/**
 * @file Performance Budget System
 * @description Comprehensive performance budget management with:
 * - Configurable budgets per metric
 * - Budget violation alerts and callbacks
 * - Automatic performance degradation strategies
 * - Budget trending and history tracking
 * - Statistical analysis of budget adherence
 *
 * This system provides fine-grained control over performance budgets,
 * enabling proactive performance management and automatic adaptation
 * when budgets are exceeded.
 *
 * @example
 * ```typescript
 * import { PerformanceBudgetManager } from '@/lib/performance';
 *
 * const budgetManager = new PerformanceBudgetManager({
 *   budgets: {
 *     'LCP': { warning: 2000, critical: 2500, unit: 'ms' },
 *     'bundle.initial': { warning: 150000, critical: 200000, unit: 'bytes' },
 *   },
 *   onViolation: (violation) => {
 *     analytics.track('performance_budget_violation', violation);
 *   },
 * });
 *
 * // Record metrics
 * budgetManager.record('LCP', 2100); // Triggers warning
 * budgetManager.record('bundle.initial', 250000); // Triggers critical
 * ```
 */
/**
 * Budget threshold configuration
 */
export interface BudgetThreshold {
    /** Warning threshold value */
    readonly warning: number;
    /** Critical threshold value */
    readonly critical: number;
    /** Unit of measurement */
    readonly unit: 'ms' | 'bytes' | 'score' | 'count' | 'percent' | 'fps';
    /** Human-readable description */
    readonly description?: string;
    /** Enable automatic degradation when exceeded */
    readonly enableDegradation?: boolean;
    /** Degradation strategy */
    readonly degradationStrategy?: DegradationStrategy;
}
/**
 * Degradation strategy for when budgets are exceeded
 */
export type DegradationStrategy = 'reduce-animations' | 'reduce-images' | 'reduce-features' | 'reduce-polling' | 'defer-non-critical' | 'custom';
/**
 * Budget violation severity
 */
export type ViolationSeverity = 'warning' | 'critical';
/**
 * Budget violation record
 */
export interface BudgetViolationRecord {
    readonly id: string;
    readonly budgetName: string;
    readonly value: number;
    readonly threshold: number;
    readonly severity: ViolationSeverity;
    readonly overage: number;
    readonly overagePercent: number;
    readonly timestamp: number;
    readonly url: string;
    readonly userAgent: string;
    readonly sessionId: string;
}
/**
 * Budget metric entry
 */
export interface BudgetMetricEntry {
    readonly budgetName: string;
    readonly value: number;
    readonly timestamp: number;
    readonly status: 'ok' | 'warning' | 'critical';
    readonly percentOfBudget: number;
}
/**
 * Budget trend data
 */
export interface BudgetTrend {
    readonly budgetName: string;
    readonly entries: BudgetMetricEntry[];
    readonly average: number;
    readonly min: number;
    readonly max: number;
    readonly p50: number;
    readonly p75: number;
    readonly p90: number;
    readonly p99: number;
    readonly trend: 'improving' | 'stable' | 'degrading';
    readonly violationRate: number;
    readonly lastUpdated: number;
}
/**
 * Budget status summary
 */
export interface BudgetStatusSummary {
    readonly budgetName: string;
    readonly threshold: BudgetThreshold;
    readonly currentValue: number | null;
    readonly status: 'ok' | 'warning' | 'critical' | 'unknown';
    readonly trend: BudgetTrend | null;
    readonly recentViolations: BudgetViolationRecord[];
}
/**
 * Degradation state
 */
export interface DegradationState {
    readonly isActive: boolean;
    readonly level: 'none' | 'light' | 'moderate' | 'aggressive';
    readonly activeStrategies: DegradationStrategy[];
    readonly reason: string | null;
    readonly activatedAt: number | null;
}
/**
 * Budget manager configuration
 */
export interface BudgetManagerConfig {
    /** Custom budget definitions */
    readonly budgets?: Record<string, BudgetThreshold>;
    /** Violation callback */
    readonly onViolation?: (violation: BudgetViolationRecord) => void;
    /** Recovery callback (when metric returns to ok) */
    readonly onRecovery?: (budgetName: string) => void;
    /** Degradation state change callback */
    readonly onDegradationChange?: (state: DegradationState) => void;
