//! Performance Monitoring and Metrics Collection Module
//!
//! This module provides comprehensive performance monitoring capabilities for the CUDA
//! optimization execution engine, including real-time metrics collection, performance
//! analysis, bottleneck detection, trend analysis, and automated optimization suggestions
//! to ensure optimal system performance and resource utilization.

use serde::{Deserialize, Serialize};
use std::collections::{HashMap, VecDeque};
use std::sync::{Arc, Mutex, RwLock};
use std::time::{Duration, Instant, SystemTime};

use super::config::ProfilingConfig;
use crate::cuda::memory::optimization::config::{AnalysisConfig, MetricsConfig};
use crate::cuda::memory::optimization::monitoring::{AlertSystemConfig, DashboardConfig};

/// Task execution status for monitoring
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum TaskStatus {
    /// Task is pending execution
    Pending,
    /// Task is currently running
    Running,
    /// Task completed successfully
    Completed,
    /// Task failed
    Failed,
    /// Task was cancelled
    Cancelled,
    /// Task timed out
    TimedOut,
}

/// Comprehensive performance monitoring manager for CUDA execution
///
/// Manages all aspects of performance monitoring including metrics collection,
/// real-time analysis, bottleneck detection, performance profiling, and
/// optimization recommendations to maintain peak system performance.
#[derive(Debug)]
pub struct PerformanceMonitoringManager {
    /// Real-time metrics collector
    metrics_collector: Arc<Mutex<MetricsCollector>>,

    /// Performance analyzer and trend detector
    performance_analyzer: Arc<Mutex<PerformanceAnalyzer>>,

    /// Bottleneck detection system
    bottleneck_detector: Arc<Mutex<BottleneckDetector>>,

    /// Resource utilization monitor
    resource_monitor: Arc<Mutex<ResourceUtilizationMonitor>>,

    /// Performance profiler
    profiler: Arc<Mutex<PerformanceProfiler>>,

    /// Optimization recommender
    optimization_recommender: Arc<Mutex<OptimizationRecommender>>,

    /// Alert system for performance issues
    alert_system: Arc<Mutex<PerformanceAlertSystem>>,

    /// Performance dashboard data provider
    dashboard_provider: Arc<Mutex<DashboardDataProvider>>,

    /// Configuration
    config: PerformanceMonitoringConfig,

    /// System performance state
    system_performance_state: Arc<RwLock<SystemPerformanceState>>,

    /// Performance statistics
    statistics: Arc<Mutex<PerformanceStatistics>>,

    /// Historical performance data
    performance_history: Arc<Mutex<PerformanceHistory>>,
}

/// Real-time metrics collection system
#[derive(Debug)]
pub struct MetricsCollector {
    /// Active metric sources
    metric_sources: HashMap<String, MetricSource>,

    /// Metrics aggregator
    aggregator: MetricsAggregator,

    /// Metrics storage engine
    storage_engine: MetricsStorageEngine,

    /// Metrics validation system
    validator: MetricsValidator,

    /// Real-time metric streams
    metric_streams: HashMap<String, MetricStream>,

    /// Metrics collection configuration
    config: MetricsConfig,

    /// Collection statistics
    collection_stats: MetricsCollectionStatistics,
}

/// Performance analysis and trend detection system
#[derive(Debug)]
pub struct PerformanceAnalyzer {
    /// Time series analyzer for performance trends
    time_series_analyzer: TimeSeriesAnalyzer,

    /// Statistical analyzer for performance patterns
    statistical_analyzer: StatisticalAnalyzer,

    /// Machine learning models for performance prediction
    ml_models: Option<PerformancePredictionModels>,

    /// Performance benchmark comparator
    benchmark_comparator: BenchmarkComparator,

    /// Anomaly detection engine
    anomaly_detector: PerformanceAnomalyDetector,

    /// Analysis configuration
    config: AnalysisConfig,

    /// Analysis results cache
    analysis_cache: AnalysisResultsCache,
}

/// Bottleneck detection and diagnosis system
#[derive(Debug)]
pub struct BottleneckDetector {
    /// Active bottleneck scanners
    bottleneck_scanners: HashMap<String, BottleneckScanner>,

    /// Dependency graph analyzer
    dependency_analyzer: DependencyGraphAnalyzer,

    /// Critical path analyzer
    critical_path_analyzer: CriticalPathAnalyzer,

    /// Resource contention detector
    contention_detector: ResourceContentionDetector,

    /// Bottleneck classification system
    classifier: BottleneckClassifier,

    /// Bottleneck history tracker
    bottleneck_history: VecDeque<BottleneckRecord>,

    /// Configuration
    config: BottleneckDetectionConfig,
}

/// Resource utilization monitoring system
#[derive(Debug)]
pub struct ResourceUtilizationMonitor {
    /// GPU utilization monitors
    gpu_monitors: HashMap<String, GpuUtilizationMonitor>,

    /// Memory utilization monitors
    memory_monitors: HashMap<String, MemoryUtilizationMonitor>,

    /// CPU utilization monitors
    cpu_monitors: HashMap<String, CpuUtilizationMonitor>,

    /// Network utilization monitors
    network_monitors: HashMap<String, NetworkUtilizationMonitor>,

    /// Storage utilization monitors
    storage_monitors: HashMap<String, StorageUtilizationMonitor>,

    /// Resource efficiency calculator
    efficiency_calculator: ResourceEfficiencyCalculator,

