scirs2-linalg 0.4.2

//! Resource monitoring and alerting system

use std::collections::HashMap;
use std::path::PathBuf;
use std::time::{Duration, Instant};

/// Resource monitoring system
#[derive(Debug)]
pub struct ResourceMonitor {
    /// Active monitoring tasks
    monitoring_tasks: HashMap<String, MonitoringTask>,
    /// Alert system
    alert_system: AlertSystem,
    /// Metrics collection
    metrics_collector: MetricsCollector,
}

/// Monitoring task
#[derive(Debug, Clone)]
pub struct MonitoringTask {
    task_id: String,
    target_nodes: Vec<usize>,
    metrics: Vec<String>,
    frequency: Duration,
    thresholds: HashMap<String, f64>,
    actions: Vec<MonitoringAction>,
}

/// Actions to take based on monitoring
#[derive(Debug, Clone)]
pub enum MonitoringAction {
    Alert(AlertLevel),
    Scale(ScaleAction),
    Migrate(MigrationAction),
    Throttle(ThrottleAction),
    Log(LogAction),
}

/// Alert levels
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub enum AlertLevel {
    Info,
    Warning,
    Error,
    Critical,
}

/// Scale action for resources
#[derive(Debug, Clone)]
pub struct ScaleAction {
    direction: ScaleDirection,
    target_nodes: Vec<usize>,
    resource_types: Vec<String>,
    scale_factor: f64,
}

/// Direction for scaling
#[derive(Debug, Clone, Copy)]
pub enum ScaleDirection {
    Up,
    Down,
    Auto,
}

/// Migration action for workloads
#[derive(Debug, Clone)]
pub struct MigrationAction {
    source_node: usize,
    target_nodes: Vec<usize>,
    workload_filter: String,
    migration_strategy: MigrationStrategy,
}

/// Strategy for workload migration
#[derive(Debug, Clone, Copy)]
pub enum MigrationStrategy {
    Live,
    Offline,
    Gradual,
    Emergency,
}

/// Throttle action for resource usage
#[derive(Debug, Clone)]
pub struct ThrottleAction {
    target_nodes: Vec<usize>,
    resource_type: String,
    throttle_percentage: f64,
    duration: Duration,
}

/// Log action for monitoring events
#[derive(Debug, Clone)]
pub struct LogAction {
    log_level: LogLevel,
    message_template: String,
    include_metrics: bool,
    external_systems: Vec<String>,
}

/// Log levels
#[derive(Debug, Clone, Copy)]
pub enum LogLevel {
    Debug,
    Info,
    Warn,
    Error,
    Fatal,
}

/// Alert system for resource monitoring
#[derive(Debug)]
pub struct AlertSystem {
    /// Alert rules
    alert_rules: Vec<AlertRule>,
    /// Active alerts
    active_alerts: HashMap<String, ActiveAlert>,
    /// Notification channels
    notification_channels: Vec<NotificationChannel>,
}

/// Rule for generating alerts
#[derive(Debug, Clone)]
pub struct AlertRule {
    rule_id: String,
    condition: AlertCondition,
    severity: AlertLevel,
    cooldown_period: Duration,
    notification_channels: Vec<String>,
    auto_resolution: bool,
}

/// Condition for triggering alerts
#[derive(Debug, Clone)]
pub enum AlertCondition {
    Threshold {
        metric: String,
        operator: ComparisonOperator,
        value: f64,
    },
    RateOfChange {
        metric: String,
        rate_threshold: f64,
        time_window: Duration,
    },
    Anomaly {
        metric: String,
        sensitivity: f64,
    },
    Custom(String),
}

/// Comparison operators for thresholds
#[derive(Debug, Clone, Copy)]
pub enum ComparisonOperator {
    GreaterThan,
    LessThan,
    Equal,
    NotEqual,
    GreaterThanOrEqual,
    LessThanOrEqual,
}

