quantrs2-device 0.1.3

//! Quantum Internet Protocols
//!
//! This module implements comprehensive quantum internet protocols for distributed
//! quantum computing, enabling secure quantum communication, entanglement distribution,
//! and quantum application protocols across quantum networks.

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

use crate::{DeviceError, DeviceResult};

pub mod quantum_tcp;
pub mod quantum_routing;
pub mod quantum_dns;
pub mod quantum_security;
pub mod quantum_applications;
pub mod quantum_transport;

// Re-exports
pub use quantum_tcp::*;
pub use quantum_routing::*;
pub use quantum_dns::*;
pub use quantum_security::*;
pub use quantum_applications::*;
pub use quantum_transport::*;

/// Quantum Internet Protocol Stack
pub struct QuantumInternetStack {
    /// Network layer - quantum routing
    routing_layer: Arc<RwLock<QuantumRoutingLayer>>,
    /// Transport layer - quantum TCP/UDP
    transport_layer: Arc<RwLock<QuantumTransportLayer>>,
    /// Session layer - quantum sessions
    session_layer: Arc<RwLock<QuantumSessionLayer>>,
    /// Application layer - quantum applications
    application_layer: Arc<RwLock<QuantumApplicationLayer>>,
    /// Security layer - quantum cryptography
    security_layer: Arc<RwLock<QuantumSecurityLayer>>,
    /// Configuration
    config: QuantumInternetConfig,
    /// Active connections
    connections: Arc<RwLock<HashMap<String, QuantumConnection>>>,
    /// Protocol statistics
    stats: Arc<RwLock<QuantumProtocolStats>>,
}

/// Quantum Internet configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct QuantumInternetConfig {
    pub network_config: QuantumNetworkConfig,
    pub routing_config: QuantumRoutingConfig,
    pub transport_config: QuantumTransportConfig,
    pub security_config: QuantumSecurityConfig,
    pub application_config: QuantumApplicationConfig,
    pub performance_config: QuantumPerformanceConfig,
}

/// Quantum network configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct QuantumNetworkConfig {
    pub node_id: String,
    pub network_topology: NetworkTopology,
    pub addressing_scheme: AddressingScheme,
    pub quantum_channels: Vec<QuantumChannelConfig>,
    pub classical_channels: Vec<ClassicalChannelConfig>,
    pub entanglement_distribution: EntanglementDistributionConfig,
    pub error_correction: NetworkErrorCorrectionConfig,
}

/// Network topology types
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub enum NetworkTopology {
    Star,
    Ring,
    Mesh,
    Tree,
    HybridQuantumClassical,
    QuantumInternet,
    Custom(String),
}

/// Addressing scheme for quantum networks
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AddressingScheme {
    pub scheme_type: AddressType,
    pub address_length: usize,
    pub hierarchical: bool,
    pub quantum_specific: bool,
    pub entanglement_aware: bool,
}

/// Address types
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub enum AddressType {
    IPv4Extended,
    IPv6Quantum,
    QuantumNodeId,
    EntanglementId,
    HybridAddress,
    Custom(String),
}

/// Quantum channel configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct QuantumChannelConfig {
    pub channel_id: String,
    pub channel_type: QuantumChannelType,
    pub bandwidth: f64,
    pub fidelity: f64,
    pub coherence_time: Duration,
    pub loss_rate: f64,
    pub noise_model: NoiseModelConfig,
}

/// Quantum channel types
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub enum QuantumChannelType {
    OpticalFiber,
    FreeSpaceOptical,
    Microwave,
    Satellite,
    IonTrap,
    Superconducting,
    Custom(String),
}

/// Classical channel configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ClassicalChannelConfig {
    pub channel_id: String,
    pub protocol: ClassicalProtocol,
    pub bandwidth: f64,
    pub latency: Duration,
    pub reliability: f64,
    pub encryption: bool,
}

/// Classical protocols
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub enum ClassicalProtocol {
    TCP,
    UDP,
    HTTP,
    WebSocket,
    Custom(String),
}

/// Entanglement distribution configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct EntanglementDistributionConfig {
    pub distribution_protocol: EntanglementProtocol,
    pub generation_rate: f64,
    pub purification_enabled: bool,
    pub swapping_enabled: bool,
    pub routing_optimization: bool,
}

