import type { NsidString } from '@atproto/lex-schema';
import type { NotificationsV2Algorithm } from '../config.js';
export type HydrationSource = 'known_likers' | 'known_followers' | 'activity_subscriptions';
/** XRPC method that owns a hydration; set on `HydrateCtx` from the method's `$lxm`. */
export type HydrationXrpcEndpoint = NsidString;
/** Reported XRPC endpoint of an external hydration traversal. */
export type ExternalHydrationXrpcEndpoint = HydrationXrpcEndpoint | 'unknown';
/** Entry point that owns an external hydration traversal. */
export type ExternalHydrationRoot = 'uris' | 'refs' | 'dependencies';
/**
 * `partial` is a returned traversal that recovered from a best-effort
 * dependency failure; `capped` takes precedence over it.
 */
export type ExternalHydrationOutcome = 'completed' | 'capped' | 'partial' | 'failed';
/** Bounded metric attributes of an external hydration traversal. */
type ExternalHydrationAttributes = {
    xrpcEndpoint: ExternalHydrationXrpcEndpoint;
    root: ExternalHydrationRoot;
    outcome: ExternalHydrationOutcome;
};
/**
 * Generic record lookup work of one external hydration traversal, across the
 * root and all nested dependency batches. Excludes profile/label hydration
 * and backlink sample/count RPCs.
 */
export type ExternalHydrationWork = {
    /**
     * Accepted latest/exact lookup identities scheduled for fetching, after
     * filtering duplicates and seen keys. Unavailable results and lookups in a
     * failed batch count; lookups skipped at the pass cap do not.
     */
    recordLookups: number;
    /** Nonempty batches that scheduled generic fetches; not a raw RPC count. */
    batches: number;
    /** Deepest fetched batch, where the root batch is pass 1; 0 if none. */
    maxPass: number;
    /**
     * Refs inspected by the traversal's first dependency discovery. A traversal
     * whose root batch failed has none.
     */
    roots: number;
    /** Roots available after takedown and owner moderation. */
    rootsResolved: number;
    /**
     * Refs inspected by later dependency discoveries: records returned by
     * successful nested batches. Lookups lost to a failed batch or the pass cap
     * are excluded.
     */
    dependencies: number;
    /** Dependencies available after takedown and owner moderation. */
    dependenciesResolved: number;
};
/**
 * Central hub for reporting AppView events. Each method reports a
 * single event to every relevant sink in one call:
 *
 *  1. a pino logger      → stdout/stderr (docker logs)
 *  2. an OTEL counter    → aggregated metric (low-cardinality dimensions only)
 *  3. the OTEL Logs SDK  → structured, trace-correlated log record (full detail)
 *
 * This keeps the three concerns in sync: there is exactly one call site per
 * event, and the counter / log / attribute definitions live together here
 * rather than being duplicated and drifting across handlers.
 *
 * @note High-cardinality attributes (e.g. `did`, `uri`) belong in the pino and
 * OTEL log records but must stay OUT of the counters, whose attributes must
 * remain low-cardinality to avoid a metric-series explosion.
 *
 * @note The OTEL counters and log records are no-ops unless the corresponding
 * OTEL exporter is configured, so calling these methods is always safe and
 * essentially free when telemetry is disabled.
 */
declare class EventReporter {
    #private;
    hydrationFailed({ source, err }: {
        source: HydrationSource;
        err: unknown;
    }): void;
    /**
     * Reports the totals of one top-level external hydration traversal. Numeric
     * totals are observations and log fields, never metric attributes.
     *
     * @note this method should never throw
     */
    externalHydrationTraversal({ xrpcEndpoint, root, outcome, durationMs, recordLookups, batches, maxPass, roots, rootsResolved, dependencies, dependenciesResolved, }: ExternalHydrationWork & ExternalHydrationAttributes & {
        durationMs: number;
    }): void;
    /** Reports compute time once per grouping invocation, excluding dataplane reads. */
    notificationGrouping({ algorithm, durationMs, }: {
        algorithm: NotificationsV2Algorithm;
        durationMs: number;
    }): void;
    /** Reports dataplane fetches, raw-item counts, and hydration time once per completed page. */
    groupedNotifications({ itemsFetched, itemsReturned, dataplaneFetches, hydrationDurationMs, }: {
        itemsFetched: number;
        itemsReturned: number;
        dataplaneFetches: number;
        hydrationDurationMs: number;
    }): void;
}
export declare const events: EventReporter;
export {};
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