trustformers-mobile 0.1.1

//! Real-Time Performance Monitor
//!
//! This module provides advanced real-time performance monitoring system with
//! live performance tracking, alerting, and trend analysis capabilities.

use anyhow::{Context, Result};
use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use std::collections::{HashMap, VecDeque};
use std::sync::{Arc, Mutex, RwLock};
use std::time::{Duration, Instant};
use std::thread;
use tracing::{debug, error, info, warn};

use super::super::types::*;
use crate::device_info::{MobileDeviceDetector, MobileDeviceInfo, ThermalState};

/// Advanced real-time performance monitoring system
#[derive(Debug)]
pub struct RealTimeMonitor {
    /// Monitoring configuration
    config: RealTimeMonitoringConfig,
    /// Current monitoring state
    current_state: RealTimeState,
    /// Alert management system
    alert_manager: AlertManager,
    /// Live metrics buffer
    live_metrics: Arc<RwLock<VecDeque<MobileMetricsSnapshot>>>,
    /// Performance trends
    trending_metrics: TrendingMetrics,
    /// System health assessment
    system_health: SystemHealth,
    /// Monitoring statistics
    monitor_stats: MonitoringStats,
    /// Background monitoring thread
    _monitor_thread: Option<thread::JoinHandle<()>>,
}

/// Current real-time monitoring state
#[derive(Debug, Clone)]
pub struct RealTimeState {
    /// Overall performance score (0-100)
    pub performance_score: f32,
    /// Currently active alerts
    pub active_alerts: Vec<PerformanceAlert>,
    /// Performance trend indicators
    pub trending_metrics: TrendingMetrics,
    /// Overall system health status
    pub system_health: SystemHealth,
    /// Last update timestamp
    pub last_update: Option<Instant>,
    /// Monitoring uptime
    pub uptime: Duration,
}

/// Real-time monitoring statistics
#[derive(Debug, Clone, Default)]
pub struct MonitoringStats {
    /// Total monitoring time
    pub total_monitor_time: Duration,
    /// Total alerts generated
    pub alerts_generated: u64,
    /// Critical alerts generated
    pub critical_alerts: u64,
    /// Average response time to alerts
    pub avg_alert_response_time_ms: f32,
    /// Monitoring accuracy
    pub monitoring_accuracy: f32,
    /// False alarm rate
    pub false_alarm_rate: f32,
}

/// Alert management system
#[derive(Debug)]
pub struct AlertManager {
    /// Alert configuration
    config: AlertManagerConfig,
    /// Active alerts
    active_alerts: HashMap<String, PerformanceAlert>,
    /// Alert history
    alert_history: VecDeque<AlertRecord>,
    /// Alert rules
    alert_rules: Vec<AlertRule>,
    /// Notification handlers
    notification_handlers: Vec<Box<dyn NotificationHandler + Send + Sync>>,
}

/// Alert record for tracking alert history
#[derive(Debug, Clone)]
pub struct AlertRecord {
    pub alert_id: String,
    pub timestamp: std::time::Instant,
    pub alert_type: String,
    pub severity: String,
    pub message: String,
    pub resolved: bool,
    pub resolution_time: Option<std::time::Instant>,
}

/// Alert rule for defining alert conditions
#[derive(Debug, Clone)]
pub struct AlertRule {
    pub rule_id: String,
    pub name: String,
    pub condition: String,
    pub threshold_value: f32,
    pub severity: String,
    pub enabled: bool,
    pub created_at: std::time::Instant,
}

/// Notification handler trait
pub trait NotificationHandler: std::fmt::Debug {
    /// Send a performance alert notification
    fn send_notification(&self, alert: &PerformanceAlert) -> Result<()>;
    /// Get handler type/name
    fn handler_type(&self) -> &str;
    /// Check if handler is available
    fn is_available(&self) -> bool;
}

impl RealTimeMonitor {
    /// Create a new real-time monitor with the given configuration
    pub fn new(config: RealTimeMonitoringConfig) -> Result<Self> {
        let alert_manager = AlertManager::new(AlertManagerConfig::default())?;