    /// Utilization trend analyzer
    trend_analyzer: UtilizationTrendAnalyzer,

    /// Configuration
    config: ResourceMonitoringConfig,
}

/// Performance profiling system
#[derive(Debug)]
pub struct PerformanceProfiler {
    /// Active profiling sessions
    active_sessions: HashMap<String, ProfilingSession>,

    /// Code profiler for kernel analysis
    code_profiler: CodeProfiler,

    /// Memory profiler for allocation analysis
    memory_profiler: MemoryProfiler,

    /// GPU profiler for CUDA analysis
    gpu_profiler: GpuProfiler,

    /// Call graph analyzer
    call_graph_analyzer: CallGraphAnalyzer,

    /// Hot path detector
    hot_path_detector: HotPathDetector,

    /// Profiling configuration
    config: ProfilingConfig,

    /// Profiling results storage
    results_storage: ProfilingResultsStorage,
}

/// Optimization recommendation system
#[derive(Debug)]
pub struct OptimizationRecommender {
    /// Recommendation engines by category
    recommendation_engines: HashMap<OptimizationCategory, RecommendationEngine>,

    /// Performance model analyzer
    model_analyzer: PerformanceModelAnalyzer,

    /// Configuration optimizer
    config_optimizer: ConfigurationOptimizer,

    /// Resource allocation optimizer
    resource_optimizer: ResourceAllocationOptimizer,

    /// Algorithm recommendation engine
    algorithm_recommender: AlgorithmRecommender,

    /// Recommendation scoring system
    scoring_system: RecommendationScoringSystem,

    /// Historical recommendation tracker
    recommendation_history: VecDeque<OptimizationRecommendation>,

    /// Configuration
    config: OptimizationRecommenderConfig,
}

/// Performance alert system
#[derive(Debug)]
pub struct PerformanceAlertSystem {
    /// Alert rules engine
    alert_rules: HashMap<String, AlertRule>,

    /// Threshold monitor
    threshold_monitor: ThresholdMonitor,

    /// Alert notification system
    notification_system: AlertNotificationSystem,

    /// Alert escalation manager
    escalation_manager: AlertEscalationManager,

    /// Alert suppression system
    suppression_system: AlertSuppressionSystem,

    /// Configuration
    config: AlertSystemConfig,

    /// Alert history
    alert_history: VecDeque<PerformanceAlert>,
}

/// Dashboard data provider for visualization
#[derive(Debug)]
pub struct DashboardDataProvider {
    /// Real-time data streams
    realtime_streams: HashMap<String, RealtimeDataStream>,

    /// Historical data aggregator
    historical_aggregator: HistoricalDataAggregator,

    /// Chart data generators
    chart_generators: HashMap<ChartType, ChartDataGenerator>,

    /// Dashboard configuration
    dashboard_config: DashboardConfig,

    /// Data cache for fast access
    data_cache: DashboardDataCache,
}

// === Core Types and Structures ===

/// Metric source for data collection
#[derive(Debug, Clone)]
pub struct MetricSource {
    /// Source identifier
    pub source_id: String,

    /// Source type
    pub source_type: MetricSourceType,

    /// Data collection function
    pub collector: Box<dyn Fn() -> MetricValue + Send + Sync>,

    /// Collection interval
    pub collection_interval: Duration,

    /// Last collection timestamp
    pub last_collected: Instant,

    /// Source configuration
    pub config: MetricSourceConfig,

    /// Collection history
    pub history: VecDeque<MetricDataPoint>,
}

/// Performance metric data point
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct MetricDataPoint {
    /// Timestamp of collection
    pub timestamp: SystemTime,

    /// Metric value
    pub value: MetricValue,

    /// Metric metadata
    pub metadata: HashMap<String, String>,

    /// Collection context
    pub context: MetricContext,
}

/// Bottleneck record for tracking performance issues
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BottleneckRecord {
    /// Bottleneck identifier
    pub bottleneck_id: String,

    /// Detection timestamp
    pub detected_at: SystemTime,

    /// Bottleneck type
    pub bottleneck_type: BottleneckType,

    /// Affected components
    pub affected_components: Vec<String>,

    /// Severity level
    pub severity: BottleneckSeverity,

    /// Performance impact
    pub performance_impact: PerformanceImpact,

    /// Suggested optimizations
    pub optimization_suggestions: Vec<OptimizationSuggestion>,

    /// Resolution status
    pub resolution_status: BottleneckResolutionStatus,
}

/// Profiling session for detailed performance analysis
#[derive(Debug, Clone)]
pub struct ProfilingSession {
    /// Session identifier
    pub session_id: String,

    /// Session type
    pub session_type: ProfilingSessionType,

    /// Target components
    pub target_components: Vec<String>,

    /// Profiling configuration
    pub config: SessionProfilingConfig,

    /// Session start time
    pub start_time: Instant,

    /// Session duration
    pub duration: Duration,

    /// Profiling data
    pub profiling_data: ProfilingData,

    /// Session status
    pub status: ProfilingSessionStatus,
}

/// Optimization recommendation
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct OptimizationRecommendation {
    /// Recommendation identifier
    pub recommendation_id: String,

    /// Recommendation category
    pub category: OptimizationCategory,

    /// Priority level
    pub priority: RecommendationPriority,

    /// Expected performance improvement
    pub expected_improvement: f64,

    /// Implementation complexity
    pub implementation_complexity: ComplexityLevel,

    /// Recommended actions
    pub recommended_actions: Vec<OptimizationAction>,

    /// Supporting evidence
    pub supporting_evidence: Vec<PerformanceEvidence>,

    /// Confidence score
    pub confidence_score: f64,

    /// Creation timestamp
    pub created_at: SystemTime,
}

/// Performance alert for issue notification
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceAlert {
    /// Alert identifier
    pub alert_id: String,

