/**
 * Copyright 2019 Google Inc. All rights reserved.
 * Modifications copyright (c) Microsoft Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { EventEmitter } from 'events';
import * as console from '../console';
import * as dom from '../dom';
import { TimeoutError } from '../Errors';
import * as frames from '../frames';
import { assert, debugError, helper, RegisteredListener } from '../helper';
import * as input from '../input';
import * as js from '../javascript';
import * as network from '../network';
import { Screenshotter } from '../screenshotter';
import { TimeoutSettings } from '../TimeoutSettings';
import * as types from '../types';
import { BrowserContext } from './Browser';
import { JugglerSession } from './Connection';
import { Events } from './events';
import { Accessibility } from './features/accessibility';
import { Interception } from './features/interception';
import { FrameManager, FrameManagerEvents, normalizeWaitUntil } from './FrameManager';
import { RawKeyboardImpl, RawMouseImpl } from './Input';
import { NavigationWatchdog } from './NavigationWatchdog';
import { NetworkManager, NetworkManagerEvents } from './NetworkManager';
import { FFScreenshotDelegate } from './Screenshotter';

export class Page extends EventEmitter {
  private _timeoutSettings: TimeoutSettings;
  private _session: JugglerSession;
  private _browserContext: BrowserContext;
  private _keyboard: input.Keyboard;
  private _mouse: input.Mouse;
  readonly accessibility: Accessibility;
  readonly interception: Interception;
  private _closed: boolean;
  private _closedCallback: () => void;
  private _closedPromise: Promise<void>;
  private _disconnected = false;
  private _disconnectedCallback: (e: Error) => void;
  private _disconnectedPromise: Promise<Error>;
  private _pageBindings: Map<string, Function>;
  private _networkManager: NetworkManager;
  _frameManager: FrameManager;
  _javascriptEnabled = true;
  private _eventListeners: RegisteredListener[];
  private _viewport: types.Viewport;
  private _fileChooserInterceptors = new Set<(chooser: FileChooser) => void>();
  _screenshotter: Screenshotter;

  static async create(session: JugglerSession, browserContext: BrowserContext, defaultViewport: types.Viewport | null) {
    const page = new Page(session, browserContext);
    await Promise.all([
      session.send('Runtime.enable'),
      session.send('Network.enable'),
      session.send('Page.enable'),
      session.send('Page.setInterceptFileChooserDialog', { enabled: true })
    ]);

    if (defaultViewport)
      await page.setViewport(defaultViewport);
    return page;
  }

  constructor(session: JugglerSession, browserContext: BrowserContext) {
    super();
    this._timeoutSettings = new TimeoutSettings();
    this._session = session;
    this._browserContext = browserContext;
    this._keyboard = new input.Keyboard(new RawKeyboardImpl(session));
    this._mouse = new input.Mouse(new RawMouseImpl(session), this._keyboard);
    this.accessibility = new Accessibility(session);
    this._closed = false;
    this._closedPromise = new Promise(f => this._closedCallback = f);
    this._disconnectedPromise = new Promise(f => this._disconnectedCallback = f);
    this._pageBindings = new Map();
    this._networkManager = new NetworkManager(session);
    this._frameManager = new FrameManager(session, this, this._networkManager, this._timeoutSettings);
    this._networkManager.setFrameManager(this._frameManager);
    this.interception = new Interception(this._networkManager);
    this._eventListeners = [
      helper.addEventListener(this._frameManager, FrameManagerEvents.Load, () => this.emit(Events.Page.Load)),
      helper.addEventListener(this._frameManager, FrameManagerEvents.DOMContentLoaded, () => this.emit(Events.Page.DOMContentLoaded)),
      helper.addEventListener(this._frameManager, FrameManagerEvents.FrameAttached, frame => this.emit(Events.Page.FrameAttached, frame)),
      helper.addEventListener(this._frameManager, FrameManagerEvents.FrameDetached, frame => this.emit(Events.Page.FrameDetached, frame)),
      helper.addEventListener(this._frameManager, FrameManagerEvents.FrameNavigated, frame => this.emit(Events.Page.FrameNavigated, frame)),
      helper.addEventListener(this._networkManager, NetworkManagerEvents.Request, request => this.emit(Events.Page.Request, request)),
      helper.addEventListener(this._networkManager, NetworkManagerEvents.Response, response => this.emit(Events.Page.Response, response)),
      helper.addEventListener(this._networkManager, NetworkManagerEvents.RequestFinished, request => this.emit(Events.Page.RequestFinished, request)),
      helper.addEventListener(this._networkManager, NetworkManagerEvents.RequestFailed, request => this.emit(Events.Page.RequestFailed, request)),
    ];
    this._viewport = null;
    this._screenshotter = new Screenshotter(this, new FFScreenshotDelegate(session, this._frameManager), browserContext.browser());
  }