        Ok(Self {
            config,
            current_state: RealTimeState::new(),
            alert_manager,
            live_metrics: Arc::new(RwLock::new(VecDeque::new())),
            trending_metrics: TrendingMetrics::default(),
            system_health: SystemHealth::default(),
            monitor_stats: MonitoringStats::default(),
            _monitor_thread: None,
        })
    }

    /// Start real-time monitoring
    pub fn start_monitoring(&mut self) -> Result<()> {
        info!("Starting real-time performance monitoring");

        // Initialize monitoring state
        self.current_state = RealTimeState::new();
        self.current_state.last_update = Some(Instant::now());

        // Start background monitoring thread if configured
        if self.config.enable_background_monitoring {
            self.start_background_monitoring()?;
        }

        Ok(())
    }

    /// Stop real-time monitoring
    pub fn stop_monitoring(&mut self) -> Result<()> {
        info!("Stopping real-time performance monitoring");

        // Update monitoring statistics
        if let Some(last_update) = self.current_state.last_update {
            let monitoring_duration = last_update.elapsed();
            self.monitor_stats.total_monitor_time += monitoring_duration;
        }

        Ok(())
    }

    /// Update monitoring state with new metrics
    pub fn update_metrics(&mut self, metrics: MobileMetricsSnapshot) -> Result<()> {
        // Add metrics to live buffer
        {
            let mut live_metrics = self.live_metrics.write()
                .expect("live_metrics lock should not be poisoned");
            live_metrics.push_back(metrics.clone());

            // Maintain buffer size limit
            if live_metrics.len() > self.config.max_metrics_buffer_size {
                live_metrics.pop_front();
            }
        }

        // Update current state
        self.update_performance_score(&metrics)?;
        self.update_trending_metrics(&metrics)?;
        self.update_system_health(&metrics)?;
        self.check_for_alerts(&metrics)?;

        self.current_state.last_update = Some(Instant::now());

        Ok(())
    }

    /// Get current monitoring state
    pub fn get_current_state(&self) -> &RealTimeState {
        &self.current_state
    }

    /// Get monitoring statistics
    pub fn get_monitoring_stats(&self) -> &MonitoringStats {
        &self.monitor_stats
    }

    /// Get recent metrics from live buffer
    pub fn get_recent_metrics(&self, limit: usize) -> Vec<MobileMetricsSnapshot> {
        let live_metrics = self.live_metrics.read()
            .expect("live_metrics lock should not be poisoned");
        live_metrics.iter().rev().take(limit).cloned().collect()
    }

    /// Start background monitoring thread
    fn start_background_monitoring(&mut self) -> Result<()> {
        let live_metrics_clone = self.live_metrics.clone();
        let monitoring_interval = self.config.monitoring_interval;

        let handle = thread::spawn(move || {
            loop {
                thread::sleep(monitoring_interval);

                // Background monitoring logic would go here
                // This is a simplified version
                debug!("Background monitoring tick");
            }
        });

        self._monitor_thread = Some(handle);
        Ok(())
    }

    /// Update overall performance score
    fn update_performance_score(&mut self, metrics: &MobileMetricsSnapshot) -> Result<()> {
        // Calculate weighted performance score (0-100)
        let memory_score = 100.0 - metrics.memory_usage_percent;
        let cpu_score = 100.0 - metrics.cpu_usage_percent;
        let latency_score = (1000.0 - metrics.inference_latency_ms.min(1000.0)) / 10.0;
        let thermal_score = match metrics.thermal_state {
            ThermalState::Nominal => 100.0,
            ThermalState::Fair => 80.0,
            ThermalState::Serious => 60.0,
            ThermalState::Hot => 40.0,
            ThermalState::Critical => 20.0,
        };

        // Weighted average
        self.current_state.performance_score = (
            memory_score * 0.3 +
            cpu_score * 0.3 +
            latency_score * 0.3 +
            thermal_score * 0.1
        ).max(0.0).min(100.0);

        Ok(())
    }

    /// Update trending metrics
    fn update_trending_metrics(&mut self, metrics: &MobileMetricsSnapshot) -> Result<()> {
        // Update memory trend
        self.trending_metrics.memory_trend = self.calculate_trend(
            metrics.memory_usage_percent,
            self.trending_metrics.memory_trend,
        );

        // Update CPU trend
        self.trending_metrics.cpu_trend = self.calculate_trend(
            metrics.cpu_usage_percent,
            self.trending_metrics.cpu_trend,
        );