    /// Alert type
    pub alert_type: AlertType,

    /// Severity level
    pub severity: AlertSeverity,

    /// Alert message
    pub message: String,

    /// Affected metrics
    pub affected_metrics: Vec<String>,

    /// Current values
    pub current_values: HashMap<String, MetricValue>,

    /// Threshold values
    pub threshold_values: HashMap<String, MetricValue>,

    /// Alert timestamp
    pub timestamp: SystemTime,

    /// Resolution suggestions
    pub resolution_suggestions: Vec<String>,
}

// === Enumerations and Configuration Types ===

/// Types of metric sources
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum MetricSourceType {
    /// GPU utilization metrics
    GpuUtilization,
    /// Memory usage metrics
    MemoryUsage,
    /// CPU performance metrics
    CpuPerformance,
    /// Network I/O metrics
    NetworkIO,
    /// Storage I/O metrics
    StorageIO,
    /// Task execution metrics
    TaskExecution,
    /// Custom metric source
    Custom,
}

/// Types of bottlenecks
#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum BottleneckType {
    /// Memory bandwidth bottleneck
    MemoryBandwidth,
    /// Compute capacity bottleneck
    ComputeCapacity,
    /// GPU memory bottleneck
    GpuMemory,
    /// CPU bottleneck
    CpuBottleneck,
    /// Network bottleneck
    NetworkBottleneck,
    /// Storage I/O bottleneck
    StorageIOBottleneck,
    /// Synchronization bottleneck
    SynchronizationBottleneck,
    /// Algorithm bottleneck
    AlgorithmBottleneck,
}

/// Bottleneck severity levels
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
pub enum BottleneckSeverity {
    Critical = 0,
    High = 1,
    Medium = 2,
    Low = 3,
}

/// Optimization categories
#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum OptimizationCategory {
    /// Memory optimization
    Memory,
    /// Computation optimization
    Computation,
    /// Algorithm optimization
    Algorithm,
    /// Configuration optimization
    Configuration,
    /// Resource allocation optimization
    ResourceAllocation,
    /// Parallelization optimization
    Parallelization,
}

/// Recommendation priorities
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
pub enum RecommendationPriority {
    Critical = 0,
    High = 1,
    Medium = 2,
    Low = 3,
}

/// Implementation complexity levels
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum ComplexityLevel {
    Low,
    Medium,
    High,
    VeryHigh,
}

/// Alert types
#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum AlertType {
    /// Performance threshold exceeded
    ThresholdExceeded,
    /// Performance degradation detected
    PerformanceDegradation,
    /// Resource exhaustion warning
    ResourceExhaustion,
    /// Bottleneck detected
    BottleneckDetected,
    /// Anomaly detected
    AnomalyDetected,
    /// System overload warning
    SystemOverload,
}

/// Alert severity levels
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
pub enum AlertSeverity {
    Critical = 0,
    Warning = 1,
    Info = 2,
}

/// Chart types for dashboard visualization
#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum ChartType {
    LineChart,
    BarChart,
    HeatMap,
    ScatterPlot,
    Histogram,
    GaugeChart,
}

/// Profiling session types
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum ProfilingSessionType {
    CpuProfiling,
    GpuProfiling,
    MemoryProfiling,
    IOProfiling,
    FullSystemProfiling,
}

/// Profiling session status
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum ProfilingSessionStatus {
    Started,
    Running,
    Paused,
    Completed,
    Failed,
    Cancelled,
}

/// Bottleneck resolution status
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum BottleneckResolutionStatus {
    Detected,
    Analyzing,
    Resolved,
    Mitigated,
    Ignored,
}

// === Configuration Structures ===

/// Performance monitoring configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceMonitoringConfig {
    /// Enable real-time monitoring
    pub enable_realtime_monitoring: bool,

    /// Metrics collection configuration
    pub metrics_config: MetricsConfig,

    /// Profiling configuration
    pub profiling_config: ProfilingConfig,

    /// Alert system configuration
    pub alert_config: AlertSystemConfig,

    /// Dashboard configuration
    pub dashboard_config: DashboardConfig,

    /// Analysis configuration
    pub analysis_config: AnalysisConfig,

    /// Data retention settings
    pub data_retention: DataRetentionConfig,
}

/// Resource monitoring configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ResourceMonitoringConfig {
    /// GPU monitoring settings
    pub gpu_monitoring: GpuMonitoringSettings,

    /// Memory monitoring settings
    pub memory_monitoring: MemoryMonitoringSettings,

    /// CPU monitoring settings
    pub cpu_monitoring: CpuMonitoringSettings,

    /// Network monitoring settings
    pub network_monitoring: NetworkMonitoringSettings,

    /// Storage monitoring settings
    pub storage_monitoring: StorageMonitoringSettings,

    /// Monitoring intervals
    pub monitoring_intervals: HashMap<String, Duration>,
}

/// Bottleneck detection configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BottleneckDetectionConfig {
    /// Detection sensitivity
    pub detection_sensitivity: DetectionSensitivity,

    /// Analysis window size
    pub analysis_window: Duration,

    /// Minimum severity for reporting
    pub min_severity_threshold: BottleneckSeverity,

    /// Enable predictive detection
    pub enable_predictive_detection: bool,

    /// Detection algorithms configuration
    pub detection_algorithms: HashMap<String, AlgorithmConfig>,
}

