oxirs_cluster/

edge_computing.rs

//! # Edge Computing Integration for Distributed RDF Storage
//!
//! This module provides comprehensive edge computing capabilities for distributed deployments,
//! enabling efficient operation at network edges with limited bandwidth, intermittent connectivity,
//! and resource constraints.

use anyhow::Result;
use serde::{Deserialize, Serialize};
use std::collections::{HashMap, HashSet, VecDeque};
use std::sync::Arc;
use std::time::{Duration, SystemTime, UNIX_EPOCH};
use tokio::sync::{Mutex, RwLock};

/// Edge device characteristics and capabilities
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct EdgeDeviceProfile {
    /// Device identifier
    pub device_id: String,
    /// Device type classification
    pub device_type: EdgeDeviceType,
    /// Available computing resources
    pub compute_resources: ComputeResources,
    /// Network connectivity characteristics
    pub network_profile: NetworkProfile,
    /// Storage capabilities
    pub storage_profile: StorageProfile,
    /// Power constraints
    pub power_profile: PowerProfile,
    /// Geographic location information
    pub location: EdgeLocation,
}

/// Classification of edge devices
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub enum EdgeDeviceType {
    /// Mobile devices (smartphones, tablets)
    Mobile,
    /// IoT sensors and actuators
    IoT,
    /// Edge servers and gateways
    EdgeServer,
    /// Embedded systems
    Embedded,
    /// Automotive computing units
    Automotive,
    /// Industrial control systems
    Industrial,
    /// Smart home devices
    SmartHome,
}

/// Computing resource specifications
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct ComputeResources {
    /// Number of CPU cores
    pub cpu_cores: u32,
    /// CPU frequency in MHz
    pub cpu_frequency_mhz: u32,
    /// Available RAM in MB
    pub memory_mb: u32,
    /// GPU availability and specs
    pub gpu: Option<GpuSpecs>,
    /// Specialized accelerators (TPU, FPGA, etc.)
    pub accelerators: Vec<AcceleratorType>,
}

/// GPU specifications
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct GpuSpecs {
    /// GPU memory in MB
    pub memory_mb: u32,
    /// Compute capability
    pub compute_capability: String,
    /// GPU type/vendor
    pub gpu_type: String,
}

/// Hardware accelerator types
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub enum AcceleratorType {
    /// Tensor Processing Unit
    TPU,
    /// Field-Programmable Gate Array
    FPGA,
    /// Neural Processing Unit
    NPU,
    /// Digital Signal Processor
    DSP,
    /// Custom ASIC
    ASIC,
}

/// Network connectivity profile
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct NetworkProfile {
    /// Connection types available
    pub connection_types: Vec<ConnectionType>,
    /// Bandwidth characteristics
    pub bandwidth: BandwidthProfile,
    /// Latency characteristics  
    pub latency: LatencyProfile,
    /// Reliability metrics
    pub reliability: ReliabilityProfile,
    /// Cost considerations
    pub cost_profile: CostProfile,
}

/// Network connection types
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub enum ConnectionType {
    /// 5G cellular
    FiveG,
    /// 4G LTE
    LTE,
    /// WiFi
    WiFi,
    /// Ethernet
    Ethernet,
    /// Satellite
    Satellite,
    /// LoRaWAN
    LoRaWAN,
    /// Bluetooth
    Bluetooth,
    /// Zigbee
    Zigbee,
}

/// Bandwidth characteristics
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct BandwidthProfile {
    /// Maximum download bandwidth (Mbps)
    pub max_download_mbps: f64,
    /// Maximum upload bandwidth (Mbps)
    pub max_upload_mbps: f64,
    /// Typical download bandwidth (Mbps)
    pub typical_download_mbps: f64,
    /// Typical upload bandwidth (Mbps)
    pub typical_upload_mbps: f64,
    /// Bandwidth variability factor (0.0-1.0)
    pub variability: f64,
}

/// Latency characteristics
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct LatencyProfile {
    /// Minimum latency in milliseconds
    pub min_latency_ms: u32,
    /// Average latency in milliseconds
    pub avg_latency_ms: u32,
    /// Maximum latency in milliseconds
    pub max_latency_ms: u32,
    /// Jitter in milliseconds
    pub jitter_ms: u32,
}

/// Network reliability characteristics
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct ReliabilityProfile {
    /// Connection uptime percentage (0.0-1.0)
    pub uptime_percentage: f64,
    /// Packet loss rate (0.0-1.0)
    pub packet_loss_rate: f64,
    /// Connection drop frequency (drops per hour)
    pub drop_frequency: f64,
    /// Recovery time in seconds
    pub recovery_time_seconds: u32,
}

/// Network cost profile
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct CostProfile {
    /// Cost per MB of data
    pub cost_per_mb: f64,
    /// Monthly data allowance in MB
    pub monthly_allowance_mb: Option<u32>,
    /// Overage cost per MB
    pub overage_cost_per_mb: Option<f64>,
}

/// Storage capabilities of edge device
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct StorageProfile {
    /// Total storage capacity in MB
    pub total_capacity_mb: u32,
    /// Available storage in MB
    pub available_capacity_mb: u32,
    /// Storage type (SSD, HDD, Flash, etc.)
    pub storage_type: StorageType,
    /// Read/write performance characteristics
    pub performance: StoragePerformance,
}

