//! Configuration Management for CUDA Optimization Execution Engine
//!
//! This module provides comprehensive configuration management for the execution engine,
//! including execution strategies, resource allocation policies, monitoring levels,
//! security configurations, fault tolerance settings, and performance tuning parameters.

use serde::{Deserialize, Serialize};
use std::time::Duration;

/// Comprehensive configuration for the execution engine
///
/// This configuration controls all aspects of execution engine behavior including
/// resource management, security, fault tolerance, monitoring, and performance optimization.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ExecutionConfig {
    /// General execution settings
    pub general: GeneralExecutionConfig,

    /// Resource allocation configuration
    pub resource_allocation: ResourceAllocationConfig,

    /// Task scheduling configuration
    pub scheduling: SchedulingConfig,

    /// Performance monitoring configuration
    pub monitoring: MonitoringConfig,

    /// Security enforcement configuration
    pub security: SecurityConfig,

    /// Fault tolerance configuration
    pub fault_tolerance: FaultToleranceConfig,

    /// Load balancing configuration
    pub load_balancing: LoadBalancingConfig,

    /// Hardware management configuration
    pub hardware: HardwareConfig,

    /// Cleanup and maintenance configuration
    pub cleanup: CleanupConfig,

    /// Advanced optimization settings
    pub advanced: AdvancedExecutionConfig,
}

/// General execution settings
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GeneralExecutionConfig {
    /// Maximum concurrent executions
    pub max_concurrent_executions: usize,

    /// Default task timeout
    pub default_timeout: Duration,

    /// Enable distributed execution
    pub enable_distributed: bool,

    /// Enable asynchronous execution
    pub enable_async_execution: bool,

    /// Engine operation mode
    pub operation_mode: OperationMode,

    /// Execution priority handling
    pub priority_handling: PriorityHandling,

    /// Task queue management
    pub queue_management: QueueManagement,
}

/// Resource allocation configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ResourceAllocationConfig {
    /// Resource allocation strategy
    pub allocation_strategy: ResourceAllocationStrategy,

    /// Memory allocation settings
    pub memory_allocation: MemoryAllocationConfig,

    /// CPU allocation settings
    pub cpu_allocation: CpuAllocationConfig,

    /// GPU allocation settings
    pub gpu_allocation: GpuAllocationConfig,

    /// Resource reservation policy
    pub reservation_policy: ReservationPolicy,

    /// Resource sharing configuration
    pub sharing_config: ResourceSharingConfig,
}

/// Task scheduling configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SchedulingConfig {
    /// Scheduling algorithm
    pub algorithm: SchedulingAlgorithm,

    /// Priority queue configuration
    pub priority_queue: PriorityQueueConfig,

    /// Time slice allocation
    pub time_slicing: TimeSlicingConfig,

    /// Deadline management
    pub deadline_management: DeadlineManagementConfig,

    /// Preemption policy
    pub preemption_policy: PreemptionPolicy,

    /// Load balancing for scheduling
    pub load_balancing: SchedulingLoadBalancingConfig,
}

/// Performance monitoring configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct MonitoringConfig {
    /// Monitoring level
    pub level: MonitoringLevel,

    /// Metrics collection settings
    pub metrics_collection: MetricsCollectionConfig,

    /// Performance tracking settings
    pub performance_tracking: PerformanceTrackingConfig,

    /// Real-time monitoring
    pub realtime_monitoring: RealtimeMonitoringConfig,

    /// Historical data retention
    pub history_retention: HistoryRetentionConfig,

    /// Alert and notification settings
    pub alerting: AlertingConfig,
}

/// Security enforcement configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SecurityConfig {
    /// Security level
    pub level: SecurityLevel,

    /// Authentication settings
    pub authentication: AuthenticationConfig,

    /// Authorization settings
    pub authorization: AuthorizationConfig,

    /// Encryption settings
    pub encryption: EncryptionConfig,

    /// Audit logging settings
    pub audit_logging: AuditLoggingConfig,

    /// Access control settings
    pub access_control: AccessControlConfig,
}

/// Fault tolerance configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct FaultToleranceConfig {
    /// Enable fault tolerance
    pub enabled: bool,

    /// Retry configuration
    pub retry: RetryConfig,

    /// Checkpointing configuration
    pub checkpointing: CheckpointConfig,

    /// Recovery strategies
    pub recovery: RecoveryConfig,

    /// Health checking
    pub health_checking: HealthCheckingConfig,

    /// Circuit breaker configuration
    pub circuit_breaker: CircuitBreakerConfig,
}