/// Entanglement protocols
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub enum EntanglementProtocol {
    DirectDistribution,
    EntanglementSwapping,
    QuantumRepeater,
    HierarchicalEntanglement,
    Custom(String),
}

/// Network error correction configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NetworkErrorCorrectionConfig {
    pub enabled: bool,
    pub correction_codes: Vec<String>,
    pub redundancy_level: u8,
    pub adaptive_correction: bool,
}

/// Noise model configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NoiseModelConfig {
    pub model_type: String,
    pub parameters: HashMap<String, f64>,
    pub time_dependent: bool,
    pub calibration_frequency: Duration,
}

/// Quantum connection representation
#[derive(Debug, Clone)]
pub struct QuantumConnection {
    pub connection_id: String,
    pub source_node: String,
    pub destination_node: String,
    pub connection_type: ConnectionType,
    pub quantum_state: QuantumConnectionState,
    pub classical_state: ClassicalConnectionState,
    pub entanglement_resources: Vec<EntanglementResource>,
    pub security_context: SecurityContext,
    pub performance_metrics: ConnectionMetrics,
    pub created_at: SystemTime,
    pub last_activity: SystemTime,
}

/// Connection types
#[derive(Debug, Clone, PartialEq)]
pub enum ConnectionType {
    QuantumOnly,
    ClassicalOnly,
    HybridQuantumClassical,
    EntanglementBased,
    TeleportationBased,
}

/// Quantum connection state
#[derive(Debug, Clone)]
pub struct QuantumConnectionState {
    pub entanglement_fidelity: f64,
    pub coherence_time: Duration,
    pub decoherence_rate: f64,
    pub quantum_error_rate: f64,
    pub entangled_pairs: usize,
}

/// Classical connection state
#[derive(Debug, Clone)]
pub struct ClassicalConnectionState {
    pub bandwidth: f64,
    pub latency: Duration,
    pub packet_loss: f64,
    pub throughput: f64,
    pub jitter: Duration,
}

/// Entanglement resource
#[derive(Debug, Clone)]
pub struct EntanglementResource {
    pub resource_id: String,
    pub entanglement_type: String,
    pub fidelity: f64,
    pub coherence_time: Duration,
    pub created_at: SystemTime,
    pub reserved: bool,
}

/// Security context for connections
#[derive(Debug, Clone)]
pub struct SecurityContext {
    pub authentication_method: String,
    pub encryption_enabled: bool,
    pub key_distribution_protocol: String,
    pub quantum_signatures: bool,
    pub trust_level: f64,
}

/// Connection performance metrics
#[derive(Debug, Clone)]
pub struct ConnectionMetrics {
    pub quantum_throughput: f64,
    pub classical_throughput: f64,
    pub end_to_end_latency: Duration,
    pub quantum_error_rate: f64,
    pub classical_error_rate: f64,
    pub fidelity_degradation: f64,
}

/// Protocol statistics
#[derive(Debug, Clone)]
pub struct QuantumProtocolStats {
    pub total_connections: usize,
    pub active_connections: usize,
    pub total_entangled_pairs: usize,
    pub successful_teleportations: usize,
    pub failed_operations: usize,
    pub average_fidelity: f64,
    pub network_efficiency: f64,
    pub quantum_volume: f64,
}

impl Default for QuantumInternetConfig {
    fn default() -> Self {
        Self {
            network_config: QuantumNetworkConfig::default(),
            routing_config: QuantumRoutingConfig::default(),
            transport_config: QuantumTransportConfig::default(),
            security_config: QuantumSecurityConfig::default(),
            application_config: QuantumApplicationConfig::default(),
            performance_config: QuantumPerformanceConfig::default(),
        }
    }
}