/// Storage technology types
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub enum StorageType {
    /// Solid State Drive
    SSD,
    /// Hard Disk Drive
    HDD,
    /// Flash memory
    Flash,
    /// eMMC
    EMMC,
    /// RAM disk
    RAM,
}

/// Storage performance characteristics
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct StoragePerformance {
    /// Sequential read speed (MB/s)
    pub sequential_read_mbps: f64,
    /// Sequential write speed (MB/s)
    pub sequential_write_mbps: f64,
    /// Random read IOPS
    pub random_read_iops: u32,
    /// Random write IOPS
    pub random_write_iops: u32,
}

/// Power consumption and battery constraints
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct PowerProfile {
    /// Maximum power consumption in watts
    pub max_power_watts: f64,
    /// Idle power consumption in watts
    pub idle_power_watts: f64,
    /// Battery capacity in watt-hours (None for AC-powered)
    pub battery_capacity_wh: Option<f64>,
    /// Power management capabilities
    pub power_management: PowerManagement,
}

/// Power management features
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct PowerManagement {
    /// Supports dynamic voltage/frequency scaling
    pub dvfs_support: bool,
    /// Supports sleep/hibernate modes
    pub sleep_support: bool,
    /// Supports component power gating
    pub power_gating: bool,
    /// Wake-on-network support
    pub wake_on_network: bool,
}

/// Geographic location and context
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct EdgeLocation {
    /// GPS coordinates
    pub coordinates: Option<(f64, f64)>,
    /// Geographic region identifier
    pub region: String,
    /// Timezone
    pub timezone: String,
    /// Mobility characteristics
    pub mobility: MobilityProfile,
}

/// Device mobility characteristics
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct MobilityProfile {
    /// Device is mobile vs stationary
    pub is_mobile: bool,
    /// Typical movement speed (m/s)
    pub typical_speed_ms: f64,
    /// Movement pattern predictability (0.0-1.0)
    pub predictability: f64,
    /// Coverage area radius in meters
    pub coverage_radius_m: f64,
}

/// Edge deployment strategy
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum EdgeDeploymentStrategy {
    /// Full replication of data to edge
    FullReplication,
    /// Partial replication based on access patterns
    PartialReplication {
        replication_factor: f64,
        selection_strategy: DataSelectionStrategy,
    },
    /// Caching with write-through
    WriteThrough,
    /// Caching with write-back
    WriteBack {
        sync_interval: Duration,
        conflict_resolution: ConflictResolution,
    },
    /// Event-driven synchronization
    EventDriven {
        trigger_conditions: Vec<TriggerCondition>,
    },
    /// Hierarchical edge topology
    Hierarchical { levels: Vec<EdgeLevel> },
}

/// Data selection strategies for partial replication
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum DataSelectionStrategy {
    /// Most recently accessed data
    LRU,
    /// Most frequently accessed data
    LFU,
    /// Data with highest access probability
    PredictiveAccess,
    /// Data based on semantic similarity
    SemanticSimilarity,
    /// Custom selection criteria
    Custom { criteria: String },
}

/// Conflict resolution for edge synchronization
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum ConflictResolution {
    /// Edge changes take precedence
    EdgeFirst,
    /// Cloud changes take precedence
    CloudFirst,
    /// Timestamp-based resolution
    TimestampBased,
    /// Vector clock-based resolution
    VectorClock,
    /// Application-specific resolution
    Custom { resolver: String },
}

/// Trigger conditions for event-driven sync
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum TriggerCondition {
    /// Time-based triggers
    Temporal {
        interval: Duration,
        time_windows: Vec<TimeWindow>,
    },
    /// Data change thresholds
    DataThreshold {
        change_percentage: f64,
        operation_count: u32,
    },
    /// Network condition triggers
    NetworkCondition {
        min_bandwidth_mbps: f64,
        max_latency_ms: u32,
        min_reliability: f64,
    },
    /// Resource availability triggers
    ResourceAvailability {
        min_cpu_usage: f64,
        min_memory_mb: u32,
        min_battery_percentage: Option<f64>,
    },
}

/// Time windows for synchronization
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct TimeWindow {
    /// Start hour (0-23)
    pub start_hour: u8,
    /// End hour (0-23)
    pub end_hour: u8,
    /// Days of week (0=Sunday)
    pub days_of_week: Vec<u8>,
}

/// Edge computing hierarchy levels
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct EdgeLevel {
    /// Level identifier
    pub level_id: String,
    /// Level in hierarchy (0 = closest to devices)
    pub level_number: u32,
    /// Device types at this level
    pub device_types: Vec<EdgeDeviceType>,
    /// Aggregation strategy
    pub aggregation_strategy: AggregationStrategy,
    /// Data retention policy
    pub retention_policy: RetentionPolicy,
}

/// Data aggregation strategies
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum AggregationStrategy {
    /// No aggregation, pass-through
    PassThrough,
    /// Temporal aggregation
    Temporal {
        window_size: Duration,
        aggregation_function: AggregationFunction,
    },
    /// Spatial aggregation
    Spatial {
        radius_meters: f64,
        aggregation_function: AggregationFunction,
    },
    /// Semantic aggregation
    Semantic {
        similarity_threshold: f64,
        merge_strategy: String,
    },
}