/// Load balancing configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct LoadBalancingConfig {
    /// Load balancing strategy
    pub strategy: LoadBalancingStrategy,

    /// Worker pool configuration
    pub worker_pool: WorkerPoolConfig,

    /// Distribution policies
    pub distribution: DistributionConfig,

    /// Health monitoring for load balancing
    pub health_monitoring: LoadBalancingHealthConfig,

    /// Dynamic scaling configuration
    pub dynamic_scaling: DynamicScalingConfig,
}

/// Hardware management configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct HardwareConfig {
    /// Hardware detection settings
    pub detection: HardwareDetectionConfig,

    /// GPU-specific configuration
    pub gpu_config: GpuHardwareConfig,

    /// CPU-specific configuration
    pub cpu_config: CpuHardwareConfig,

    /// Memory hierarchy configuration
    pub memory_config: MemoryHierarchyConfig,

    /// Hardware optimization settings
    pub optimization: HardwareOptimizationConfig,

    /// Thermal management
    pub thermal_management: ThermalManagementConfig,
}

/// Cleanup and maintenance configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CleanupConfig {
    /// Resource cleanup policy
    pub resource_cleanup: ResourceCleanupPolicy,

    /// Automatic cleanup settings
    pub automatic_cleanup: AutomaticCleanupConfig,

    /// Memory cleanup configuration
    pub memory_cleanup: MemoryCleanupConfig,

    /// Log cleanup settings
    pub log_cleanup: LogCleanupConfig,

    /// Garbage collection settings
    pub garbage_collection: GarbageCollectionConfig,
}

/// Advanced execution settings
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AdvancedExecutionConfig {
    /// Enable experimental features
    pub enable_experimental: bool,

    /// Machine learning optimizations
    pub ml_optimizations: MlOptimizationConfig,

    /// Adaptive behavior settings
    pub adaptive_behavior: AdaptiveBehaviorConfig,

    /// Profiling and debugging
    pub profiling: ProfilingConfig,

    /// Custom plugin support
    pub plugin_support: PluginSupportConfig,

    /// Advanced scheduling features
    pub advanced_scheduling: AdvancedSchedulingConfig,
}

// === Enumerations for Configuration Options ===

/// Engine operation modes
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum OperationMode {
    /// High-performance mode with maximum resource usage
    HighPerformance,
    /// Balanced mode balancing performance and resource usage
    Balanced,
    /// Power-efficient mode minimizing resource consumption
    PowerEfficient,
    /// Debug mode with extensive logging and validation
    Debug,
    /// Custom mode with user-defined parameters
    Custom,
}

/// Priority handling strategies
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum PriorityHandling {
    /// Strict priority ordering
    Strict,
    /// Weighted fair queuing
    WeightedFair,
    /// Round-robin with priority bias
    RoundRobinBiased,
    /// Deadline-aware priority
    DeadlineAware,
    /// Dynamic priority adjustment
    Dynamic,
}

/// Queue management strategies
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum QueueManagement {
    /// First-In-First-Out
    FIFO,
    /// Last-In-First-Out
    LIFO,
    /// Priority-based queuing
    Priority,
    /// Shortest job first
    ShortestJobFirst,
    /// Earliest deadline first
    EarliestDeadlineFirst,
    /// Multi-level feedback queue
    MultilevelFeedback,
}

/// Resource allocation strategies
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum ResourceAllocationStrategy {
    /// First-fit allocation
    FirstFit,
    /// Best-fit allocation
    BestFit,
    /// Worst-fit allocation
    WorstFit,
    /// Dynamic allocation based on current load
    Dynamic,
    /// Predictive allocation using historical data
    Predictive,
    /// Machine learning-based allocation
    MachineLearning,
    /// Custom allocation strategy
    Custom,
}

/// Memory allocation configurations
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct MemoryAllocationConfig {
    /// Memory pool size in bytes
    pub pool_size: usize,
    /// Enable memory pool
    pub enable_pool: bool,
    /// Memory alignment requirements
    pub alignment: usize,
    /// Fragmentation threshold
    pub fragmentation_threshold: f64,
    /// Memory pressure handling
    pub pressure_handling: MemoryPressureHandling,
}

