const {helper} = require('./helper');
const {Events} = require('./Events');

/**
 * @internal
 */
class NextNavigationWatchdog {
  constructor(session, navigatedFrame) {
    this._navigatedFrame = navigatedFrame;
    this._promise = new Promise(x => this._resolveCallback = x);
    this._navigation = null;
    this._eventListeners = [
      helper.addEventListener(session, 'Page.navigationStarted', this._onNavigationStarted.bind(this)),
      helper.addEventListener(session, 'Page.sameDocumentNavigation', this._onSameDocumentNavigation.bind(this)),
    ];
  }

  promise() {
    return this._promise;
  }

  navigation() {
    return this._navigation;
  }

  _onNavigationStarted(params) {
    if (params.frameId === this._navigatedFrame._frameId) {
      this._navigation = {
        navigationId: params.navigationId,
        url: params.url,
      };
      this._resolveCallback();
    }
  }

  _onSameDocumentNavigation(params) {
    if (params.frameId === this._navigatedFrame._frameId) {
      this._navigation = {
        navigationId: null,
      };
      this._resolveCallback();
    }
  }

  dispose() {
    helper.removeEventListeners(this._eventListeners);
  }
}

/**
 * @internal
 */
class NavigationWatchdog {
  constructor(session, navigatedFrame, networkManager, targetNavigationId, targetURL, firedEvents) {
    this._navigatedFrame = navigatedFrame;
    this._targetNavigationId = targetNavigationId;
    this._firedEvents = firedEvents;
    this._targetURL = targetURL;

    this._promise = new Promise(x => this._resolveCallback = x);
    this._navigationRequest = null;

    const check = this._checkNavigationComplete.bind(this);
    this._eventListeners = [
      helper.addEventListener(session, 'Page.eventFired', check),
      helper.addEventListener(session, 'Page.frameAttached', check),
      helper.addEventListener(session, 'Page.frameDetached', check),
      helper.addEventListener(session, 'Page.navigationStarted', check),
      helper.addEventListener(session, 'Page.navigationCommitted', check),
      helper.addEventListener(session, 'Page.navigationAborted', this._onNavigationAborted.bind(this)),
      helper.addEventListener(networkManager, Events.NetworkManager.Request, this._onRequest.bind(this)),
    ];
    check();
  }

  _onRequest(request) {
    if (request.frame() !== this._navigatedFrame || !request.isNavigationRequest())
      return;
    this._navigationRequest = request;
  }

  navigationResponse() {
    return this._navigationRequest ? this._navigationRequest.response() : null;
  }

  _checkNavigationComplete() {
    if (this._navigatedFrame._lastCommittedNavigationId === this._targetNavigationId
        && checkFiredEvents(this._navigatedFrame, this._firedEvents)) {
      this._resolveCallback(null);
    }

    function checkFiredEvents(frame, firedEvents) {
      for (const subframe of frame._children) {
        if (!checkFiredEvents(subframe, firedEvents))
          return false;
      }
      return firedEvents.every(event => frame._firedEvents.has(event));
    }
  }

  _onNavigationAborted(params) {
    if (params.frameId === this._navigatedFrame._frameId && params.navigationId === this._targetNavigationId)
      this._resolveCallback(new Error('Navigation to ' + this._targetURL + ' failed: ' + params.errorText));
  }

  promise() {
    return this._promise;
  }

  dispose() {
    helper.removeEventListeners(this._eventListeners);
  }
}

module.exports = {NavigationWatchdog, NextNavigationWatchdog};