        // Update latency trend
        self.trending_metrics.latency_trend = self.calculate_trend(
            metrics.inference_latency_ms,
            self.trending_metrics.latency_trend,
        );

        Ok(())
    }

    /// Calculate trend direction for a metric
    fn calculate_trend(&self, current_value: f32, previous_trend: TrendDirection) -> TrendDirection {
        // Simplified trend calculation
        // In reality, this would use statistical analysis over a window of values
        let threshold = 5.0; // 5% change threshold

        // This is a simplified version - you'd want to track historical values
        match previous_trend {
            TrendDirection::Increasing => TrendDirection::Stable, // Simplified
            TrendDirection::Decreasing => TrendDirection::Stable, // Simplified
            TrendDirection::Stable => TrendDirection::Stable,
        }
    }

    /// Update system health assessment
    fn update_system_health(&mut self, metrics: &MobileMetricsSnapshot) -> Result<()> {
        // Assess overall system health based on multiple factors
        let health_score = self.calculate_health_score(metrics);

        self.system_health.overall_status = if health_score > 80.0 {
            HealthStatus::Excellent
        } else if health_score > 60.0 {
            HealthStatus::Good
        } else if health_score > 40.0 {
            HealthStatus::Fair
        } else if health_score > 20.0 {
            HealthStatus::Poor
        } else {
            HealthStatus::Critical
        };

        self.system_health.last_check = Some(Instant::now());

        Ok(())
    }

    /// Calculate system health score
    fn calculate_health_score(&self, metrics: &MobileMetricsSnapshot) -> f32 {
        let memory_health = if metrics.memory_usage_percent < 70.0 { 100.0 }
                          else if metrics.memory_usage_percent < 85.0 { 60.0 }
                          else { 20.0 };

        let cpu_health = if metrics.cpu_usage_percent < 70.0 { 100.0 }
                        else if metrics.cpu_usage_percent < 90.0 { 60.0 }
                        else { 20.0 };

        let thermal_health = match metrics.thermal_state {
            ThermalState::Nominal => 100.0,
            ThermalState::Fair => 80.0,
            ThermalState::Serious => 50.0,
            ThermalState::Hot => 20.0,
            ThermalState::Critical => 0.0,
        };

        (memory_health + cpu_health + thermal_health) / 3.0
    }

    /// Check for alert conditions
    fn check_for_alerts(&mut self, metrics: &MobileMetricsSnapshot) -> Result<()> {
        let alerts = self.alert_manager.evaluate_alerts(metrics)?;

        for alert in alerts {
            self.current_state.active_alerts.push(alert.clone());
            self.monitor_stats.alerts_generated += 1;

            if alert.severity == AlertSeverity::Critical {
                self.monitor_stats.critical_alerts += 1;
            }

            debug!("Performance alert triggered: {}", alert.title);
        }

        Ok(())
    }
}

impl RealTimeState {
    /// Create a new real-time state
    pub fn new() -> Self {
        Self {
            performance_score: 100.0,
            active_alerts: Vec::new(),
            trending_metrics: TrendingMetrics::default(),
            system_health: SystemHealth::default(),
            last_update: None,
            uptime: Duration::from_secs(0),
        }
    }

    /// Update uptime
    pub fn update_uptime(&mut self, start_time: Instant) {
        self.uptime = start_time.elapsed();
    }
}

impl AlertManager {
    /// Create a new alert manager
    pub fn new(config: AlertManagerConfig) -> Result<Self> {
        let alert_rules = Self::initialize_default_alert_rules();

        Ok(Self {
            config,
            active_alerts: HashMap::new(),
            alert_history: VecDeque::new(),
            alert_rules,
            notification_handlers: Vec::new(),
        })
    }

    /// Evaluate alert conditions against metrics
    pub fn evaluate_alerts(&mut self, metrics: &MobileMetricsSnapshot) -> Result<Vec<PerformanceAlert>> {
        let mut triggered_alerts = Vec::new();

        for rule in &self.alert_rules {
            if !rule.enabled {
                continue;
            }

            if self.evaluate_alert_rule(rule, metrics)? {
                let alert = self.create_alert_from_rule(rule, metrics)?;
                triggered_alerts.push(alert.clone());

