scirs2-metrics 0.3.2

//! Distributed neuromorphic coordination
//!
//! This module provides distributed computing capabilities for neuromorphic systems,
//! including network topology management, load balancing, and fault tolerance.

#![allow(clippy::too_many_arguments)]
#![allow(dead_code)]

use crate::error::Result;
use scirs2_core::numeric::Float;
use std::collections::HashMap;

/// Distributed neuromorphic coordinator
#[derive(Debug)]
pub struct DistributedNeuromorphicCoordinator<F: Float> {
    /// Network topology for distributed computing
    pub network_topology: DistributedTopology,
    /// Inter-node communication protocols
    pub communication_protocols: Vec<InterNodeProtocol>,
    /// Load balancing strategies
    pub load_balancers: Vec<NeuromorphicLoadBalancer<F>>,
    /// Consensus mechanisms for distributed learning
    pub consensus_mechanisms: Vec<DistributedConsensus<F>>,
    /// Fault tolerance systems
    pub fault_tolerance: DistributedFaultTolerance<F>,
}

/// Network topology for distributed neuromorphic computing
#[derive(Debug)]
pub struct DistributedTopology {
    /// Node information
    pub nodes: HashMap<String, NodeInfo>,
    /// Connection graph
    pub connections: HashMap<String, Vec<String>>,
    /// Topology type
    pub topology_type: TopologyType,
    /// Network parameters
    pub parameters: HashMap<String, f64>,
}

/// Information about a compute node
#[derive(Debug)]
pub struct NodeInfo {
    /// Node identifier
    pub id: String,
    /// Node capabilities
    pub capabilities: NodeCapabilities,
    /// Current load
    pub current_load: f64,
    /// Status
    pub status: NodeStatus,
    /// Performance metrics
    pub performance: NodePerformance,
}

/// Node capabilities
#[derive(Debug)]
pub struct NodeCapabilities {
    /// Computing power (FLOPS)
    pub computing_power: f64,
    /// Memory capacity (GB)
    pub memory_capacity: f64,
    /// Network bandwidth (Mbps)
    pub bandwidth: f64,
    /// Specialized hardware
    pub specialized_hardware: Vec<String>,
}

/// Node status
#[derive(Debug, Clone)]
pub enum NodeStatus {
    /// Node is active and available
    Active,
    /// Node is busy
    Busy,
    /// Node is offline
    Offline,
    /// Node has errors
    Error(String),
}

/// Node performance metrics
#[derive(Debug)]
pub struct NodePerformance {
    /// Average response time
    pub response_time: f64,
    /// Throughput
    pub throughput: f64,
    /// Error rate
    pub error_rate: f64,
    /// Uptime
    pub uptime: f64,
}

/// Types of network topology
#[derive(Debug, Clone)]
pub enum TopologyType {
    /// Fully connected network
    FullyConnected,
    /// Ring topology
    Ring,
    /// Star topology
    Star,
    /// Mesh topology
    Mesh,
    /// Tree topology
    Tree,
    /// Custom topology
    Custom(String),
}

/// Inter-node communication protocol
#[derive(Debug)]
pub struct InterNodeProtocol {
    /// Protocol name
    pub name: String,
    /// Protocol type
    pub protocol_type: ProtocolType,
    /// Communication parameters
    pub parameters: HashMap<String, String>,
    /// Quality of service requirements
    pub qos_requirements: QoSRequirements,
}

/// Types of communication protocols
#[derive(Debug, Clone)]
pub enum ProtocolType {
    /// Synchronous communication
    Synchronous,
    /// Asynchronous communication
    Asynchronous,
    /// Publish-subscribe
    PubSub,
    /// Request-response
    RequestResponse,
    /// Streaming
    Streaming,
}

/// Quality of service requirements
#[derive(Debug)]
pub struct QoSRequirements {
    /// Maximum latency (ms)
    pub max_latency: f64,
    /// Minimum bandwidth (Mbps)
    pub min_bandwidth: f64,
    /// Reliability level
    pub reliability: f64,
    /// Security level
    pub security_level: SecurityLevel,
}

/// Security levels for communication
#[derive(Debug, Clone)]
pub enum SecurityLevel {
    /// No encryption
    None,
    /// Basic encryption
    Basic,
    /// Strong encryption
    Strong,
    /// Quantum-safe encryption
    QuantumSafe,
}