/// Aggregation functions
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub enum AggregationFunction {
    /// Count of items
    Count,
    /// Sum of values
    Sum,
    /// Average of values
    Average,
    /// Minimum value
    Min,
    /// Maximum value
    Max,
    /// Median value
    Median,
    /// First value
    First,
    /// Last value
    Last,
    /// Most frequent value
    Mode,
}

/// Data retention policies
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub struct RetentionPolicy {
    /// Maximum age before deletion
    pub max_age: Duration,
    /// Maximum number of items
    pub max_items: Option<u32>,
    /// Maximum storage usage
    pub max_storage_mb: Option<u32>,
    /// Cleanup strategy
    pub cleanup_strategy: CleanupStrategy,
}

/// Data cleanup strategies
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum CleanupStrategy {
    /// Remove oldest data first
    FIFO,
    /// Remove least recently used
    LRU,
    /// Remove least frequently used
    LFU,
    /// Remove by priority score
    Priority,
}

/// Edge computing manager
#[derive(Debug)]
pub struct EdgeComputingManager {
    /// Edge device profiles
    device_profiles: Arc<RwLock<HashMap<String, EdgeDeviceProfile>>>,
    /// Deployment strategies per device
    deployment_strategies: Arc<RwLock<HashMap<String, EdgeDeploymentStrategy>>>,
    /// Synchronization queue
    sync_queue: Arc<Mutex<VecDeque<SyncOperation>>>,
    /// Network condition monitor
    network_monitor: Arc<NetworkConditionMonitor>,
    /// Data placement optimizer
    #[allow(dead_code)]
    placement_optimizer: Arc<DataPlacementOptimizer>,
    /// Edge cache manager
    cache_manager: Arc<EdgeCacheManager>,
}

/// Synchronization operation
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SyncOperation {
    /// Operation identifier
    pub operation_id: String,
    /// Source device
    pub source_device: String,
    /// Target device or cloud
    pub target: String,
    /// Data to synchronize
    pub data: SyncData,
    /// Priority (higher = more urgent)
    pub priority: u32,
    /// Timestamp
    pub timestamp: SystemTime,
    /// Retry count
    pub retry_count: u32,
}

/// Data for synchronization
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum SyncData {
    /// RDF triples
    Triples {
        triples: Vec<(String, String, String)>,
        graph: Option<String>,
    },
    /// Named graph
    Graph { graph_name: String, content: String },
    /// Metadata update
    Metadata {
        metadata_type: String,
        content: HashMap<String, String>,
    },
    /// Configuration change
    Configuration {
        config_key: String,
        config_value: String,
    },
}

/// Network condition monitoring
#[derive(Debug)]
pub struct NetworkConditionMonitor {
    /// Current network conditions per device
    conditions: Arc<RwLock<HashMap<String, NetworkCondition>>>,
    /// Condition history for analysis
    history: Arc<RwLock<VecDeque<(SystemTime, String, NetworkCondition)>>>,
}

/// Current network condition snapshot
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NetworkCondition {
    /// Current bandwidth (Mbps)
    pub current_bandwidth_mbps: f64,
    /// Current latency (ms)
    pub current_latency_ms: u32,
    /// Current packet loss rate
    pub packet_loss_rate: f64,
    /// Connection stability score (0.0-1.0)
    pub stability_score: f64,
    /// Signal strength (for wireless)
    pub signal_strength: Option<f64>,
    /// Last measurement time
    pub last_measured: SystemTime,
}

/// Data placement optimization
#[derive(Debug)]
pub struct DataPlacementOptimizer {
    /// Access pattern analytics
    access_patterns: Arc<RwLock<HashMap<String, AccessPattern>>>,
    /// Placement recommendations
    placement_cache: Arc<RwLock<HashMap<String, PlacementRecommendation>>>,
}

/// Data access patterns
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AccessPattern {
    /// Data identifier
    pub data_id: String,
    /// Access frequency (accesses per hour)
    pub access_frequency: f64,
    /// Access recency (last access time)
    pub last_access: SystemTime,
    /// Access devices
    pub accessing_devices: HashSet<String>,
    /// Access times distribution
    pub temporal_pattern: Vec<f64>, // 24-hour distribution
    /// Access correlation with other data
    pub correlations: HashMap<String, f64>,
}

/// Data placement recommendation
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PlacementRecommendation {
    /// Data identifier
    pub data_id: String,
    /// Recommended devices for placement
    pub recommended_devices: Vec<String>,
    /// Confidence score (0.0-1.0)
    pub confidence: f64,
    /// Expected access latency improvement
    pub latency_improvement_ms: f64,
    /// Estimated bandwidth savings
    pub bandwidth_savings_mbps: f64,
    /// Recommendation timestamp
    pub timestamp: SystemTime,
}

/// Edge cache management
#[derive(Debug)]
pub struct EdgeCacheManager {
    /// Cache states per device
    cache_states: Arc<RwLock<HashMap<String, CacheState>>>,
    /// Cache policies per device
    cache_policies: Arc<RwLock<HashMap<String, CachePolicy>>>,
}