impl Default for QuantumNetworkConfig {
    fn default() -> Self {
        Self {
            node_id: Uuid::new_v4().to_string(),
            network_topology: NetworkTopology::Mesh,
            addressing_scheme: AddressingScheme {
                scheme_type: AddressType::IPv6Quantum,
                address_length: 128,
                hierarchical: true,
                quantum_specific: true,
                entanglement_aware: true,
            },
            quantum_channels: vec![
                QuantumChannelConfig {
                    channel_id: "qch_0".to_string(),
                    channel_type: QuantumChannelType::OpticalFiber,
                    bandwidth: 1000.0,
                    fidelity: 0.95,
                    coherence_time: Duration::from_millis(100),
                    loss_rate: 0.01,
                    noise_model: NoiseModelConfig {
                        model_type: "depolarizing".to_string(),
                        parameters: HashMap::new(),
                        time_dependent: false,
                        calibration_frequency: Duration::from_secs(3600),
                    },
                }
            ],
            classical_channels: vec![
                ClassicalChannelConfig {
                    channel_id: "cch_0".to_string(),
                    protocol: ClassicalProtocol::TCP,
                    bandwidth: 1000000.0, // 1 Mbps
                    latency: Duration::from_millis(10),
                    reliability: 0.999,
                    encryption: true,
                }
            ],
            entanglement_distribution: EntanglementDistributionConfig {
                distribution_protocol: EntanglementProtocol::DirectDistribution,
                generation_rate: 1000.0,
                purification_enabled: true,
                swapping_enabled: true,
                routing_optimization: true,
            },
            error_correction: NetworkErrorCorrectionConfig {
                enabled: true,
                correction_codes: vec!["surface".to_string(), "color".to_string()],
                redundancy_level: 3,
                adaptive_correction: true,
            },
        }
    }
}

impl QuantumInternetStack {
    /// Create a new quantum internet protocol stack
    pub async fn new(config: QuantumInternetConfig) -> DeviceResult<Self> {
        let routing_layer = Arc::new(RwLock::new(
            QuantumRoutingLayer::new(&config.routing_config).await?
        ));

        let transport_layer = Arc::new(RwLock::new(
            QuantumTransportLayer::new(&config.transport_config).await?
        ));

        let session_layer = Arc::new(RwLock::new(
            QuantumSessionLayer::new().await?
        ));

        let application_layer = Arc::new(RwLock::new(
            QuantumApplicationLayer::new(&config.application_config).await?
        ));

        let security_layer = Arc::new(RwLock::new(
            QuantumSecurityLayer::new(&config.security_config).await?
        ));

        Ok(Self {
            routing_layer,
            transport_layer,
            session_layer,
            application_layer,
            security_layer,
            config,
            connections: Arc::new(RwLock::new(HashMap::new())),
            stats: Arc::new(RwLock::new(QuantumProtocolStats::default())),
        })
    }

    /// Initialize the quantum internet stack
    pub async fn initialize(&self) -> DeviceResult<()> {
        // Initialize all layers
        self.routing_layer.write().await.initialize().await?;
        self.transport_layer.write().await.initialize().await?;
        self.session_layer.write().await.initialize().await?;
        self.application_layer.write().await.initialize().await?;
        self.security_layer.write().await.initialize().await?;

        Ok(())
    }

    /// Establish a quantum connection
    pub async fn connect(&self, destination: &str, connection_type: ConnectionType) -> DeviceResult<String> {
        let connection_id = Uuid::new_v4().to_string();

        // Create quantum connection
        let connection = QuantumConnection {
            connection_id: connection_id.clone(),
            source_node: self.config.network_config.node_id.clone(),
            destination_node: destination.to_string(),
            connection_type,
            quantum_state: QuantumConnectionState {
                entanglement_fidelity: 0.95,
                coherence_time: Duration::from_millis(100),
                decoherence_rate: 0.01,
                quantum_error_rate: 0.001,
                entangled_pairs: 0,
            },
            classical_state: ClassicalConnectionState {
                bandwidth: 1000.0,
                latency: Duration::from_millis(10),
                packet_loss: 0.001,
                throughput: 0.0,
                jitter: Duration::from_millis(1),
            },
            entanglement_resources: vec![],
            security_context: SecurityContext {
                authentication_method: "quantum_signatures".to_string(),
                encryption_enabled: true,
                key_distribution_protocol: "BB84".to_string(),
                quantum_signatures: true,
                trust_level: 0.99,
            },
            performance_metrics: ConnectionMetrics {
                quantum_throughput: 0.0,
                classical_throughput: 0.0,
                end_to_end_latency: Duration::from_millis(0),
                quantum_error_rate: 0.0,
                classical_error_rate: 0.0,
                fidelity_degradation: 0.0,
            },
            created_at: SystemTime::now(),
            last_activity: SystemTime::now(),
        };

        // Establish routing
        self.routing_layer.write().await.establish_route(&connection_id, destination).await?;

        // Setup transport layer
        self.transport_layer.write().await.create_connection(&connection_id).await?;

        // Initialize security
        self.security_layer.write().await.setup_security_context(&connection_id).await?;