/// Optimization recommender configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct OptimizationRecommenderConfig {
    /// Recommendation confidence threshold
    pub confidence_threshold: f64,

    /// Maximum recommendations per category
    pub max_recommendations_per_category: usize,

    /// Enable machine learning recommendations
    pub enable_ml_recommendations: bool,

    /// Recommendation update frequency
    pub update_frequency: Duration,

    /// Historical data window for analysis
    pub analysis_window: Duration,
}

// === Implementation ===

impl PerformanceMonitoringManager {
    /// Create a new performance monitoring manager
    pub fn new(config: PerformanceMonitoringConfig) -> Self {
        Self {
            metrics_collector: Arc::new(Mutex::new(MetricsCollector::new(&config.metrics_config))),
            performance_analyzer: Arc::new(Mutex::new(PerformanceAnalyzer::new(
                &config.analysis_config,
            ))),
            bottleneck_detector: Arc::new(Mutex::new(BottleneckDetector::new(&config))),
            resource_monitor: Arc::new(Mutex::new(ResourceUtilizationMonitor::new(&config))),
            profiler: Arc::new(Mutex::new(PerformanceProfiler::new(
                &config.profiling_config,
            ))),
            optimization_recommender: Arc::new(Mutex::new(OptimizationRecommender::new(&config))),
            alert_system: Arc::new(Mutex::new(PerformanceAlertSystem::new(
                &config.alert_config,
            ))),
            dashboard_provider: Arc::new(Mutex::new(DashboardDataProvider::new(
                &config.dashboard_config,
            ))),
            config,
            system_performance_state: Arc::new(RwLock::new(SystemPerformanceState::new())),
            statistics: Arc::new(Mutex::new(PerformanceStatistics::new())),
            performance_history: Arc::new(Mutex::new(PerformanceHistory::new())),
        }
    }

    /// Start performance monitoring
    pub fn start_monitoring(&self) -> Result<(), PerformanceMonitoringError> {
        // Start metrics collection
        {
            let mut collector = self.metrics_collector.lock().expect("lock should not be poisoned");
            collector.start_collection()?;
        }

        // Start bottleneck detection
        {
            let mut detector = self.bottleneck_detector.lock().expect("lock should not be poisoned");
            detector.start_detection()?;
        }

        // Start resource monitoring
        {
            let mut monitor = self.resource_monitor.lock().expect("lock should not be poisoned");
            monitor.start_monitoring()?;
        }

        // Update statistics
        {
            let mut stats = self.statistics.lock().expect("lock should not be poisoned");
            stats.monitoring_started_at = Some(SystemTime::now());
            stats.monitoring_sessions += 1;
        }

        Ok(())
    }

    /// Collect current performance metrics
    pub fn collect_metrics(&self) -> Result<Vec<MetricDataPoint>, PerformanceMonitoringError> {
        let collector = self.metrics_collector.lock().expect("lock should not be poisoned");
        collector.collect_current_metrics()
    }

    /// Detect performance bottlenecks
    pub fn detect_bottlenecks(&self) -> Result<Vec<BottleneckRecord>, PerformanceMonitoringError> {
        let mut detector = self.bottleneck_detector.lock().expect("lock should not be poisoned");
        detector.analyze_and_detect()
    }

    /// Get optimization recommendations
    pub fn get_optimization_recommendations(
        &self,
    ) -> Result<Vec<OptimizationRecommendation>, PerformanceMonitoringError> {
        let mut recommender = self.optimization_recommender.lock().expect("lock should not be poisoned");
        recommender.generate_recommendations()
    }

    /// Start a profiling session
    pub fn start_profiling_session(
        &self,
        session_type: ProfilingSessionType,
        components: Vec<String>,
    ) -> Result<String, PerformanceMonitoringError> {
        let mut profiler = self.profiler.lock().expect("lock should not be poisoned");
        let session_id = profiler.start_session(session_type, components)?;

        // Update statistics
        {
            let mut stats = self.statistics.lock().expect("lock should not be poisoned");
            stats.profiling_sessions_started += 1;
        }

        Ok(session_id)
    }

    /// Get system performance status
    pub fn get_performance_status(&self) -> SystemPerformanceStatus {
        let state = self.system_performance_state.read().expect("lock should not be poisoned");
        state.get_current_status()
    }

    /// Get performance statistics
    pub fn get_performance_statistics(&self) -> PerformanceStatistics {
        let stats = self.statistics.lock().expect("lock should not be poisoned");
        stats.clone()
    }

    /// Get dashboard data for visualization
    pub fn get_dashboard_data(
        &self,
        chart_type: ChartType,
        time_range: Duration,
    ) -> Result<DashboardData, PerformanceMonitoringError> {
        let provider = self.dashboard_provider.lock().expect("lock should not be poisoned");
        provider.generate_dashboard_data(chart_type, time_range)
    }
}

impl MetricsCollector {
    fn new(config: &MetricsConfig) -> Self {
        Self {
            metric_sources: HashMap::new(),
            aggregator: MetricsAggregator::new(),
            storage_engine: MetricsStorageEngine::new(config),
            validator: MetricsValidator::new(),
            metric_streams: HashMap::new(),
            config: config.clone(),
            collection_stats: MetricsCollectionStatistics::new(),
        }
    }

    fn start_collection(&mut self) -> Result<(), PerformanceMonitoringError> {
        // Initialize default metric sources
        self.initialize_default_sources()?;

        // Start collection threads
        for (source_id, source) in &self.metric_sources {
            self.start_source_collection(source_id, source)?;
        }

