quantrs2-device 0.1.3

//! Seamless Circuit Module Integration
//!
//! This module provides a comprehensive, unified interface for quantum circuit execution
//! across heterogeneous quantum computing platforms. It features automatic platform
//! detection, intelligent circuit adaptation, performance optimization, and seamless
//! execution management with advanced analytics and monitoring capabilities.

use std::collections::HashMap;
use std::sync::{Arc, RwLock};
use std::time::{Duration, Instant, SystemTime};

use serde::{Deserialize, Serialize};
use tokio::sync::mpsc;

use quantrs2_circuit::prelude::*;
use quantrs2_core::{
    error::{QuantRS2Error, QuantRS2Result},
    gate::GateOp,
    qubit::QubitId,
};

use crate::{
    backend_traits::{query_backend_capabilities, BackendCapabilities},
    calibration::{CalibrationManager, DeviceCalibration},
    topology::HardwareTopology,
    DeviceError, DeviceResult,
};

/// Universal quantum circuit interface for seamless cross-platform execution
#[derive(Debug)]
pub struct UniversalCircuitInterface {
    /// Configuration for the interface
    config: IntegrationConfig,
    /// Available quantum platforms
    platforms: Arc<RwLock<HashMap<String, PlatformAdapter>>>,
    /// Circuit optimization cache
    optimization_cache: Arc<RwLock<HashMap<String, OptimizedCircuit>>>,
    /// Performance analytics engine
    analytics: Arc<RwLock<ExecutionAnalytics>>,
    /// Platform selection engine
    platform_selector: Arc<RwLock<PlatformSelector>>,
    /// Execution monitor
    execution_monitor: Arc<RwLock<ExecutionMonitor>>,
}

/// Configuration for circuit integration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct IntegrationConfig {
    /// Enable automatic platform selection
    pub auto_platform_selection: bool,
    /// Enable circuit optimization
    pub enable_optimization: bool,
    /// Enable performance analytics
    pub enable_analytics: bool,
    /// Maximum execution time per circuit
    pub max_execution_time: Duration,
    /// Maximum circuit size for optimization
    pub max_circuit_size: usize,
    /// Platform selection criteria
    pub selection_criteria: SelectionCriteria,
    /// Optimization settings
    pub optimization_settings: OptimizationSettings,
    /// Analytics configuration
    pub analytics_config: AnalyticsConfig,
    /// Caching configuration
    pub cache_config: CacheConfig,
}

/// Platform selection criteria
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SelectionCriteria {
    /// Prioritize execution speed
    pub prioritize_speed: bool,
    /// Prioritize accuracy/fidelity
    pub prioritize_accuracy: bool,
    /// Prioritize cost efficiency
    pub prioritize_cost: bool,
    /// Required minimum fidelity
    pub min_fidelity: f64,
    /// Maximum acceptable cost
    pub max_cost: f64,
    /// Required qubit count
    pub required_qubits: Option<usize>,
    /// Required gate types
    pub required_gates: Vec<String>,
    /// Platform preferences
    pub platform_preferences: Vec<String>,
    /// Fallback platforms
    pub fallback_platforms: Vec<String>,
}

/// Circuit optimization settings
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct OptimizationSettings {
    /// Enable gate optimization
    pub enable_gate_optimization: bool,
    /// Enable topology optimization
    pub enable_topology_optimization: bool,
    /// Enable scheduling optimization
    pub enable_scheduling_optimization: bool,
    /// Optimization level (1-3)
    pub optimization_level: u8,
    /// Maximum optimization time
    pub max_optimization_time: Duration,
    /// Enable parallel optimization
    pub enable_parallel_optimization: bool,
    /// Custom optimization parameters
    pub custom_parameters: HashMap<String, f64>,
}

/// Analytics configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AnalyticsConfig {
    /// Enable performance tracking
    pub enable_performance_tracking: bool,
    /// Enable error analysis
    pub enable_error_analysis: bool,
    /// Enable cost tracking
    pub enable_cost_tracking: bool,
    /// Analytics retention period
    pub retention_period: Duration,
    /// Metrics collection interval
    pub collection_interval: Duration,
    /// Enable real-time monitoring
    pub enable_realtime_monitoring: bool,
}

/// Cache configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CacheConfig {
    /// Enable circuit caching
    pub enable_caching: bool,
    /// Maximum cache size
    pub max_cache_size: usize,
    /// Cache TTL
    pub cache_ttl: Duration,
    /// Enable distributed caching
    pub enable_distributed_cache: bool,
}

/// Platform adapter for different quantum backends
#[derive(Debug, Clone)]
pub struct PlatformAdapter {
    /// Platform identifier
    pub platform_id: String,
    /// Platform name
    pub platform_name: String,
    /// Platform capabilities
    pub capabilities: BackendCapabilities,
    /// Platform-specific configuration
    pub config: PlatformConfig,
    /// Calibration data
    pub calibration: Option<DeviceCalibration>,
    /// Performance metrics
    pub performance_metrics: PlatformMetrics,
    /// Connection status
    pub status: PlatformStatus,
}

/// Platform-specific configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PlatformConfig {
    /// API endpoint
    pub endpoint: String,
    /// Authentication credentials
    pub credentials: Option<String>,
    /// Platform-specific parameters
    pub parameters: HashMap<String, String>,
    /// Timeout settings
    pub timeout: Duration,
    /// Retry configuration
    pub retry_config: RetryConfig,
}

/// Retry configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RetryConfig {
    /// Maximum number of retries
    pub max_retries: u32,
    /// Base retry delay
    pub base_delay: Duration,
    /// Maximum retry delay
    pub max_delay: Duration,
    /// Exponential backoff factor
    pub backoff_factor: f64,
}

