bzzz/test/utils/load_testing_framework.go

// Load Testing Framework for BZZZ Integration Tests
// This comprehensive load testing framework provides advanced load generation,
// performance monitoring, and stress testing capabilities for the BZZZ system.
//
// Key Features:
// - Multi-pattern load generation (constant, burst, ramp, sine wave)
// - Role-based collaboration load simulation
// - Performance monitoring with detailed metrics collection
// - Real-time performance visualization and alerting
// - Comprehensive load test reporting and analysis
// - Resource usage tracking and optimization recommendations

package utils

import (
	"context"
	"encoding/json"
	"fmt"
	"math"
	"runtime"
	"sync"
	"sync/atomic"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"

	"chorus.services/bzzz/pkg/config"
)

// LoadTestFramework provides comprehensive load testing capabilities
type LoadTestFramework struct {
	config              *config.Config
	loadGenerators      map[string]*LoadGenerator
	performanceMonitor  *PerformanceMonitor
	metricsCollector    *MetricsCollector
	resourceTracker     *ResourceTracker
	alertManager        *AlertManager
	reportGenerator     *ReportGenerator
	testScenarios       []LoadTestScenario
	activeTests         map[string]*ActiveLoadTest
	globalMetrics       *GlobalMetrics
	mutex               sync.RWMutex
}

// LoadTestScenario defines a complete load testing scenario
type LoadTestScenario struct {
	ID                 string                    `json:"id"`
	Name               string                    `json:"name"`
	Description        string                    `json:"description"`
	Duration           time.Duration             `json:"duration"`
	LoadPatterns       []LoadPattern             `json:"load_patterns"`
	RoleDistribution   map[string]float64        `json:"role_distribution"`
	PerformanceTargets LoadTestPerformanceTargets `json:"performance_targets"`
	StressConditions   []StressCondition         `json:"stress_conditions"`
	ValidationCriteria []ValidationCriterion     `json:"validation_criteria"`
	ResourceLimits     ResourceLimits            `json:"resource_limits"`
}

// LoadPattern defines how load should be generated over time
type LoadPattern struct {
	Type           string                 `json:"type"` // "constant", "ramp", "burst", "sine", "random"
	StartRate      float64                `json:"start_rate"`
	EndRate        float64                `json:"end_rate"`
	Duration       time.Duration          `json:"duration"`
	BurstIntensity float64                `json:"burst_intensity,omitempty"`
	BurstDuration  time.Duration          `json:"burst_duration,omitempty"`
	Parameters     map[string]interface{} `json:"parameters,omitempty"`
}

// LoadTestPerformanceTargets defines expected performance during load tests
type LoadTestPerformanceTargets struct {
	MaxResponseTime    time.Duration `json:"max_response_time"`
	MinThroughput      float64       `json:"min_throughput"`
	MaxErrorRate       float64       `json:"max_error_rate"`
	MaxMemoryUsage     int64         `json:"max_memory_usage"`
	MaxCPUUsage        float64       `json:"max_cpu_usage"`
	MaxGoroutines      int           `json:"max_goroutines"`
	MaxOpenFiles       int           `json:"max_open_files"`
	P95ResponseTime    time.Duration `json:"p95_response_time"`
	P99ResponseTime    time.Duration `json:"p99_response_time"`
}

// StressCondition defines stress testing conditions
type StressCondition struct {
	Type            string                 `json:"type"`
	Intensity       float64                `json:"intensity"`
	Duration        time.Duration          `json:"duration"`
	InjectionPoint  string                 `json:"injection_point"`
	RecoveryTime    time.Duration          `json:"recovery_time"`
	Parameters      map[string]interface{} `json:"parameters"`
}

// ValidationCriterion defines validation criteria for load tests
type ValidationCriterion struct {
	Metric      string      `json:"metric"`
	Operator    string      `json:"operator"` // "<", ">", "<=", ">=", "==", "!="
	Threshold   interface{} `json:"threshold"`
	Description string      `json:"description"`
	Critical    bool        `json:"critical"`
}

