scirs2-linalg 0.4.2

//! MPI Topology Management
//!
//! This module provides advanced topology management for MPI communications
//! including tree topologies, graph representations, and topology optimization
//! for different communication patterns and network architectures.

use std::collections::HashMap;

/// Tree topology for hierarchical operations
#[derive(Debug, Clone)]
pub enum TreeTopology {
    Binomial,
    Flat,
    Pipeline,
    Scatter,
    Custom(Vec<Vec<i32>>),
}

/// MPI topology manager
#[derive(Debug)]
pub struct MPITopologyManager {
    current_topology: MPITopology,
    topology_optimizer: TopologyOptimizer,
    virtual_topologies: HashMap<String, VirtualTopology>,
    topology_history: Vec<TopologyChange>,
}

/// MPI topology representation
#[derive(Debug, Clone)]
pub struct MPITopology {
    topology_type: MPITopologyType,
    dimensions: Vec<i32>,
    process_coordinates: HashMap<i32, Vec<i32>>,
    neighbor_map: HashMap<i32, Vec<i32>>,
    communication_graph: CommunicationGraph,
}

/// Types of MPI topologies
#[derive(Debug, Clone, Copy)]
pub enum MPITopologyType {
    Linear,
    Ring,
    Mesh2D,
    Mesh3D,
    Torus2D,
    Torus3D,
    Hypercube,
    Tree,
    FatTree,
    Butterfly,
    Custom,
}

/// Graph representing communication patterns
#[derive(Debug, Clone)]
pub struct CommunicationGraph {
    edges: HashMap<(i32, i32), EdgeProperties>,
    vertices: HashMap<i32, VertexProperties>,
}

/// Properties of communication edges
#[derive(Debug, Clone)]
pub struct EdgeProperties {
    bandwidth: f64,
    latency: f64,
    reliability: f64,
    usage_frequency: usize,
}

/// Properties of topology vertices
#[derive(Debug, Clone)]
pub struct VertexProperties {
    process_rank: i32,
    compute_capability: f64,
    memory_capacity: usize,
    load: f64,
}

/// Optimizer for MPI topologies
#[derive(Debug)]
pub struct TopologyOptimizer {
    optimization_algorithms: Vec<TopologyOptimizationAlgorithm>,
    performance_models: HashMap<String, PerformanceModel>,
    optimization_history: Vec<OptimizationResult>,
}

/// Algorithm for topology optimization
#[derive(Debug)]
pub enum TopologyOptimizationAlgorithm {
    GreedyImprovement,
    SimulatedAnnealing,
    GeneticAlgorithm,
    MachineLearning(String),
}

/// Model for predicting topology performance
#[derive(Debug)]
pub struct PerformanceModel {
    model_type: String,
    parameters: HashMap<String, f64>,
    accuracy: f64,
    training_data: Vec<PerformanceDataPoint>,
}

/// Data point for performance modeling
#[derive(Debug, Clone)]
pub struct PerformanceDataPoint {
    topology: MPITopology,
    workload: WorkloadCharacteristics,
    performance: PerformanceMetrics,
}

/// Characteristics of computational workload
#[derive(Debug, Clone)]
pub struct WorkloadCharacteristics {
    computation_pattern: ComputationPattern,
    communication_pattern: CommunicationPattern,
    datasize: usize,
    process_count: i32,
}

/// Pattern of computation
#[derive(Debug, Clone, Copy)]
pub enum ComputationPattern {
    CpuIntensive,
    MemoryIntensive,
    NetworkIntensive,
    Balanced,
    Irregular,
}

/// Pattern of communication
#[derive(Debug, Clone, Copy)]
pub enum CommunicationPattern {
    AllToAll,
    NearestNeighbor,
    MasterSlave,
    Pipeline,
    Tree,
    Irregular,
}

/// Result of topology optimization
#[derive(Debug, Clone)]
pub struct OptimizationResult {
    original_topology: MPITopology,
    optimized_topology: MPITopology,
    performance_improvement: f64,
    optimization_time: std::time::Duration,
    algorithm_used: String,
}

/// Virtual topology for application-specific optimization
#[derive(Debug, Clone)]
pub struct VirtualTopology {
    topology_id: String,
    virtual_graph: CommunicationGraph,
    mapping_to_physical: HashMap<i32, i32>,
    performance_characteristics: HashMap<String, f64>,
}

/// Change in topology configuration
#[derive(Debug, Clone)]
pub struct TopologyChange {
    timestamp: std::time::Instant,
    change_type: TopologyChangeType,
    affected_processes: Vec<i32>,
    reason: String,
    impact: TopologyImpact,
}