/// Edge cache state
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CacheState {
    /// Device identifier
    pub device_id: String,
    /// Cached data items
    pub cached_items: HashMap<String, CacheItem>,
    /// Total cache size in bytes
    pub total_size_bytes: u64,
    /// Available cache space in bytes
    pub available_space_bytes: u64,
    /// Cache hit rate
    pub hit_rate: f64,
    /// Last cleanup time
    pub last_cleanup: SystemTime,
}

/// Cached data item
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CacheItem {
    /// Data identifier
    pub data_id: String,
    /// Data content
    pub content: Vec<u8>,
    /// Access count
    pub access_count: u32,
    /// Last access time
    pub last_access: SystemTime,
    /// Cache time
    pub cached_time: SystemTime,
    /// Priority score
    pub priority: f64,
    /// Size in bytes
    pub size_bytes: u64,
}

/// Cache policy configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CachePolicy {
    /// Maximum cache size in bytes
    pub max_size_bytes: u64,
    /// Eviction strategy
    pub eviction_strategy: EvictionStrategy,
    /// Prefetch strategy
    pub prefetch_strategy: PrefetchStrategy,
    /// Consistency requirements
    pub consistency_level: ConsistencyLevel,
}

/// Cache eviction strategies
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum EvictionStrategy {
    /// Least Recently Used
    LRU,
    /// Least Frequently Used
    LFU,
    /// Time-based expiration
    TTL { ttl_seconds: u64 },
    /// Priority-based eviction
    Priority,
    /// Adaptive based on access patterns
    Adaptive,
}

/// Cache prefetch strategies
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum PrefetchStrategy {
    /// No prefetching
    None,
    /// Prefetch related data
    Related { correlation_threshold: f64 },
    /// Predictive prefetching
    Predictive { prediction_model: String },
    /// Time-based prefetching
    Temporal { prefetch_window: Duration },
}

/// Cache consistency levels
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum ConsistencyLevel {
    /// No consistency guarantees
    None,
    /// Eventual consistency
    Eventual,
    /// Strong consistency
    Strong,
    /// Session consistency
    Session,
    /// Monotonic read consistency
    MonotonicRead,
}

impl Default for EdgeComputingManager {
    fn default() -> Self {
        Self::new()
    }
}

impl EdgeComputingManager {
    /// Create a new edge computing manager
    pub fn new() -> Self {
        Self {
            device_profiles: Arc::new(RwLock::new(HashMap::new())),
            deployment_strategies: Arc::new(RwLock::new(HashMap::new())),
            sync_queue: Arc::new(Mutex::new(VecDeque::new())),
            network_monitor: Arc::new(NetworkConditionMonitor::new()),
            placement_optimizer: Arc::new(DataPlacementOptimizer::new()),
            cache_manager: Arc::new(EdgeCacheManager::new()),
        }
    }

    /// Register an edge device with its profile
    pub async fn register_device(&self, device_profile: EdgeDeviceProfile) -> Result<()> {
        let device_id = device_profile.device_id.clone();

        // Store device profile
        self.device_profiles
            .write()
            .await
            .insert(device_id.clone(), device_profile.clone());

        // Initialize deployment strategy based on device capabilities
        let strategy = self.recommend_deployment_strategy(&device_profile).await?;
        self.deployment_strategies
            .write()
            .await
            .insert(device_id.clone(), strategy);

        // Initialize cache policy
        let cache_policy = self.create_cache_policy(&device_profile).await?;
        self.cache_manager
            .set_cache_policy(&device_id, cache_policy)
            .await?;

        tracing::info!("Registered edge device: {}", device_id);
        Ok(())
    }

    /// Recommend optimal deployment strategy for a device
    pub async fn recommend_deployment_strategy(
        &self,
        device_profile: &EdgeDeviceProfile,
    ) -> Result<EdgeDeploymentStrategy> {
        let strategy = match device_profile.device_type {
            EdgeDeviceType::Mobile => {
                // Mobile devices: partial replication with LRU
                EdgeDeploymentStrategy::PartialReplication {
                    replication_factor: 0.1, // Only 10% of data
                    selection_strategy: DataSelectionStrategy::LRU,
                }
            }
            EdgeDeviceType::IoT => {
                // IoT devices: event-driven sync
                EdgeDeploymentStrategy::EventDriven {
                    trigger_conditions: vec![
                        TriggerCondition::NetworkCondition {
                            min_bandwidth_mbps: 1.0,
                            max_latency_ms: 100,
                            min_reliability: 0.8,
                        },
                        TriggerCondition::Temporal {
                            interval: Duration::from_secs(3600), // Hourly
                            time_windows: vec![TimeWindow {
                                start_hour: 2,
                                end_hour: 4,
                                days_of_week: vec![1, 2, 3, 4, 5], // Weekdays
                            }],
                        },
                    ],
                }
            }
            EdgeDeviceType::EdgeServer => {
                // Edge servers: write-back with hierarchical topology
                EdgeDeploymentStrategy::WriteBack {
                    sync_interval: Duration::from_secs(300), // 5 minutes
                    conflict_resolution: ConflictResolution::VectorClock,
                }
            }
            EdgeDeviceType::Embedded => {
                // Embedded systems: write-through
                EdgeDeploymentStrategy::WriteThrough
            }
            _ => {
                // Default strategy
                EdgeDeploymentStrategy::PartialReplication {
                    replication_factor: 0.2,
                    selection_strategy: DataSelectionStrategy::LFU,
                }
            }
        };