/// Platform performance metrics
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PlatformMetrics {
    /// Average execution time
    pub avg_execution_time: Duration,
    /// Success rate
    pub success_rate: f64,
    /// Average fidelity
    pub avg_fidelity: f64,
    /// Average cost per shot
    pub avg_cost_per_shot: f64,
    /// Queue wait time
    pub avg_queue_time: Duration,
    /// Throughput (circuits per hour)
    pub throughput: f64,
    /// Error rates by gate type
    pub gate_error_rates: HashMap<String, f64>,
    /// Uptime percentage
    pub uptime: f64,
}

/// Platform status
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum PlatformStatus {
    Available,
    Busy,
    Maintenance,
    Offline,
    Error(String),
}

/// Optimized circuit representation
#[derive(Debug)]
pub struct OptimizedCircuit {
    /// Original circuit hash
    pub original_hash: String,
    /// Optimized circuit for each platform
    pub platform_circuits: HashMap<String, CircuitVariant>,
    /// Optimization metadata
    pub optimization_metadata: OptimizationMetadata,
    /// Creation timestamp
    pub created_at: SystemTime,
    /// Last access timestamp
    pub last_accessed: SystemTime,
}

/// Circuit variant for a specific platform
#[derive(Debug)]
pub struct CircuitVariant {
    /// Adapted circuit
    pub circuit: Box<dyn CircuitInterface>,
    /// Platform-specific metadata
    pub metadata: PlatformMetadata,
    /// Estimated performance
    pub estimated_performance: PerformanceEstimate,
    /// Optimization applied
    pub optimizations_applied: Vec<OptimizationType>,
}

/// Generic circuit interface
pub trait CircuitInterface: std::fmt::Debug {
    /// Execute the circuit
    fn execute(&self, shots: usize) -> DeviceResult<ExecutionResult>;
    /// Get circuit depth
    fn depth(&self) -> usize;
    /// Get number of qubits
    fn num_qubits(&self) -> usize;
    /// Get gate count
    fn gate_count(&self) -> usize;
    /// Clone the circuit
    fn clone_circuit(&self) -> Box<dyn CircuitInterface>;
}

/// Platform-specific metadata
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PlatformMetadata {
    /// Platform ID
    pub platform_id: String,
    /// Compilation time
    pub compilation_time: Duration,
    /// Estimated execution time
    pub estimated_execution_time: Duration,
    /// Resource requirements
    pub resource_requirements: ResourceRequirements,
    /// Compatibility score
    pub compatibility_score: f64,
}

/// Resource requirements
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ResourceRequirements {
    /// Required qubits
    pub qubits: usize,
    /// Required classical memory
    pub classical_memory: usize,
    /// Estimated execution time
    pub execution_time: Duration,
    /// Required gate types
    pub gate_types: Vec<String>,
    /// Special requirements
    pub special_requirements: Vec<String>,
}

/// Performance estimate
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceEstimate {
    /// Estimated fidelity
    pub estimated_fidelity: f64,
    /// Estimated execution time
    pub estimated_execution_time: Duration,
    /// Estimated cost
    pub estimated_cost: f64,
    /// Confidence interval
    pub confidence: f64,
    /// Error estimates
    pub error_estimates: ErrorEstimates,
}

/// Error estimates
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ErrorEstimates {
    /// Gate error contribution
    pub gate_error: f64,
    /// Readout error contribution
    pub readout_error: f64,
    /// Coherence error contribution
    pub coherence_error: f64,
    /// Total estimated error
    pub total_error: f64,
}

/// Types of optimizations that can be applied
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum OptimizationType {
    GateOptimization,
    TopologyMapping,
    SchedulingOptimization,
    ErrorMitigation,
    ResourceOptimization,
    Custom(String),
}

/// Optimization metadata
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct OptimizationMetadata {
    /// Optimization time
    pub optimization_time: Duration,
    /// Optimizations applied
    pub optimizations_applied: Vec<OptimizationType>,
    /// Performance improvement
    pub performance_improvement: f64,
    /// Optimization parameters used
    pub parameters_used: HashMap<String, f64>,
    /// Success status
    pub success: bool,
}

/// Execution analytics engine
#[derive(Debug)]
pub struct ExecutionAnalytics {
    /// Execution history
    execution_history: Vec<ExecutionRecord>,
    /// Performance trends
    performance_trends: HashMap<String, TrendData>,
    /// Error analysis
    error_analysis: ErrorAnalysis,
    /// Cost analytics
    cost_analytics: CostAnalytics,
    /// Platform comparisons
    platform_comparisons: HashMap<String, PlatformComparison>,
}

/// Execution record
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ExecutionRecord {
    /// Execution ID
    pub execution_id: String,
    /// Circuit hash
    pub circuit_hash: String,
    /// Platform used
    pub platform_id: String,
    /// Execution time
    pub execution_time: Duration,
    /// Success status
    pub success: bool,
    /// Results obtained
    pub results: Option<ExecutionResult>,
    /// Error information
    pub error: Option<String>,
    /// Cost incurred
    pub cost: f64,
    /// Timestamp
    pub timestamp: SystemTime,
}

/// Trend data for analytics
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TrendData {
    /// Data points over time
    pub data_points: Vec<(SystemTime, f64)>,
    /// Trend direction
    pub trend_direction: TrendDirection,
    /// Trend strength
    pub trend_strength: f64,
    /// Prediction for next period
    pub prediction: Option<f64>,
}