/// CPU allocation configurations
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CpuAllocationConfig {
    /// Number of worker threads
    pub worker_threads: usize,
    /// CPU affinity settings
    pub cpu_affinity: CpuAffinityConfig,
    /// Thread priority settings
    pub thread_priority: ThreadPriorityConfig,
    /// NUMA awareness
    pub numa_aware: bool,
}

/// GPU allocation configurations
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GpuAllocationConfig {
    /// GPU device selection
    pub device_selection: GpuDeviceSelection,
    /// Memory allocation strategy
    pub memory_strategy: GpuMemoryStrategy,
    /// Compute capability requirements
    pub compute_capability: ComputeCapabilityConfig,
    /// Multi-GPU coordination
    pub multi_gpu: MultiGpuConfig,
}

/// Scheduling algorithms
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum SchedulingAlgorithm {
    /// Round-robin scheduling
    RoundRobin,
    /// Priority-based scheduling
    Priority,
    /// Shortest remaining time first
    ShortestRemainingTime,
    /// Completely fair scheduler
    CompletelyFair,
    /// Multi-level feedback queue
    MultilevelFeedback,
    /// Lottery scheduling
    Lottery,
    /// Proportional share scheduling
    ProportionalShare,
    /// Real-time scheduling
    RealTime,
}

/// Monitoring levels for performance tracking
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum MonitoringLevel {
    /// Minimal monitoring - basic counters only
    Minimal,
    /// Standard monitoring - essential metrics
    Standard,
    /// Detailed monitoring - comprehensive metrics
    Detailed,
    /// Comprehensive monitoring - all available metrics
    Comprehensive,
    /// Debug monitoring - extensive logging and tracing
    Debug,
}

/// Security enforcement levels
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum SecurityLevel {
    /// No security enforcement
    Disabled,
    /// Basic security checks
    Basic,
    /// Standard security enforcement
    Standard,
    /// High security with additional checks
    High,
    /// Maximum security with all features enabled
    Maximum,
}

/// Load balancing strategies
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum LoadBalancingStrategy {
    /// Round-robin distribution
    RoundRobin,
    /// Least connections
    LeastConnections,
    /// Weighted round-robin
    WeightedRoundRobin,
    /// Least response time
    LeastResponseTime,
    /// Resource-based balancing
    ResourceBased,
    /// Adaptive balancing
    Adaptive,
}

/// Resource cleanup policies
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum ResourceCleanupPolicy {
    /// Immediate cleanup after task completion
    Immediate,
    /// Deferred cleanup during idle periods
    Deferred,
    /// Lazy cleanup when resources are needed
    Lazy,
    /// Manual cleanup only
    Manual,
    /// Adaptive cleanup based on system load
    Adaptive,
}

// === Detailed Configuration Substructures ===

/// Retry configuration for failed tasks
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RetryConfig {
    /// Maximum retry attempts
    pub max_retries: usize,
    /// Retry delay strategy
    pub delay_strategy: RetryDelayStrategy,
    /// Base delay between retries
    pub base_delay: Duration,
    /// Maximum delay between retries
    pub max_delay: Duration,
    /// Jitter for delay randomization (0.0-1.0)
    pub jitter: f32,
    /// Retry condition checker
    pub retry_condition: RetryCondition,
    /// Exponential backoff multiplier
    pub backoff_multiplier: f64,
    /// Retry on specific error types
    pub retry_on_errors: Vec<String>,
}

/// Retry delay strategies
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum RetryDelayStrategy {
    /// Fixed delay between attempts
    Fixed,
    /// Linear increase in delay
    Linear,
    /// Exponential backoff
    Exponential,
    /// Fibonacci-based delay
    Fibonacci,
    /// Random jitter delay
    RandomJitter,
    /// Custom delay calculation
    Custom,
}

/// Conditions for determining if a task should be retried
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum RetryCondition {
    /// Always retry on failure
    Always,
    /// Never retry
    Never,
    /// Retry on transient errors only
    TransientErrorsOnly,
    /// Retry based on error type
    ErrorTypeBased,
    /// Custom retry logic
    Custom,
}

/// Checkpointing configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CheckpointConfig {
    /// Enable automatic checkpointing
    pub enabled: bool,
    /// Checkpoint interval
    pub interval: Duration,
    /// Maximum number of checkpoints to keep
    pub max_checkpoints: usize,
    /// Checkpoint storage location
    pub storage_location: String,
    /// Compression for checkpoint data
    pub compression_enabled: bool,
    /// Checkpoint validation
    pub validation_enabled: bool,
}