/// Neuromorphic load balancer
#[derive(Debug)]
pub struct NeuromorphicLoadBalancer<F: Float> {
    /// Load balancing algorithm
    pub algorithm: LoadBalancingAlgorithm,
    /// Current load distribution
    pub load_distribution: HashMap<String, F>,
    /// Balancing parameters
    pub parameters: HashMap<String, F>,
    /// Performance metrics
    pub metrics: LoadBalancingMetrics<F>,
}

/// Load balancing algorithms
#[derive(Debug, Clone)]
pub enum LoadBalancingAlgorithm {
    /// Round robin
    RoundRobin,
    /// Weighted round robin
    WeightedRoundRobin,
    /// Least connections
    LeastConnections,
    /// Least response time
    LeastResponseTime,
    /// Resource-based
    ResourceBased,
    /// Neuromorphic-aware
    NeuromorphicAware,
}

/// Load balancing performance metrics
#[derive(Debug)]
pub struct LoadBalancingMetrics<F: Float> {
    /// Average load
    pub average_load: F,
    /// Load variance
    pub load_variance: F,
    /// Balancing efficiency
    pub efficiency: F,
    /// Adaptation speed
    pub adaptation_speed: F,
}

/// Distributed consensus mechanism
#[derive(Debug)]
pub struct DistributedConsensus<F: Float> {
    /// Consensus algorithm
    pub algorithm: ConsensusAlgorithm,
    /// Consensus parameters
    pub parameters: HashMap<String, F>,
    /// Participant nodes
    pub participants: Vec<String>,
    /// Current consensus state
    pub state: ConsensusState<F>,
}

/// Consensus algorithms
#[derive(Debug, Clone)]
pub enum ConsensusAlgorithm {
    /// Byzantine fault tolerant
    ByzantineFaultTolerant,
    /// Proof of work
    ProofOfWork,
    /// Proof of stake
    ProofOfStake,
    /// Practical Byzantine fault tolerance
    PBFT,
    /// Raft consensus
    Raft,
    /// Neuromorphic consensus
    NeuromorphicConsensus,
}

/// Consensus state
#[derive(Debug)]
pub struct ConsensusState<F: Float> {
    /// Current proposal
    pub current_proposal: Option<Vec<F>>,
    /// Votes received
    pub votes: HashMap<String, Vote<F>>,
    /// Consensus reached
    pub consensus_reached: bool,
    /// Final decision
    pub final_decision: Option<Vec<F>>,
}

/// Vote in consensus
#[derive(Debug)]
pub struct Vote<F: Float> {
    /// Voter node ID
    pub voter_id: String,
    /// Vote value
    pub value: Vec<F>,
    /// Vote confidence
    pub confidence: F,
    /// Timestamp
    pub timestamp: u64,
}

/// Distributed fault tolerance system
#[derive(Debug)]
pub struct DistributedFaultTolerance<F: Float> {
    /// Fault detection mechanisms
    pub fault_detectors: Vec<FaultDetector<F>>,
    /// Recovery strategies
    pub recovery_strategies: Vec<RecoveryStrategy<F>>,
    /// Redundancy management
    pub redundancy_manager: RedundancyManager<F>,
    /// Checkpoint system
    pub checkpoint_system: CheckpointSystem<F>,
}

/// Fault detector
#[derive(Debug)]
pub struct FaultDetector<F: Float> {
    /// Detection method
    pub method: FaultDetectionMethod,
    /// Detection threshold
    pub threshold: F,
    /// Monitoring parameters
    pub parameters: HashMap<String, F>,
    /// Detection history
    pub detection_history: Vec<FaultEvent>,
}

/// Fault detection methods
#[derive(Debug, Clone)]
pub enum FaultDetectionMethod {
    /// Heartbeat monitoring
    Heartbeat,
    /// Performance monitoring
    Performance,
    /// Checksum verification
    Checksum,
    /// Byzantine detection
    Byzantine,
    /// Statistical anomaly detection
    StatisticalAnomaly,
}

/// Fault event
#[derive(Debug)]
pub struct FaultEvent {
    /// Event timestamp
    pub timestamp: u64,
    /// Faulty node
    pub node_id: String,
    /// Fault type
    pub fault_type: FaultType,
    /// Fault severity
    pub severity: FaultSeverity,
    /// Description
    pub description: String,
}

/// Types of faults
#[derive(Debug, Clone)]
pub enum FaultType {
    /// Node failure
    NodeFailure,
    /// Network partition
    NetworkPartition,
    /// Byzantine behavior
    Byzantine,
    /// Performance degradation
    PerformanceDegradation,
    /// Data corruption
    DataCorruption,
}

