import {Injectable} from "@extollo/di";
import {AppClass} from "../../lifecycle/AppClass";
import {HTTPKernel} from "./HTTPKernel";
import {Request} from "../lifecycle/Request";

/**
 * Base class for modules that define logic that is applied to requests
 * handled by the HTTP kernel.
 */
@Injectable()
export class HTTPKernelModule extends AppClass {
    /**
     * By default, if a kernel module interrupts the request flow to send a response
     * (for example, if an error occurs), subsequent modules are skipped.
     *
     * However, a module can override this property to be true and its logic will still
     * be applied, even after a module has interrupted the request flow.
     */
    public readonly executeWithBlockingWriteback: boolean = false

    /**
     * Returns true if the given module should be applied to the incoming request.
     * @param {Request} request
     * @return Promise<boolean>
     */
    public async match(request: Request): Promise<boolean> {
        return true
    }

    /**
     * Apply the module to the incoming request.
     * @param {Request} request
     * @return Promise<Request>
     */
    public async apply(request: Request): Promise<Request> {
        return request
    }

    /**
     * Register this module with the given HTTP kernel.
     * @param {HTTPKernel} kernel
     */
    public static register(kernel: HTTPKernel) {
        kernel.register(this).before()
    }
}