import type { ObservationIndex, ObservationType } from "../types";
/** Parameters that influence observation relevance scoring. */
export interface ScoringContext {
    /** Boost observations from the current session */
    currentSessionId?: string;
    /** Reference time for recency scoring */
    now: Date;
}
/**
 * Compute recency score using a step function.
 *
 * - Today (< 24h): 1.0
 * - Yesterday (24-48h): 0.8
 * - Last week (2-7 days): 0.5
 * - Older (> 7 days): 0.2
 */
export declare function scoreRecency(createdAt: string, now: Date): number;
/**
 * Score based on observation type importance.
 * Decisions and bugfixes are most valuable; changes are least.
 */
export declare function scoreTypeImportance(type: ObservationType): number;
/**
 * Boost observations from the current session.
 * Current session = 1.0, other sessions = 0.3.
 */
export declare function scoreSessionAffinity(entrySessionId: string, currentSessionId: string | undefined): number;
/**
 * Smaller observations score higher — they give more info per token.
 * Linear interpolation between MIN_EFFICIENT_TOKENS (score=1.0)
 * and MAX_EFFICIENT_TOKENS (score=0.2).
 */
export declare function scoreTokenEfficiency(tokenCount: number): number;
/**
 * Compute a weighted relevance score for an observation index entry.
 *
 * Score = recency * 0.4 + typeImportance * 0.3 + sessionAffinity * 0.2 + tokenEfficiency * 0.1
 *
 * Returns a value in [0, 1] where higher = more relevant.
 */
export declare function scoreObservation(entry: ObservationIndex, context: ScoringContext): number;
/**
 * Sort observation index entries by relevance score (descending).
 * Returns a new array — does not mutate the input.
 */
export declare function sortByRelevance(entries: ReadonlyArray<ObservationIndex>, context: ScoringContext): ObservationIndex[];
//# sourceMappingURL=relevance.d.ts.map