// ResourceLimits defines resource usage limits during tests
type ResourceLimits struct {
	MaxMemoryMB      int64 `json:"max_memory_mb"`
	MaxCPUPercent    int   `json:"max_cpu_percent"`
	MaxOpenFiles     int   `json:"max_open_files"`
	MaxGoroutines    int   `json:"max_goroutines"`
	MaxNetworkMbps   int   `json:"max_network_mbps"`
}

// ActiveLoadTest tracks an active load test
type ActiveLoadTest struct {
	Scenario       LoadTestScenario
	StartTime      time.Time
	EndTime        time.Time
	Status         string
	CurrentMetrics *LoadTestMetrics
	Results        *LoadTestResult
	StopChannel    chan bool
	Workers        []*LoadTestWorker
	mutex          sync.RWMutex
}

// LoadTestMetrics tracks metrics during load testing
type LoadTestMetrics struct {
	Timestamp         time.Time     `json:"timestamp"`
	CurrentRPS        float64       `json:"current_rps"`
	TotalRequests     int64         `json:"total_requests"`
	SuccessfulReqs    int64         `json:"successful_requests"`
	FailedRequests    int64         `json:"failed_requests"`
	AvgResponseTime   time.Duration `json:"avg_response_time"`
	P95ResponseTime   time.Duration `json:"p95_response_time"`
	P99ResponseTime   time.Duration `json:"p99_response_time"`
	MaxResponseTime   time.Duration `json:"max_response_time"`
	MinResponseTime   time.Duration `json:"min_response_time"`
	ErrorRate         float64       `json:"error_rate"`
	Throughput        float64       `json:"throughput"`
	MemoryUsage       int64         `json:"memory_usage"`
	CPUUsage          float64       `json:"cpu_usage"`
	GoroutineCount    int           `json:"goroutine_count"`
	ActiveConnections int           `json:"active_connections"`
}

// LoadTestResult represents the final result of a load test
type LoadTestResult struct {
	ScenarioID        string                    `json:"scenario_id"`
	StartTime         time.Time                 `json:"start_time"`
	EndTime           time.Time                 `json:"end_time"`
	Duration          time.Duration             `json:"duration"`
	Success           bool                      `json:"success"`
	TotalRequests     int64                     `json:"total_requests"`
	SuccessfulReqs    int64                     `json:"successful_requests"`
	FailedRequests    int64                     `json:"failed_requests"`
	OverallErrorRate  float64                   `json:"overall_error_rate"`
	PeakRPS           float64                   `json:"peak_rps"`
	AvgRPS            float64                   `json:"avg_rps"`
	PerformanceMetrics LoadTestPerformanceMetrics `json:"performance_metrics"`
	ResourceUsage     ResourceUsageMetrics      `json:"resource_usage"`
	ValidationResults []ValidationResult        `json:"validation_results"`
	ErrorBreakdown    map[string]int64          `json:"error_breakdown"`
	Recommendations   []string                  `json:"recommendations"`
	DetailedReport    string                    `json:"detailed_report"`
}

// LoadTestPerformanceMetrics contains detailed performance metrics
type LoadTestPerformanceMetrics struct {
	ResponseTimes        ResponseTimeMetrics `json:"response_times"`
	ThroughputMetrics    ThroughputMetrics   `json:"throughput_metrics"`
	LatencyDistribution  []LatencyBucket     `json:"latency_distribution"`
	ErrorDistribution    []ErrorBucket       `json:"error_distribution"`
	PerformanceTimeline  []TimelinePoint     `json:"performance_timeline"`
}

// ResponseTimeMetrics contains response time statistics
type ResponseTimeMetrics struct {
	Min    time.Duration `json:"min"`
	Max    time.Duration `json:"max"`
	Mean   time.Duration `json:"mean"`
	Median time.Duration `json:"median"`
	P90    time.Duration `json:"p90"`
	P95    time.Duration `json:"p95"`
	P99    time.Duration `json:"p99"`
	StdDev time.Duration `json:"std_dev"`
}