/// Memory pressure handling strategies
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum MemoryPressureHandling {
    /// Fail tasks when memory is low
    FailOnPressure,
    /// Queue tasks until memory is available
    QueueOnPressure,
    /// Spill to disk when memory is low
    SpillToDisk,
    /// Compress data to reduce memory usage
    Compress,
    /// Use memory-mapped files
    MemoryMap,
}

/// CPU affinity configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CpuAffinityConfig {
    /// Enable CPU affinity
    pub enabled: bool,
    /// Specific CPU cores to bind to
    pub cpu_cores: Vec<usize>,
    /// NUMA node preference
    pub numa_node: Option<usize>,
    /// Thread binding strategy
    pub binding_strategy: ThreadBindingStrategy,
}

/// Thread binding strategies
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum ThreadBindingStrategy {
    /// No specific binding
    None,
    /// Bind to specific cores
    CoreBinding,
    /// NUMA-aware binding
    NumaAware,
    /// Spread across available cores
    Spread,
    /// Compact allocation
    Compact,
}

/// GPU device selection configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GpuDeviceSelection {
    /// Specific GPU device IDs to use
    pub device_ids: Vec<usize>,
    /// Automatic device selection based on capability
    pub auto_select: bool,
    /// Minimum compute capability required
    pub min_compute_capability: (u32, u32),
    /// Memory requirements per device
    pub min_memory_gb: f64,
}

/// Configuration builder for easy setup
pub struct ExecutionConfigBuilder {
    config: ExecutionConfig,
}

impl ExecutionConfigBuilder {
    pub fn new() -> Self {
        Self {
            config: ExecutionConfig::default(),
        }
    }

    pub fn max_concurrent_executions(mut self, count: usize) -> Self {
        self.config.general.max_concurrent_executions = count;
        self
    }

    pub fn default_timeout(mut self, timeout: Duration) -> Self {
        self.config.general.default_timeout = timeout;
        self
    }

    pub fn enable_distributed(mut self, enabled: bool) -> Self {
        self.config.general.enable_distributed = enabled;
        self
    }

    pub fn resource_strategy(mut self, strategy: ResourceAllocationStrategy) -> Self {
        self.config.resource_allocation.allocation_strategy = strategy;
        self
    }

    pub fn scheduling_algorithm(mut self, algorithm: SchedulingAlgorithm) -> Self {
        self.config.scheduling.algorithm = algorithm;
        self
    }

    pub fn monitoring_level(mut self, level: MonitoringLevel) -> Self {
        self.config.monitoring.level = level;
        self
    }

    pub fn security_level(mut self, level: SecurityLevel) -> Self {
        self.config.security.level = level;
        self
    }

    pub fn enable_fault_tolerance(mut self, enabled: bool) -> Self {
        self.config.fault_tolerance.enabled = enabled;
        self
    }

    pub fn load_balancing_strategy(mut self, strategy: LoadBalancingStrategy) -> Self {
        self.config.load_balancing.strategy = strategy;
        self
    }

    pub fn build(self) -> ExecutionConfig {
        self.config
    }
}

// === Default Implementations ===

impl Default for ExecutionConfig {
    fn default() -> Self {
        Self {
            general: GeneralExecutionConfig::default(),
            resource_allocation: ResourceAllocationConfig::default(),
            scheduling: SchedulingConfig::default(),
            monitoring: MonitoringConfig::default(),
            security: SecurityConfig::default(),
            fault_tolerance: FaultToleranceConfig::default(),
            load_balancing: LoadBalancingConfig::default(),
            hardware: HardwareConfig::default(),
            cleanup: CleanupConfig::default(),
            advanced: AdvancedExecutionConfig::default(),
        }
    }
}

impl Default for GeneralExecutionConfig {
    fn default() -> Self {
        Self {
            max_concurrent_executions: 8,
            default_timeout: Duration::from_secs(300), // 5 minutes
            enable_distributed: false,
            enable_async_execution: true,
            operation_mode: OperationMode::Balanced,
            priority_handling: PriorityHandling::WeightedFair,
            queue_management: QueueManagement::Priority,
        }
    }
}

