/**
 * Sync pipeline metrics — CloudWatch custom metrics for the event-driven push
 * receive loop (project event-driven-sync-menubar US-011).
 *
 * Publishes one `hq-cloud.sync.p95_latency_seconds` datum per successfully
 * processed push event to the `HQPro/Sync` namespace, with a `TenantId`
 * dimension so the dashboard widget can be filtered per tenant. CloudWatch
 * aggregates p50/p95/p99 across the time window via the dashboard's
 * `Statistics` setting; the receive-loop side just emits one raw value per
 * event.
 *
 * Best-effort emission
 * ────────────────────
 *   - module-level singleton CloudWatchClient with a `_setSyncCloudWatchClient`
 *     test seam
 *   - `publishSyncLatencyMetric` catches all errors and NEVER throws — a
 *     CloudWatch outage MUST NOT crash the sync receive loop. The cadence
 *     safety net still picks up missed work and metric blanks are recoverable;
 *     a crashed loop is not.
 *   - explicit `Unit` + `Timestamp` + `Dimensions` per datum
 *
 * Why latency (and not also "events received" / "events failed")?
 * ───────────────────────────────────────────────────────────────
 * US-011 AC#1 calls for the p95 latency metric specifically. The receive-loop's
 * existing `processedCount` / log lines cover the count/failure dimensions for
 * now; widening to additional metric names happens in a follow-up if the
 * operator dashboard grows.
 *
 * Adapted from indigoai-us/hq-pro PR #112 (src/sync/metrics.ts) into
 * @indigoai-us/hq-cloud (Path B).
 */
import { CloudWatchClient } from "@aws-sdk/client-cloudwatch";
import type { Logger } from "pino";
/**
 * CloudWatch metric namespace for the sync pipeline. Matches the server-side
 * namespace (hq-pro PR #112) so the dashboard + alarm cover the client path.
 */
export declare const SYNC_METRIC_NAMESPACE = "HQPro/Sync";
/**
 * Metric name for per-event sync latency in seconds. The dashboard widget
 * applies `Statistics: ["p95"]` to aggregate across the time window — the
 * receive loop just emits one raw `Seconds` value per processed event.
 *
 * Name chosen to match the PRD's alarm threshold (`p95 > 10s`).
 */
export declare const SYNC_LATENCY_METRIC_NAME = "hq-cloud.sync.p95_latency_seconds";
/**
 * One latency observation. `latencySeconds` is the wall-clock duration from
 * save-on-A to visible-on-B (or, on the receive loop, the `syncFn(ctx)`
 * duration); we ONLY publish on the success path so failed syncs don't skew
 * p95 toward infinity.
 *
 * `relativePath` and `sequenceNumber` are NOT used as CloudWatch dimensions
 * (cardinality explosion) — they're captured here for the optional debug log
 * emitted on failure so operators can correlate back to the 3-log chain when
 * investigating a spike.
 */
export interface SyncLatencyMetric {
    tenantId: string;
    relativePath: string;
    sequenceNumber: number;
    latencySeconds: number;
    timestamp: Date;
}
export interface SyncMetricCredentials {
    accessKeyId: string;
    secretAccessKey: string;
    sessionToken?: string;
    expiration?: string;
}
type CloudWatchClientConfig = NonNullable<ConstructorParameters<typeof CloudWatchClient>[0]>;
type CloudWatchClientLike = Pick<CloudWatchClient, "send">;
/**
 * Replace the CloudWatch client (for testing).
 * @internal
 */
export declare function _setSyncCloudWatchClient(client: CloudWatchClient): void;
export interface CreateSyncLatencyMetricPublisherOptions {
    region: string;
    credentials: SyncMetricCredentials;
    /** Override CloudWatch construction (tests). */
    buildClient?: (config: CloudWatchClientConfig) => CloudWatchClientLike;
}
export declare function createSyncLatencyMetricPublisher(opts: CreateSyncLatencyMetricPublisherOptions): (metric: SyncLatencyMetric) => Promise<void>;
export interface PublishSyncLatencyMetricOptions {
    /** Override the CloudWatch client (tests). Defaults to the module singleton. */
    client?: CloudWatchClientLike;
    /** Optional pino logger for emission failures. */
    logger?: Logger;
}
/**
 * Publish a single latency datum to CloudWatch.
 *
 * Best-effort: any error from the SDK is CAUGHT and logged. A CloudWatch outage
 * MUST NOT crash the sync receive loop — the cadence safety net still picks up
 * missed work, and metric blanks are recoverable; a crashed loop is not.
 *
 * Dimension: `TenantId` only. The `relativePath`/`sequenceNumber` fields on the
 * input are intentionally NOT promoted to dimensions (cardinality), but they
 * ride along on the failure log so an operator can correlate a missed datum to
 * its 3-log chain entry.
 */
export declare function publishSyncLatencyMetric(metric: SyncLatencyMetric, opts?: PublishSyncLatencyMetricOptions): Promise<void>;
export {};
//# sourceMappingURL=metrics.d.ts.map