        Ok(())
    }

    fn collect_current_metrics(&self) -> Result<Vec<MetricDataPoint>, PerformanceMonitoringError> {
        let mut metrics = Vec::new();

        for (source_id, source) in &self.metric_sources {
            let value = (source.collector)();
            let data_point = MetricDataPoint {
                timestamp: SystemTime::now(),
                value,
                metadata: HashMap::new(),
                context: MetricContext::new(source_id.clone()),
            };
            metrics.push(data_point);
        }

        Ok(metrics)
    }

    fn initialize_default_sources(&mut self) -> Result<(), PerformanceMonitoringError> {
        // Add GPU utilization source
        self.add_metric_source(
            "gpu_utilization",
            MetricSourceType::GpuUtilization,
            Box::new(|| {
                // Implementation would get actual GPU utilization
                MetricValue::Percentage(75.0)
            }),
        )?;

        // Add memory usage source
        self.add_metric_source(
            "memory_usage",
            MetricSourceType::MemoryUsage,
            Box::new(|| {
                // Implementation would get actual memory usage
                MetricValue::Bytes(1024 * 1024 * 512) // 512MB
            }),
        )?;

        // Add CPU performance source
        self.add_metric_source(
            "cpu_performance",
            MetricSourceType::CpuPerformance,
            Box::new(|| {
                // Implementation would get actual CPU performance
                MetricValue::Percentage(45.0)
            }),
        )?;

        Ok(())
    }

    fn add_metric_source(
        &mut self,
        source_id: &str,
        source_type: MetricSourceType,
        collector: Box<dyn Fn() -> MetricValue + Send + Sync>,
    ) -> Result<(), PerformanceMonitoringError> {
        let source = MetricSource {
            source_id: source_id.to_string(),
            source_type,
            collector,
            collection_interval: Duration::from_secs(1),
            last_collected: Instant::now(),
            config: MetricSourceConfig::default(),
            history: VecDeque::new(),
        };

        self.metric_sources.insert(source_id.to_string(), source);
        Ok(())
    }

    fn start_source_collection(
        &self,
        source_id: &str,
        source: &MetricSource,
    ) -> Result<(), PerformanceMonitoringError> {
        // Implementation would start background collection thread
        Ok(())
    }
}

impl BottleneckDetector {
    fn new(config: &PerformanceMonitoringConfig) -> Self {
        Self {
            bottleneck_scanners: HashMap::new(),
            dependency_analyzer: DependencyGraphAnalyzer::new(),
            critical_path_analyzer: CriticalPathAnalyzer::new(),
            contention_detector: ResourceContentionDetector::new(),
            classifier: BottleneckClassifier::new(),
            bottleneck_history: VecDeque::new(),
            config: BottleneckDetectionConfig::default(),
        }
    }

    fn start_detection(&mut self) -> Result<(), PerformanceMonitoringError> {
        // Initialize bottleneck scanners
        self.initialize_scanners()?;
        Ok(())
    }

    fn analyze_and_detect(&mut self) -> Result<Vec<BottleneckRecord>, PerformanceMonitoringError> {
        let mut bottlenecks = Vec::new();

        // Analyze different bottleneck types
        for (scanner_id, scanner) in &self.bottleneck_scanners {
            if let Some(bottleneck) = scanner.scan_for_bottlenecks()? {
                bottlenecks.push(bottleneck);
            }
        }

        // Update history
        for bottleneck in &bottlenecks {
            self.bottleneck_history.push_back(bottleneck.clone());
        }

        // Limit history size
        if self.bottleneck_history.len() > 1000 {
            self.bottleneck_history.pop_front();
        }

        Ok(bottlenecks)
    }

    fn initialize_scanners(&mut self) -> Result<(), PerformanceMonitoringError> {
        // Add memory bandwidth scanner
        self.bottleneck_scanners.insert(
            "memory_bandwidth".to_string(),
            BottleneckScanner::new(BottleneckType::MemoryBandwidth),
        );

        // Add compute capacity scanner
        self.bottleneck_scanners.insert(
            "compute_capacity".to_string(),
            BottleneckScanner::new(BottleneckType::ComputeCapacity),
        );

        Ok(())
    }
}

// === Error Handling ===

/// Performance monitoring errors
#[derive(Debug, Clone)]
pub enum PerformanceMonitoringError {
    /// Metrics collection error
    MetricsCollectionError(String),
    /// Analysis error
    AnalysisError(String),
    /// Bottleneck detection error
    BottleneckDetectionError(String),
    /// Profiling error
    ProfilingError(String),
    /// Configuration error
    ConfigurationError(String),
    /// Data storage error
    DataStorageError(String),
    /// System resource error
    SystemResourceError(String),
}

// === Placeholder Types and Default Implementations ===

macro_rules! default_placeholder_type {
    ($name:ident) => {
        #[derive(Debug, Clone, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
        pub struct $name {
            pub placeholder: bool,
        }
    };
}

