import type { ApiRoute, JsonData, ApiProxyHandler, PluginLogger } from './types.js';
import type { Connect } from 'vite';
/**
 * Callback that processes a service discovery response and produces
 * transformed data plus dynamically generated API routes.
 *
 * `ApiDataProcessor` is the core integration point for service discovery:
 * the plugin calls this function with the JSON body returned by the
 * discovery endpoint, and the function returns the data to send to the
 * client together with proxy routes the plugin should register.
 *
 * @template TResponse - Shape of the raw JSON response from the discovery endpoint.
 * @template TResult - Shape of the transformed JSON sent back to the client.
 *
 * @param data - The raw service discovery response body.
 * @param args - Contextual information about the current request.
 * @param args.route - The base API route path (e.g. `'/@fusion-api'`).
 * @param args.request - The original incoming Connect request.
 * @returns An object with `data` (the response payload for the client) and an
 *   optional `routes` array of {@link ApiRoute} definitions to register.
 */
export type ApiDataProcessor<TResponse extends JsonData = JsonData, TResult extends JsonData = TResponse> = (data: TResponse, args: {
    route: string;
    request: Connect.IncomingMessage;
}) => {
    data: TResult;
    routes?: ApiRoute[];
};
/**
 * Creates an {@link ApiProxyHandler} that proxies requests to a service
 * discovery endpoint, transforms the response using `generateRoutes`, and
 * dynamically registers the resulting API routes for subsequent proxying.
 *
 * The returned handler is intended to be passed as the `proxyHandler` argument
 * to the {@link plugin} factory. On each service discovery response the
 * handler re-generates its route table, so route changes are picked up
 * automatically.
 *
 * @template TResponse - Shape of the raw JSON response from the discovery endpoint.
 * @template TResult - Shape of the transformed JSON sent back to the client.
 *
 * @param target - The URL of the upstream service discovery endpoint.
 * @param generateRoutes - Callback that processes the discovery response and
 *   returns the client payload and the API routes to register.
 * @param args - Optional configuration.
 * @param args.route - Route path where the discovery proxy is mounted.
 *   Defaults to {@link DEFAULT_VALUES.SERVICES_PATH}.
 * @param args.apiRoute - Base path prepended to generated API routes.
 *   Defaults to {@link DEFAULT_VALUES.API_PATH}.
 * @param args.proxyOptions - Extra `http-proxy` options merged into the
 *   generated proxy configuration.
 * @param args.logger - Logger for proxy diagnostics.
 * @returns An {@link ApiProxyHandler} with `route`, `routes`, and
 *   `createProxyOptions` members.
 *
 * @example
 * ```ts
 * import { createProxyHandler } from '@equinor/fusion-framework-vite-plugin-api-service';
 *
 * const handler = createProxyHandler(
 *   'https://discovery.example.com/services',
 *   (services, { route }) => {
 *     const routes = services.map((svc) => ({
 *       match: `${route}/${svc.name}/:path*`,
 *       proxy: { target: svc.url, rewrite: (p) => p.replace(`${route}/${svc.name}`, '') },
 *     }));
 *     return { data: services, routes };
 *   },
 * );
 * ```
 */
export declare function createProxyHandler<TResponse extends JsonData, TResult extends JsonData = TResponse>(target: string, generateRoutes: ApiDataProcessor<TResponse, TResult>, args?: {
    route?: string;
    apiRoute?: string;
    proxyOptions?: Omit<ApiProxyHandler['createProxyOptions'] | ReturnType<ApiProxyHandler['createProxyOptions']>, 'target' | 'transformResponse' | 'selfHandleResponse'>;
    logger?: PluginLogger;
}): ApiProxyHandler;