// ThroughputMetrics contains throughput statistics
type ThroughputMetrics struct {
	Min     float64 `json:"min"`
	Max     float64 `json:"max"`
	Mean    float64 `json:"mean"`
	Median  float64 `json:"median"`
	StdDev  float64 `json:"std_dev"`
	P95     float64 `json:"p95"`
	P99     float64 `json:"p99"`
}

// LatencyBucket represents a latency distribution bucket
type LatencyBucket struct {
	Range string  `json:"range"`
	Count int64   `json:"count"`
	Percent float64 `json:"percent"`
}

// ErrorBucket represents an error distribution bucket
type ErrorBucket struct {
	ErrorType string  `json:"error_type"`
	Count     int64   `json:"count"`
	Percent   float64 `json:"percent"`
	Examples  []string `json:"examples"`
}

// TimelinePoint represents a point in the performance timeline
type TimelinePoint struct {
	Timestamp   time.Time `json:"timestamp"`
	RPS         float64   `json:"rps"`
	ResponseTime time.Duration `json:"response_time"`
	ErrorRate   float64   `json:"error_rate"`
	MemoryUsage int64     `json:"memory_usage"`
	CPUUsage    float64   `json:"cpu_usage"`
}

// ResourceUsageMetrics contains resource usage statistics
type ResourceUsageMetrics struct {
	PeakMemoryUsage    int64   `json:"peak_memory_usage"`
	AvgMemoryUsage     int64   `json:"avg_memory_usage"`
	PeakCPUUsage       float64 `json:"peak_cpu_usage"`
	AvgCPUUsage        float64 `json:"avg_cpu_usage"`
	MaxGoroutines      int     `json:"max_goroutines"`
	AvgGoroutines      int     `json:"avg_goroutines"`
	MaxOpenFiles       int     `json:"max_open_files"`
	NetworkBytesIn     int64   `json:"network_bytes_in"`
	NetworkBytesOut    int64   `json:"network_bytes_out"`
	DiskReads          int64   `json:"disk_reads"`
	DiskWrites         int64   `json:"disk_writes"`
}

// LoadGenerator generates load for testing
type LoadGenerator struct {
	id              string
	pattern         LoadPattern
	targetEndpoint  string
	requestTemplate RequestTemplate
	workers         []*LoadTestWorker
	metrics         *LoadGeneratorMetrics
	active          bool
	stopChannel     chan bool
	mutex           sync.RWMutex
}

// RequestTemplate defines how to generate requests
type RequestTemplate struct {
	Method      string                 `json:"method"`
	Path        string                 `json:"path"`
	Headers     map[string]string      `json:"headers"`
	Body        string                 `json:"body"`
	Parameters  map[string]interface{} `json:"parameters"`
	Validation  RequestValidation      `json:"validation"`
}

// RequestValidation defines how to validate responses
type RequestValidation struct {
	ExpectedStatus   []int    `json:"expected_status"`
	RequiredHeaders  []string `json:"required_headers"`
	BodyContains     []string `json:"body_contains"`
	MaxResponseTime  time.Duration `json:"max_response_time"`
	ValidateJSON     bool     `json:"validate_json"`
	JSONSchema       string   `json:"json_schema,omitempty"`
}

// LoadTestWorker represents a worker that generates load
type LoadTestWorker struct {
	id               string
	generator        *LoadGenerator
	requestCount     int64
	successCount     int64
	errorCount       int64
	lastRequestTime  time.Time
	responseTimeSum  int64
	active           bool
	stopChannel      chan bool
}

// LoadGeneratorMetrics tracks metrics for a load generator
type LoadGeneratorMetrics struct {
	TotalRequests   int64         `json:"total_requests"`
	SuccessRequests int64         `json:"success_requests"`
	ErrorRequests   int64         `json:"error_requests"`
	AvgResponseTime time.Duration `json:"avg_response_time"`
	CurrentRPS      float64       `json:"current_rps"`
	LastUpdated     time.Time     `json:"last_updated"`
}