/// Active alert
#[derive(Debug, Clone)]
pub struct ActiveAlert {
    alert_id: String,
    rule_id: String,
    triggered_at: Instant,
    current_value: f64,
    threshold_value: f64,
    affected_nodes: Vec<usize>,
    acknowledgment_status: AcknowledgmentStatus,
}

/// Status of alert acknowledgment
#[derive(Debug, Clone)]
pub enum AcknowledgmentStatus {
    Pending,
    Acknowledged {
        by_user: String,
        at_time: Instant,
        comment: Option<String>,
    },
    AutoResolved {
        at_time: Instant,
    },
}

/// Notification channel for alerts
#[derive(Debug, Clone)]
pub enum NotificationChannel {
    Email {
        addresses: Vec<String>,
        template: String,
    },
    Slack {
        webhook_url: String,
        channel: String,
    },
    HTTP {
        endpoint: String,
        headers: HashMap<String, String>,
    },
    SMS {
        phone_numbers: Vec<String>,
        provider: String,
    },
}

/// Metrics collection system
#[derive(Debug)]
pub struct MetricsCollector {
    /// Metrics definitions
    metrics_definitions: HashMap<String, MetricDefinition>,
    /// Collection agents
    collection_agents: HashMap<usize, CollectionAgent>,
    /// Storage backend
    storage_backend: MetricsStorage,
}

/// Definition of a metric
#[derive(Debug, Clone)]
pub struct MetricDefinition {
    metric_name: String,
    metric_type: MetricType,
    unit: String,
    collection_method: CollectionMethod,
    aggregation_strategy: crate::distributed::redundancy::UpdateStrategy,
    retention_period: Duration,
}

/// Types of metrics
#[derive(Debug, Clone, Copy)]
pub enum MetricType {
    Counter,
    Gauge,
    Histogram,
    Summary,
    Timer,
}

/// Method for collecting metrics
#[derive(Debug, Clone)]
pub enum CollectionMethod {
    SystemCall(String),
    FileRead(PathBuf),
    NetworkQuery(String),
    CustomFunction(String),
}

/// Agent for collecting metrics from nodes
#[derive(Debug)]
pub struct CollectionAgent {
    agent_id: String,
    node_id: usize,
    active_collectors: HashMap<String, MetricCollector>,
    collection_schedule: HashMap<String, Duration>,
    last_collection: HashMap<String, Instant>,
}

/// Individual metric collector
#[derive(Debug)]
pub struct MetricCollector {
    metric_name: String,
    collection_function: String, // Function name or command
    last_value: Option<f64>,
    error_count: usize,
    success_count: usize,
}

/// Storage backend for metrics
#[derive(Debug)]
pub enum MetricsStorage {
    InMemory {
        max_points: usize,
        data: HashMap<String, Vec<MetricPoint>>,
    },
    Database {
        connection_string: String,
        table_name: String,
    },
    TimeSeriesDB {
        endpoint: String,
        database: String,
    },
    Files {
        directory: PathBuf,
        rotation_policy: FileRotationPolicy,
    },
}

/// Point in time for metrics
#[derive(Debug, Clone)]
pub struct MetricPoint {
    timestamp: Instant,
    value: f64,
    labels: HashMap<String, String>,
}

/// Policy for rotating metric files
#[derive(Debug, Clone)]
pub struct FileRotationPolicy {
    max_filesize: usize,
    max_files: usize,
    rotation_frequency: Duration,
    compression: bool,
}

impl ResourceMonitor {
    /// Create a new resource monitor
    pub fn new() -> Self {
        Self {
            monitoring_tasks: HashMap::new(),
            alert_system: AlertSystem::new(),
            metrics_collector: MetricsCollector::new(),
        }
    }

    /// Add a monitoring task
    pub fn add_task(&mut self, task: MonitoringTask) {
        self.monitoring_tasks.insert(task.task_id.clone(), task);
    }