impl Default for ResourceAllocationConfig {
    fn default() -> Self {
        Self {
            allocation_strategy: ResourceAllocationStrategy::Dynamic,
            memory_allocation: MemoryAllocationConfig::default(),
            cpu_allocation: CpuAllocationConfig::default(),
            gpu_allocation: GpuAllocationConfig::default(),
            reservation_policy: ReservationPolicy::default(),
            sharing_config: ResourceSharingConfig::default(),
        }
    }
}

impl Default for MemoryAllocationConfig {
    fn default() -> Self {
        Self {
            pool_size: 1024 * 1024 * 1024, // 1GB
            enable_pool: true,
            alignment: 256,
            fragmentation_threshold: 0.3,
            pressure_handling: MemoryPressureHandling::QueueOnPressure,
        }
    }
}

impl Default for RetryConfig {
    fn default() -> Self {
        Self {
            max_retries: 3,
            delay_strategy: RetryDelayStrategy::Exponential,
            base_delay: Duration::from_millis(100),
            max_delay: Duration::from_secs(30),
            jitter: 0.1,
            retry_condition: RetryCondition::TransientErrorsOnly,
            backoff_multiplier: 2.0,
            retry_on_errors: vec![
                "NetworkError".to_string(),
                "TemporaryResourceUnavailable".to_string(),
                "TransientFailure".to_string(),
            ],
        }
    }
}

// === Preset Configurations ===

impl ExecutionConfig {
    /// High-performance configuration for maximum throughput
    pub fn high_performance() -> Self {
        ExecutionConfigBuilder::new()
            .max_concurrent_executions(16)
            .default_timeout(Duration::from_secs(600))
            .resource_strategy(ResourceAllocationStrategy::MachineLearning)
            .scheduling_algorithm(SchedulingAlgorithm::CompletelyFair)
            .monitoring_level(MonitoringLevel::Standard)
            .security_level(SecurityLevel::Basic)
            .enable_fault_tolerance(true)
            .load_balancing_strategy(LoadBalancingStrategy::Adaptive)
            .build()
    }

    /// Balanced configuration for general use
    pub fn balanced() -> Self {
        ExecutionConfig::default()
    }

    /// Power-efficient configuration for resource conservation
    pub fn power_efficient() -> Self {
        ExecutionConfigBuilder::new()
            .max_concurrent_executions(4)
            .default_timeout(Duration::from_secs(900))
            .resource_strategy(ResourceAllocationStrategy::BestFit)
            .scheduling_algorithm(SchedulingAlgorithm::Priority)
            .monitoring_level(MonitoringLevel::Minimal)
            .security_level(SecurityLevel::Standard)
            .enable_fault_tolerance(false)
            .load_balancing_strategy(LoadBalancingStrategy::RoundRobin)
            .build()
    }

    /// Debug configuration with extensive monitoring
    pub fn debug() -> Self {
        ExecutionConfigBuilder::new()
            .max_concurrent_executions(2)
            .default_timeout(Duration::from_secs(1200))
            .resource_strategy(ResourceAllocationStrategy::FirstFit)
            .scheduling_algorithm(SchedulingAlgorithm::RoundRobin)
            .monitoring_level(MonitoringLevel::Debug)
            .security_level(SecurityLevel::High)
            .enable_fault_tolerance(true)
            .load_balancing_strategy(LoadBalancingStrategy::LeastConnections)
            .build()
    }
}

// === Placeholder Types (to be implemented in other modules) ===

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ReservationPolicy {
    pub enable_reservations: bool,
    pub reservation_timeout: Duration,
    pub overbooking_factor: f64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ResourceSharingConfig {
    pub enable_sharing: bool,
    pub sharing_policy: String,
    pub isolation_level: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PriorityQueueConfig {
    pub max_priority_levels: usize,
    pub starvation_prevention: bool,
    pub aging_factor: f64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TimeSlicingConfig {
    pub time_slice_duration: Duration,
    pub enable_preemption: bool,
    pub quantum_adjustment: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DeadlineManagementConfig {
    pub enable_deadlines: bool,
    pub deadline_miss_action: String,
    pub deadline_prediction: bool,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum PreemptionPolicy {
    None,
    TimeSliced,
    PriorityBased,
    DeadlineBased,
    Cooperative,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SchedulingLoadBalancingConfig {
    pub enable_load_balancing: bool,
    pub rebalancing_interval: Duration,
    pub load_threshold: f64,
}