        Ok(strategy)
    }

    /// Create cache policy based on device capabilities
    pub async fn create_cache_policy(
        &self,
        device_profile: &EdgeDeviceProfile,
    ) -> Result<CachePolicy> {
        let max_size_bytes =
            (device_profile.storage_profile.available_capacity_mb as u64 / 4) * 1024 * 1024; // Use 25% of available storage

        let eviction_strategy = match device_profile.device_type {
            EdgeDeviceType::Mobile => EvictionStrategy::LRU,
            EdgeDeviceType::IoT => EvictionStrategy::TTL { ttl_seconds: 3600 },
            EdgeDeviceType::EdgeServer => EvictionStrategy::Adaptive,
            _ => EvictionStrategy::LFU,
        };

        let prefetch_strategy = if device_profile
            .network_profile
            .bandwidth
            .typical_download_mbps
            > 10.0
        {
            PrefetchStrategy::Related {
                correlation_threshold: 0.7,
            }
        } else {
            PrefetchStrategy::None
        };

        let consistency_level = match device_profile.device_type {
            EdgeDeviceType::EdgeServer => ConsistencyLevel::Strong,
            EdgeDeviceType::Mobile => ConsistencyLevel::Session,
            _ => ConsistencyLevel::Eventual,
        };

        Ok(CachePolicy {
            max_size_bytes,
            eviction_strategy,
            prefetch_strategy,
            consistency_level,
        })
    }

    /// Schedule data synchronization
    pub async fn schedule_sync(
        &self,
        source_device: String,
        target: String,
        data: SyncData,
        priority: u32,
    ) -> Result<String> {
        let operation_id = uuid::Uuid::new_v4().to_string();

        let sync_op = SyncOperation {
            operation_id: operation_id.clone(),
            source_device,
            target,
            data,
            priority,
            timestamp: SystemTime::now(),
            retry_count: 0,
        };

        let mut queue = self.sync_queue.lock().await;

        // Insert maintaining priority order
        let insert_pos = queue
            .iter()
            .position(|op| op.priority < priority)
            .unwrap_or(queue.len());
        queue.insert(insert_pos, sync_op);

        tracing::debug!("Scheduled sync operation: {}", operation_id);
        Ok(operation_id)
    }

    /// Process synchronization queue
    pub async fn process_sync_queue(&self) -> Result<u32> {
        let mut processed_count = 0;
        let mut queue = self.sync_queue.lock().await;

        while let Some(sync_op) = queue.pop_front() {
            drop(queue); // Release lock during processing

            match self.execute_sync_operation(&sync_op).await {
                Ok(_) => {
                    processed_count += 1;
                    tracing::debug!(
                        "Successfully processed sync operation: {}",
                        sync_op.operation_id
                    );
                }
                Err(e) => {
                    tracing::warn!(
                        "Failed to process sync operation {}: {}",
                        sync_op.operation_id,
                        e
                    );

                    // Re-queue for retry if under retry limit
                    if sync_op.retry_count < 3 {
                        let mut retry_op = sync_op;
                        retry_op.retry_count += 1;

                        let mut queue = self.sync_queue.lock().await;
                        queue.push_back(retry_op);
                    }
                }
            }

            queue = self.sync_queue.lock().await;
        }

        Ok(processed_count)
    }

    /// Execute a single sync operation
    async fn execute_sync_operation(&self, sync_op: &SyncOperation) -> Result<()> {
        // Check network conditions
        let network_ok = self
            .check_network_conditions(&sync_op.source_device)
            .await?;
        if !network_ok {
            return Err(anyhow::anyhow!("Network conditions not suitable for sync"));
        }

        // Execute based on sync data type
        match &sync_op.data {
            SyncData::Triples { triples, graph } => {
                self.sync_triples(
                    &sync_op.source_device,
                    &sync_op.target,
                    triples,
                    graph.as_ref(),
                )
                .await
            }
            SyncData::Graph {
                graph_name,
                content,
            } => {
                self.sync_graph(&sync_op.source_device, &sync_op.target, graph_name, content)
                    .await
            }
            SyncData::Metadata {
                metadata_type,
                content,
            } => {
                self.sync_metadata(
                    &sync_op.source_device,
                    &sync_op.target,
                    metadata_type,
                    content,
                )
                .await
            }
            SyncData::Configuration {
                config_key,
                config_value,
            } => {
                self.sync_configuration(
                    &sync_op.source_device,
                    &sync_op.target,
                    config_key,
                    config_value,
                )
                .await
            }
        }
    }

    /// Check if network conditions are suitable for sync
    async fn check_network_conditions(&self, device_id: &str) -> Result<bool> {
        if let Some(condition) = self
            .network_monitor
            .get_current_condition(device_id)
            .await?
        {
            // Simple heuristic: require at least 1 Mbps bandwidth and <500ms latency
            Ok(condition.current_bandwidth_mbps >= 1.0
                && condition.current_latency_ms <= 500
                && condition.packet_loss_rate <= 0.05)
        } else {
            Ok(false) // No network condition data available
        }
    }

    /// Synchronize RDF triples
    async fn sync_triples(
        &self,
        source_device: &str,
        target: &str,
        triples: &[(String, String, String)],
        graph: Option<&String>,
    ) -> Result<()> {
        tracing::info!(
            "Synchronizing {} triples from {} to {} in graph {:?}",
            triples.len(),
            source_device,
            target,
            graph
        );