    /// Remove a monitoring task
    pub fn remove_task(&mut self, task_id: &str) -> Option<MonitoringTask> {
        self.monitoring_tasks.remove(task_id)
    }

    /// Execute monitoring tasks
    pub fn execute_monitoring(&mut self) -> Result<(), String> {
        for task in self.monitoring_tasks.values() {
            self.execute_task(task)?;
        }
        Ok(())
    }

    /// Execute a single monitoring task
    fn execute_task(&mut self, task: &MonitoringTask) -> Result<(), String> {
        // Collect metrics for the task
        for metric in &task.metrics {
            for &node_id in &task.target_nodes {
                let value = self.metrics_collector.collect_metric(node_id, metric)?;

                // Check thresholds
                if let Some(&threshold) = task.thresholds.get(metric) {
                    if value > threshold {
                        // Execute actions
                        for action in &task.actions {
                            self.execute_action(action, node_id, value)?;
                        }
                    }
                }
            }
        }
        Ok(())
    }

    /// Execute a monitoring action
    fn execute_action(&mut self, action: &MonitoringAction, node_id: usize, value: f64) -> Result<(), String> {
        match action {
            MonitoringAction::Alert(level) => {
                self.alert_system.trigger_alert(node_id, *level, value)?;
            }
            MonitoringAction::Scale(scale_action) => {
                self.execute_scale_action(scale_action)?;
            }
            MonitoringAction::Migrate(migration_action) => {
                self.execute_migration_action(migration_action)?;
            }
            MonitoringAction::Throttle(throttle_action) => {
                self.execute_throttle_action(throttle_action)?;
            }
            MonitoringAction::Log(log_action) => {
                self.execute_log_action(log_action, node_id, value)?;
            }
        }
        Ok(())
    }

    fn execute_scale_action(&self, _action: &ScaleAction) -> Result<(), String> {
        // Implementation would depend on the specific scaling mechanism
        Ok(())
    }

    fn execute_migration_action(&self, _action: &MigrationAction) -> Result<(), String> {
        // Implementation would depend on the workload migration system
        Ok(())
    }

    fn execute_throttle_action(&self, _action: &ThrottleAction) -> Result<(), String> {
        // Implementation would throttle resource usage
        Ok(())
    }

    fn execute_log_action(&self, _action: &LogAction, _node_id: usize, _value: f64) -> Result<(), String> {
        // Implementation would log the event
        Ok(())
    }
}

impl AlertSystem {
    fn new() -> Self {
        Self {
            alert_rules: Vec::new(),
            active_alerts: HashMap::new(),
            notification_channels: Vec::new(),
        }
    }

    fn trigger_alert(&mut self, node_id: usize, level: AlertLevel, value: f64) -> Result<(), String> {
        let alert_id = format!("alert_{}_{}", node_id, Instant::now().elapsed().as_millis());
        let alert = ActiveAlert {
            alert_id: alert_id.clone(),
            rule_id: String::new(),
            triggered_at: Instant::now(),
            current_value: value,
            threshold_value: 0.0,
            affected_nodes: vec![node_id],
            acknowledgment_status: AcknowledgmentStatus::Pending,
        };

        self.active_alerts.insert(alert_id, alert);
        Ok(())
    }
}

impl MetricsCollector {
    fn new() -> Self {
        Self {
            metrics_definitions: HashMap::new(),
            collection_agents: HashMap::new(),
            storage_backend: MetricsStorage::InMemory {
                max_points: 10000,
                data: HashMap::new(),
            },
        }
    }

    fn collect_metric(&self, node_id: usize, metric_name: &str) -> Result<f64, String> {
        // Simplified metric collection - would use actual system metrics in practice
        if let Some(_agent) = self.collection_agents.get(&node_id) {
            // Return a dummy value for now
            Ok(0.5)
        } else {
            Err(format!("No collection agent found for node {}", node_id))
        }
    }
}