import { method, request, responder, response } from './interface/index';

export class handler<RequestCustomType, ResponseCustomType> {
    public responders: responder<RequestCustomType, ResponseCustomType>[];
    public method: method;

    constructor(
        method: method,
        responders: responder<RequestCustomType, ResponseCustomType>[],
    ) {
        this.responders = responders;
        this.method = method;
    }

    add(responder: responder<RequestCustomType, ResponseCustomType>) {
        this.responders.push(responder);
    }

    async respond(
        request: request<RequestCustomType>,
        responseMessage: response<ResponseCustomType> = new response<ResponseCustomType>(
            '',
        ),
    ): Promise<response<ResponseCustomType> | void> {
        switch (this.responders.length) {
            case 0:
                Promise.reject('No responders found in this handler.');
                break;
            case 1:
                return this.responders[0](request, responseMessage);
            default:
                for (const responder of this.responders) {
                    const thisResponse = await responder(
                        request,
                        responseMessage,
                    );
                    if (thisResponse instanceof response) {
                        responseMessage = thisResponse;
                    }
                }
                return responseMessage;
        }
    }
}

export default handler;