//go:build stress
// +build stress

package stress_test

import (
	"context"
	"fmt"
	"math/big"
	"math/rand"
	"os"
	"os/signal"
	"sync"
	"sync/atomic"
	"syscall"
	"time"

	"github.com/ethereum/go-ethereum/common"
	"github.com/holiman/uint256"

	"github.com/fraktal/mev-beta/internal/logger"
	"github.com/fraktal/mev-beta/pkg/arbitrum"
	"github.com/fraktal/mev-beta/pkg/events"
	"github.com/fraktal/mev-beta/pkg/marketdata"
	"github.com/fraktal/mev-beta/pkg/pools"
	"github.com/fraktal/mev-beta/pkg/profitcalc"
	"github.com/fraktal/mev-beta/pkg/scanner/market"
	"github.com/fraktal/mev-beta/pkg/scanner/swap"
)

// StressTestRunner runs comprehensive stress tests for the MEV bot
type StressTestRunner struct {
	suite    *StressTestSuite
	logger   *logger.Logger
	wg       sync.WaitGroup
	ctx      context.Context
	cancel   context.CancelFunc
	shutdown chan struct{}
}

// NewStressTestRunner creates a new stress test runner
func NewStressTestRunner() *StressTestRunner {
	// Initialize logger
	log := logger.New("debug", "text", "logs/stress_test.log")

	// Create test components
	protocolRegistry := arbitrum.NewArbitrumProtocolRegistry(log)
	poolCache := pools.NewPoolCache(10000, time.Hour)
	marketDiscovery := market.NewMarketDiscovery(nil, log, "")
	strategyEngine := arbitrum.NewMEVStrategyEngine(log, protocolRegistry)
	profitCalculator := profitcalc.NewProfitCalculatorWithClient(log, nil)
	marketDataLogger := marketdata.NewMarketDataLogger(log, nil)
	swapAnalyzer := swap.NewSwapAnalyzer(log, marketDataLogger, profitCalculator, nil)

	ctx, cancel := context.WithCancel(context.Background())

	runner := &StressTestRunner{
		logger:   log,
		ctx:      ctx,
		cancel:   cancel,
		shutdown: make(chan struct{}),
	}

	// Create stress test suite
	runner.suite = NewStressTestSuite(
		log,
		protocolRegistry,
		poolCache,
		marketDiscovery,
		strategyEngine,
		profitCalculator,
		nil, // mevAnalyzer
		nil, // slippageProtector
		nil, // capitalOptimizer
		nil, // profitTracker
	)

	return runner
}

// RunAllStressTests runs all stress tests
func (str *StressTestRunner) RunAllStressTests() {
	str.logger.Info("🚀 Starting comprehensive stress tests...")

	// Set up graceful shutdown
	str.setupGracefulShutdown()

	// Run individual stress tests
	tests := []struct {
		name string
		fn   func() *StressTestResult
	}{
		{"Market Scanner Stress Test", str.suite.RunMarketScannerStressTest},
		{"Swap Analyzer Stress Test", str.suite.RunSwapAnalyzerStressTest},
		{"Pool Discovery Stress Test", str.suite.RunPoolDiscoveryStressTest},
		{"Arbitrage Engine Stress Test", str.suite.RunArbitrageEngineStressTest},
		{"Event Processing Stress Test", str.suite.RunEventProcessingStressTest},
		{"Profit Calculation Stress Test", str.suite.RunProfitCalculationStressTest},
		{"Concurrency Stress Test", str.suite.RunConcurrencyStressTest},
		{"Memory Stress Test", str.suite.RunMemoryStressTest},
		{"Performance Regression Test", str.suite.RunPerformanceRegressionTest},
	}

	results := make([]*StressTestResult, len(tests))

	// Run tests concurrently
	for i, test := range tests {
		str.wg.Add(1)
		go func(idx int, t struct {
			name string
			fn   func() *StressTestResult
		}) {
			defer str.wg.Done()

			str.logger.Info(fmt.Sprintf("🧪 Running %s...", t.name))
			result := t.fn()
			results[idx] = result

			if result.Passed {
				str.logger.Info(fmt.Sprintf("✅ %s PASSED", t.name))
			} else {
				str.logger.Error(fmt.Sprintf("❌ %s FAILED", t.name))
			}
		}(i, test)
	}

	// Wait for all tests to complete
	str.wg.Wait()

	// Generate and log summary report
	str.generateSummaryReport(results)

	// Close resources
	close(str.shutdown)
}

// generateSummaryReport generates and logs a summary report of stress test results
func (str *StressTestRunner) generateSummaryReport(results []*StressTestResult) {
	str.logger.Info("📊 STRESS TEST SUMMARY REPORT")
	str.logger.Info("================================")

	passed := 0
	failed := 0
	totalTests := len(results)

	for _, result := range results {
		if result.Passed {
			passed++
		} else {
			failed++
		}

		status := "✅ PASS"
		if !result.Passed {
			status = "❌ FAIL"
		}

		str.logger.Info(fmt.Sprintf("%s %s - Score: %.1f%%", status, result.TestName, result.PerformanceScore))
	}

	str.logger.Info("================================")
	str.logger.Info(fmt.Sprintf("TOTAL: %d tests, %d passed, %d failed", totalTests, passed, failed))
	str.logger.Info(fmt.Sprintf("SUCCESS RATE: %.1f%%", float64(passed)/float64(totalTests)*100))

	if failed == 0 {
		str.logger.Info("🎉 ALL STRESS TESTS PASSED!")
	} else {
		str.logger.Warn(fmt.Sprintf("⚠️  %d STRESS TESTS FAILED - REVIEW RESULTS", failed))
	}
}