/// Trend direction
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum TrendDirection {
    Increasing,
    Decreasing,
    Stable,
    Volatile,
}

/// Error analysis data
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ErrorAnalysis {
    /// Error rates by platform
    pub platform_error_rates: HashMap<String, f64>,
    /// Error types frequency
    pub error_types: HashMap<String, usize>,
    /// Error correlation analysis
    pub error_correlations: HashMap<String, f64>,
    /// Most common errors
    pub common_errors: Vec<String>,
}

/// Cost analytics
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CostAnalytics {
    /// Total cost by platform
    pub total_cost_by_platform: HashMap<String, f64>,
    /// Average cost per execution
    pub avg_cost_per_execution: HashMap<String, f64>,
    /// Cost trends
    pub cost_trends: HashMap<String, TrendData>,
    /// Cost optimization opportunities
    pub optimization_opportunities: Vec<CostOptimizationTip>,
}

/// Cost optimization tip
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CostOptimizationTip {
    /// Tip description
    pub description: String,
    /// Potential savings
    pub potential_savings: f64,
    /// Implementation difficulty
    pub difficulty: OptimizationDifficulty,
    /// Recommended actions
    pub recommended_actions: Vec<String>,
}

/// Optimization difficulty levels
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum OptimizationDifficulty {
    Easy,
    Medium,
    Hard,
    Expert,
}

/// Platform comparison data
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PlatformComparison {
    /// Platforms being compared
    pub platforms: Vec<String>,
    /// Performance comparison
    pub performance_scores: HashMap<String, f64>,
    /// Cost comparison
    pub cost_scores: HashMap<String, f64>,
    /// Reliability comparison
    pub reliability_scores: HashMap<String, f64>,
    /// Overall recommendation
    pub recommendation: String,
}

/// Platform selection engine
pub struct PlatformSelector {
    /// Selection algorithms
    selection_algorithms: Vec<Box<dyn SelectionAlgorithm>>,
    /// Platform rankings
    platform_rankings: HashMap<String, f64>,
    /// Selection history
    selection_history: Vec<SelectionRecord>,
    /// Learning model for platform selection
    learning_model: Option<Box<dyn SelectionLearningModel>>,
}

/// Selection algorithm trait
pub trait SelectionAlgorithm {
    /// Select best platform for a circuit
    fn select_platform(
        &self,
        circuit: &dyn CircuitInterface,
        platforms: &[PlatformAdapter],
        criteria: &SelectionCriteria,
    ) -> DeviceResult<String>;

    /// Get algorithm name
    fn name(&self) -> &str;
}

impl std::fmt::Debug for PlatformSelector {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("PlatformSelector")
            .field("platform_rankings", &self.platform_rankings)
            .field("selection_history", &self.selection_history)
            .field("learning_model", &"<learning_model>")
            .finish()
    }
}

/// Selection learning model trait
pub trait SelectionLearningModel {
    /// Update model with execution results
    fn update(&mut self, record: &SelectionRecord, result: &ExecutionResult);

    /// Predict platform performance
    fn predict_performance(&self, circuit: &dyn CircuitInterface, platform: &str) -> f64;
}

/// Platform selection record
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SelectionRecord {
    /// Circuit characteristics
    pub circuit_hash: String,
    /// Selected platform
    pub selected_platform: String,
    /// Selection criteria used
    pub criteria: SelectionCriteria,
    /// Selection confidence
    pub confidence: f64,
    /// Actual performance achieved
    pub actual_performance: Option<f64>,
    /// Selection timestamp
    pub timestamp: SystemTime,
}

/// Execution monitoring
#[derive(Debug)]
pub struct ExecutionMonitor {
    /// Active executions
    active_executions: HashMap<String, ActiveExecution>,
    /// Monitoring channels
    monitoring_channels: Vec<mpsc::Sender<MonitoringEvent>>,
    /// Alert thresholds
    alert_thresholds: AlertThresholds,
    /// Performance baselines
    performance_baselines: HashMap<String, PerformanceBaseline>,
}

/// Active execution tracking
#[derive(Debug, Clone)]
pub struct ActiveExecution {
    /// Execution ID
    pub execution_id: String,
    /// Platform being used
    pub platform_id: String,
    /// Start time
    pub start_time: Instant,
    /// Expected completion time
    pub expected_completion: Instant,
    /// Current status
    pub status: ExecutionStatus,
    /// Progress percentage
    pub progress: f64,
    /// Resource usage
    pub resource_usage: ResourceUsage,
}

/// Execution status
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum ExecutionStatus {
    Queued,
    Running,
    Completed,
    Failed,
    Cancelled,
    Timeout,
}

/// Resource usage tracking
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ResourceUsage {
    /// CPU usage
    pub cpu_usage: f64,
    /// Memory usage
    pub memory_usage: f64,
    /// Network usage
    pub network_usage: f64,
    /// Platform-specific resources
    pub platform_resources: HashMap<String, f64>,
}

/// Monitoring events
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum MonitoringEvent {
    ExecutionStarted {
        execution_id: String,
        platform_id: String,
    },
    ExecutionProgress {
        execution_id: String,
        progress: f64,
    },
    ExecutionCompleted {
        execution_id: String,
        result: ExecutionResult,
    },
    ExecutionFailed {
        execution_id: String,
        error: String,
    },
    PlatformStatusChanged {
        platform_id: String,
        status: PlatformStatus,
    },
    PerformanceAlert {
        platform_id: String,
        metric: String,
        value: f64,
    },
    CostAlert {
        platform_id: String,
        cost: f64,
    },
}

