import type { AgentMessage } from "@earendil-works/pi-agent-core";
import { type CustomEntry, type ExtensionContext, type SessionEntry } from "@earendil-works/pi-coding-agent";
import type { SessionReader } from "../session-reader.js";
export type WindowMarker = CustomEntry<{
    windowId: string;
}> & {
    data: {
        windowId: string;
    };
};
export declare function isWindowMarker(entry: SessionEntry): entry is WindowMarker;
/** Only the active branch can supply a window boundary. */
export declare function currentReset(ctx: SessionReader): WindowMarker | undefined;
/** A reset is checkpoint-backed only when its marker directly follows a native compaction. */
export declare function isCheckpointBackedReset(ctx: SessionReader, marker?: WindowMarker | undefined): boolean;
/** Mint the durable identity of a session's root history window. */
export declare function rootWindowId(sessionId: string): string;
/** Persisted messages in the active window, excluding earlier windows on this branch. */
export declare function hasWindowMessage(ctx: SessionReader, customType: string): boolean;
/** The root or latest durable marker on the active branch. */
export declare function currentWindowId(ctx: SessionReader): string;
/** The durable window active just before the marker: the last earlier marker, else the root window. */
export declare function previousWindowId(ctx: SessionReader, markerId: string): string;
/** Match a provider-facing boot message, optionally by window identity. */
export declare function isWindowBoot(message: AgentMessage, windowId?: string): boolean;
/** Match a persisted boot entry by raw identity, even when a later edit hides it from projection. */
export declare function isWindowBootEntry(entry: SessionEntry, windowId: string): boolean;
/**
 * The durable marker selects a boot message by identity, never by wall-clock time.
 * The boot is the first conversation message of the window. Folding only its prefix
 * preserves later prompt/tool patches in place, including their cacheable ordering.
 */
export declare function projectWindow(messages: AgentMessage[], windowId: string): AgentMessage[];
/**
 * Root windows are not reset boundaries. A forked session can copy a root boot whose
 * details name the source session; refresh that boot in-place in the provider projection
 * while retaining every user/assistant/tool message from the copied root transcript.
 */
export declare function projectRootWindow(messages: AgentMessage[], windowId: string): AgentMessage[];
/** Usage for the selected window, excluding provider usage recorded before its marker. */
export declare function windowUsage(ctx: Pick<ExtensionContext, "sessionManager" | "getContextUsage" | "model">): import("@earendil-works/pi-coding-agent").ContextUsage | undefined;