import { Dialog } from './dialog';
import { DialogContext } from './dialogContext';
import { WaterfallStepContext } from './waterfallStepContext';
import { DialogTurnResult } from './dialogTurnResult';
import { DialogReason } from './dialogReason';
/**
 * Function signature of an individual waterfall step.
 *
 * @param O (Optional) type of dialog options passed into the step.
 * @param step Contextual information for the current step being executed.
 */
export type WaterfallStep<O extends object = {}> = (step: WaterfallStepContext<O>) => Promise<DialogTurnResult>;
/**
 * A waterfall is a dialog that's optimized for prompting a user with a series of questions.
 *
 */
export declare class WaterfallDialog<O extends object = {}> extends Dialog<O> {
    private readonly steps;
    /**
       * Creates a new waterfall dialog containing the given array of steps.
       *
       * @param dialogId Unique ID of the dialog within the component or set its being added to.
       * @param steps (Optional) array of asynchronous waterfall step functions.
       *
       * @remarks
       * See the {@link WaterfallDialog.addStep | addStep function} for details on creating a valid step function.
  
       */
    constructor(dialogId: string, steps?: WaterfallStep<O>[]);
    /**
       * Gets the dialog version, composed of the ID and number of steps.
       *
       * @returns Dialog version, composed of the ID and number of steps.
       */
    getVersion(): string;
    /**
       * Adds a new step to the waterfall.
       *
       * @param step Asynchronous step function to call.
       * @returns Waterfall dialog for fluent calls to `addStep()`.
       */
    addStep(step: WaterfallStep<O>): this;
    /**
       * Called when the WaterfallDialog is started and pushed onto the dialog stack.
       *
       * @param dialogContext The {@link DialogContext} for the current turn of conversation.
       * @param options Optional, initial information to pass to the Dialog.
       * @returns A Promise representing the asynchronous operation.
       *
       * @remarks
       * If the task is successful, the result indicates whether the Dialog is still
       * active after the turn has been processed by the dialog.
       *
       */
    beginDialog(dialogContext: DialogContext, options?: O): Promise<DialogTurnResult>;
    /**
       * Called when the WaterfallDialog is _continued_, where it is the active dialog and the
       * user replies with a new Activity.
       *
       * @param dialogContext The {@link DialogContext} for the current turn of conversation.
       * @returns A Promise representing the asynchronous operation.
       *
       * @remarks
       * If the task is successful, the result indicates whether the dialog is still
       * active after the turn has been processed by the dialog. The result may also contain a
       * return value.
       *
       */
    continueDialog(dialogContext: DialogContext): Promise<DialogTurnResult>;
    /**
       * Called when a child WaterfallDialog completed its turn, returning control to this dialog.
       *
       * @param dc The {@link DialogContext} for the current turn of the conversation.
       * @param reason DialogReason why the dialog resumed.
       * @param result Optional, value returned from the dialog that was called. The type
       * of the value returned is dependent on the child dialog.
       * @returns A Promise representing the asynchronous operation.
       */
    resumeDialog(dc: DialogContext, reason: DialogReason, result?: any): Promise<DialogTurnResult>;
    /**
       * Called when an individual waterfall step is being executed.
       *
       * @param step Context object for the waterfall step to execute.
       * @returns A promise with the DialogTurnResult.
       *
       * @remarks
       * SHOULD be overridden by derived class that want to add custom logging semantics.
       *
       */
    protected onStep(step: WaterfallStepContext<O>): Promise<DialogTurnResult>;
    /**
       * Executes a step of the WaterfallDialog.
       *
       * @param dc The {@link DialogContext} for the current turn of conversation.
       * @param index The index of the current waterfall step to execute.
       * @param reason The DialogReason the waterfall step is being executed.
       * @param result Optional, result returned by a dialog called in the previous waterfall step.
       * @returns A Promise that represents the work queued to execute.
       */
    protected runStep(dc: DialogContext, index: number, reason: DialogReason, result?: any): Promise<DialogTurnResult>;
    /**
       * Identifies the step name by its position index.
       *
       * @param index Step position
       * @returns A string that identifies the step name.
       */
    private waterfallStepName;
}