    /** History retention period (ms) */
    readonly historyRetention?: number;
    /** Maximum history entries per budget */
    readonly maxHistoryEntries?: number;
    /** Enable automatic degradation */
    readonly enableAutoDegradation?: boolean;
    /** Consecutive violations before degradation */
    readonly degradationThreshold?: number;
    /** Session ID for tracking */
    readonly sessionId?: string;
    /** Enable debug logging */
    readonly debug?: boolean;
}
/**
 * Default budget definitions combining Core Web Vitals and resource budgets
 */
export declare const DEFAULT_BUDGETS: Record<string, BudgetThreshold>;
/**
 * Format value based on unit
 */
export declare function formatBudgetValue(value: number, unit: BudgetThreshold['unit']): string;
/**
 * Comprehensive performance budget management system
 */
export declare class PerformanceBudgetManager {
    private readonly config;
    private readonly budgets;
    private readonly history;
    private readonly violations;
    private readonly currentValues;
    private readonly consecutiveViolations;
    private degradationState;
    constructor(config?: BudgetManagerConfig);
    /**
     * Register a custom budget
     */
    registerBudget(name: string, threshold: BudgetThreshold): void;
    /**
     * Update an existing budget threshold
     */
    updateBudget(name: string, updates: Partial<BudgetThreshold>): void;
    /**
     * Remove a budget
     */
    removeBudget(name: string): void;
    /**
     * Get budget threshold
     */
    getBudget(name: string): BudgetThreshold | undefined;
    /**
     * Get all budgets
     */
    getAllBudgets(): Map<string, BudgetThreshold>;
    /**
     * Record a metric value
     */
    record(budgetName: string, value: number): BudgetMetricEntry;
    /**
     * Batch record multiple metrics
     */
    recordBatch(metrics: Record<string, number>): BudgetMetricEntry[];
    /**
     * Deactivate degradation
     */
    deactivateDegradation(): void;
    /**
     * Get current degradation state
     */
    getDegradationState(): DegradationState;
    /**
     * Check if a specific strategy is active
     */
    isStrategyActive(strategy: DegradationStrategy): boolean;
    /**
     * Get trend data for a budget
     */
    getTrend(budgetName: string): BudgetTrend | null;
    /**
     * Get all trends
     */
    getAllTrends(): Map<string, BudgetTrend | null>;
    /**
     * Get status summary for a budget
     */
    getStatus(budgetName: string): BudgetStatusSummary | null;
    /**
     * Get all status summaries
     */
    getAllStatuses(): BudgetStatusSummary[];
    /**
     * Get all violations
     */
    getViolations(): BudgetViolationRecord[];
    /**
     * Get violations for a specific budget
     */
    getViolationsFor(budgetName: string): BudgetViolationRecord[];
    /**
     * Get overall health score (0-100)
     */
    getHealthScore(): number;
    /**
     * Generate report
     */
    generateReport(): string;
    /**
     * Clear all history
     */
    clearHistory(): void;
    /**
     * Evaluate metric status against threshold
     */
    private evaluateStatus;
    /**
     * Calculate percentage of budget used
     */
    private calculatePercentOfBudget;
    /**
     * Handle a budget violation
     */
    private handleViolation;
    /**
     * Handle recovery from violation
     */
    private handleRecovery;
    /**
     * Activate degradation for a budget
     */
    private activateDegradation;
    /**
     * Check if degradation can be deactivated
     */
    private checkDegradationRecovery;
    /**
     * Calculate degradation level based on active strategies
     */
    private calculateDegradationLevel;
    /**
     * Calculate trend direction
     */
    private calculateTrendDirection;
    /**
     * Trim history to max entries
     */
    private trimHistory;
    /**
     * Trim violations to reasonable size
     */
    private trimViolations;
    /**
     * Debug logging
     */
    private log;
}
/**
 * Get or create the global PerformanceBudgetManager instance
 */
export declare function getBudgetManager(config?: BudgetManagerConfig): PerformanceBudgetManager;
/**
 * Reset the global instance (for testing)
 */
export declare function resetBudgetManager(): void;