import { PostEntity } from '@10up/headless-core';
import type { NextApiRequest, NextApiResponse } from 'next';
import { PreviewData } from './types';
/**
 * The options supported by {@link previewHandler}
 */
export type PreviewHandlerOptions = {
    /**
     * If passed will override the behavior of redirecting to the previewed post.
     *
     * If set you should handle the redirect yourself by calling `res.redirect`.
     *
     * **Important**: You should not need to override this but if you do, uou must append `-preview=true` to the end of the redirected url.
     *
     * This can be used to customize the preview url.
     *
     * ```ts
     * // pages/api/preview.js
     * import { previewHandler } from '@10up/headless-next';
     *
     * export default async function handler(req, res) {
     * 	return previewHandler(req, res, {
     * 		onRedirect(req, res, previewData) => {
     *			res.redirect(`/my-custom-preview-route/${previewData.id}-preview=true`);
     * 		}
     * 	});
     * }
     * ```
     */
    onRedirect?: (req: NextApiRequest, res: NextApiResponse, previewData: PreviewData, defaultRedirect?: PreviewHandlerOptions['onRedirect']) => NextApiResponse;
    /**
     * If passed, this function will be called when the preview data is fetched and allows
     * for additional preview data to be set.
     *
     * The preview data is then passed to `res.setPreviewData`. Be mindful of limitations of this function.
     * You should not pass full post objects, just ids and other data that can be used to fetch the post.
     */
    preparePreviewData?: (req: NextApiRequest, res: NextApiResponse, post: PostEntity, previewData: PreviewData) => PreviewData;
};
/**
 * The PreviewHandler is responsible for handling preview requests.
 *
 * Handling Previews requires the Headless WordPress Plugin.
 *
 * **Important**: This function is meant to be used in a api route at `/pages/api/preview`.
 *
 * ### Usage
 *
 * ```ts
 * // pages/api/preview.js
 * import { previewHandler } from '@10up/headless-next';
 *
 * export default async function handler(req, res) {
 * 	return previewHandler(req, res);
 * }
 * ```
 *
 * @param req The request object,
 * @param res The response object.
 * @param options The PreviewHandlerOptions {@link PreviewHandlerOptions}
 *
 * @returns A response object.
 *
 * @category API handlers
 */
export declare function previewHandler(req: NextApiRequest, res: NextApiResponse, options?: PreviewHandlerOptions): Promise<void | NextApiResponse<any>>;