// Metric-related types
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum MetricValue {
    Integer(i64),
    Float(f64),
    Percentage(f64),
    Bytes(u64),
    Duration(Duration),
    Boolean(bool),
    String(String),
}

default_placeholder_type!(MetricSourceConfig);
default_placeholder_type!(MetricContext);
default_placeholder_type!(MetricsAggregator);
default_placeholder_type!(MetricsStorageEngine);
default_placeholder_type!(MetricsValidator);
default_placeholder_type!(MetricStream);
default_placeholder_type!(MetricsCollectionStatistics);
default_placeholder_type!(TimeSeriesAnalyzer);
default_placeholder_type!(StatisticalAnalyzer);
default_placeholder_type!(PerformancePredictionModels);
default_placeholder_type!(BenchmarkComparator);
default_placeholder_type!(PerformanceAnomalyDetector);
default_placeholder_type!(AnalysisResultsCache);
default_placeholder_type!(BottleneckScanner);
default_placeholder_type!(DependencyGraphAnalyzer);
default_placeholder_type!(CriticalPathAnalyzer);
default_placeholder_type!(ResourceContentionDetector);
default_placeholder_type!(BottleneckClassifier);
default_placeholder_type!(GpuUtilizationMonitor);
default_placeholder_type!(MemoryUtilizationMonitor);
default_placeholder_type!(CpuUtilizationMonitor);
default_placeholder_type!(NetworkUtilizationMonitor);
default_placeholder_type!(StorageUtilizationMonitor);
default_placeholder_type!(ResourceEfficiencyCalculator);
default_placeholder_type!(UtilizationTrendAnalyzer);
default_placeholder_type!(CodeProfiler);
default_placeholder_type!(MemoryProfiler);
default_placeholder_type!(GpuProfiler);
default_placeholder_type!(CallGraphAnalyzer);
default_placeholder_type!(HotPathDetector);
default_placeholder_type!(ProfilingResultsStorage);
default_placeholder_type!(RecommendationEngine);
default_placeholder_type!(PerformanceModelAnalyzer);
default_placeholder_type!(ConfigurationOptimizer);
default_placeholder_type!(ResourceAllocationOptimizer);
default_placeholder_type!(AlgorithmRecommender);
default_placeholder_type!(RecommendationScoringSystem);
default_placeholder_type!(AlertRule);
default_placeholder_type!(ThresholdMonitor);
default_placeholder_type!(AlertNotificationSystem);
default_placeholder_type!(AlertEscalationManager);
default_placeholder_type!(AlertSuppressionSystem);
default_placeholder_type!(RealtimeDataStream);
default_placeholder_type!(HistoricalDataAggregator);
default_placeholder_type!(ChartDataGenerator);
default_placeholder_type!(DashboardDataCache);
default_placeholder_type!(PerformanceImpact);
default_placeholder_type!(OptimizationSuggestion);
default_placeholder_type!(SessionProfilingConfig);
default_placeholder_type!(ProfilingData);
default_placeholder_type!(OptimizationAction);
default_placeholder_type!(PerformanceEvidence);
default_placeholder_type!(GpuMonitoringSettings);
default_placeholder_type!(MemoryMonitoringSettings);
default_placeholder_type!(CpuMonitoringSettings);
default_placeholder_type!(NetworkMonitoringSettings);
default_placeholder_type!(StorageMonitoringSettings);
default_placeholder_type!(DetectionSensitivity);
default_placeholder_type!(AlgorithmConfig);
default_placeholder_type!(DataRetentionConfig);
default_placeholder_type!(SystemPerformanceState);
default_placeholder_type!(SystemPerformanceStatus);
default_placeholder_type!(DashboardData);

// Performance statistics with actual fields
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceStatistics {
    pub monitoring_started_at: Option<SystemTime>,
    pub monitoring_sessions: u64,
    pub metrics_collected: u64,
    pub bottlenecks_detected: u64,
    pub profiling_sessions_started: u64,
    pub recommendations_generated: u64,
    pub alerts_triggered: u64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceHistory {
    pub entries: VecDeque<PerformanceHistoryEntry>,
    pub max_entries: usize,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceHistoryEntry {
    pub timestamp: SystemTime,
    pub metrics: HashMap<String, MetricValue>,
    pub performance_score: f64,
}

// Implement constructors and methods
impl MetricContext {
    fn new(source_id: String) -> Self {
        Self::default()
    }
}

impl MetricsAggregator {
    fn new() -> Self {
        Self::default()
    }
}

impl MetricsStorageEngine {
    fn new(config: &MetricsConfig) -> Self {
        Self::default()
    }
}

impl MetricsValidator {
    fn new() -> Self {
        Self::default()
    }
}

impl MetricsCollectionStatistics {
    fn new() -> Self {
        Self::default()
    }
}

impl PerformanceAnalyzer {
    fn new(config: &AnalysisConfig) -> Self {
        Self {
            time_series_analyzer: TimeSeriesAnalyzer::new(),
            statistical_analyzer: StatisticalAnalyzer::new(),
            ml_models: None,
            benchmark_comparator: BenchmarkComparator::new(),
            anomaly_detector: PerformanceAnomalyDetector::new(),
            config: config.clone(),
            analysis_cache: AnalysisResultsCache::new(),
        }
    }
}

impl ResourceUtilizationMonitor {
    fn new(config: &PerformanceMonitoringConfig) -> Self {
        Self {
            gpu_monitors: HashMap::new(),
            memory_monitors: HashMap::new(),
            cpu_monitors: HashMap::new(),
            network_monitors: HashMap::new(),
            storage_monitors: HashMap::new(),
            efficiency_calculator: ResourceEfficiencyCalculator::new(),
            trend_analyzer: UtilizationTrendAnalyzer::new(),
            config: ResourceMonitoringConfig::default(),
        }
    }

    fn start_monitoring(&mut self) -> Result<(), PerformanceMonitoringError> {
        Ok(())
    }
}

impl PerformanceProfiler {
    fn new(config: &ProfilingConfig) -> Self {
        Self {
            active_sessions: HashMap::new(),
            code_profiler: CodeProfiler::new(),
            memory_profiler: MemoryProfiler::new(),
            gpu_profiler: GpuProfiler::new(),
            call_graph_analyzer: CallGraphAnalyzer::new(),
            hot_path_detector: HotPathDetector::new(),
            config: config.clone(),
            results_storage: ProfilingResultsStorage::new(),
        }
    }