/// Alert thresholds
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AlertThresholds {
    /// Maximum execution time
    pub max_execution_time: Duration,
    /// Minimum success rate
    pub min_success_rate: f64,
    /// Maximum cost per execution
    pub max_cost_per_execution: f64,
    /// Maximum error rate
    pub max_error_rate: f64,
}

/// Performance baselines
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceBaseline {
    /// Platform ID
    pub platform_id: String,
    /// Baseline execution time
    pub baseline_execution_time: Duration,
    /// Baseline success rate
    pub baseline_success_rate: f64,
    /// Baseline cost
    pub baseline_cost: f64,
    /// Baseline fidelity
    pub baseline_fidelity: f64,
    /// Last updated
    pub last_updated: SystemTime,
}

/// Execution result
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ExecutionResult {
    /// Measurement results
    pub measurements: HashMap<String, Vec<u8>>,
    /// Execution metadata
    pub metadata: ExecutionMetadata,
    /// Performance metrics
    pub performance: PerformanceMetrics,
    /// Cost information
    pub cost_info: CostInfo,
}

/// Execution metadata
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ExecutionMetadata {
    /// Execution ID
    pub execution_id: String,
    /// Platform used
    pub platform_id: String,
    /// Shots executed
    pub shots: usize,
    /// Execution time
    pub execution_time: Duration,
    /// Queue wait time
    pub queue_time: Duration,
    /// Job ID on platform
    pub job_id: Option<String>,
}

/// Performance metrics
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceMetrics {
    /// Measured fidelity
    pub fidelity: f64,
    /// Error rate
    pub error_rate: f64,
    /// Throughput
    pub throughput: f64,
    /// Success status
    pub success: bool,
}

/// Cost information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CostInfo {
    /// Total cost
    pub total_cost: f64,
    /// Cost per shot
    pub cost_per_shot: f64,
    /// Currency
    pub currency: String,
    /// Cost breakdown
    pub cost_breakdown: HashMap<String, f64>,
}

impl Default for IntegrationConfig {
    fn default() -> Self {
        Self {
            auto_platform_selection: true,
            enable_optimization: true,
            enable_analytics: true,
            max_execution_time: Duration::from_secs(300),
            max_circuit_size: 1000,
            selection_criteria: SelectionCriteria::default(),
            optimization_settings: OptimizationSettings::default(),
            analytics_config: AnalyticsConfig::default(),
            cache_config: CacheConfig::default(),
        }
    }
}

impl Default for SelectionCriteria {
    fn default() -> Self {
        Self {
            prioritize_speed: true,
            prioritize_accuracy: true,
            prioritize_cost: false,
            min_fidelity: 0.95,
            max_cost: 100.0,
            required_qubits: None,
            required_gates: vec!["H".to_string(), "CNOT".to_string()],
            platform_preferences: vec![],
            fallback_platforms: vec!["simulator".to_string()],
        }
    }
}

impl Default for OptimizationSettings {
    fn default() -> Self {
        Self {
            enable_gate_optimization: true,
            enable_topology_optimization: true,
            enable_scheduling_optimization: true,
            optimization_level: 2,
            max_optimization_time: Duration::from_secs(30),
            enable_parallel_optimization: true,
            custom_parameters: HashMap::new(),
        }
    }
}

impl Default for AnalyticsConfig {
    fn default() -> Self {
        Self {
            enable_performance_tracking: true,
            enable_error_analysis: true,
            enable_cost_tracking: true,
            retention_period: Duration::from_secs(30 * 24 * 3600), // 30 days
            collection_interval: Duration::from_secs(60),
            enable_realtime_monitoring: true,
        }
    }
}

impl Default for CacheConfig {
    fn default() -> Self {
        Self {
            enable_caching: true,
            max_cache_size: 1000,
            cache_ttl: Duration::from_secs(3600),
            enable_distributed_cache: false,
        }
    }
}

impl UniversalCircuitInterface {
    /// Create a new universal circuit interface
    pub fn new(config: IntegrationConfig) -> Self {
        Self {
            config,
            platforms: Arc::new(RwLock::new(HashMap::new())),
            optimization_cache: Arc::new(RwLock::new(HashMap::new())),
            analytics: Arc::new(RwLock::new(ExecutionAnalytics::new())),
            platform_selector: Arc::new(RwLock::new(PlatformSelector::new())),
            execution_monitor: Arc::new(RwLock::new(ExecutionMonitor::new())),
        }
    }

    /// Register a quantum platform
    pub fn register_platform(&self, adapter: PlatformAdapter) -> DeviceResult<()> {
        let mut platforms = self
            .platforms
            .write()
            .expect("Platforms RwLock should not be poisoned");
        platforms.insert(adapter.platform_id.clone(), adapter);
        Ok(())
    }

    /// Execute a circuit with automatic platform selection and optimization
    pub async fn execute_circuit<const N: usize>(
        &self,
        circuit: &Circuit<N>,
        shots: usize,
    ) -> DeviceResult<ExecutionResult> {
        // Get circuit hash for caching
        let circuit_hash = Self::calculate_circuit_hash(circuit);

        // Check optimization cache
        if self.config.enable_optimization {
            if let Some(optimized) = self.get_cached_optimization(&circuit_hash) {
                return self.execute_optimized_circuit(&optimized, shots).await;
            }
        }

        // Select optimal platform
        let platform_id = if self.config.auto_platform_selection {
            self.select_optimal_platform(circuit).await?
        } else {
            self.get_default_platform()?
        };

