/**
 * Shared retention bounds for routing telemetry (in-memory and SQLite).
 */

import type { RoutingTelemetry } from '../../domain/types/index.js';

export const TELEMETRY_WINDOW_HOURS = 168;
export const TELEMETRY_WINDOW_MS = TELEMETRY_WINDOW_HOURS * 60 * 60 * 1000;
export const TELEMETRY_MAX_ENTRIES = 1111;

export const DEFAULT_HISTORY_LIMIT = 10;
export const MAX_HISTORY_LIMIT = 100;

/** Remove entries older than the rolling window. */
export function evictExpiredTelemetryEntries(
  entries: RoutingTelemetry[],
  windowMs: number = TELEMETRY_WINDOW_MS,
): void {
  const cutoff = Date.now() - windowMs;

  while (entries.length > 0) {
    const oldest = entries[0]!;
    if (new Date(oldest.timestamp).getTime() < cutoff) {
      entries.shift();
    } else {
      break;
    }
  }
}

/** Trim oldest entries until count is at most maxEntries. */
export function trimTelemetryEntriesToMax(
  entries: RoutingTelemetry[],
  maxEntries: number = TELEMETRY_MAX_ENTRIES,
): void {
  while (entries.length > maxEntries) {
    entries.shift();
  }
}

/** Make room for one more entry before append. */
export function makeTelemetryRoom(
  entries: RoutingTelemetry[],
  maxEntries: number = TELEMETRY_MAX_ENTRIES,
): void {
  evictExpiredTelemetryEntries(entries);
  while (entries.length >= maxEntries) {
    entries.shift();
  }
}