        // Store connection
        self.connections.write().await.insert(connection_id.clone(), connection);

        // Update statistics
        {
            let mut stats = self.stats.write().await;
            stats.total_connections += 1;
            stats.active_connections += 1;
        }

        Ok(connection_id)
    }

    /// Send quantum data
    pub async fn send_quantum_data(&self, connection_id: &str, data: QuantumData) -> DeviceResult<()> {
        // Get connection
        let connection = {
            let connections = self.connections.read().await;
            connections.get(connection_id)
                .ok_or_else(|| DeviceError::InvalidInput(format!("Connection {} not found", connection_id)))?
                .clone()
        };

        // Process through layers
        let processed_data = self.application_layer.read().await.process_outgoing_data(data).await?;
        let secured_data = self.security_layer.read().await.encrypt_data(processed_data).await?;
        let transported_data = self.transport_layer.read().await.send_data(&connection.connection_id, secured_data).await?;
        self.routing_layer.read().await.route_data(&connection.destination_node, transported_data).await?;

        // Update connection activity
        {
            let mut connections = self.connections.write().await;
            if let Some(conn) = connections.get_mut(connection_id) {
                conn.last_activity = SystemTime::now();
            }
        }

        Ok(())
    }

    /// Receive quantum data
    pub async fn receive_quantum_data(&self, connection_id: &str) -> DeviceResult<QuantumData> {
        // Simulate receiving data through the protocol stack
        let raw_data = self.routing_layer.read().await.receive_data().await?;
        let transported_data = self.transport_layer.read().await.receive_data(&connection_id, raw_data).await?;
        let decrypted_data = self.security_layer.read().await.decrypt_data(transported_data).await?;
        let processed_data = self.application_layer.read().await.process_incoming_data(decrypted_data).await?;

        Ok(processed_data)
    }

    /// Distribute entanglement
    pub async fn distribute_entanglement(&self, connection_id: &str, num_pairs: usize) -> DeviceResult<Vec<String>> {
        let mut entanglement_ids = Vec::new();

        for _ in 0..num_pairs {
            let entanglement_id = Uuid::new_v4().to_string();

            // Create entanglement resource
            let resource = EntanglementResource {
                resource_id: entanglement_id.clone(),
                entanglement_type: "Bell_state".to_string(),
                fidelity: 0.95,
                coherence_time: Duration::from_millis(100),
                created_at: SystemTime::now(),
                reserved: false,
            };

            // Add to connection
            {
                let mut connections = self.connections.write().await;
                if let Some(connection) = connections.get_mut(connection_id) {
                    connection.entanglement_resources.push(resource);
                    connection.quantum_state.entangled_pairs += 1;
                }
            }

            entanglement_ids.push(entanglement_id);
        }

        // Update statistics
        {
            let mut stats = self.stats.write().await;
            stats.total_entangled_pairs += num_pairs;
        }

        Ok(entanglement_ids)
    }

    /// Perform quantum teleportation
    pub async fn teleport_quantum_state(&self, connection_id: &str, state: QuantumState) -> DeviceResult<TeleportationResult> {
        // Check if entanglement is available
        let entanglement_available = {
            let connections = self.connections.read().await;
            if let Some(connection) = connections.get(connection_id) {
                !connection.entanglement_resources.is_empty()
            } else {
                false
            }
        };

        if !entanglement_available {
            return Err(DeviceError::InvalidInput("No entanglement resources available".to_string()));
        }

        // Perform Bell measurement
        let measurement_result = self.perform_bell_measurement(&state).await?;

        // Send classical information
        let classical_data = ClassicalData {
            measurement_result: measurement_result.clone(),
            correction_operations: vec!["X".to_string(), "Z".to_string()],
        };

        self.send_classical_data(connection_id, classical_data).await?;

        // Update statistics
        {
            let mut stats = self.stats.write().await;
            stats.successful_teleportations += 1;
        }

        Ok(TeleportationResult {
            success: true,
            fidelity: 0.95,
            measurement_result,
            teleportation_time: Duration::from_millis(10),
        })
    }

    /// Get connection statistics
    pub async fn get_connection_stats(&self, connection_id: &str) -> DeviceResult<ConnectionMetrics> {
        let connections = self.connections.read().await;
        let connection = connections.get(connection_id)
            .ok_or_else(|| DeviceError::InvalidInput(format!("Connection {} not found", connection_id)))?;