// GlobalMetrics tracks system-wide metrics
type GlobalMetrics struct {
	SystemStartTime    time.Time `json:"system_start_time"`
	TotalTestsRun      int64     `json:"total_tests_run"`
	ActiveTests        int       `json:"active_tests"`
	TotalRequestsSent  int64     `json:"total_requests_sent"`
	TotalErrors        int64     `json:"total_errors"`
	SystemMemoryUsage  int64     `json:"system_memory_usage"`
	SystemCPUUsage     float64   `json:"system_cpu_usage"`
}

// NewLoadTestFramework creates a new load testing framework
func NewLoadTestFramework(config *config.Config) *LoadTestFramework {
	return &LoadTestFramework{
		config:          config,
		loadGenerators:  make(map[string]*LoadGenerator),
		activeTests:     make(map[string]*ActiveLoadTest),
		globalMetrics:   &GlobalMetrics{SystemStartTime: time.Now()},
		performanceMonitor: NewPerformanceMonitor(config),
		metricsCollector:   NewMetricsCollector(config),
		resourceTracker:    NewResourceTracker(config),
		alertManager:       NewAlertManager(config),
		reportGenerator:    NewReportGenerator(config),
	}
}

// RunLoadTest executes a complete load test scenario
func (ltf *LoadTestFramework) RunLoadTest(t *testing.T, scenario LoadTestScenario) *LoadTestResult {
	ltf.mutex.Lock()
	ltf.globalMetrics.TotalTestsRun++
	ltf.mutex.Unlock()

	// Create active test tracker
	activeTest := &ActiveLoadTest{
		Scenario:    scenario,
		StartTime:   time.Now(),
		Status:      "initializing",
		StopChannel: make(chan bool),
		Workers:     make([]*LoadTestWorker, 0),
	}

	ltf.mutex.Lock()
	ltf.activeTests[scenario.ID] = activeTest
	ltf.globalMetrics.ActiveTests++
	ltf.mutex.Unlock()

	defer func() {
		ltf.mutex.Lock()
		delete(ltf.activeTests, scenario.ID)
		ltf.globalMetrics.ActiveTests--
		ltf.mutex.Unlock()
	}()

	// Start performance monitoring
	ltf.performanceMonitor.StartMonitoring(scenario.ID)
	defer ltf.performanceMonitor.StopMonitoring(scenario.ID)

	// Initialize load generators for each load pattern
	for i, pattern := range scenario.LoadPatterns {
		generatorID := fmt.Sprintf("%s-generator-%d", scenario.ID, i)
		generator := ltf.createLoadGenerator(generatorID, pattern, scenario)
		ltf.loadGenerators[generatorID] = generator
		defer ltf.stopLoadGenerator(generatorID)
	}

	// Execute load test phases
	activeTest.Status = "running"
	result := ltf.executeLoadTestScenario(t, activeTest)

	// Finalize results
	activeTest.Status = "completed"
	activeTest.EndTime = time.Now()
	activeTest.Results = result

	return result
}

// executeLoadTestScenario executes the actual load test scenario
func (ltf *LoadTestFramework) executeLoadTestScenario(t *testing.T, activeTest *ActiveLoadTest) *LoadTestResult {
	scenario := activeTest.Scenario
	startTime := time.Now()

	// Initialize result tracking
	result := &LoadTestResult{
		ScenarioID:         scenario.ID,
		StartTime:          startTime,
		Success:            true,
		ValidationResults:  make([]ValidationResult, 0),
		ErrorBreakdown:     make(map[string]int64),
		Recommendations:    make([]string, 0),
	}

	// Start load generation
	var wg sync.WaitGroup
	for generatorID, generator := range ltf.loadGenerators {
		if strings.HasPrefix(generatorID, scenario.ID) {
			wg.Add(1)
			go func(gen *LoadGenerator) {
				defer wg.Done()
				ltf.runLoadGenerator(gen, scenario.Duration)
			}(generator)
		}
	}