        // Create sync operation for triple synchronization
        let sync_operation = SyncOperation {
            operation_id: format!(
                "sync-triples-{}-{}",
                source_device,
                SystemTime::now().duration_since(UNIX_EPOCH)?.as_millis()
            ),
            source_device: source_device.to_string(),
            target: target.to_string(),
            data: SyncData::Triples {
                triples: triples.to_vec(),
                graph: graph.map(|g| g.to_string()),
            },
            priority: 50, // Medium priority
            timestamp: SystemTime::now(),
            retry_count: 0,
        };

        // Add to sync queue
        self.sync_queue.lock().await.push_back(sync_operation);

        // Check network conditions and decide on sync strategy
        let network_conditions = self
            .network_monitor
            .get_current_condition(source_device)
            .await;

        if let Ok(Some(condition)) = network_conditions {
            if condition.current_bandwidth_mbps < 1.0 || condition.packet_loss_rate > 0.05 {
                // Poor network conditions - defer sync
                tracing::warn!("Poor network conditions detected, deferring sync");
                return Ok(());
            }
        }

        // Note: Sync operation is queued, processing handled by background task

        tracing::info!("Triple synchronization completed successfully");
        Ok(())
    }

    /// Synchronize named graph
    async fn sync_graph(
        &self,
        source_device: &str,
        target: &str,
        graph_name: &str,
        content: &str,
    ) -> Result<()> {
        tracing::info!(
            "Synchronizing graph '{}' from {} to {} ({} bytes)",
            graph_name,
            source_device,
            target,
            content.len()
        );

        // Create sync operation for graph synchronization
        let sync_operation = SyncOperation {
            operation_id: format!(
                "sync-graph-{}-{}",
                graph_name,
                SystemTime::now().duration_since(UNIX_EPOCH)?.as_millis()
            ),
            source_device: source_device.to_string(),
            target: target.to_string(),
            data: SyncData::Graph {
                graph_name: graph_name.to_string(),
                content: content.to_string(),
            },
            priority: 70, // High priority for graph sync
            timestamp: SystemTime::now(),
            retry_count: 0,
        };

        // Add to sync queue
        self.sync_queue.lock().await.push_back(sync_operation);

        // Check if target device can handle the graph size
        if let Some(target_profile) = self.device_profiles.read().await.get(target) {
            let estimated_size_mb = content.len() as f64 / 1024.0 / 1024.0;
            if estimated_size_mb > target_profile.storage_profile.available_capacity_mb as f64 * 0.8
            {
                tracing::warn!("Target device may not have enough space for graph sync");
                return Err(anyhow::anyhow!(
                    "Insufficient storage space on target device"
                ));
            }
        }

        // Note: Sync operation is queued, processing handled by background task

        tracing::info!("Graph synchronization completed successfully");
        Ok(())
    }

    /// Synchronize metadata
    async fn sync_metadata(
        &self,
        source_device: &str,
        target: &str,
        metadata_type: &str,
        content: &HashMap<String, String>,
    ) -> Result<()> {
        tracing::info!(
            "Synchronizing metadata type '{}' from {} to {} ({} entries)",
            metadata_type,
            source_device,
            target,
            content.len()
        );

        // Create sync operation for metadata synchronization
        let sync_operation = SyncOperation {
            operation_id: format!(
                "sync-metadata-{}-{}",
                metadata_type,
                SystemTime::now().duration_since(UNIX_EPOCH)?.as_millis()
            ),
            source_device: source_device.to_string(),
            target: target.to_string(),
            data: SyncData::Metadata {
                metadata_type: metadata_type.to_string(),
                content: content.clone(),
            },
            priority: 30, // Lower priority for metadata
            timestamp: SystemTime::now(),
            retry_count: 0,
        };

        // Add to sync queue
        self.sync_queue.lock().await.push_back(sync_operation);

        // Metadata sync is usually small and can be processed immediately
        // unless network conditions are extremely poor
        let network_conditions = self
            .network_monitor
            .get_current_condition(source_device)
            .await;

        if let Ok(Some(condition)) = network_conditions {
            if condition.packet_loss_rate > 0.10 {
                // Very poor network conditions - defer sync
                tracing::warn!("Very poor network conditions detected, deferring metadata sync");
                return Ok(());
            }
        }

        // Note: Sync operation is queued, processing handled by background task

        tracing::info!("Metadata synchronization completed successfully");
        Ok(())
    }

    /// Synchronize configuration
    async fn sync_configuration(
        &self,
        source_device: &str,
        target: &str,
        config_key: &str,
        config_value: &str,
    ) -> Result<()> {
        tracing::info!(
            "Synchronizing configuration key '{}' from {} to {}",
            config_key,
            source_device,
            target
        );

        // Create sync operation for configuration synchronization
        let sync_operation = SyncOperation {
            operation_id: format!(
                "sync-config-{}-{}",
                config_key,
                SystemTime::now().duration_since(UNIX_EPOCH)?.as_millis()
            ),
            source_device: source_device.to_string(),
            target: target.to_string(),
            data: SyncData::Configuration {
                config_key: config_key.to_string(),
                config_value: config_value.to_string(),
            },
            priority: 80, // High priority for configuration changes
            timestamp: SystemTime::now(),
            retry_count: 0,
        };