                // Track active alert
                self.active_alerts.insert(rule.rule_id.clone(), alert);

                // Record alert history
                let record = AlertRecord {
                    alert_id: rule.rule_id.clone(),
                    timestamp: Instant::now(),
                    alert_type: rule.name.clone(),
                    severity: rule.severity.clone(),
                    message: format!("Alert triggered: {}", rule.name),
                    resolved: false,
                    resolution_time: None,
                };

                self.alert_history.push_back(record);
            }
        }

        Ok(triggered_alerts)
    }

    /// Initialize default alert rules
    fn initialize_default_alert_rules() -> Vec<AlertRule> {
        vec![
            AlertRule {
                rule_id: "high_memory_usage".to_string(),
                name: "High Memory Usage".to_string(),
                condition: "memory_usage_percent > threshold".to_string(),
                threshold_value: 90.0,
                severity: "High".to_string(),
                enabled: true,
                created_at: Instant::now(),
            },
            AlertRule {
                rule_id: "high_cpu_usage".to_string(),
                name: "High CPU Usage".to_string(),
                condition: "cpu_usage_percent > threshold".to_string(),
                threshold_value: 95.0,
                severity: "High".to_string(),
                enabled: true,
                created_at: Instant::now(),
            },
            AlertRule {
                rule_id: "thermal_throttling".to_string(),
                name: "Thermal Throttling".to_string(),
                condition: "thermal_state >= Hot".to_string(),
                threshold_value: 0.0, // Not used for enum conditions
                severity: "Critical".to_string(),
                enabled: true,
                created_at: Instant::now(),
            },
        ]
    }

    /// Evaluate an alert rule against current metrics
    fn evaluate_alert_rule(&self, rule: &AlertRule, metrics: &MobileMetricsSnapshot) -> Result<bool> {
        match rule.rule_id.as_str() {
            "high_memory_usage" => Ok(metrics.memory_usage_percent > rule.threshold_value),
            "high_cpu_usage" => Ok(metrics.cpu_usage_percent > rule.threshold_value),
            "thermal_throttling" => Ok(matches!(
                metrics.thermal_state,
                ThermalState::Hot | ThermalState::Critical
            )),
            _ => Ok(false),
        }
    }

    /// Create a performance alert from a triggered rule
    fn create_alert_from_rule(&self, rule: &AlertRule, metrics: &MobileMetricsSnapshot) -> Result<PerformanceAlert> {
        let severity = match rule.severity.as_str() {
            "Low" => AlertSeverity::Low,
            "Medium" => AlertSeverity::Medium,
            "High" => AlertSeverity::High,
            "Critical" => AlertSeverity::Critical,
            _ => AlertSeverity::Medium,
        };

        Ok(PerformanceAlert {
            alert_type: AlertType::PerformanceIssue,
            severity,
            title: rule.name.clone(),
            description: format!("Alert condition triggered: {}", rule.condition),
            timestamp: Instant::now(),
            metrics_snapshot: Some(metrics.clone()),
            suggested_actions: self.get_suggested_actions_for_rule(rule),
            alert_id: Some(rule.rule_id.clone()),
            resolution_status: AlertResolutionStatus::Open,
        })
    }

    /// Get suggested actions for an alert rule
    fn get_suggested_actions_for_rule(&self, rule: &AlertRule) -> Vec<String> {
        match rule.rule_id.as_str() {
            "high_memory_usage" => vec![
                "Consider reducing batch size".to_string(),
                "Enable memory optimization settings".to_string(),
                "Monitor for memory leaks".to_string(),
            ],
            "high_cpu_usage" => vec![
                "Enable GPU acceleration if available".to_string(),
                "Reduce thread count".to_string(),
                "Optimize model operations".to_string(),
            ],
            "thermal_throttling" => vec![
                "Reduce inference frequency".to_string(),
                "Implement thermal management".to_string(),
                "Allow device cooldown".to_string(),
            ],
            _ => vec!["Review performance metrics".to_string()],
        }
    }
}

impl Default for RealTimeMonitor {
    fn default() -> Self {
        Self::new(RealTimeMonitoringConfig::default())
            .expect("Failed to create default real-time monitor")
    }
}