/**
 * @typedef {ReturnType<getApp>} KoaApplication
 */
/**
 * @typedef {object} GetAppOptions
 * @property {boolean|undefined} [proxy] Trust proxy headers, defaults to true in
 *   production.
 * @property {boolean|undefined} [disableHeaders] Skip CORS and Strict Transport Security
 *   headers.
 * @property {boolean|undefined} [disableHealthRoute] Disable GET /_health
 * @property {ErrorHandlerOptions|undefined} [errorOptions] Flexible error handling
 *   options
 * @property {HeaderOptions|undefined} [headers] Argument for defaultHeader middleware.
 *   Can only be completely disabled by setting `disableHeaders`.
 * @property {import("./middleware/log.js").LogOptions|undefined} [logOptions] Pass
 *   custom log options to the log middleware.
 */
/**
 * @typedef {object} ErrorHandlerOptions
 * @property {((
 *     ctx: Koa.Context,
 *     key: string,
 *     info: any
 *   ) => Record<string, any> )| undefined} [onAppError] Called to set the initial body
 *   when the error is an AppError
 * @property {((ctx: Koa.Context, err: Error) => boolean)|undefined} [onError] Called
 *   before any logic, to let the user handle errors. If 'true' is returned, no other
 *   logic is applied.
 */
/**
 * @typedef {object} HeaderOptions
 * @property {CorsOptions|undefined} [cors] CORS options, defaults to empty object.
 */
/**
 * @typedef {object} CorsOptions
 * @property {string|((ctx: Koa.Context) => (string|undefined))} [origin]
 *   'Access-Control-Allow-Origin', defaults to the 'Origin' header.
 * @property {string | Array<string> | undefined} [exposeHeaders] 'Access-Control-Expose-Headers'
 * @property {string|number|undefined} [maxAge] 'Access-Control-Max-Age' in seconds
 * @property {boolean|undefined} [credentials] 'Access-Control-Allow-Credentials'
 * @property {string | Array<string> | undefined} [allowMethods] 'Access-Control-Allow-Methods',
 *   defaults to ["DELETE", "GET", "PUT", "POST", "PATCH", "HEAD", "OPTIONS"]
 * @property {string | Array<string> | undefined} [allowHeaders] 'Access-Control-Allow-Headers'
 */
/**
 * Create a new Koa instance with default middleware applied.
 * Adds the following:
 *
 * - Health check route on `/_health`
 * - Log middleware to add the Logger from @compas/stdlib on `ctx.log`
 * - Error handler to catch any errors thrown by route handlers
 * - A 404 handler when no response is set by other middleware
 * - Default headers to respond to things like CORS requests
 *
 * @since 0.1.0
 * @summary Create a new Koa instance with default middleware applied.
 *
 * @param {GetAppOptions} [opts={}]
 */
export function getApp(opts?: GetAppOptions): Koa<Koa.DefaultState, Koa.DefaultContext>;
export type KoaApplication = ReturnType<typeof getApp>;
export type GetAppOptions = {
    /**
     * Trust proxy headers, defaults to true in
     * production.
     */
    proxy?: boolean | undefined;
    /**
     * Skip CORS and Strict Transport Security
     * headers.
     */
    disableHeaders?: boolean | undefined;
    /**
     * Disable GET /_health
     */
    disableHealthRoute?: boolean | undefined;
    /**
     * Flexible error handling
     * options
     */
    errorOptions?: ErrorHandlerOptions | undefined;
    /**
     * Argument for defaultHeader middleware.
     * Can only be completely disabled by setting `disableHeaders`.
     */
    headers?: HeaderOptions | undefined;
    /**
     * Pass
     * custom log options to the log middleware.
     */
    logOptions?: import("./middleware/log.js").LogOptions | undefined;
};
export type ErrorHandlerOptions = {
    /**
     * Called to set the initial body
     * when the error is an AppError
     */
    onAppError?: ((ctx: Koa.Context, key: string, info: any) => Record<string, any>) | undefined;
    /**
     * Called
     * before any logic, to let the user handle errors. If 'true' is returned, no other
     * logic is applied.
     */
    onError?: ((ctx: Koa.Context, err: Error) => boolean) | undefined;
};
export type HeaderOptions = {
    /**
     * CORS options, defaults to empty object.
     */
    cors?: CorsOptions | undefined;
};
export type CorsOptions = {
    /**
     * 'Access-Control-Allow-Origin', defaults to the 'Origin' header.
     */
    origin?: string | ((ctx: Koa.Context) => (string | undefined)) | undefined;
    /**
     * 'Access-Control-Expose-Headers'
     */
    exposeHeaders?: string | Array<string> | undefined;
    /**
     * 'Access-Control-Max-Age' in seconds
     */
    maxAge?: string | number | undefined;
    /**
     * 'Access-Control-Allow-Credentials'
     */
    credentials?: boolean | undefined;
    /**
     * 'Access-Control-Allow-Methods',
     * defaults to ["DELETE", "GET", "PUT", "POST", "PATCH", "HEAD", "OPTIONS"]
     */
    allowMethods?: string | Array<string> | undefined;
    /**
     * 'Access-Control-Allow-Headers'
     */
    allowHeaders?: string | Array<string> | undefined;
};
import Koa from "koa";