/// Fault severity levels
#[derive(Debug, Clone)]
pub enum FaultSeverity {
    /// Low severity
    Low,
    /// Medium severity
    Medium,
    /// High severity
    High,
    /// Critical severity
    Critical,
}

/// Recovery strategy
#[derive(Debug)]
pub struct RecoveryStrategy<F: Float> {
    /// Recovery method
    pub method: RecoveryMethod,
    /// Recovery parameters
    pub parameters: HashMap<String, F>,
    /// Success rate
    pub success_rate: F,
    /// Recovery time estimate
    pub estimated_time: f64,
}

/// Recovery methods
#[derive(Debug, Clone)]
pub enum RecoveryMethod {
    /// Restart failed node
    Restart,
    /// Migrate computation
    Migration,
    /// Rollback to checkpoint
    Rollback,
    /// Reconfigure network
    Reconfiguration,
    /// Graceful degradation
    GracefulDegradation,
}

/// Redundancy manager
#[derive(Debug)]
pub struct RedundancyManager<F: Float> {
    /// Redundancy level
    pub redundancy_level: usize,
    /// Replication strategy
    pub replication_strategy: ReplicationStrategy,
    /// Replica placement
    pub replica_placement: HashMap<String, Vec<String>>,
    /// Consistency protocol
    pub consistency_protocol: ConsistencyProtocol<F>,
}

/// Replication strategies
#[derive(Debug, Clone)]
pub enum ReplicationStrategy {
    /// Full replication
    Full,
    /// Partial replication
    Partial,
    /// Erasure coding
    ErasureCoding,
    /// Adaptive replication
    Adaptive,
}

/// Consistency protocol
#[derive(Debug)]
pub struct ConsistencyProtocol<F: Float> {
    /// Consistency model
    pub model: ConsistencyModel,
    /// Protocol parameters
    pub parameters: HashMap<String, F>,
}

/// Consistency models
#[derive(Debug, Clone)]
pub enum ConsistencyModel {
    /// Strong consistency
    Strong,
    /// Eventual consistency
    Eventual,
    /// Causal consistency
    Causal,
    /// Session consistency
    Session,
}

/// Checkpoint system
#[derive(Debug)]
pub struct CheckpointSystem<F: Float> {
    /// Checkpointing strategy
    pub strategy: CheckpointingStrategy,
    /// Checkpoint frequency
    pub frequency: f64,
    /// Storage location
    pub storage_location: String,
    /// Compression parameters
    pub compression: HashMap<String, F>,
}

/// Checkpointing strategies
#[derive(Debug, Clone)]
pub enum CheckpointingStrategy {
    /// Periodic checkpointing
    Periodic,
    /// Event-driven checkpointing
    EventDriven,
    /// Adaptive checkpointing
    Adaptive,
    /// Coordinated checkpointing
    Coordinated,
}

impl<F: Float> DistributedNeuromorphicCoordinator<F> {
    /// Create new distributed coordinator
    pub fn new() -> Result<Self> {
        Ok(Self {
            network_topology: DistributedTopology::new(),
            communication_protocols: Vec::new(),
            load_balancers: Vec::new(),
            consensus_mechanisms: Vec::new(),
            fault_tolerance: DistributedFaultTolerance::new()?,
        })
    }

    /// Add node to the distributed system
    pub fn add_node(&mut self, node_info: NodeInfo) -> Result<()> {
        self.network_topology
            .nodes
            .insert(node_info.id.clone(), node_info);
        Ok(())
    }

    /// Remove node from the distributed system
    pub fn remove_node(&mut self, node_id: &str) -> Result<()> {
        self.network_topology.nodes.remove(node_id);
        self.network_topology.connections.remove(node_id);
        // Remove connections to this node from other nodes
        for connections in self.network_topology.connections.values_mut() {
            connections.retain(|id| id != node_id);
        }
        Ok(())
    }

    /// Distribute computation across nodes
    pub fn distribute_computation(&mut self, computation: &[F]) -> Result<HashMap<String, Vec<F>>> {
        let mut distributions = HashMap::new();

        // Simple distribution: split computation evenly across active nodes
        let active_nodes: Vec<_> = self
            .network_topology
            .nodes
            .iter()
            .filter(|(_, node)| matches!(node.status, NodeStatus::Active))
            .map(|(id, _)| id.clone())
            .collect();

        if active_nodes.is_empty() {
            return Ok(distributions);
        }

        let chunk_size = computation.len() / active_nodes.len();
        let remainder = computation.len() % active_nodes.len();

        let mut start_idx = 0;
        for (i, node_id) in active_nodes.iter().enumerate() {
            let end_idx = start_idx + chunk_size + if i < remainder { 1 } else { 0 };
            let chunk = computation[start_idx..end_idx].to_vec();
            distributions.insert(node_id.clone(), chunk);
            start_idx = end_idx;
        }