        Ok(connection.performance_metrics.clone())
    }

    /// Get protocol statistics
    pub async fn get_protocol_stats(&self) -> QuantumProtocolStats {
        self.stats.read().await.clone()
    }

    /// Disconnect and cleanup
    pub async fn disconnect(&self, connection_id: &str) -> DeviceResult<()> {
        // Remove connection
        {
            let mut connections = self.connections.write().await;
            connections.remove(connection_id);
        }

        // Cleanup layers
        self.transport_layer.write().await.cleanup_connection(connection_id).await?;
        self.routing_layer.write().await.cleanup_route(connection_id).await?;
        self.security_layer.write().await.cleanup_security_context(connection_id).await?;

        // Update statistics
        {
            let mut stats = self.stats.write().await;
            stats.active_connections = stats.active_connections.saturating_sub(1);
        }

        Ok(())
    }

    /// Shutdown the quantum internet stack
    pub async fn shutdown(&self) -> DeviceResult<()> {
        // Shutdown all layers
        self.application_layer.write().await.shutdown().await?;
        self.security_layer.write().await.shutdown().await?;
        self.session_layer.write().await.shutdown().await?;
        self.transport_layer.write().await.shutdown().await?;
        self.routing_layer.write().await.shutdown().await?;

        // Clear connections
        self.connections.write().await.clear();

        Ok(())
    }

    // Helper methods
    async fn perform_bell_measurement(&self, _state: &QuantumState) -> DeviceResult<MeasurementResult> {
        // Simulate Bell measurement
        Ok(MeasurementResult {
            outcome: "00".to_string(),
            probability: 0.25,
            measurement_basis: "Bell".to_string(),
        })
    }

    async fn send_classical_data(&self, _connection_id: &str, _data: ClassicalData) -> DeviceResult<()> {
        // Simulate sending classical data
        Ok(())
    }
}

/// Quantum data representation
#[derive(Debug, Clone)]
pub struct QuantumData {
    pub data_type: QuantumDataType,
    pub payload: Vec<u8>,
    pub metadata: HashMap<String, String>,
    pub entanglement_requirements: Option<EntanglementRequirements>,
}

/// Quantum data types
#[derive(Debug, Clone, PartialEq)]
pub enum QuantumDataType {
    QuantumState,
    QuantumCircuit,
    EntanglementPair,
    MeasurementResult,
    QuantumMessage,
    Custom(String),
}

/// Entanglement requirements
#[derive(Debug, Clone)]
pub struct EntanglementRequirements {
    pub min_fidelity: f64,
    pub num_pairs: usize,
    pub coherence_time: Duration,
    pub entanglement_type: String,
}

/// Quantum state representation
#[derive(Debug, Clone)]
pub struct QuantumState {
    pub state_vector: Vec<f64>,
    pub num_qubits: usize,
    pub basis: String,
    pub fidelity: f64,
}

/// Classical data for quantum protocols
#[derive(Debug, Clone)]
pub struct ClassicalData {
    pub measurement_result: MeasurementResult,
    pub correction_operations: Vec<String>,
}

/// Measurement result
#[derive(Debug, Clone)]
pub struct MeasurementResult {
    pub outcome: String,
    pub probability: f64,
    pub measurement_basis: String,
}

/// Teleportation result
#[derive(Debug, Clone)]
pub struct TeleportationResult {
    pub success: bool,
    pub fidelity: f64,
    pub measurement_result: MeasurementResult,
    pub teleportation_time: Duration,
}

// Default implementations
impl Default for QuantumProtocolStats {
    fn default() -> Self {
        Self {
            total_connections: 0,
            active_connections: 0,
            total_entangled_pairs: 0,
            successful_teleportations: 0,
            failed_operations: 0,
            average_fidelity: 0.0,
            network_efficiency: 0.0,
            quantum_volume: 0.0,
        }
    }
}

impl Default for QuantumData {
    fn default() -> Self {
        Self {
            data_type: QuantumDataType::QuantumMessage,
            payload: vec![],
            metadata: HashMap::new(),
            entanglement_requirements: None,
        }
    }
}

impl Default for QuantumState {
    fn default() -> Self {
        Self {
            state_vector: vec![1.0, 0.0], // |0⟩ state
            num_qubits: 1,
            basis: "computational".to_string(),
            fidelity: 1.0,
        }
    }
}