/**
 * Performance configuration for Phase 1 optimization
 */

export const PERFORMANCE_CONFIG = {
  // Metadata cache TTL (5 minutes)
  METADATA_CACHE_TTL: 5 * 60 * 1000,
  
  // Preload nearby notes (number of notes before/after)
  PRELOAD_NEARBY: 5,
  
  // Pagination size for large vaults
  PAGINATION_SIZE: 100,
  
  // Maximum notes to load in metadata endpoint
  MAX_METADATA_ITEMS: 10000,
  
  // Enable performance logging
  ENABLE_PERF_LOGGING: process.env.PERF_LOGGING === 'true',
};

/**
 * Simple in-memory cache for metadata
 */
export class MetadataCache {
  constructor(ttl = PERFORMANCE_CONFIG.METADATA_CACHE_TTL) {
    this.cache = null;
    this.ttl = ttl;
    this.timestamp = null;
  }

  set(data) {
    this.cache = data;
    this.timestamp = Date.now();
  }

  get() {
    if (!this.cache || !this.timestamp) {
      return null;
    }
    
    if (Date.now() - this.timestamp > this.ttl) {
      this.cache = null;
      this.timestamp = null;
      return null;
    }
    
    return this.cache;
  }

  invalidate() {
    this.cache = null;
    this.timestamp = null;
  }

  isValid() {
    return this.cache !== null && (Date.now() - this.timestamp) < this.ttl;
  }
}

/**
 * Performance logger
 */
export class PerformanceLogger {
  static log(operation, duration, metadata = {}) {
    if (!PERFORMANCE_CONFIG.ENABLE_PERF_LOGGING) {
      return;
    }
    
    const level = duration > 1000 ? 'warn' : 'info';
    const message = `[PERF] ${operation}: ${duration.toFixed(0)}ms`;
    
    if (level === 'warn') {
      console.warn(message, metadata);
    } else {
      console.log(message, metadata);
    }
  }

  static mark(label) {
    if (typeof performance !== 'undefined' && performance.mark) {
      performance.mark(label);
    }
  }

  static measure(label, startMark, endMark) {
    if (typeof performance !== 'undefined' && performance.measure) {
      try {
        performance.measure(label, startMark, endMark);
      } catch (e) {
        // Ignore if marks don't exist
      }
    }
  }
}