	// Monitor test progress
	monitorCtx, monitorCancel := context.WithCancel(context.Background())
	go ltf.monitorLoadTest(monitorCtx, activeTest)

	// Wait for test completion or timeout
	testDone := make(chan bool)
	go func() {
		wg.Wait()
		testDone <- true
	}()

	select {
	case <-testDone:
		// Test completed normally
	case <-time.After(scenario.Duration + time.Minute):
		// Test timed out
		result.Success = false
		result.Recommendations = append(result.Recommendations, "Test exceeded expected duration - investigate performance issues")
	}

	monitorCancel()

	// Collect final metrics and generate report
	result.EndTime = time.Now()
	result.Duration = result.EndTime.Sub(result.StartTime)
	ltf.collectFinalMetrics(result)
	ltf.validateResults(result, scenario)
	ltf.generateRecommendations(result)

	return result
}

// CreateStandardLoadTestScenarios creates a set of standard load testing scenarios
func (ltf *LoadTestFramework) CreateStandardLoadTestScenarios() []LoadTestScenario {
	return []LoadTestScenario{
		{
			ID:          "smoke-test",
			Name:        "Smoke Test",
			Description: "Basic functionality test with minimal load",
			Duration:    time.Minute * 2,
			LoadPatterns: []LoadPattern{
				{Type: "constant", StartRate: 1, EndRate: 1, Duration: time.Minute * 2},
			},
			PerformanceTargets: LoadTestPerformanceTargets{
				MaxResponseTime: time.Second * 2,
				MinThroughput:   0.8,
				MaxErrorRate:    0.01,
			},
		},
		{
			ID:          "load-test",
			Name:        "Standard Load Test",
			Description: "Standard load test with realistic user patterns",
			Duration:    time.Minute * 10,
			LoadPatterns: []LoadPattern{
				{Type: "ramp", StartRate: 1, EndRate: 20, Duration: time.Minute * 3},
				{Type: "constant", StartRate: 20, EndRate: 20, Duration: time.Minute * 5},
				{Type: "ramp", StartRate: 20, EndRate: 1, Duration: time.Minute * 2},
			},
			PerformanceTargets: LoadTestPerformanceTargets{
				MaxResponseTime: time.Second * 5,
				MinThroughput:   15,
				MaxErrorRate:    0.05,
			},
		},
		{
			ID:          "stress-test",
			Name:        "Stress Test",
			Description: "High load stress test to find system limits",
			Duration:    time.Minute * 15,
			LoadPatterns: []LoadPattern{
				{Type: "ramp", StartRate: 1, EndRate: 100, Duration: time.Minute * 5},
				{Type: "constant", StartRate: 100, EndRate: 100, Duration: time.Minute * 8},
				{Type: "ramp", StartRate: 100, EndRate: 1, Duration: time.Minute * 2},
			},
			PerformanceTargets: LoadTestPerformanceTargets{
				MaxResponseTime: time.Second * 10,
				MinThroughput:   50,
				MaxErrorRate:    0.10,
			},
			StressConditions: []StressCondition{
				{Type: "memory_pressure", Intensity: 0.8, Duration: time.Minute * 3},
				{Type: "cpu_spike", Intensity: 0.9, Duration: time.Minute * 2},
			},
		},
		{
			ID:          "spike-test",
			Name:        "Spike Test",
			Description: "Sudden traffic spike test",
			Duration:    time.Minute * 8,
			LoadPatterns: []LoadPattern{
				{Type: "constant", StartRate: 10, EndRate: 10, Duration: time.Minute * 2},
				{Type: "burst", StartRate: 10, EndRate: 100, BurstIntensity: 200, BurstDuration: time.Second * 30, Duration: time.Minute * 2},
				{Type: "constant", StartRate: 10, EndRate: 10, Duration: time.Minute * 4},
			},
			PerformanceTargets: LoadTestPerformanceTargets{
				MaxResponseTime: time.Second * 15,
				MinThroughput:   8,
				MaxErrorRate:    0.15,
			},
		},
		{
			ID:          "endurance-test",
			Name:        "Endurance Test",
			Description: "Long-running test to detect memory leaks and degradation",
			Duration:    time.Hour * 2,
			LoadPatterns: []LoadPattern{
				{Type: "constant", StartRate: 15, EndRate: 15, Duration: time.Hour * 2},
			},
			PerformanceTargets: LoadTestPerformanceTargets{
				MaxResponseTime: time.Second * 3,
				MinThroughput:   14,
				MaxErrorRate:    0.02,
			},
			ValidationCriteria: []ValidationCriterion{
				{Metric: "memory_growth_rate", Operator: "<", Threshold: 0.1, Description: "Memory growth should be less than 10% per hour"},
				{Metric: "response_time_degradation", Operator: "<", Threshold: 0.05, Description: "Response time degradation should be less than 5% per hour"},
			},
		},
	}
}