  _didClose() {
    assert(!this._closed, 'Page closed twice');
    this._closed = true;
    this._frameManager.dispose();
    this._networkManager.dispose();
    helper.removeEventListeners(this._eventListeners);
    this.emit(Events.Page.Close);
    this._closedCallback();
  }

  _didDisconnect() {
    assert(!this._disconnected, 'Page disconnected twice');
    this._disconnected = true;
    this._disconnectedCallback(new Error('Target closed'));
  }

  async setExtraHTTPHeaders(headers) {
    await this._networkManager.setExtraHTTPHeaders(headers);
  }

  async emulateMedia(options: {
      type?: ''|'screen'|'print',
      colorScheme?: 'dark' | 'light' | 'no-preference' }) {
    assert(!options.type || input.mediaTypes.has(options.type), 'Unsupported media type: ' + options.type);
    assert(!options.colorScheme || input.mediaColorSchemes.has(options.colorScheme), 'Unsupported color scheme: ' + options.colorScheme);
    await this._session.send('Page.setEmulatedMedia', options);
  }

  async exposeFunction(name: string, playwrightFunction: Function) {
    if (this._pageBindings.has(name))
      throw new Error(`Failed to add page binding with name ${name}: window['${name}'] already exists!`);
    this._pageBindings.set(name, playwrightFunction);
    await this._frameManager._exposeBinding(name, helper.evaluationString(addPageBinding, name));

    function addPageBinding(bindingName: string) {
      const binding: (string) => void = window[bindingName];
      window[bindingName] = (...args) => {
        const me = window[bindingName];
        let callbacks = me['callbacks'];
        if (!callbacks) {
          callbacks = new Map();
          me['callbacks'] = callbacks;
        }
        const seq = (me['lastSeq'] || 0) + 1;
        me['lastSeq'] = seq;
        const promise = new Promise((resolve, reject) => callbacks.set(seq, {resolve, reject}));
        binding(JSON.stringify({name: bindingName, seq, args}));
        return promise;
      };
    }
  }

  async _onBindingCalled(payload: string, context: js.ExecutionContext) {
    const {name, seq, args} = JSON.parse(payload);
    let expression = null;
    try {
      const result = await this._pageBindings.get(name)(...args);
      expression = helper.evaluationString(deliverResult, name, seq, result);
    } catch (error) {
      if (error instanceof Error)
        expression = helper.evaluationString(deliverError, name, seq, error.message, error.stack);
      else
        expression = helper.evaluationString(deliverErrorValue, name, seq, error);
    }
    context.evaluate(expression).catch(debugError);

    function deliverResult(name: string, seq: number, result: any) {
      window[name]['callbacks'].get(seq).resolve(result);
      window[name]['callbacks'].delete(seq);
    }

    function deliverError(name: string, seq: number, message: string, stack: string) {
      const error = new Error(message);
      error.stack = stack;
      window[name]['callbacks'].get(seq).reject(error);
      window[name]['callbacks'].delete(seq);
    }