// Additional placeholder implementations for completeness
impl Default for ReservationPolicy {
    fn default() -> Self {
        Self {
            enable_reservations: false,
            reservation_timeout: Duration::from_secs(60),
            overbooking_factor: 1.2,
        }
    }
}

impl Default for ResourceSharingConfig {
    fn default() -> Self {
        Self {
            enable_sharing: true,
            sharing_policy: "fair".to_string(),
            isolation_level: "process".to_string(),
        }
    }
}

impl Default for CpuAllocationConfig {
    fn default() -> Self {
        Self {
            worker_threads: num_cpus::get(),
            cpu_affinity: CpuAffinityConfig::default(),
            thread_priority: ThreadPriorityConfig::default(),
            numa_aware: true,
        }
    }
}

impl Default for CpuAffinityConfig {
    fn default() -> Self {
        Self {
            enabled: false,
            cpu_cores: Vec::new(),
            numa_node: None,
            binding_strategy: ThreadBindingStrategy::None,
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ThreadPriorityConfig {
    pub base_priority: i32,
    pub priority_boost: i32,
    pub dynamic_adjustment: bool,
}

impl Default for ThreadPriorityConfig {
    fn default() -> Self {
        Self {
            base_priority: 0,
            priority_boost: 0,
            dynamic_adjustment: false,
        }
    }
}

impl Default for GpuAllocationConfig {
    fn default() -> Self {
        Self {
            device_selection: GpuDeviceSelection::default(),
            memory_strategy: GpuMemoryStrategy::default(),
            compute_capability: ComputeCapabilityConfig::default(),
            multi_gpu: MultiGpuConfig::default(),
        }
    }
}

impl Default for GpuDeviceSelection {
    fn default() -> Self {
        Self {
            device_ids: Vec::new(),
            auto_select: true,
            min_compute_capability: (3, 5),
            min_memory_gb: 2.0,
        }
    }
}

// Additional placeholder types for GPU configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GpuMemoryStrategy {
    pub allocation_method: String,
    pub memory_pool_size: usize,
    pub enable_unified_memory: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ComputeCapabilityConfig {
    pub minimum_major: u32,
    pub minimum_minor: u32,
    pub preferred_architecture: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct MultiGpuConfig {
    pub enable_multi_gpu: bool,
    pub synchronization_method: String,
    pub load_balancing: bool,
}

// Default implementations for GPU types
impl Default for GpuMemoryStrategy {
    fn default() -> Self {
        Self {
            allocation_method: "dynamic".to_string(),
            memory_pool_size: 512 * 1024 * 1024, // 512MB
            enable_unified_memory: false,
        }
    }
}

impl Default for ComputeCapabilityConfig {
    fn default() -> Self {
        Self {
            minimum_major: 3,
            minimum_minor: 5,
            preferred_architecture: "auto".to_string(),
        }
    }
}

impl Default for MultiGpuConfig {
    fn default() -> Self {
        Self {
            enable_multi_gpu: false,
            synchronization_method: "explicit".to_string(),
            load_balancing: true,
        }
    }
}

// === Comprehensive Default Implementations for All Config Types ===

// Placeholder defaults for remaining configuration types
impl Default for SchedulingConfig {
    fn default() -> Self {
        Self {
            algorithm: SchedulingAlgorithm::CompletelyFair,
            priority_queue: PriorityQueueConfig::default(),
            time_slicing: TimeSlicingConfig::default(),
            deadline_management: DeadlineManagementConfig::default(),
            preemption_policy: PreemptionPolicy::TimeSliced,
            load_balancing: SchedulingLoadBalancingConfig::default(),
        }
    }
}

impl Default for PriorityQueueConfig {
    fn default() -> Self {
        Self {
            max_priority_levels: 10,
            starvation_prevention: true,
            aging_factor: 1.1,
        }
    }
}

impl Default for TimeSlicingConfig {
    fn default() -> Self {
        Self {
            time_slice_duration: Duration::from_millis(20),
            enable_preemption: true,
            quantum_adjustment: true,
        }
    }
}

impl Default for DeadlineManagementConfig {
    fn default() -> Self {
        Self {
            enable_deadlines: true,
            deadline_miss_action: "reschedule".to_string(),
            deadline_prediction: false,
        }
    }
}

impl Default for SchedulingLoadBalancingConfig {
    fn default() -> Self {
        Self {
            enable_load_balancing: true,
            rebalancing_interval: Duration::from_secs(30),
            load_threshold: 0.8,
        }
    }
}