        Ok(distributions)
    }

    /// Collect results from distributed computation
    pub fn collect_results(&self, partial_results: HashMap<String, Vec<F>>) -> Result<Vec<F>> {
        let mut combined_results = Vec::new();

        // Simple collection: concatenate results in node order
        let node_order: Vec<_> = self.network_topology.nodes.keys().cloned().collect();
        for node_id in node_order {
            if let Some(result) = partial_results.get(&node_id) {
                combined_results.extend_from_slice(result);
            }
        }

        Ok(combined_results)
    }

    /// Perform consensus on a value
    pub fn reach_consensus(&mut self, proposal: Vec<F>) -> Result<Option<Vec<F>>> {
        // Simplified consensus: use first available consensus mechanism
        if let Some(consensus) = self.consensus_mechanisms.first_mut() {
            consensus.propose(proposal)?;
            Ok(consensus.get_decision())
        } else {
            Ok(Some(proposal)) // No consensus mechanism, accept proposal
        }
    }

    /// Handle node failure
    pub fn handle_node_failure(&mut self, node_id: &str) -> Result<()> {
        // Mark node as offline
        if let Some(node) = self.network_topology.nodes.get_mut(node_id) {
            node.status = NodeStatus::Offline;
        }

        // Trigger fault tolerance mechanisms
        self.fault_tolerance.handle_failure(node_id)?;

        // Redistribute load
        self.redistribute_load()?;

        Ok(())
    }

    /// Redistribute load after node failure
    fn redistribute_load(&mut self) -> Result<()> {
        // Simplified load redistribution
        for balancer in &mut self.load_balancers {
            balancer.rebalance(&self.network_topology)?;
        }
        Ok(())
    }
}

impl DistributedTopology {
    /// Create new distributed topology
    pub fn new() -> Self {
        Self {
            nodes: HashMap::new(),
            connections: HashMap::new(),
            topology_type: TopologyType::Mesh,
            parameters: HashMap::new(),
        }
    }

    /// Add connection between nodes
    pub fn add_connection(&mut self, node1: &str, node2: &str) {
        self.connections
            .entry(node1.to_string())
            .or_default()
            .push(node2.to_string());
        self.connections
            .entry(node2.to_string())
            .or_default()
            .push(node1.to_string());
    }

    /// Get neighbors of a node
    pub fn get_neighbors(&self, node_id: &str) -> Option<&Vec<String>> {
        self.connections.get(node_id)
    }

    /// Check if topology is connected
    pub fn is_connected(&self) -> bool {
        if self.nodes.is_empty() {
            return true;
        }

        // Simple connectivity check using DFS
        let start_node = self.nodes.keys().next().expect("Operation failed");
        let mut visited = std::collections::HashSet::new();
        let mut stack = vec![start_node.clone()];

        while let Some(node) = stack.pop() {
            if visited.insert(node.clone()) {
                if let Some(neighbors) = self.connections.get(&node) {
                    for neighbor in neighbors {
                        if !visited.contains(neighbor) {
                            stack.push(neighbor.clone());
                        }
                    }
                }
            }
        }

        visited.len() == self.nodes.len()
    }
}

impl<F: Float> NeuromorphicLoadBalancer<F> {
    /// Create new load balancer
    pub fn new(algorithm: LoadBalancingAlgorithm) -> Self {
        Self {
            algorithm,
            load_distribution: HashMap::new(),
            parameters: HashMap::new(),
            metrics: LoadBalancingMetrics::new(),
        }
    }

    /// Rebalance load across nodes
    pub fn rebalance(&mut self, topology: &DistributedTopology) -> Result<()> {
        match self.algorithm {
            LoadBalancingAlgorithm::RoundRobin => {
                self.round_robin_balance(topology)?;
            }
            LoadBalancingAlgorithm::LeastConnections => {
                self.least_connections_balance(topology)?;
            }
            _ => {
                // Default balancing
                self.default_balance(topology)?;
            }
        }
        Ok(())
    }

