oxirs-vec 0.2.4

//! Cache optimization engine with adaptive algorithms

use anyhow::Result;
use std::collections::VecDeque;
use std::time::{Duration, SystemTime};

use super::config::CacheConfiguration;
use super::metrics::CachePerformanceMetrics;
use super::tier::CacheTier;
use super::types::{
    ImprovementTracker, OptimizationEvent, OptimizationResult, OptimizationState,
    OptimizationStatistics, RegressionDetector,
};

/// Cache optimization engine with adaptive algorithms
#[allow(dead_code)]
#[derive(Debug)]
pub struct CacheOptimizer {
    /// Optimization algorithms
    pub(crate) algorithms: Vec<Box<dyn OptimizationAlgorithm>>,
    /// Optimization history
    optimization_history: Vec<OptimizationEvent>,
    /// Current optimization state
    current_state: OptimizationState,
    /// Performance improvement tracking
    improvements: ImprovementTracker,
}

/// Optimization algorithm trait
pub trait OptimizationAlgorithm: Send + Sync + std::fmt::Debug {
    /// Apply optimization to the cache system
    fn optimize_cache(
        &mut self,
        tiers: &[CacheTier],
        metrics: &CachePerformanceMetrics,
        config: &CacheConfiguration,
    ) -> Result<OptimizationResult>;

    /// Get algorithm name
    fn name(&self) -> &str;

    /// Get optimization score for current state
    fn score(&self, metrics: &CachePerformanceMetrics) -> f64;
}

impl Default for CacheOptimizer {
    fn default() -> Self {
        Self::new()
    }
}

impl CacheOptimizer {
    pub fn new() -> Self {
        Self {
            algorithms: vec![], // Would contain actual optimization algorithms
            optimization_history: Vec::new(),
            current_state: OptimizationState {
                last_optimization: SystemTime::now(),
                optimization_frequency: Duration::from_secs(3600),
                pending_optimizations: Vec::new(),
                optimization_backlog: 0,
            },
            improvements: ImprovementTracker {
                baseline_metrics: CachePerformanceMetrics::default(),
                current_improvement: 0.0,
                improvement_history: VecDeque::new(),
                regression_detection: RegressionDetector {
                    regression_threshold: -0.05,
                    detection_window: Duration::from_secs(1800),
                    recent_scores: VecDeque::new(),
                },
            },
        }
    }

    pub fn record_optimization_event(&mut self, event: OptimizationEvent) {
        self.optimization_history.push(event);
    }

    pub fn get_statistics(&self) -> OptimizationStatistics {
        OptimizationStatistics {
            total_optimizations: self.optimization_history.len() as u64,
            successful_optimizations: self
                .optimization_history
                .iter()
                .filter(|e| !e.changes.is_empty())
                .count() as u64,
            avg_improvement_score: self.improvements.current_improvement,
            last_optimization: self.optimization_history.last().map(|e| e.timestamp),
        }
    }

    pub fn export_history(&self) -> String {
        "{}".to_string() // Simplified
    }
}