/// Types of topology changes
#[derive(Debug, Clone, Copy)]
pub enum TopologyChangeType {
    ProcessAddition,
    ProcessRemoval,
    ConnectionModification,
    Restructuring,
    Migration,
}

/// Impact of topology change
#[derive(Debug, Clone)]
pub struct TopologyImpact {
    performance_delta: f64,
    affected_operations: Vec<String>,
    adaptation_time: std::time::Duration,
}

/// Performance metrics for topology evaluation
#[derive(Debug, Clone)]
pub struct PerformanceMetrics {
    throughput: f64,
    latency: f64,
    bandwidth_utilization: f64,
    load_balance: f64,
    energy_efficiency: f64,
}

/// Network topology information
#[derive(Debug, Default)]
pub struct NetworkTopologyInfo {
    pub topology_type: String,
    pub node_connections: HashMap<i32, Vec<i32>>,
    pub link_capacities: HashMap<(i32, i32), f64>,
}

impl MPITopologyManager {
    /// Create a new topology manager
    pub fn new(initial_topology: MPITopology) -> Self {
        Self {
            current_topology: initial_topology,
            topology_optimizer: TopologyOptimizer::new(),
            virtual_topologies: HashMap::new(),
            topology_history: Vec::new(),
        }
    }

    /// Get the current topology
    pub fn current_topology(&self) -> &MPITopology {
        &self.current_topology
    }

    /// Optimize the current topology for a given workload
    pub fn optimize_for_workload(
        &mut self,
        workload: &WorkloadCharacteristics,
    ) -> Result<OptimizationResult, String> {
        self.topology_optimizer.optimize(&self.current_topology, workload)
    }

    /// Add a virtual topology
    pub fn add_virtual_topology(&mut self, topology: VirtualTopology) {
        let id = topology.topology_id.clone();
        self.virtual_topologies.insert(id, topology);
    }

    /// Get a virtual topology
    pub fn get_virtual_topology(&self, id: &str) -> Option<&VirtualTopology> {
        self.virtual_topologies.get(id)
    }

    /// Record a topology change
    pub fn record_change(&mut self, change: TopologyChange) {
        self.topology_history.push(change);
    }

    /// Get topology change history
    pub fn get_change_history(&self) -> &[TopologyChange] {
        &self.topology_history
    }
}

impl MPITopology {
    /// Create a new MPI topology
    pub fn new(topology_type: MPITopologyType, dimensions: Vec<i32>) -> Self {
        Self {
            topology_type,
            dimensions,
            process_coordinates: HashMap::new(),
            neighbor_map: HashMap::new(),
            communication_graph: CommunicationGraph::new(),
        }
    }

    /// Get the topology type
    pub fn topology_type(&self) -> MPITopologyType {
        self.topology_type
    }

    /// Get the dimensions
    pub fn dimensions(&self) -> &[i32] {
        &self.dimensions
    }

    /// Get process coordinates
    pub fn process_coordinates(&self) -> &HashMap<i32, Vec<i32>> {
        &self.process_coordinates
    }

    /// Get neighbor map
    pub fn neighbor_map(&self) -> &HashMap<i32, Vec<i32>> {
        &self.neighbor_map
    }

    /// Get communication graph
    pub fn communication_graph(&self) -> &CommunicationGraph {
        &self.communication_graph
    }

    /// Set process coordinates
    pub fn set_process_coordinates(&mut self, rank: i32, coordinates: Vec<i32>) {
        self.process_coordinates.insert(rank, coordinates);
    }

    /// Add neighbor relationship
    pub fn add_neighbor(&mut self, rank: i32, neighbor: i32) {
        self.neighbor_map.entry(rank).or_insert_with(Vec::new).push(neighbor);
    }

    /// Get neighbors of a process
    pub fn get_neighbors(&self, rank: i32) -> Option<&Vec<i32>> {
        self.neighbor_map.get(&rank)
    }

    /// Check if two processes are neighbors
    pub fn are_neighbors(&self, rank1: i32, rank2: i32) -> bool {
        if let Some(neighbors) = self.neighbor_map.get(&rank1) {
            neighbors.contains(&rank2)
        } else {
            false
        }
    }
}

impl CommunicationGraph {
    /// Create a new communication graph
    pub fn new() -> Self {
        Self {
            edges: HashMap::new(),
            vertices: HashMap::new(),
        }
    }

    /// Add an edge with properties
    pub fn add_edge(&mut self, from: i32, to: i32, properties: EdgeProperties) {
        self.edges.insert((from, to), properties);
    }