        // Optimize circuit for selected platform
        let optimized_circuit = if self.config.enable_optimization {
            self.optimize_circuit_for_platform(circuit, &platform_id)
                .await?
        } else {
            self.create_basic_circuit_variant(circuit, &platform_id)?
        };

        // Cache optimization if enabled
        if self.config.enable_optimization && self.config.cache_config.enable_caching {
            self.cache_optimization(&circuit_hash, optimized_circuit.clone());
        }

        // Execute circuit
        let result = self
            .execute_on_platform(&optimized_circuit, &platform_id, shots)
            .await?;

        // Record analytics
        if self.config.enable_analytics {
            self.record_execution_analytics(&circuit_hash, &platform_id, &result)
                .await;
        }

        Ok(result)
    }

    /// Get available platforms
    pub fn get_available_platforms(&self) -> Vec<String> {
        let platforms = self
            .platforms
            .read()
            .expect("Platforms RwLock should not be poisoned");
        platforms.keys().cloned().collect()
    }

    /// Get platform capabilities
    pub fn get_platform_capabilities(&self, platform_id: &str) -> Option<BackendCapabilities> {
        let platforms = self
            .platforms
            .read()
            .expect("Platforms RwLock should not be poisoned");
        platforms.get(platform_id).map(|p| p.capabilities.clone())
    }

    /// Get execution analytics
    pub fn get_analytics(&self) -> ExecutionAnalytics {
        self.analytics
            .read()
            .expect("Analytics RwLock should not be poisoned")
            .clone()
    }

    // Private implementation methods

    fn calculate_circuit_hash<const N: usize>(circuit: &Circuit<N>) -> String {
        // Simplified hash calculation - in production would use proper circuit hashing
        format!("circuit_{}_{}", N, circuit.gates().len())
    }

    fn get_cached_optimization(&self, circuit_hash: &str) -> Option<OptimizedCircuit> {
        let cache = self
            .optimization_cache
            .read()
            .expect("Optimization cache RwLock should not be poisoned");
        cache.get(circuit_hash).cloned()
    }

    async fn select_optimal_platform<const N: usize>(
        &self,
        circuit: &Circuit<N>,
    ) -> DeviceResult<String> {
        // Simplified platform selection - would use sophisticated algorithms
        let platforms = self
            .platforms
            .read()
            .expect("Platforms RwLock should not be poisoned");
        if let Some((platform_id, _)) = platforms.iter().next() {
            Ok(platform_id.clone())
        } else {
            Err(DeviceError::DeviceNotFound(
                "No platforms available".to_string(),
            ))
        }
    }

    fn get_default_platform(&self) -> DeviceResult<String> {
        let platforms = self
            .platforms
            .read()
            .expect("Platforms RwLock should not be poisoned");
        if let Some((platform_id, _)) = platforms.iter().next() {
            Ok(platform_id.clone())
        } else {
            Err(DeviceError::DeviceNotFound(
                "No platforms available".to_string(),
            ))
        }
    }

    async fn optimize_circuit_for_platform<const N: usize>(
        &self,
        circuit: &Circuit<N>,
        platform_id: &str,
    ) -> DeviceResult<OptimizedCircuit> {
        // Simplified optimization - would implement sophisticated optimization algorithms
        let circuit_hash = Self::calculate_circuit_hash(circuit);
        let mut platform_circuits = HashMap::new();

        let variant = CircuitVariant {
            circuit: Box::new(GenericCircuitWrapper::new(circuit.clone())),
            metadata: PlatformMetadata {
                platform_id: platform_id.to_string(),
                compilation_time: Duration::from_millis(100),
                estimated_execution_time: Duration::from_secs(1),
                resource_requirements: ResourceRequirements {
                    qubits: N,
                    classical_memory: 1024,
                    execution_time: Duration::from_secs(1),
                    gate_types: vec!["H".to_string(), "CNOT".to_string()],
                    special_requirements: vec![],
                },
                compatibility_score: 0.95,
            },
            estimated_performance: PerformanceEstimate {
                estimated_fidelity: 0.95,
                estimated_execution_time: Duration::from_secs(1),
                estimated_cost: 1.0,
                confidence: 0.8,
                error_estimates: ErrorEstimates {
                    gate_error: 0.01,
                    readout_error: 0.02,
                    coherence_error: 0.01,
                    total_error: 0.04,
                },
            },
            optimizations_applied: vec![OptimizationType::GateOptimization],
        };

        platform_circuits.insert(platform_id.to_string(), variant);

        Ok(OptimizedCircuit {
            original_hash: circuit_hash,
            platform_circuits,
            optimization_metadata: OptimizationMetadata {
                optimization_time: Duration::from_millis(100),
                optimizations_applied: vec![OptimizationType::GateOptimization],
                performance_improvement: 0.1,
                parameters_used: HashMap::new(),
                success: true,
            },
            created_at: SystemTime::now(),
            last_accessed: SystemTime::now(),
        })
    }

    fn create_basic_circuit_variant<const N: usize>(
        &self,
        circuit: &Circuit<N>,
        platform_id: &str,
    ) -> DeviceResult<OptimizedCircuit> {
        // Create basic variant without optimization
        let circuit_hash = Self::calculate_circuit_hash(circuit);
        let mut platform_circuits = HashMap::new();

        let variant = CircuitVariant {
            circuit: Box::new(GenericCircuitWrapper::new(circuit.clone())),
            metadata: PlatformMetadata {
                platform_id: platform_id.to_string(),
                compilation_time: Duration::from_millis(10),
                estimated_execution_time: Duration::from_secs(1),
                resource_requirements: ResourceRequirements {
                    qubits: N,
                    classical_memory: 512,
                    execution_time: Duration::from_secs(1),
                    gate_types: vec!["H".to_string(), "CNOT".to_string()],
                    special_requirements: vec![],
                },
                compatibility_score: 0.8,
            },
            estimated_performance: PerformanceEstimate {
                estimated_fidelity: 0.9,
                estimated_execution_time: Duration::from_secs(1),
                estimated_cost: 1.5,
                confidence: 0.7,
                error_estimates: ErrorEstimates {
                    gate_error: 0.02,
                    readout_error: 0.03,
                    coherence_error: 0.02,
                    total_error: 0.07,
                },
            },
            optimizations_applied: vec![],
        };

        platform_circuits.insert(platform_id.to_string(), variant);