// Placeholder defaults for remaining major configuration sections
impl Default for MonitoringConfig {
    fn default() -> Self {
        Self {
            level: MonitoringLevel::Standard,
            metrics_collection: MetricsCollectionConfig::default(),
            performance_tracking: PerformanceTrackingConfig::default(),
            realtime_monitoring: RealtimeMonitoringConfig::default(),
            history_retention: HistoryRetentionConfig::default(),
            alerting: AlertingConfig::default(),
        }
    }
}

impl Default for SecurityConfig {
    fn default() -> Self {
        Self {
            level: SecurityLevel::Standard,
            authentication: AuthenticationConfig::default(),
            authorization: AuthorizationConfig::default(),
            encryption: EncryptionConfig::default(),
            audit_logging: AuditLoggingConfig::default(),
            access_control: AccessControlConfig::default(),
        }
    }
}

impl Default for FaultToleranceConfig {
    fn default() -> Self {
        Self {
            enabled: true,
            retry: RetryConfig::default(),
            checkpointing: CheckpointConfig::default(),
            recovery: RecoveryConfig::default(),
            health_checking: HealthCheckingConfig::default(),
            circuit_breaker: CircuitBreakerConfig::default(),
        }
    }
}

impl Default for LoadBalancingConfig {
    fn default() -> Self {
        Self {
            strategy: LoadBalancingStrategy::RoundRobin,
            worker_pool: WorkerPoolConfig::default(),
            distribution: DistributionConfig::default(),
            health_monitoring: LoadBalancingHealthConfig::default(),
            dynamic_scaling: DynamicScalingConfig::default(),
        }
    }
}

impl Default for HardwareConfig {
    fn default() -> Self {
        Self {
            detection: HardwareDetectionConfig::default(),
            gpu_config: GpuHardwareConfig::default(),
            cpu_config: CpuHardwareConfig::default(),
            memory_config: MemoryHierarchyConfig::default(),
            optimization: HardwareOptimizationConfig::default(),
            thermal_management: ThermalManagementConfig::default(),
        }
    }
}

impl Default for CleanupConfig {
    fn default() -> Self {
        Self {
            resource_cleanup: ResourceCleanupPolicy::Deferred,
            automatic_cleanup: AutomaticCleanupConfig::default(),
            memory_cleanup: MemoryCleanupConfig::default(),
            log_cleanup: LogCleanupConfig::default(),
            garbage_collection: GarbageCollectionConfig::default(),
        }
    }
}

impl Default for AdvancedExecutionConfig {
    fn default() -> Self {
        Self {
            enable_experimental: false,
            ml_optimizations: MlOptimizationConfig::default(),
            adaptive_behavior: AdaptiveBehaviorConfig::default(),
            profiling: ProfilingConfig::default(),
            plugin_support: PluginSupportConfig::default(),
            advanced_scheduling: AdvancedSchedulingConfig::default(),
        }
    }
}

impl Default for CheckpointConfig {
    fn default() -> Self {
        Self {
            enabled: false,
            interval: Duration::from_secs(300),
            max_checkpoints: 5,
            storage_location: std::env::temp_dir().join("checkpoints").display().to_string(),
            compression_enabled: true,
            validation_enabled: true,
        }
    }
}

// === Additional Placeholder Configuration Types ===

// These would be fully implemented in their respective modules
macro_rules! default_placeholder_config {
    ($type_name:ident) => {
        #[derive(Debug, Clone, Serialize, Deserialize)]
        pub struct $type_name {
            pub enabled: bool,
            pub configuration: HashMap<String, String>,
        }

        impl Default for $type_name {
            fn default() -> Self {
                Self {
                    enabled: true,
                    configuration: HashMap::new(),
                }
            }
        }
    };
}

use std::collections::HashMap;