    /// Add a vertex with properties
    pub fn add_vertex(&mut self, rank: i32, properties: VertexProperties) {
        self.vertices.insert(rank, properties);
    }

    /// Get edge properties
    pub fn get_edge_properties(&self, from: i32, to: i32) -> Option<&EdgeProperties> {
        self.edges.get(&(from, to))
    }

    /// Get vertex properties
    pub fn get_vertex_properties(&self, rank: i32) -> Option<&VertexProperties> {
        self.vertices.get(&rank)
    }

    /// Get all edges
    pub fn edges(&self) -> &HashMap<(i32, i32), EdgeProperties> {
        &self.edges
    }

    /// Get all vertices
    pub fn vertices(&self) -> &HashMap<i32, VertexProperties> {
        &self.vertices
    }
}

impl EdgeProperties {
    /// Create new edge properties
    pub fn new(bandwidth: f64, latency: f64, reliability: f64) -> Self {
        Self {
            bandwidth,
            latency,
            reliability,
            usage_frequency: 0,
        }
    }

    /// Get bandwidth
    pub fn bandwidth(&self) -> f64 {
        self.bandwidth
    }

    /// Get latency
    pub fn latency(&self) -> f64 {
        self.latency
    }

    /// Get reliability
    pub fn reliability(&self) -> f64 {
        self.reliability
    }

    /// Get usage frequency
    pub fn usage_frequency(&self) -> usize {
        self.usage_frequency
    }

    /// Increment usage frequency
    pub fn increment_usage(&mut self) {
        self.usage_frequency += 1;
    }
}

impl VertexProperties {
    /// Create new vertex properties
    pub fn new(process_rank: i32, compute_capability: f64, memory_capacity: usize) -> Self {
        Self {
            process_rank,
            compute_capability,
            memory_capacity,
            load: 0.0,
        }
    }

    /// Get process rank
    pub fn process_rank(&self) -> i32 {
        self.process_rank
    }

    /// Get compute capability
    pub fn compute_capability(&self) -> f64 {
        self.compute_capability
    }

    /// Get memory capacity
    pub fn memory_capacity(&self) -> usize {
        self.memory_capacity
    }

    /// Get load
    pub fn load(&self) -> f64 {
        self.load
    }

    /// Set load
    pub fn set_load(&mut self, load: f64) {
        self.load = load;
    }
}

impl TopologyOptimizer {
    /// Create a new topology optimizer
    pub fn new() -> Self {
        Self {
            optimization_algorithms: vec![
                TopologyOptimizationAlgorithm::GreedyImprovement,
                TopologyOptimizationAlgorithm::SimulatedAnnealing,
            ],
            performance_models: HashMap::new(),
            optimization_history: Vec::new(),
        }
    }

    /// Optimize a topology for a given workload
    pub fn optimize(
        &mut self,
        topology: &MPITopology,
        workload: &WorkloadCharacteristics,
    ) -> Result<OptimizationResult, String> {
        // Simplified optimization - in practice would use sophisticated algorithms
        Ok(OptimizationResult {
            original_topology: topology.clone(),
            optimized_topology: topology.clone(), // Placeholder
            performance_improvement: 0.0,
            optimization_time: std::time::Duration::from_secs(0),
            algorithm_used: "placeholder".to_string(),
        })
    }

    /// Add a performance model
    pub fn add_performance_model(&mut self, name: String, model: PerformanceModel) {
        self.performance_models.insert(name, model);
    }

    /// Get optimization history
    pub fn get_optimization_history(&self) -> &[OptimizationResult] {
        &self.optimization_history
    }
}

impl Default for PerformanceMetrics {
    fn default() -> Self {
        Self {
            throughput: 0.0,
            latency: 0.0,
            bandwidth_utilization: 0.0,
            load_balance: 0.0,
            energy_efficiency: 0.0,
        }
    }
}

impl WorkloadCharacteristics {
    /// Create new workload characteristics
    pub fn new(
        computation_pattern: ComputationPattern,
        communication_pattern: CommunicationPattern,
        datasize: usize,
        process_count: i32,
    ) -> Self {
        Self {
            computation_pattern,
            communication_pattern,
            datasize,
            process_count,
        }
    }

    /// Get computation pattern
    pub fn computation_pattern(&self) -> ComputationPattern {
        self.computation_pattern
    }

    /// Get communication pattern
    pub fn communication_pattern(&self) -> CommunicationPattern {
        self.communication_pattern
    }

    /// Get data size
    pub fn datasize(&self) -> usize {
        self.datasize
    }

    /// Get process count
    pub fn process_count(&self) -> i32 {
        self.process_count
    }
}