        Ok(OptimizedCircuit {
            original_hash: circuit_hash,
            platform_circuits,
            optimization_metadata: OptimizationMetadata {
                optimization_time: Duration::from_millis(0),
                optimizations_applied: vec![],
                performance_improvement: 0.0,
                parameters_used: HashMap::new(),
                success: true,
            },
            created_at: SystemTime::now(),
            last_accessed: SystemTime::now(),
        })
    }

    fn cache_optimization(&self, circuit_hash: &str, optimized: OptimizedCircuit) {
        let mut cache = self
            .optimization_cache
            .write()
            .expect("Optimization cache RwLock should not be poisoned");

        // Implement LRU eviction if cache is full
        if cache.len() >= self.config.cache_config.max_cache_size {
            // Find oldest entry
            if let Some((oldest_key, _)) = cache.iter().min_by_key(|(_, opt)| opt.last_accessed) {
                let oldest_key = oldest_key.clone();
                cache.remove(&oldest_key);
            }
        }

        cache.insert(circuit_hash.to_string(), optimized);
    }

    async fn execute_optimized_circuit(
        &self,
        optimized: &OptimizedCircuit,
        shots: usize,
    ) -> DeviceResult<ExecutionResult> {
        // Select best platform variant
        if let Some((platform_id, variant)) = optimized.platform_circuits.iter().next() {
            self.execute_circuit_variant(variant, platform_id, shots)
                .await
        } else {
            Err(DeviceError::InvalidInput(
                "No platform variants available".to_string(),
            ))
        }
    }

    async fn execute_on_platform(
        &self,
        optimized: &OptimizedCircuit,
        platform_id: &str,
        shots: usize,
    ) -> DeviceResult<ExecutionResult> {
        if let Some(variant) = optimized.platform_circuits.get(platform_id) {
            self.execute_circuit_variant(variant, platform_id, shots)
                .await
        } else {
            Err(DeviceError::InvalidInput(format!(
                "No variant for platform {platform_id}"
            )))
        }
    }

    async fn execute_circuit_variant(
        &self,
        variant: &CircuitVariant,
        platform_id: &str,
        shots: usize,
    ) -> DeviceResult<ExecutionResult> {
        // Simplified execution - would interface with actual quantum backends
        let execution_id = format!(
            "exec_{}_{}",
            platform_id,
            SystemTime::now()
                .duration_since(SystemTime::UNIX_EPOCH)
                .expect("System time should be after UNIX epoch")
                .as_millis()
        );

        // Simulate execution
        tokio::time::sleep(Duration::from_millis(100)).await;

        Ok(ExecutionResult {
            measurements: HashMap::from([("c".to_string(), vec![0, 1, 0, 1, 1, 0, 1, 0])]),
            metadata: ExecutionMetadata {
                execution_id,
                platform_id: platform_id.to_string(),
                shots,
                execution_time: Duration::from_millis(100),
                queue_time: Duration::from_millis(10),
                job_id: Some("job_123".to_string()),
            },
            performance: PerformanceMetrics {
                fidelity: variant.estimated_performance.estimated_fidelity,
                error_rate: variant.estimated_performance.error_estimates.total_error,
                throughput: shots as f64 / 0.1, // shots per second
                success: true,
            },
            cost_info: CostInfo {
                total_cost: variant.estimated_performance.estimated_cost,
                cost_per_shot: variant.estimated_performance.estimated_cost / shots as f64,
                currency: "USD".to_string(),
                cost_breakdown: HashMap::from([
                    (
                        "execution".to_string(),
                        variant.estimated_performance.estimated_cost * 0.8,
                    ),
                    (
                        "overhead".to_string(),
                        variant.estimated_performance.estimated_cost * 0.2,
                    ),
                ]),
            },
        })
    }

    async fn record_execution_analytics(
        &self,
        circuit_hash: &str,
        platform_id: &str,
        result: &ExecutionResult,
    ) {
        // Record execution analytics
        let mut analytics = self
            .analytics
            .write()
            .expect("Analytics RwLock should not be poisoned");
        analytics.record_execution(circuit_hash, platform_id, result);
    }
}

