quantrs2-device 0.1.3

//! Resource monitoring and load balancing

use super::config::*;
use super::types::*;
use crate::translation::HardwareBackend;
use crate::DeviceResult;
use serde::{Deserialize, Serialize};
use std::collections::{HashMap, VecDeque};
use std::time::{Duration, SystemTime};

pub struct ResourceMonitor {
    cpu_usage: HashMap<usize, f64>,
    memory_usage: f64,
    qpu_usage: HashMap<HardwareBackend, f64>,
    network_usage: f64,
    storage_usage: f64,
    monitoring_start_time: SystemTime,
    last_update: SystemTime,
}

/// Performance tracker for optimization
pub struct PerformanceTracker {
    pub execution_history: VecDeque<ExecutionRecord>,
    pub performance_metrics: PerformanceMetrics,
    pub optimization_suggestions: Vec<OptimizationSuggestion>,
    pub baseline_metrics: Option<PerformanceMetrics>,
}

/// Execution record
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ExecutionRecord {
    pub task_id: String,
    pub task_type: TaskType,
    pub execution_time: Duration,
    pub resource_usage: ResourceUsage,
    pub quality_metrics: ExecutionQualityMetrics,
    pub timestamp: SystemTime,
    pub backend: HardwareBackend,
}

/// Task types
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum TaskType {
    /// Circuit-level task
    Circuit,
    /// Gate-level task
    Gate,
    /// Batch task
    Batch,
    /// System task
    System,
}

/// Resource usage metrics
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ResourceUsage {
    pub cpu_usage: f64,
    pub memory_usage: f64,
    pub qpu_usage: f64,
    pub network_usage: f64,
    pub storage_usage: f64,
    pub energy_consumption: f64,
}

/// Execution quality metrics
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ExecutionQualityMetrics {
    pub fidelity: Option<f64>,
    pub error_rate: Option<f64>,
    pub success_rate: f64,
    pub calibration_quality: Option<f64>,
    pub result_consistency: Option<f64>,
}

/// Performance metrics
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceMetrics {
    pub throughput: f64,          // circuits per second
    pub latency: Duration,        // average execution time
    pub resource_efficiency: f64, // 0.0 to 1.0
    pub quality_score: f64,       // 0.0 to 1.0
    pub cost_efficiency: f64,     // performance per cost unit
    pub energy_efficiency: f64,   // performance per energy unit
}

/// Optimization suggestion
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct OptimizationSuggestion {
    pub category: OptimizationCategory,
    pub description: String,
    pub expected_improvement: f64,
    pub implementation_cost: f64,
    pub priority: SuggestionPriority,
    pub applicable_conditions: Vec<String>,
}

/// Optimization categories
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum OptimizationCategory {
    /// Resource allocation optimization
    ResourceAllocation,
    /// Scheduling optimization
    Scheduling,
    /// Load balancing optimization
    LoadBalancing,
    /// Caching optimization
    Caching,
    /// Network optimization
    Network,
    /// Hardware utilization optimization
    HardwareUtilization,
}

/// Suggestion priorities
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
pub enum SuggestionPriority {
    /// Low priority suggestion
    Low,
    /// Medium priority suggestion
    Medium,
    /// High priority suggestion
    High,
    /// Critical priority suggestion
    Critical,
}

/// Load balancer for distributing work
pub struct LoadBalancer {
    algorithm: LoadBalancingAlgorithm,
    backend_loads: HashMap<HardwareBackend, LoadMetrics>,
    load_history: VecDeque<LoadSnapshot>,
    rebalancing_strategy: RebalancingStrategy,
    migration_tracker: MigrationTracker,
}

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

impl ResourceMonitor {
    pub fn new() -> Self {
        Self {
            cpu_usage: HashMap::new(),
            memory_usage: 0.0,
            qpu_usage: HashMap::new(),
            network_usage: 0.0,
            storage_usage: 0.0,
            monitoring_start_time: SystemTime::now(),
            last_update: SystemTime::now(),
        }
    }
}

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

impl PerformanceTracker {
    pub const fn new() -> Self {
        Self {
            execution_history: VecDeque::new(),
            performance_metrics: PerformanceMetrics {
                throughput: 0.0,
                latency: Duration::from_secs(0),
                resource_efficiency: 0.0,
                quality_score: 0.0,
                cost_efficiency: 0.0,
                energy_efficiency: 0.0,
            },
            optimization_suggestions: Vec::new(),
            baseline_metrics: None,
        }
    }
}

impl LoadBalancer {
    pub fn new(algorithm: LoadBalancingAlgorithm) -> Self {
        Self {
            algorithm,
            backend_loads: HashMap::new(),
            load_history: VecDeque::new(),
            rebalancing_strategy: RebalancingStrategy::Hybrid,
            migration_tracker: MigrationTracker::new(),
        }
    }

    pub async fn rebalance_loads(&mut self) -> DeviceResult<LoadBalancingResult> {
        // Implementation for load rebalancing
        Ok(LoadBalancingResult {
            rebalancing_performed: false,
            migrations_performed: 0,
            load_improvement: 0.0,
            estimated_performance_gain: 0.0,
            rebalancing_cost: 0.0,
        })
    }
}

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

impl MigrationTracker {
    pub fn new() -> Self {
        Self {
            active_migrations: HashMap::new(),
            migration_history: VecDeque::new(),
            migration_costs: HashMap::new(),
        }
    }
}