    /// Round robin load balancing
    fn round_robin_balance(&mut self, topology: &DistributedTopology) -> Result<()> {
        let active_nodes: Vec<_> = topology
            .nodes
            .iter()
            .filter(|(_, node)| matches!(node.status, NodeStatus::Active))
            .map(|(id, _)| id.clone())
            .collect();

        if !active_nodes.is_empty() {
            let load_per_node = F::one() / F::from(active_nodes.len()).expect("Operation failed");
            for node_id in active_nodes {
                self.load_distribution.insert(node_id, load_per_node);
            }
        }

        Ok(())
    }

    /// Least connections load balancing
    fn least_connections_balance(&mut self, topology: &DistributedTopology) -> Result<()> {
        // Simplified implementation: equal distribution
        self.round_robin_balance(topology)
    }

    /// Default load balancing
    fn default_balance(&mut self, topology: &DistributedTopology) -> Result<()> {
        self.round_robin_balance(topology)
    }
}

impl<F: Float> LoadBalancingMetrics<F> {
    /// Create new metrics
    pub fn new() -> Self {
        Self {
            average_load: F::zero(),
            load_variance: F::zero(),
            efficiency: F::one(),
            adaptation_speed: F::from(0.5).expect("Failed to convert constant to float"),
        }
    }
}

impl<F: Float> DistributedConsensus<F> {
    /// Create new consensus mechanism
    pub fn new(algorithm: ConsensusAlgorithm) -> Self {
        Self {
            algorithm,
            parameters: HashMap::new(),
            participants: Vec::new(),
            state: ConsensusState::new(),
        }
    }

    /// Propose a value for consensus
    pub fn propose(&mut self, proposal: Vec<F>) -> Result<()> {
        self.state.current_proposal = Some(proposal);
        self.state.votes.clear();
        self.state.consensus_reached = false;
        self.state.final_decision = None;
        Ok(())
    }

    /// Get consensus decision if reached
    pub fn get_decision(&self) -> Option<Vec<F>> {
        if self.state.consensus_reached {
            self.state.final_decision.clone()
        } else {
            None
        }
    }

    /// Add vote to consensus
    pub fn add_vote(&mut self, vote: Vote<F>) -> Result<()> {
        self.state.votes.insert(vote.voter_id.clone(), vote);
        self.check_consensus()?;
        Ok(())
    }

    /// Check if consensus is reached
    fn check_consensus(&mut self) -> Result<()> {
        let required_votes = (self.participants.len() * 2 / 3) + 1; // 2/3 majority
        if self.state.votes.len() >= required_votes {
            // Simplified consensus: take the proposal if majority votes
            if let Some(proposal) = &self.state.current_proposal {
                self.state.final_decision = Some(proposal.clone());
                self.state.consensus_reached = true;
            }
        }
        Ok(())
    }
}

impl<F: Float> ConsensusState<F> {
    /// Create new consensus state
    pub fn new() -> Self {
        Self {
            current_proposal: None,
            votes: HashMap::new(),
            consensus_reached: false,
            final_decision: None,
        }
    }
}

impl<F: Float> DistributedFaultTolerance<F> {
    /// Create new fault tolerance system
    pub fn new() -> Result<Self> {
        Ok(Self {
            fault_detectors: Vec::new(),
            recovery_strategies: Vec::new(),
            redundancy_manager: RedundancyManager::new(),
            checkpoint_system: CheckpointSystem::new(),
        })
    }

    /// Handle node failure
    pub fn handle_failure(&mut self, _node_id: &str) -> Result<()> {
        // Simplified failure handling
        // In practice, this would:
        // 1. Detect the type of failure
        // 2. Select appropriate recovery strategy
        // 3. Execute recovery
        // 4. Update redundancy if needed
        Ok(())
    }
}

impl<F: Float> RedundancyManager<F> {
    /// Create new redundancy manager
    pub fn new() -> Self {
        Self {
            redundancy_level: 3,
            replication_strategy: ReplicationStrategy::Partial,
            replica_placement: HashMap::new(),
            consistency_protocol: ConsistencyProtocol::new(),
        }
    }
}

impl<F: Float> ConsistencyProtocol<F> {
    /// Create new consistency protocol
    pub fn new() -> Self {
        Self {
            model: ConsistencyModel::Eventual,
            parameters: HashMap::new(),
        }
    }
}

impl<F: Float> CheckpointSystem<F> {
    /// Create new checkpoint system
    pub fn new() -> Self {
        Self {
            strategy: CheckpointingStrategy::Periodic,
            frequency: 60.0, // Every 60 seconds
            storage_location: "/tmp/checkpoints".to_string(),
            compression: HashMap::new(),
        }
    }
}