export type TimelineStageId = 'PLAN' | 'READ' | 'EDIT' | 'VERIFY' | 'SUMMARY';
export type TimelineStageStatus = 'done' | 'active' | 'pending';
export interface TimelineAction {
    type: string;
    target: string;
    result: string;
}
export interface TimelineStage {
    id: TimelineStageId;
    status: TimelineStageStatus;
    summary: string;
    detail: string;
}
export interface TimelineFile {
    type: 'write' | 'edit' | 'delete' | 'mkdir';
    target: string;
    result: string;
}
export interface TimelineCheck {
    target: string;
    result: string;
}
export interface AgentTimelineModel {
    currentStage: TimelineStageId;
    currentTarget: string;
    stages: TimelineStage[];
    files: TimelineFile[];
    checks: TimelineCheck[];
    progress: number;
}
export declare function buildAgentTimelineModel(args: {
    actions: TimelineAction[];
    thinking: string;
    waitingForAI: boolean;
    iteration: number;
    maxIterations: number;
}): AgentTimelineModel;
export declare function formatElapsed(milliseconds: number): string;
/**
 * Truncate to a column budget, not a code-unit budget: Screen.write advances
 * by charWidth, so a CJK/emoji prompt measured with String.length would draw
 * up to twice as wide as the pane it was sized for.
 */
export declare function truncateMiddle(value: string, maxLength: number): string;