        // Add to sync queue
        self.sync_queue.lock().await.push_back(sync_operation);

        // Configuration changes should be synchronized immediately
        // regardless of network conditions (but with retry logic)
        tracing::info!("Configuration sync queued with high priority");
        // Note: Sync operation is queued, processing handled by background task

        tracing::info!("Configuration synchronization completed successfully");
        Ok(())
    }

    /// Get device profiles
    pub async fn get_device_profiles(&self) -> HashMap<String, EdgeDeviceProfile> {
        self.device_profiles.read().await.clone()
    }

    /// Get deployment strategies
    pub async fn get_deployment_strategies(&self) -> HashMap<String, EdgeDeploymentStrategy> {
        self.deployment_strategies.read().await.clone()
    }

    /// Get sync queue status
    pub async fn get_sync_queue_status(&self) -> (usize, u32) {
        let queue = self.sync_queue.lock().await;
        let queue_length = queue.len();
        let total_priority: u32 = queue.iter().map(|op| op.priority).sum();
        (queue_length, total_priority)
    }
}

impl Default for NetworkConditionMonitor {
    fn default() -> Self {
        Self::new()
    }
}

impl NetworkConditionMonitor {
    pub fn new() -> Self {
        Self {
            conditions: Arc::new(RwLock::new(HashMap::new())),
            history: Arc::new(RwLock::new(VecDeque::new())),
        }
    }

    pub async fn update_condition(
        &self,
        device_id: String,
        condition: NetworkCondition,
    ) -> Result<()> {
        // Store current condition
        self.conditions
            .write()
            .await
            .insert(device_id.clone(), condition.clone());

        // Add to history
        let mut history = self.history.write().await;
        history.push_back((SystemTime::now(), device_id, condition));

        // Limit history size
        while history.len() > 1000 {
            history.pop_front();
        }

        Ok(())
    }

    pub async fn get_current_condition(&self, device_id: &str) -> Result<Option<NetworkCondition>> {
        Ok(self.conditions.read().await.get(device_id).cloned())
    }
}

impl Default for DataPlacementOptimizer {
    fn default() -> Self {
        Self::new()
    }
}

impl DataPlacementOptimizer {
    pub fn new() -> Self {
        Self {
            access_patterns: Arc::new(RwLock::new(HashMap::new())),
            placement_cache: Arc::new(RwLock::new(HashMap::new())),
        }
    }

    pub async fn update_access_pattern(
        &self,
        data_id: String,
        accessing_device: String,
    ) -> Result<()> {
        let mut patterns = self.access_patterns.write().await;

        let pattern = patterns
            .entry(data_id.clone())
            .or_insert_with(|| AccessPattern {
                data_id: data_id.clone(),
                access_frequency: 0.0,
                last_access: UNIX_EPOCH,
                accessing_devices: HashSet::new(),
                temporal_pattern: vec![0.0; 24],
                correlations: HashMap::new(),
            });

        pattern.access_frequency += 1.0;
        pattern.last_access = SystemTime::now();
        pattern.accessing_devices.insert(accessing_device);

        // Update temporal pattern
        if let Ok(duration) = SystemTime::now().duration_since(UNIX_EPOCH) {
            let hour = (duration.as_secs() / 3600) % 24;
            pattern.temporal_pattern[hour as usize] += 1.0;
        }

        Ok(())
    }

    pub async fn get_placement_recommendation(
        &self,
        data_id: &str,
    ) -> Option<PlacementRecommendation> {
        self.placement_cache.read().await.get(data_id).cloned()
    }
}

impl Default for EdgeCacheManager {
    fn default() -> Self {
        Self::new()
    }
}

impl EdgeCacheManager {
    pub fn new() -> Self {
        Self {
            cache_states: Arc::new(RwLock::new(HashMap::new())),
            cache_policies: Arc::new(RwLock::new(HashMap::new())),
        }
    }

    pub async fn set_cache_policy(&self, device_id: &str, policy: CachePolicy) -> Result<()> {
        self.cache_policies
            .write()
            .await
            .insert(device_id.to_string(), policy);
        Ok(())
    }

    pub async fn get_cache_state(&self, device_id: &str) -> Option<CacheState> {
        self.cache_states.read().await.get(device_id).cloned()
    }
}

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

    #[tokio::test]
    async fn test_edge_device_registration() {
        let manager = EdgeComputingManager::new();