default_placeholder_config!(MetricsCollectionConfig);
default_placeholder_config!(PerformanceTrackingConfig);
default_placeholder_config!(RealtimeMonitoringConfig);
default_placeholder_config!(HistoryRetentionConfig);
default_placeholder_config!(AlertingConfig);
default_placeholder_config!(AuthenticationConfig);
default_placeholder_config!(AuthorizationConfig);
default_placeholder_config!(EncryptionConfig);
default_placeholder_config!(AuditLoggingConfig);
default_placeholder_config!(AccessControlConfig);
default_placeholder_config!(RecoveryConfig);
default_placeholder_config!(HealthCheckingConfig);
default_placeholder_config!(CircuitBreakerConfig);
default_placeholder_config!(WorkerPoolConfig);
default_placeholder_config!(DistributionConfig);
default_placeholder_config!(LoadBalancingHealthConfig);
default_placeholder_config!(DynamicScalingConfig);
default_placeholder_config!(HardwareDetectionConfig);
default_placeholder_config!(GpuHardwareConfig);
default_placeholder_config!(CpuHardwareConfig);
default_placeholder_config!(MemoryHierarchyConfig);
default_placeholder_config!(HardwareOptimizationConfig);
default_placeholder_config!(ThermalManagementConfig);
default_placeholder_config!(AutomaticCleanupConfig);
default_placeholder_config!(MemoryCleanupConfig);
default_placeholder_config!(LogCleanupConfig);
default_placeholder_config!(GarbageCollectionConfig);
default_placeholder_config!(MlOptimizationConfig);
default_placeholder_config!(AdaptiveBehaviorConfig);
default_placeholder_config!(ProfilingConfig);
default_placeholder_config!(PluginSupportConfig);
default_placeholder_config!(AdvancedSchedulingConfig);

/// GPU configuration stub type
#[derive(Debug, Clone, Default, Serialize, Deserialize)]
pub struct GpuConfig {}

/// Thermal configuration stub type
#[derive(Debug, Clone, Default, Serialize, Deserialize)]
pub struct ThermalConfig {}

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

    #[test]
    fn test_default_execution_config() {
        let config = ExecutionConfig::default();
        assert_eq!(config.general.max_concurrent_executions, 8);
        assert_eq!(config.general.operation_mode, OperationMode::Balanced);
        assert_eq!(
            config.resource_allocation.allocation_strategy,
            ResourceAllocationStrategy::Dynamic
        );
        assert_eq!(config.monitoring.level, MonitoringLevel::Standard);
    }

    #[test]
    fn test_config_builder() {
        let config = ExecutionConfigBuilder::new()
            .max_concurrent_executions(16)
            .enable_distributed(true)
            .monitoring_level(MonitoringLevel::Comprehensive)
            .build();

        assert_eq!(config.general.max_concurrent_executions, 16);
        assert!(config.general.enable_distributed);
        assert_eq!(config.monitoring.level, MonitoringLevel::Comprehensive);
    }

    #[test]
    fn test_preset_configurations() {
        let high_perf = ExecutionConfig::high_performance();
        assert_eq!(high_perf.general.max_concurrent_executions, 16);
        assert_eq!(
            high_perf.resource_allocation.allocation_strategy,
            ResourceAllocationStrategy::MachineLearning
        );

        let power_efficient = ExecutionConfig::power_efficient();
        assert_eq!(power_efficient.general.max_concurrent_executions, 4);
        assert_eq!(power_efficient.monitoring.level, MonitoringLevel::Minimal);

        let debug = ExecutionConfig::debug();
        assert_eq!(debug.monitoring.level, MonitoringLevel::Debug);
        assert_eq!(debug.security.level, SecurityLevel::High);
    }

    #[test]
    fn test_retry_config() {
        let retry_config = RetryConfig::default();
        assert_eq!(retry_config.max_retries, 3);
        assert_eq!(retry_config.delay_strategy, RetryDelayStrategy::Exponential);
        assert_eq!(
            retry_config.retry_condition,
            RetryCondition::TransientErrorsOnly
        );
    }

    #[test]
    fn test_memory_allocation_config() {
        let mem_config = MemoryAllocationConfig::default();
        assert!(mem_config.enable_pool);
        assert_eq!(mem_config.alignment, 256);
        assert_eq!(
            mem_config.pressure_handling,
            MemoryPressureHandling::QueueOnPressure
        );
    }

    #[test]
    fn test_serialization() {
        let config = ExecutionConfig::default();
        let serialized = serde_json::to_string(&config).expect("Serialization failed");
        let deserialized: ExecutionConfig =
            serde_json::from_str(&serialized).expect("Deserialization failed");

        assert_eq!(
            config.general.max_concurrent_executions,
            deserialized.general.max_concurrent_executions
        );
        assert_eq!(config.monitoring.level, deserialized.monitoring.level);
    }
}