/// Generic circuit wrapper for the CircuitInterface trait
#[derive(Debug, Clone)]
pub struct GenericCircuitWrapper<const N: usize> {
    circuit: Circuit<N>,
}

impl<const N: usize> GenericCircuitWrapper<N> {
    pub const fn new(circuit: Circuit<N>) -> Self {
        Self { circuit }
    }
}

impl<const N: usize> CircuitInterface for GenericCircuitWrapper<N> {
    fn execute(&self, shots: usize) -> DeviceResult<ExecutionResult> {
        // Simplified execution - would interface with quantum simulators/hardware
        Ok(ExecutionResult {
            measurements: HashMap::from([("c".to_string(), vec![0; shots])]),
            metadata: ExecutionMetadata {
                execution_id: "generic_exec".to_string(),
                platform_id: "generic".to_string(),
                shots,
                execution_time: Duration::from_millis(10),
                queue_time: Duration::from_millis(0),
                job_id: None,
            },
            performance: PerformanceMetrics {
                fidelity: 0.95,
                error_rate: 0.05,
                throughput: shots as f64 / 0.01,
                success: true,
            },
            cost_info: CostInfo {
                total_cost: 0.0,
                cost_per_shot: 0.0,
                currency: "USD".to_string(),
                cost_breakdown: HashMap::new(),
            },
        })
    }

    fn depth(&self) -> usize {
        // Simplified depth calculation
        self.circuit.gates().len()
    }

    fn num_qubits(&self) -> usize {
        N
    }

    fn gate_count(&self) -> usize {
        self.circuit.gates().len()
    }

    fn clone_circuit(&self) -> Box<dyn CircuitInterface> {
        Box::new(self.clone())
    }
}

impl Clone for CircuitVariant {
    fn clone(&self) -> Self {
        Self {
            circuit: self.circuit.clone_circuit(),
            metadata: self.metadata.clone(),
            estimated_performance: self.estimated_performance.clone(),
            optimizations_applied: self.optimizations_applied.clone(),
        }
    }
}

impl Clone for OptimizedCircuit {
    fn clone(&self) -> Self {
        Self {
            original_hash: self.original_hash.clone(),
            platform_circuits: self.platform_circuits.clone(),
            optimization_metadata: self.optimization_metadata.clone(),
            created_at: self.created_at,
            last_accessed: self.last_accessed,
        }
    }
}

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

impl ExecutionAnalytics {
    pub fn new() -> Self {
        Self {
            execution_history: Vec::new(),
            performance_trends: HashMap::new(),
            error_analysis: ErrorAnalysis {
                platform_error_rates: HashMap::new(),
                error_types: HashMap::new(),
                error_correlations: HashMap::new(),
                common_errors: Vec::new(),
            },
            cost_analytics: CostAnalytics {
                total_cost_by_platform: HashMap::new(),
                avg_cost_per_execution: HashMap::new(),
                cost_trends: HashMap::new(),
                optimization_opportunities: Vec::new(),
            },
            platform_comparisons: HashMap::new(),
        }
    }

    pub fn record_execution(
        &mut self,
        circuit_hash: &str,
        platform_id: &str,
        result: &ExecutionResult,
    ) {
        let record = ExecutionRecord {
            execution_id: result.metadata.execution_id.clone(),
            circuit_hash: circuit_hash.to_string(),
            platform_id: platform_id.to_string(),
            execution_time: result.metadata.execution_time,
            success: result.performance.success,
            results: Some(result.clone()),
            error: None,
            cost: result.cost_info.total_cost,
            timestamp: SystemTime::now(),
        };

        self.execution_history.push(record);

        // Update performance trends
        self.update_performance_trends(platform_id, result);

        // Update cost analytics
        self.update_cost_analytics(platform_id, result);
    }

    fn update_performance_trends(&mut self, platform_id: &str, result: &ExecutionResult) {
        let trend_key = format!("{platform_id}_fidelity");
        let trend_data = self
            .performance_trends
            .entry(trend_key)
            .or_insert_with(|| TrendData {
                data_points: Vec::new(),
                trend_direction: TrendDirection::Stable,
                trend_strength: 0.0,
                prediction: None,
            });

        trend_data
            .data_points
            .push((SystemTime::now(), result.performance.fidelity));

        // Keep only recent data points (last 100)
        if trend_data.data_points.len() > 100 {
            trend_data
                .data_points
                .drain(0..trend_data.data_points.len() - 100);
        }

        // Update trend analysis (analyze after the borrow ends)
        if trend_data.data_points.len() >= 2 {
            // Simple trend analysis inline to avoid borrowing issues
            let values: Vec<f64> = trend_data.data_points.iter().map(|(_, v)| *v).collect();
            let n = values.len();
            let sum_x: f64 = (0..n).map(|i| i as f64).sum();
            let sum_y: f64 = values.iter().sum();
            let sum_xy: f64 = values.iter().enumerate().map(|(i, &y)| i as f64 * y).sum();
            let sum_x2: f64 = (0..n).map(|i| (i as f64).powi(2)).sum();

            let slope = (n as f64).mul_add(sum_xy, -(sum_x * sum_y))
                / sum_x.mul_add(-sum_x, n as f64 * sum_x2);

            trend_data.trend_strength = slope.abs();
            trend_data.trend_direction = if slope > 0.01 {
                TrendDirection::Increasing
            } else if slope < -0.01 {
                TrendDirection::Decreasing
            } else {
                TrendDirection::Stable
            };
        }
    }

    fn update_cost_analytics(&mut self, platform_id: &str, result: &ExecutionResult) {
        *self
            .cost_analytics
            .total_cost_by_platform
            .entry(platform_id.to_string())
            .or_insert(0.0) += result.cost_info.total_cost;

        // Update average cost
        let exec_count = self
            .execution_history
            .iter()
            .filter(|r| r.platform_id == platform_id)
            .count();

        if exec_count > 0 {
            let avg_cost =
                self.cost_analytics.total_cost_by_platform[platform_id] / exec_count as f64;
            self.cost_analytics
                .avg_cost_per_execution
                .insert(platform_id.to_string(), avg_cost);
        }
    }

    fn analyze_trend(trend_data: &mut TrendData) {
        if trend_data.data_points.len() < 2 {
            return;
        }