    fn start_session(
        &mut self,
        session_type: ProfilingSessionType,
        components: Vec<String>,
    ) -> Result<String, PerformanceMonitoringError> {
        let session_id = uuid::Uuid::new_v4().to_string();

        let session = ProfilingSession {
            session_id: session_id.clone(),
            session_type,
            target_components: components,
            config: SessionProfilingConfig::default(),
            start_time: Instant::now(),
            duration: Duration::from_secs(60), // Default 1 minute
            profiling_data: ProfilingData::default(),
            status: ProfilingSessionStatus::Started,
        };

        self.active_sessions.insert(session_id.clone(), session);
        Ok(session_id)
    }
}

impl OptimizationRecommender {
    fn new(config: &PerformanceMonitoringConfig) -> Self {
        Self {
            recommendation_engines: HashMap::new(),
            model_analyzer: PerformanceModelAnalyzer::new(),
            config_optimizer: ConfigurationOptimizer::new(),
            resource_optimizer: ResourceAllocationOptimizer::new(),
            algorithm_recommender: AlgorithmRecommender::new(),
            scoring_system: RecommendationScoringSystem::new(),
            recommendation_history: VecDeque::new(),
            config: OptimizationRecommenderConfig::default(),
        }
    }

    fn generate_recommendations(
        &mut self,
    ) -> Result<Vec<OptimizationRecommendation>, PerformanceMonitoringError> {
        let mut recommendations = Vec::new();

        // Generate memory optimization recommendations
        if let Some(memory_rec) = self.generate_memory_recommendation()? {
            recommendations.push(memory_rec);
        }

        // Generate compute optimization recommendations
        if let Some(compute_rec) = self.generate_compute_recommendation()? {
            recommendations.push(compute_rec);
        }

        Ok(recommendations)
    }

    fn generate_memory_recommendation(
        &self,
    ) -> Result<Option<OptimizationRecommendation>, PerformanceMonitoringError> {
        // Implementation would analyze memory usage patterns and generate recommendations
        Ok(Some(OptimizationRecommendation {
            recommendation_id: uuid::Uuid::new_v4().to_string(),
            category: OptimizationCategory::Memory,
            priority: RecommendationPriority::High,
            expected_improvement: 15.0,
            implementation_complexity: ComplexityLevel::Medium,
            recommended_actions: vec![OptimizationAction::default()],
            supporting_evidence: vec![PerformanceEvidence::default()],
            confidence_score: 0.85,
            created_at: SystemTime::now(),
        }))
    }

    fn generate_compute_recommendation(
        &self,
    ) -> Result<Option<OptimizationRecommendation>, PerformanceMonitoringError> {
        // Implementation would analyze compute patterns and generate recommendations
        Ok(Some(OptimizationRecommendation {
            recommendation_id: uuid::Uuid::new_v4().to_string(),
            category: OptimizationCategory::Computation,
            priority: RecommendationPriority::Medium,
            expected_improvement: 20.0,
            implementation_complexity: ComplexityLevel::High,
            recommended_actions: vec![OptimizationAction::default()],
            supporting_evidence: vec![PerformanceEvidence::default()],
            confidence_score: 0.75,
            created_at: SystemTime::now(),
        }))
    }
}

impl PerformanceAlertSystem {
    fn new(config: &AlertSystemConfig) -> Self {
        Self {
            alert_rules: HashMap::new(),
            threshold_monitor: ThresholdMonitor::new(),
            notification_system: AlertNotificationSystem::new(),
            escalation_manager: AlertEscalationManager::new(),
            suppression_system: AlertSuppressionSystem::new(),
            config: config.clone(),
            alert_history: VecDeque::new(),
        }
    }
}

impl DashboardDataProvider {
    fn new(config: &DashboardConfig) -> Self {
        Self {
            realtime_streams: HashMap::new(),
            historical_aggregator: HistoricalDataAggregator::new(),
            chart_generators: HashMap::new(),
            dashboard_config: config.clone(),
            data_cache: DashboardDataCache::new(),
        }
    }

    fn generate_dashboard_data(
        &self,
        chart_type: ChartType,
        time_range: Duration,
    ) -> Result<DashboardData, PerformanceMonitoringError> {
        // Implementation would generate dashboard data based on chart type and time range
        Ok(DashboardData::default())
    }
}

impl BottleneckScanner {
    fn new(bottleneck_type: BottleneckType) -> Self {
        Self::default()
    }

    fn scan_for_bottlenecks(&self) -> Result<Option<BottleneckRecord>, PerformanceMonitoringError> {
        // Implementation would scan for specific bottleneck types
        Ok(None)
    }
}

impl SystemPerformanceState {
    fn new() -> Self {
        Self::default()
    }

    fn get_current_status(&self) -> SystemPerformanceStatus {
        SystemPerformanceStatus::default()
    }
}

impl PerformanceStatistics {
    fn new() -> Self {
        Self {
            monitoring_started_at: None,
            monitoring_sessions: 0,
            metrics_collected: 0,
            bottlenecks_detected: 0,
            profiling_sessions_started: 0,
            recommendations_generated: 0,
            alerts_triggered: 0,
        }
    }
}

impl PerformanceHistory {
    fn new() -> Self {
        Self {
            entries: VecDeque::new(),
            max_entries: 10000,
        }
    }
}