// setupGracefulShutdown sets up signal handling for graceful shutdown
func (str *StressTestRunner) setupGracefulShutdown() {
	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt, syscall.SIGTERM)

	go func() {
		<-c
		str.logger.Info("🛑 Shutdown signal received, stopping stress tests...")
		str.cancel()
		close(str.shutdown)
	}()
}

// generateTestLoad generates synthetic load for stress testing
func (str *StressTestRunner) generateTestLoad(duration time.Duration, transactionsPerSecond int) {
	str.logger.Info(fmt.Sprintf("💥 Generating synthetic load: %d TPS for %v", transactionsPerSecond, duration))

	// Calculate interval between transactions for precise TPS
	interval := time.Duration(int64(time.Second) / int64(transactionsPerSecond))
	if interval == 0 {
		interval = time.Nanosecond // Minimum interval for very high TPS
	}
	ticker := time.NewTicker(interval)
	defer ticker.Stop()

	startTime := time.Now()
	transactionCount := uint64(0)

	for {
		select {
		case <-str.ctx.Done():
			str.logger.Info(fmt.Sprintf("⏹️  Load generation stopped. Generated %d transactions in %v", transactionCount, time.Since(startTime)))
			return
		case <-ticker.C:
			// Generate synthetic transaction
			str.generateSyntheticTransaction()
			atomic.AddUint64(&transactionCount, 1)

			// Check if duration has elapsed
			if time.Since(startTime) >= duration {
				str.logger.Info(fmt.Sprintf("⏰ Load generation completed. Generated %d transactions in %v", transactionCount, time.Since(startTime)))
				return
			}
		}
	}
}

// generateSyntheticTransaction generates a synthetic transaction for stress testing
func (str *StressTestRunner) generateSyntheticTransaction() {
	// Generate random transaction data
	txHash := common.BigToHash(big.NewInt(rand.Int63()))
	blockNumber := uint64(rand.Int63n(100000000) + 100000000)
	poolAddr := common.BigToAddress(big.NewInt(rand.Int63()))
	token0 := common.BigToAddress(big.NewInt(rand.Int63()))
	token1 := common.BigToAddress(big.NewInt(rand.Int63()))
	amount0 := big.NewInt(rand.Int63n(1000000000000000000)) // Up to 1 ETH
	amount1 := big.NewInt(rand.Int63n(1000000000000000000)) // Up to 1 ETH

	// Create event with random protocol
	protocols := []string{"uniswap_v2", "uniswap_v3", "sushiswap", "camelot_v2", "camelot_v3", "balancer_v2", "curve", "algebra"}
	protocol := protocols[rand.Intn(len(protocols))]

	event := events.Event{
		Timestamp:       time.Now(),
		BlockNumber:     blockNumber,
		TransactionHash: txHash,
		LogIndex:        uint(rand.Intn(100)),
		Type:            events.Swap,
		Protocol:        protocol,
		PoolAddress:     poolAddr,
		Token0:          token0,
		Token1:          token1,
		Amount0:         amount0,
		Amount1:         amount1,
		Liquidity:       uint256.NewInt(uint64(rand.Int63n(1000000000000000000))), // Up to 1 ETH equivalent
		SqrtPriceX96:    uint256.NewInt(uint64(rand.Int63n(1000000000000000000))), // Random sqrt price
		Tick:            int32(rand.Int31n(100000) - 50000),                       // Random tick between -50000 and 50000
	}

	// Process event through the system
	// Note: In a real implementation, this would call the actual processing methods
	// For stress testing, we'll just simulate the processing
	time.Sleep(time.Duration(rand.Intn(5)) * time.Millisecond)
}

func main() {
	fmt.Println("🚀 MEV Bot Stress Test Runner")
	fmt.Println("=============================")

	// Create stress test runner
	runner := NewStressTestRunner()
	defer runner.logger.Close()

	// Parse command line arguments
	args := os.Args[1:]
	if len(args) == 0 {
		fmt.Println("Usage: stress-test-runner [options]")
		fmt.Println("Options:")
		fmt.Println("  --load-test        Run load generation test")
		fmt.Println("  --full-suite       Run full stress test suite")
		fmt.Println("  --duration <sec>   Set test duration (default: 60)")
		fmt.Println("  --tps <count>      Set transactions per second (default: 1000)")
		os.Exit(1)
	}

	// Parse arguments
	duration := 60 * time.Second
	tps := 1000
	runLoadTest := false
	runFullSuite := false

	for i := 0; i < len(args); i++ {
		switch args[i] {
		case "--duration":
			if i+1 < len(args) {
				if sec, err := fmt.Sscanf(args[i+1], "%d", &duration); err == nil && sec == 1 {
					duration = time.Duration(sec) * time.Second
				}
				i++
			}
		case "--tps":
			if i+1 < len(args) {
				if count, err := fmt.Sscanf(args[i+1], "%d", &tps); err == nil && count == 1 {
					tps = int(count)
				}
				i++
			}
		case "--load-test":
			runLoadTest = true
		case "--full-suite":
			runFullSuite = true
		}
	}

	// Run selected tests
	if runLoadTest {
		fmt.Printf("🏃 Running load test for %v at %d TPS...\n", duration, tps)
		go runner.generateTestLoad(duration, tps)

		// Wait for completion or shutdown
		select {
		case <-runner.shutdown:
			fmt.Println("🛑 Load test interrupted")
		case <-time.After(duration + 5*time.Second):
			fmt.Println("✅ Load test completed")
		}
	}

	if runFullSuite {
		fmt.Println("🧪 Running full stress test suite...")
		runner.RunAllStressTests()
		fmt.Println("✅ Full stress test suite completed")
	}

	if !runLoadTest && !runFullSuite {
		fmt.Println("❌ No test specified. Use --load-test or --full-suite")
		os.Exit(1)
	}
}