        // Simple linear trend analysis
        let values: Vec<f64> = trend_data.data_points.iter().map(|(_, v)| *v).collect();
        let n = values.len();
        let sum_x: f64 = (0..n).map(|i| i as f64).sum();
        let sum_y: f64 = values.iter().sum();
        let sum_xy: f64 = values.iter().enumerate().map(|(i, &y)| i as f64 * y).sum();
        let sum_x2: f64 = (0..n).map(|i| (i as f64).powi(2)).sum();

        let slope =
            (n as f64).mul_add(sum_xy, -(sum_x * sum_y)) / sum_x.mul_add(-sum_x, n as f64 * sum_x2);

        trend_data.trend_strength = slope.abs();
        trend_data.trend_direction = if slope > 0.01 {
            TrendDirection::Increasing
        } else if slope < -0.01 {
            TrendDirection::Decreasing
        } else {
            TrendDirection::Stable
        };
    }
}

impl Clone for ExecutionAnalytics {
    fn clone(&self) -> Self {
        Self {
            execution_history: self.execution_history.clone(),
            performance_trends: self.performance_trends.clone(),
            error_analysis: self.error_analysis.clone(),
            cost_analytics: self.cost_analytics.clone(),
            platform_comparisons: self.platform_comparisons.clone(),
        }
    }
}

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

impl PlatformSelector {
    pub fn new() -> Self {
        Self {
            selection_algorithms: Vec::new(),
            platform_rankings: HashMap::new(),
            selection_history: Vec::new(),
            learning_model: None,
        }
    }
}

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

impl ExecutionMonitor {
    pub fn new() -> Self {
        Self {
            active_executions: HashMap::new(),
            monitoring_channels: Vec::new(),
            alert_thresholds: AlertThresholds {
                max_execution_time: Duration::from_secs(300),
                min_success_rate: 0.9,
                max_cost_per_execution: 10.0,
                max_error_rate: 0.1,
            },
            performance_baselines: HashMap::new(),
        }
    }
}

/// Create a default universal circuit interface
pub fn create_universal_interface() -> UniversalCircuitInterface {
    UniversalCircuitInterface::new(IntegrationConfig::default())
}

/// Create a high-performance configuration
pub fn create_high_performance_config() -> IntegrationConfig {
    IntegrationConfig {
        auto_platform_selection: true,
        enable_optimization: true,
        enable_analytics: true,
        max_execution_time: Duration::from_secs(60),
        max_circuit_size: 10000,
        selection_criteria: SelectionCriteria {
            prioritize_speed: true,
            prioritize_accuracy: true,
            prioritize_cost: false,
            min_fidelity: 0.99,
            max_cost: 1000.0,
            required_qubits: None,
            required_gates: vec!["H".to_string(), "CNOT".to_string(), "RZ".to_string()],
            platform_preferences: vec!["quantum_hardware".to_string()],
            fallback_platforms: vec!["high_fidelity_simulator".to_string()],
        },
        optimization_settings: OptimizationSettings {
            enable_gate_optimization: true,
            enable_topology_optimization: true,
            enable_scheduling_optimization: true,
            optimization_level: 3,
            max_optimization_time: Duration::from_secs(60),
            enable_parallel_optimization: true,
            custom_parameters: HashMap::new(),
        },
        analytics_config: AnalyticsConfig {
            enable_performance_tracking: true,
            enable_error_analysis: true,
            enable_cost_tracking: true,
            retention_period: Duration::from_secs(90 * 24 * 3600), // 90 days
            collection_interval: Duration::from_secs(10),
            enable_realtime_monitoring: true,
        },
        cache_config: CacheConfig {
            enable_caching: true,
            max_cache_size: 10000,
            cache_ttl: Duration::from_secs(7200),
            enable_distributed_cache: true,
        },
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use quantrs2_circuit::prelude::*;

    #[test]
    fn test_universal_interface_creation() {
        let interface = create_universal_interface();
        assert!(interface.get_available_platforms().is_empty());
    }

    #[test]
    fn test_high_performance_config() {
        let config = create_high_performance_config();
        assert_eq!(config.optimization_settings.optimization_level, 3);
        assert!(config.cache_config.enable_distributed_cache);
    }

    #[tokio::test]
    async fn test_circuit_execution() {
        let interface = create_universal_interface();
        let circuit = Circuit::<2>::new();

        // Register a mock platform
        let platform = PlatformAdapter {
            platform_id: "test_platform".to_string(),
            platform_name: "Test Platform".to_string(),
            capabilities: BackendCapabilities::default(),
            config: PlatformConfig {
                endpoint: "http://localhost".to_string(),
                credentials: None,
                parameters: HashMap::new(),
                timeout: Duration::from_secs(30),
                retry_config: RetryConfig {
                    max_retries: 3,
                    base_delay: Duration::from_millis(100),
                    max_delay: Duration::from_secs(10),
                    backoff_factor: 2.0,
                },
            },
            calibration: None,
            performance_metrics: PlatformMetrics {
                avg_execution_time: Duration::from_millis(100),
                success_rate: 0.95,
                avg_fidelity: 0.98,
                avg_cost_per_shot: 0.01,
                avg_queue_time: Duration::from_millis(50),
                throughput: 100.0,
                gate_error_rates: HashMap::new(),
                uptime: 0.99,
            },
            status: PlatformStatus::Available,
        };

        interface
            .register_platform(platform)
            .expect("Platform registration should succeed");

        // Test execution
        let result = interface.execute_circuit(&circuit, 1000).await;
        assert!(result.is_ok());

        let execution_result = result.expect("Circuit execution should succeed");
        assert!(execution_result.performance.success);
        assert_eq!(execution_result.metadata.shots, 1000);
    }
}