    function deliverErrorValue(name: string, seq: number, value: any) {
      window[name]['callbacks'].get(seq).reject(value);
      window[name]['callbacks'].delete(seq);
    }
  }

  async waitForRequest(urlOrPredicate: (string | Function), options: { timeout?: number; } | undefined = {}): Promise<network.Request> {
    const {
      timeout = this._timeoutSettings.timeout(),
    } = options;
    return helper.waitForEvent(this._networkManager, NetworkManagerEvents.Request, request => {
      if (helper.isString(urlOrPredicate))
        return (urlOrPredicate === request.url());
      if (typeof urlOrPredicate === 'function')
        return !!(urlOrPredicate(request));
      return false;
    }, timeout, this._disconnectedPromise);
  }

  async waitForResponse(urlOrPredicate: (string | Function), options: { timeout?: number; } | undefined = {}): Promise<network.Response> {
    const {
      timeout = this._timeoutSettings.timeout(),
    } = options;
    return helper.waitForEvent(this._networkManager, NetworkManagerEvents.Response, response => {
      if (helper.isString(urlOrPredicate))
        return (urlOrPredicate === response.url());
      if (typeof urlOrPredicate === 'function')
        return !!(urlOrPredicate(response));
      return false;
    }, timeout, this._disconnectedPromise);
  }

  setDefaultNavigationTimeout(timeout: number) {
    this._timeoutSettings.setDefaultNavigationTimeout(timeout);
  }

  setDefaultTimeout(timeout: number) {
    this._timeoutSettings.setDefaultTimeout(timeout);
  }

  async setUserAgent(userAgent: string) {
    await this._session.send('Page.setUserAgent', {userAgent});
  }

  async setJavaScriptEnabled(enabled) {
    this._javascriptEnabled = enabled;
    await this._session.send('Page.setJavascriptEnabled', {enabled});
  }

  async setBypassCSP(enabled: boolean) {
    await this._session.send('Page.setBypassCSP', { enabled });
  }

  async setCacheEnabled(enabled) {
    await this._session.send('Page.setCacheDisabled', {cacheDisabled: !enabled});
  }

  async emulate(options: { viewport: types.Viewport; userAgent: string; }) {
    await Promise.all([
      this.setViewport(options.viewport),
      this.setUserAgent(options.userAgent),
    ]);
  }

  browserContext(): BrowserContext {
    return this._browserContext;
  }

  viewport() {
    return this._viewport;
  }

  async setViewport(viewport: types.Viewport) {
    const {
      width,
      height,
      isMobile = false,
      deviceScaleFactor = 1,
      hasTouch = false,
      isLandscape = false,
    } = viewport;
    await this._session.send('Page.setViewport', {
      viewport: { width, height, isMobile, deviceScaleFactor, hasTouch, isLandscape },
    });
    const oldIsMobile = this._viewport ? !!this._viewport.isMobile : false;
    const oldHasTouch = this._viewport ? !!this._viewport.hasTouch : false;
    this._viewport = viewport;
    if (oldIsMobile !== isMobile || oldHasTouch !== hasTouch)
      await this.reload();
  }

  async evaluateOnNewDocument(pageFunction: Function | string, ...args: Array<any>) {
    const script = helper.evaluationString(pageFunction, ...args);
    await this._session.send('Page.addScriptToEvaluateOnNewDocument', { script });
  }

  browser() {
    return this._browserContext.browser();
  }

  url() {
    return this._frameManager.mainFrame().url();
  }

  frames() {
    return this._frameManager.frames();
  }

  mainFrame(): frames.Frame {
    return this._frameManager.mainFrame();
  }

  get keyboard(): input.Keyboard {
    return this._keyboard;
  }

  get mouse(): input.Mouse {
    return this._mouse;
  }

  async waitForNavigation(options: { timeout?: number; waitUntil?: string | Array<string>; } = {}) {
    return this._frameManager.mainFrame().waitForNavigation(options);
  }

