/**
 * @fileoverview SessionJanitor - Nightly context reset and transcript distillation
 *
 * Distills large session transcripts into compact summaries using LLM (google/gemini-flash-1.5),
 * purpleucing token costs by ~90% while preserving essential context for future sessions.
 */
import type Database from "better-sqlite3";
import { type Model, type Api } from "@mariozechner/pi-ai";
import type { BulletinService } from "../sophia/types/bulletin.types.js";
export interface DistillOptions {
    /** Target model for distillation (default: google/gemini-flash-1.5) */
    model?: string;
    /** Maximum words in output summary (default: 500) */
    maxWords?: number;
    /** Minimum tokens to trigger distillation (default: 1000) */
    minTokens?: number;
    /** Whether to preserve code blocks verbatim */
    preserveCode?: boolean;
    /** Custom instructions for the distillation prompt */
    customInstructions?: string;
}
export interface JanitorResult {
    sessionId: string;
    success: boolean;
    summary?: string;
    originalTokens: number;
    distilledTokens: number;
    compressionRatio: number;
    archiveId?: string;
    error?: string;
    skipped?: boolean;
    skipReason?: string;
}
export interface JanitorMetrics {
    runAt: Date;
    sessionsProcessed: number;
    sessionsSkipped: number;
    sessionsFailed: number;
    totalTokensBefore: number;
    totalTokensAfter: number;
    totalTokensSaved: number;
    avgCompressionRatio: number;
    durationMs: number;
}
export interface SessionArchive {
    id: string;
    sessionId: string;
    summary: string;
    originalTokenCount: number;
    distilledTokenCount: number;
    compressionRatio: number;
    metadata?: Record<string, unknown>;
    archivedAt: Date;
    restoredAt?: Date;
    restoreCount: number;
}
export interface JanitorConfig {
    /** Number of summaries to retain per session (default: 5) */
    retentionCount: number;
    /** Whether auto-archiving is enabled (default: true) */
    autoArchiveEnabled: boolean;
    /** Minimum tokens to trigger distillation (default: 1000) */
    minTokensThreshold: number;
}
export interface SessionJanitorDeps {
    db: Database.Database;
    bulletin: BulletinService;
    archiveDir: string;
    modelRegistry?: ModelRegistry;
    log?: JanitorLogger;
}
export interface ModelRegistry {
    find(provider: string, model: string): Model<Api> | null;
    getDefaultDistillationModel(): Model<Api>;
}
export interface JanitorLogger {
    debug(message: string, meta?: Record<string, unknown>): void;
    info(message: string, meta?: Record<string, unknown>): void;
    warn(message: string, meta?: Record<string, unknown>): void;
    error(message: string, meta?: Record<string, unknown>): void;
}
export declare class SessionJanitor {
    private readonly db;
    private readonly bulletin;
    private readonly archiveDir;
    private readonly log;
    private readonly modelRegistry?;
    private readonly summaryCache;
    private readonly CACHE_TTL_MS;
    constructor(deps: SessionJanitorDeps);
    private ensureArchiveDir;
    /**
     * Distills a large transcript into a compact summary using LLM.
     * Uses gemini-flash-1.5 for cost-effective summarization.
     */
    distill(transcript: string, options?: DistillOptions): Promise<string>;
    private callDistillationModel;
    private fallbackTruncate;
    /**
     * Process all active sessions for nightly reset.
     * Finds sessions older than 24h with no activity, distills them, and archives.
     */
    processNightlyResets(): Promise<JanitorResult[]>;
    private findSessionsForReset;
    private processSession;
    private getSessionTranscript;
    /**
     * Archives a session summary to the database.
     */
    archiveSession(sessionId: string): Promise<void>;
    private archiveSummary;
    private writeFilesystemArchive;
    /**
     * Restores session context from the most recent archive.
     */
    restoreSessionContext(sessionId: string): Promise<string | null>;
    private getSessionConfig;
    private touchSessionConfig;
    private getArchiveCount;
    private getMostRecentArchive;
    private pruneOldestArchive;
    private recordMetrics;
    /**
     * Gets janitor metrics for the last N runs.
     */
    getMetrics(limit?: number): JanitorMetrics[];
    /**
     * Gets total tokens saved across all runs.
     */
    getTotalTokensSaved(): number;
    private estimateTokens;
    private hashTranscript;
    private cleanCache;
}
export interface CreateJanitorParams {
    db: Database.Database;
    bulletin: BulletinService;
    archiveDir?: string;
    modelRegistry?: ModelRegistry;
    log?: JanitorLogger;
}
export declare function createSessionJanitor(params: CreateJanitorParams): SessionJanitor;