        let device_profile = EdgeDeviceProfile {
            device_id: "test-device-1".to_string(),
            device_type: EdgeDeviceType::Mobile,
            compute_resources: ComputeResources {
                cpu_cores: 4,
                cpu_frequency_mhz: 2400,
                memory_mb: 4096,
                gpu: None,
                accelerators: vec![],
            },
            network_profile: NetworkProfile {
                connection_types: vec![ConnectionType::LTE, ConnectionType::WiFi],
                bandwidth: BandwidthProfile {
                    max_download_mbps: 100.0,
                    max_upload_mbps: 50.0,
                    typical_download_mbps: 30.0,
                    typical_upload_mbps: 10.0,
                    variability: 0.3,
                },
                latency: LatencyProfile {
                    min_latency_ms: 20,
                    avg_latency_ms: 50,
                    max_latency_ms: 200,
                    jitter_ms: 10,
                },
                reliability: ReliabilityProfile {
                    uptime_percentage: 0.95,
                    packet_loss_rate: 0.01,
                    drop_frequency: 2.0,
                    recovery_time_seconds: 30,
                },
                cost_profile: CostProfile {
                    cost_per_mb: 0.01,
                    monthly_allowance_mb: Some(10240),
                    overage_cost_per_mb: Some(0.05),
                },
            },
            storage_profile: StorageProfile {
                total_capacity_mb: 64000,
                available_capacity_mb: 32000,
                storage_type: StorageType::Flash,
                performance: StoragePerformance {
                    sequential_read_mbps: 500.0,
                    sequential_write_mbps: 300.0,
                    random_read_iops: 50000,
                    random_write_iops: 30000,
                },
            },
            power_profile: PowerProfile {
                max_power_watts: 15.0,
                idle_power_watts: 2.0,
                battery_capacity_wh: Some(50.0),
                power_management: PowerManagement {
                    dvfs_support: true,
                    sleep_support: true,
                    power_gating: true,
                    wake_on_network: true,
                },
            },
            location: EdgeLocation {
                coordinates: Some((37.7749, -122.4194)),
                region: "us-west-1".to_string(),
                timezone: "America/Los_Angeles".to_string(),
                mobility: MobilityProfile {
                    is_mobile: true,
                    typical_speed_ms: 5.0,
                    predictability: 0.7,
                    coverage_radius_m: 10000.0,
                },
            },
        };

        assert!(manager.register_device(device_profile).await.is_ok());

        let profiles = manager.get_device_profiles().await;
        assert!(profiles.contains_key("test-device-1"));

        let strategies = manager.get_deployment_strategies().await;
        assert!(strategies.contains_key("test-device-1"));
    }

    #[tokio::test]
    async fn test_sync_operation_scheduling() {
        let manager = EdgeComputingManager::new();

        let sync_data = SyncData::Triples {
            triples: vec![
                (
                    "subject1".to_string(),
                    "predicate1".to_string(),
                    "object1".to_string(),
                ),
                (
                    "subject2".to_string(),
                    "predicate2".to_string(),
                    "object2".to_string(),
                ),
            ],
            graph: Some("test-graph".to_string()),
        };

        let operation_id = manager
            .schedule_sync("device1".to_string(), "cloud".to_string(), sync_data, 10)
            .await
            .unwrap();

        assert!(!operation_id.is_empty());

        let (queue_length, _) = manager.get_sync_queue_status().await;
        assert_eq!(queue_length, 1);
    }

    #[test]
    fn test_deployment_strategy_recommendation() {
        // Test that mobile devices get partial replication
        let mobile_profile = EdgeDeviceProfile {
            device_id: "mobile-1".to_string(),
            device_type: EdgeDeviceType::Mobile,
            compute_resources: ComputeResources {
                cpu_cores: 4,
                cpu_frequency_mhz: 2400,
                memory_mb: 4096,
                gpu: None,
                accelerators: vec![],
            },
            network_profile: NetworkProfile {
                connection_types: vec![ConnectionType::LTE],
                bandwidth: BandwidthProfile {
                    max_download_mbps: 50.0,
                    max_upload_mbps: 20.0,
                    typical_download_mbps: 20.0,
                    typical_upload_mbps: 5.0,
                    variability: 0.4,
                },
                latency: LatencyProfile {
                    min_latency_ms: 30,
                    avg_latency_ms: 80,
                    max_latency_ms: 300,
                    jitter_ms: 20,
                },
                reliability: ReliabilityProfile {
                    uptime_percentage: 0.9,
                    packet_loss_rate: 0.02,
                    drop_frequency: 5.0,
                    recovery_time_seconds: 60,
                },
                cost_profile: CostProfile {
                    cost_per_mb: 0.02,
                    monthly_allowance_mb: Some(5120),
                    overage_cost_per_mb: Some(0.1),
                },
            },
            storage_profile: StorageProfile {
                total_capacity_mb: 32000,
                available_capacity_mb: 16000,
                storage_type: StorageType::Flash,
                performance: StoragePerformance {
                    sequential_read_mbps: 300.0,
                    sequential_write_mbps: 200.0,
                    random_read_iops: 30000,
                    random_write_iops: 20000,
                },
            },
            power_profile: PowerProfile {
                max_power_watts: 10.0,
                idle_power_watts: 1.5,
                battery_capacity_wh: Some(30.0),
                power_management: PowerManagement {
                    dvfs_support: true,
                    sleep_support: true,
                    power_gating: true,
                    wake_on_network: false,
                },
            },
            location: EdgeLocation {
                coordinates: Some((40.7128, -74.0060)),
                region: "us-east-1".to_string(),
                timezone: "America/New_York".to_string(),
                mobility: MobilityProfile {
                    is_mobile: true,
                    typical_speed_ms: 10.0,
                    predictability: 0.5,
                    coverage_radius_m: 50000.0,
                },
            },
        };

        // In a real test, we'd create the manager and call recommend_deployment_strategy
        // This is just testing the structure
        assert_eq!(mobile_profile.device_type, EdgeDeviceType::Mobile);
    }
}