// Helper methods for load generation and monitoring

func (ltf *LoadTestFramework) createLoadGenerator(id string, pattern LoadPattern, scenario LoadTestScenario) *LoadGenerator {
	// Implementation for creating load generators
	return &LoadGenerator{
		id:       id,
		pattern:  pattern,
		metrics:  &LoadGeneratorMetrics{},
		stopChannel: make(chan bool),
	}
}

func (ltf *LoadTestFramework) runLoadGenerator(generator *LoadGenerator, duration time.Duration) {
	// Implementation for running load generators with specified patterns
	generator.active = true
	defer func() { generator.active = false }()

	startTime := time.Now()
	for time.Since(startTime) < duration {
		select {
		case <-generator.stopChannel:
			return
		default:
			// Generate load based on pattern
			ltf.executeLoadPattern(generator)
			time.Sleep(ltf.calculatePatternDelay(generator.pattern, time.Since(startTime)))
		}
	}
}

func (ltf *LoadTestFramework) executeLoadPattern(generator *LoadGenerator) {
	// Implementation for executing specific load patterns
	switch generator.pattern.Type {
	case "constant":
		ltf.executeConstantLoad(generator)
	case "ramp":
		ltf.executeRampLoad(generator)
	case "burst":
		ltf.executeBurstLoad(generator)
	case "sine":
		ltf.executeSineLoad(generator)
	case "random":
		ltf.executeRandomLoad(generator)
	}
}

func (ltf *LoadTestFramework) calculatePatternDelay(pattern LoadPattern, elapsed time.Duration) time.Duration {
	// Calculate delay based on load pattern and current time
	baseDelay := time.Second / time.Duration(pattern.StartRate)
	
	switch pattern.Type {
	case "ramp":
		// Linear interpolation for ramp pattern
		progress := float64(elapsed) / float64(pattern.Duration)
		if progress > 1.0 {
			progress = 1.0
		}
		currentRate := pattern.StartRate + (pattern.EndRate-pattern.StartRate)*progress
		return time.Second / time.Duration(currentRate)
	case "sine":
		// Sine wave pattern
		progress := float64(elapsed) / float64(pattern.Duration)
		sineValue := math.Sin(2 * math.Pi * progress)
		rate := pattern.StartRate + (pattern.EndRate-pattern.StartRate)*(sineValue+1)/2
		return time.Second / time.Duration(rate)
	default:
		return baseDelay
	}
}

func (ltf *LoadTestFramework) executeConstantLoad(generator *LoadGenerator) {
	// Implementation for constant load generation
}

func (ltf *LoadTestFramework) executeRampLoad(generator *LoadGenerator) {
	// Implementation for ramp load generation
}

func (ltf *LoadTestFramework) executeBurstLoad(generator *LoadGenerator) {
	// Implementation for burst load generation
}

func (ltf *LoadTestFramework) executeSineLoad(generator *LoadGenerator) {
	// Implementation for sine wave load generation
}

func (ltf *LoadTestFramework) executeRandomLoad(generator *LoadGenerator) {
	// Implementation for random load generation
}

func (ltf *LoadTestFramework) monitorLoadTest(ctx context.Context, activeTest *ActiveLoadTest) {
	// Implementation for monitoring active load tests
	ticker := time.NewTicker(time.Second * 5)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			ltf.updateTestMetrics(activeTest)
			ltf.checkAlerts(activeTest)
		}
	}
}

func (ltf *LoadTestFramework) updateTestMetrics(activeTest *ActiveLoadTest) {
	// Implementation for updating test metrics
	activeTest.mutex.Lock()
	defer activeTest.mutex.Unlock()

