'use strict';

const { parseHeaders } = require('../core/util');
const { InvalidArgumentError } = require('../core/errors');

const kResume = Symbol('resume');

class UnwrapController {
  #paused = false;
  #reason = null;
  #aborted = false;
  #abort;

  [kResume] = null;

  constructor(abort) {
    this.#abort = abort;
  }

  pause() {
    this.#paused = true;
  }

  resume() {
    if (this.#paused) {
      this.#paused = false;
      this[kResume]?.();
    }
  }

  abort(reason) {
    if (!this.#aborted) {
      this.#aborted = true;
      this.#reason = reason;
      this.#abort(reason);
    }
  }

  get aborted() {
    return this.#aborted;
  }

  get reason() {
    return this.#reason;
  }

  get paused() {
    return this.#paused;
  }
}

module.exports = class UnwrapHandler {
  #handler;
  #controller;

  constructor(handler) {
    this.#handler = handler;
  }

  static unwrap(handler) {
    // TODO (fix): More checks...
    return !handler.onRequestStart ? handler : new UnwrapHandler(handler);
  }

  onConnect(abort, context) {
    this.#controller = new UnwrapController(abort);
    this.#handler.onRequestStart?.(this.#controller, context);
  }

  onUpgrade(statusCode, rawHeaders, socket) {
    this.#handler.onRequestUpgrade?.(
      this.#controller,
      statusCode,
      parseHeaders(rawHeaders),
      socket
    );
  }

  onHeaders(statusCode, rawHeaders, resume, statusMessage) {
    this.#controller[kResume] = resume;
    this.#handler.onResponseStart?.(
      this.#controller,
      statusCode,
      parseHeaders(rawHeaders),
      statusMessage
    );
    return !this.#controller.paused;
  }

  onData(data) {
    this.#handler.onResponseData?.(this.#controller, data);
    return !this.#controller.paused;
  }

  onComplete(rawTrailers) {
    this.#handler.onResponseEnd?.(this.#controller, parseHeaders(rawTrailers));
  }

  onError(err) {
    if (!this.#handler.onResponseError) {
      throw new InvalidArgumentError('invalid onError method');
    }

    this.#handler.onResponseError?.(this.#controller, err);
  }
};