// Default implementations for configurations
impl Default for BottleneckDetectionConfig {
    fn default() -> Self {
        Self {
            detection_sensitivity: DetectionSensitivity::default(),
            analysis_window: Duration::from_secs(5 * 60),
            min_severity_threshold: BottleneckSeverity::Low,
            enable_predictive_detection: true,
            detection_algorithms: HashMap::new(),
        }
    }
}

impl Default for OptimizationRecommenderConfig {
    fn default() -> Self {
        Self {
            confidence_threshold: 0.7,
            max_recommendations_per_category: 5,
            enable_ml_recommendations: false,
            update_frequency: Duration::from_secs(10 * 60),
            analysis_window: Duration::from_secs(1 * 60 * 60),
        }
    }
}

impl Default for ResourceMonitoringConfig {
    fn default() -> Self {
        Self {
            gpu_monitoring: GpuMonitoringSettings::default(),
            memory_monitoring: MemoryMonitoringSettings::default(),
            cpu_monitoring: CpuMonitoringSettings::default(),
            network_monitoring: NetworkMonitoringSettings::default(),
            storage_monitoring: StorageMonitoringSettings::default(),
            monitoring_intervals: HashMap::new(),
        }
    }
}

// Implement constructors for all placeholder types
impl TimeSeriesAnalyzer {
    fn new() -> Self {
        Self::default()
    }
}

impl StatisticalAnalyzer {
    fn new() -> Self {
        Self::default()
    }
}

impl BenchmarkComparator {
    fn new() -> Self {
        Self::default()
    }
}

impl PerformanceAnomalyDetector {
    fn new() -> Self {
        Self::default()
    }
}

impl AnalysisResultsCache {
    fn new() -> Self {
        Self::default()
    }
}

impl DependencyGraphAnalyzer {
    fn new() -> Self {
        Self::default()
    }
}

impl CriticalPathAnalyzer {
    fn new() -> Self {
        Self::default()
    }
}

impl ResourceContentionDetector {
    fn new() -> Self {
        Self::default()
    }
}

impl BottleneckClassifier {
    fn new() -> Self {
        Self::default()
    }
}

impl ResourceEfficiencyCalculator {
    fn new() -> Self {
        Self::default()
    }
}

impl UtilizationTrendAnalyzer {
    fn new() -> Self {
        Self::default()
    }
}

impl CodeProfiler {
    fn new() -> Self {
        Self::default()
    }
}

impl MemoryProfiler {
    fn new() -> Self {
        Self::default()
    }
}

impl GpuProfiler {
    fn new() -> Self {
        Self::default()
    }
}

impl CallGraphAnalyzer {
    fn new() -> Self {
        Self::default()
    }
}

impl HotPathDetector {
    fn new() -> Self {
        Self::default()
    }
}

impl ProfilingResultsStorage {
    fn new() -> Self {
        Self::default()
    }
}

impl PerformanceModelAnalyzer {
    fn new() -> Self {
        Self::default()
    }
}

impl ConfigurationOptimizer {
    fn new() -> Self {
        Self::default()
    }
}

impl ResourceAllocationOptimizer {
    fn new() -> Self {
        Self::default()
    }
}

impl AlgorithmRecommender {
    fn new() -> Self {
        Self::default()
    }
}

impl RecommendationScoringSystem {
    fn new() -> Self {
        Self::default()
    }
}

impl ThresholdMonitor {
    fn new() -> Self {
        Self::default()
    }
}

impl AlertNotificationSystem {
    fn new() -> Self {
        Self::default()
    }
}

impl AlertEscalationManager {
    fn new() -> Self {
        Self::default()
    }
}

impl AlertSuppressionSystem {
    fn new() -> Self {
        Self::default()
    }
}

impl HistoricalDataAggregator {
    fn new() -> Self {
        Self::default()
    }
}

impl DashboardDataCache {
    fn new() -> Self {
        Self::default()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_performance_monitoring_manager_creation() {
        let config = PerformanceMonitoringConfig::default();
        let manager = PerformanceMonitoringManager::new(config);
        let stats = manager.get_performance_statistics();
        assert_eq!(stats.monitoring_sessions, 0);
    }

    #[test]
    fn test_metrics_collection() {
        let config = MetricsConfig::default();
        let mut collector = MetricsCollector::new(&config);

        collector
            .add_metric_source(
                "test",
                MetricSourceType::Custom,
                Box::new(|| MetricValue::Integer(42)),
            )
            .unwrap();

        let metrics = collector.collect_current_metrics().unwrap();
        assert!(!metrics.is_empty());
    }

    #[test]
    fn test_bottleneck_detection() {
        let config = PerformanceMonitoringConfig::default();
        let mut detector = BottleneckDetector::new(&config);

        let bottlenecks = detector.analyze_and_detect().unwrap();
        assert!(bottlenecks.is_empty()); // No bottlenecks initially
    }

    #[test]
    fn test_optimization_recommendations() {
        let config = PerformanceMonitoringConfig::default();
        let mut recommender = OptimizationRecommender::new(&config);

        let recommendations = recommender.generate_recommendations().unwrap();
        assert!(!recommendations.is_empty());
    }

    #[test]
    fn test_profiling_session() {
        let config = ProfilingConfig::default();
        let mut profiler = PerformanceProfiler::new(&config);

        let session_id = profiler
            .start_session(
                ProfilingSessionType::CpuProfiling,
                vec!["test_component".to_string()],
            )
            .unwrap();

        assert!(!session_id.is_empty());
        assert!(profiler.active_sessions.contains_key(&session_id));
    }
}