	// Collect current metrics from all generators
	var totalRequests, successfulRequests, failedRequests int64
	var totalResponseTime int64
	var requestCount int64

	for generatorID, generator := range ltf.loadGenerators {
		if strings.HasPrefix(generatorID, activeTest.Scenario.ID) {
			totalRequests += generator.metrics.TotalRequests
			successfulRequests += generator.metrics.SuccessRequests
			failedRequests += generator.metrics.ErrorRequests
			totalResponseTime += int64(generator.metrics.AvgResponseTime)
			requestCount++
		}
	}

	// Update active test metrics
	if activeTest.CurrentMetrics == nil {
		activeTest.CurrentMetrics = &LoadTestMetrics{}
	}

	activeTest.CurrentMetrics.Timestamp = time.Now()
	activeTest.CurrentMetrics.TotalRequests = totalRequests
	activeTest.CurrentMetrics.SuccessfulReqs = successfulRequests
	activeTest.CurrentMetrics.FailedRequests = failedRequests
	if totalRequests > 0 {
		activeTest.CurrentMetrics.ErrorRate = float64(failedRequests) / float64(totalRequests)
	}
	if requestCount > 0 {
		activeTest.CurrentMetrics.AvgResponseTime = time.Duration(totalResponseTime / requestCount)
	}

	// Get system resource usage
	var memStats runtime.MemStats
	runtime.ReadMemStats(&memStats)
	activeTest.CurrentMetrics.MemoryUsage = int64(memStats.Alloc)
	activeTest.CurrentMetrics.GoroutineCount = runtime.NumGoroutine()
}

func (ltf *LoadTestFramework) checkAlerts(activeTest *ActiveLoadTest) {
	// Implementation for checking performance alerts
	if activeTest.CurrentMetrics == nil {
		return
	}

	targets := activeTest.Scenario.PerformanceTargets
	metrics := activeTest.CurrentMetrics

	// Check response time alerts
	if metrics.AvgResponseTime > targets.MaxResponseTime {
		ltf.alertManager.TriggerAlert("high_response_time", activeTest.Scenario.ID, map[string]interface{}{
			"current": metrics.AvgResponseTime,
			"threshold": targets.MaxResponseTime,
		})
	}

	// Check error rate alerts
	if metrics.ErrorRate > targets.MaxErrorRate {
		ltf.alertManager.TriggerAlert("high_error_rate", activeTest.Scenario.ID, map[string]interface{}{
			"current": metrics.ErrorRate,
			"threshold": targets.MaxErrorRate,
		})
	}

	// Check memory usage alerts
	if metrics.MemoryUsage > targets.MaxMemoryUsage {
		ltf.alertManager.TriggerAlert("high_memory_usage", activeTest.Scenario.ID, map[string]interface{}{
			"current": metrics.MemoryUsage,
			"threshold": targets.MaxMemoryUsage,
		})
	}

