import { type GjcSessionContext, type GjcSessionSource } from "./session-layout";
/** Window within which two activity timestamps are treated as an ambiguous tie. */
export declare const LATEST_SESSION_TIE_WINDOW_MS = 1000;
export interface SessionIdSources {
    /** Raw `--session-id` value: `undefined` = flag absent; `""` = present-but-blank (invalid). */
    flagValue?: string | undefined;
    payloadSessionId?: unknown;
    envSessionId?: string | undefined;
}
export declare class SessionResolutionError extends Error {
    readonly code: "blank_flag" | "unsafe_session" | "no_session" | "ambiguous" | "missing_for_write";
    constructor(message: string, code: "blank_flag" | "unsafe_session" | "no_session" | "ambiguous" | "missing_for_write");
}
interface ResolvedFromSources {
    gjcSessionId: string;
    source: GjcSessionSource;
}
/**
 * Resolve a session id from explicit sources only (flag -> payload -> env).
 * Returns `undefined` when none is present. A blank explicit flag throws.
 */
export declare function resolveSessionIdFromSources(sources: SessionIdSources): ResolvedFromSources | undefined;
/** Resolve session context for a WRITE command. Errors when no explicit id is present. */
export declare function resolveGjcSessionForWrite(cwd: string, sources: SessionIdSources): GjcSessionContext;
/**
 * Resolve session context for a READ/STATUS/CLEAR command. Falls back to the
 * latest active session by activity marker when no explicit id is present.
 */
export declare function resolveGjcSessionForRead(cwd: string, sources: SessionIdSources): Promise<GjcSessionContext>;
/**
 * Scan `.gjc/_session-*` directories and select the most-recently-active one by
 * its activity marker. Never uses raw directory mtime. Throws on zero candidates
 * or an ambiguous tie.
 */
export declare function detectLatestSession(cwd: string): Promise<GjcSessionContext>;
export interface ActivityMarkerInfo {
    writer: string;
    /** Relative generated path that was just written, for diagnostics. */
    path?: string;
}
/**
 * Best-effort write of the per-session activity marker. State-command callers
 * MUST treat a thrown error as a command failure (auto-detect depends on it);
 * non-critical writers may swallow it.
 */
export declare function writeSessionActivityMarker(cwd: string, gjcSessionId: string, info: ActivityMarkerInfo): Promise<void>;
export {};