics()

	return map[string]interface{}{
		"parser": parserMetrics,
		"monitor": map[string]interface{}{
			"blocks_processed":    bot.monitor.blocksProcessed,
			"events_detected":     bot.monitor.eventsDetected,
			"opportunities_found": bot.monitor.opportunitiesFound,
		},
		"scanner": map[string]interface{}{
			"scans_completed":     bot.scanner.scansCompleted,
			"opportunities_found": bot.scanner.opportunitiesFound,
		},
		"executor": map[string]interface{}{
			"executions_attempted":  bot.executor.executionsAttempted,
			"executions_successful": bot.executor.executionsSuccessful,
			"total_profit_usd":      bot.executor.totalProfitUSD,
		},
	}
}