	// Check goroutine count alerts
	if metrics.GoroutineCount > targets.MaxGoroutines {
		ltf.alertManager.TriggerAlert("high_goroutine_count", activeTest.Scenario.ID, map[string]interface{}{
			"current": metrics.GoroutineCount,
			"threshold": targets.MaxGoroutines,
		})
	}
}

func (ltf *LoadTestFramework) stopLoadGenerator(generatorID string) {
	// Implementation for stopping load generators
	if generator, exists := ltf.loadGenerators[generatorID]; exists {
		close(generator.stopChannel)
		delete(ltf.loadGenerators, generatorID)
	}
}

func (ltf *LoadTestFramework) collectFinalMetrics(result *LoadTestResult) {
	// Implementation for collecting final metrics
	var totalRequests, successfulRequests, failedRequests int64
	for _, generator := range ltf.loadGenerators {
		totalRequests += generator.metrics.TotalRequests
		successfulRequests += generator.metrics.SuccessRequests
		failedRequests += generator.metrics.ErrorRequests
	}

	result.TotalRequests = totalRequests
	result.SuccessfulReqs = successfulRequests
	result.FailedRequests = failedRequests
	if totalRequests > 0 {
		result.OverallErrorRate = float64(failedRequests) / float64(totalRequests)
	}
	result.AvgRPS = float64(totalRequests) / result.Duration.Seconds()
}

func (ltf *LoadTestFramework) validateResults(result *LoadTestResult, scenario LoadTestScenario) {
	// Implementation for validating results against criteria
	for _, criterion := range scenario.ValidationCriteria {
		validationResult := ltf.validateCriterion(result, criterion)
		result.ValidationResults = append(result.ValidationResults, validationResult)
		if !validationResult.Passed && criterion.Critical {
			result.Success = false
		}
	}
}

func (ltf *LoadTestFramework) validateCriterion(result *LoadTestResult, criterion ValidationCriterion) ValidationResult {
	// Implementation for validating individual criteria
	return ValidationResult{
		CheckType:   criterion.Metric,
		Expected:    criterion.Threshold,
		Description: criterion.Description,
		Critical:    criterion.Critical,
		// Additional validation logic would go here
	}
}

func (ltf *LoadTestFramework) generateRecommendations(result *LoadTestResult) {
	// Implementation for generating performance recommendations
	if result.OverallErrorRate > 0.05 {
		result.Recommendations = append(result.Recommendations, "High error rate detected - investigate error handling and system capacity")
	}

	if result.AvgRPS < 10 {
		result.Recommendations = append(result.Recommendations, "Low throughput detected - consider performance optimization")
	}

	// Add more recommendation logic based on various metrics
}

// Cleanup stops all active tests and cleans up resources
func (ltf *LoadTestFramework) Cleanup() {
	for generatorID := range ltf.loadGenerators {
		ltf.stopLoadGenerator(generatorID)
	}

	ltf.performanceMonitor.Stop()
	ltf.metricsCollector.Stop()
	ltf.resourceTracker.Stop()
	ltf.alertManager.Stop()
}

// Supporting types and placeholder implementations

type PerformanceMonitor struct{}
type MetricsCollector struct{}
type ResourceTracker struct{}
type AlertManager struct{}
type ReportGenerator struct{}

func NewPerformanceMonitor(cfg *config.Config) *PerformanceMonitor { return &PerformanceMonitor{} }
func NewMetricsCollector(cfg *config.Config) *MetricsCollector { return &MetricsCollector{} }
func NewResourceTracker(cfg *config.Config) *ResourceTracker { return &ResourceTracker{} }
func NewAlertManager(cfg *config.Config) *AlertManager { return &AlertManager{} }
func NewReportGenerator(cfg *config.Config) *ReportGenerator { return &ReportGenerator{} }

func (p *PerformanceMonitor) StartMonitoring(scenarioID string) {}
func (p *PerformanceMonitor) StopMonitoring(scenarioID string) {}
func (p *PerformanceMonitor) Stop() {}
func (m *MetricsCollector) Stop() {}
func (r *ResourceTracker) Stop() {}
func (a *AlertManager) Stop() {}
func (a *AlertManager) TriggerAlert(alertType, scenarioID string, data map[string]interface{}) {}

type ValidationResult struct {
	CheckType   string      `json:"check_type"`
	Expected    interface{} `json:"expected"`
	Actual      interface{} `json:"actual"`
	Passed      bool        `json:"passed"`
	Description string      `json:"description"`
	Critical    bool        `json:"critical"`
}