  async goto(url: string, options: { timeout?: number; waitUntil?: string | Array<string>; } = {}) {
    return this._frameManager.mainFrame().goto(url, options);
  }

  async goBack(options: { timeout?: number; waitUntil?: string | Array<string>; } = {}) {
    const {
      timeout = this._timeoutSettings.navigationTimeout(),
      waitUntil = ['load'],
    } = options;
    const frame = this._frameManager.mainFrame();
    const normalizedWaitUntil = normalizeWaitUntil(waitUntil);
    const {navigationId, navigationURL} = await this._session.send('Page.goBack', {
      frameId: this._frameManager._frameData(frame).frameId,
    });
    if (!navigationId)
      return null;

    const timeoutError = new TimeoutError('Navigation timeout of ' + timeout + ' ms exceeded');
    let timeoutCallback;
    const timeoutPromise = new Promise(resolve => timeoutCallback = resolve.bind(null, timeoutError));
    const timeoutId = timeout ? setTimeout(timeoutCallback, timeout) : null;

    const watchDog = new NavigationWatchdog(this._frameManager, frame, this._networkManager, navigationId, navigationURL, normalizedWaitUntil);
    const error = await Promise.race([
      timeoutPromise,
      watchDog.promise(),
    ]);
    watchDog.dispose();
    clearTimeout(timeoutId);
    if (error)
      throw error;
    return watchDog.navigationResponse();
  }

  async goForward(options: { timeout?: number; waitUntil?: string | Array<string>; } = {}) {
    const {
      timeout = this._timeoutSettings.navigationTimeout(),
      waitUntil = ['load'],
    } = options;
    const frame = this._frameManager.mainFrame();
    const normalizedWaitUntil = normalizeWaitUntil(waitUntil);
    const {navigationId, navigationURL} = await this._session.send('Page.goForward', {
      frameId: this._frameManager._frameData(frame).frameId,
    });
    if (!navigationId)
      return null;

    const timeoutError = new TimeoutError('Navigation timeout of ' + timeout + ' ms exceeded');
    let timeoutCallback;
    const timeoutPromise = new Promise(resolve => timeoutCallback = resolve.bind(null, timeoutError));
    const timeoutId = timeout ? setTimeout(timeoutCallback, timeout) : null;

    const watchDog = new NavigationWatchdog(this._frameManager, frame, this._networkManager, navigationId, navigationURL, normalizedWaitUntil);
    const error = await Promise.race([
      timeoutPromise,
      watchDog.promise(),
    ]);
    watchDog.dispose();
    clearTimeout(timeoutId);
    if (error)
      throw error;
    return watchDog.navigationResponse();
  }

  async reload(options: { timeout?: number; waitUntil?: string | Array<string>; } = {}) {
    const {
      timeout = this._timeoutSettings.navigationTimeout(),
      waitUntil = ['load'],
    } = options;
    const frame = this._frameManager.mainFrame();
    const normalizedWaitUntil = normalizeWaitUntil(waitUntil);
    const {navigationId, navigationURL} = await this._session.send('Page.reload', {
      frameId: this._frameManager._frameData(frame).frameId,
    });
    if (!navigationId)
      return null;

    const timeoutError = new TimeoutError('Navigation timeout of ' + timeout + ' ms exceeded');
    let timeoutCallback;
    const timeoutPromise = new Promise(resolve => timeoutCallback = resolve.bind(null, timeoutError));
    const timeoutId = timeout ? setTimeout(timeoutCallback, timeout) : null;

    const watchDog = new NavigationWatchdog(this._frameManager, frame, this._networkManager, navigationId, navigationURL, normalizedWaitUntil);
    const error = await Promise.race([
      timeoutPromise,
      watchDog.promise(),
    ]);
    watchDog.dispose();
    clearTimeout(timeoutId);
    if (error)
      throw error;
    return watchDog.navigationResponse();
  }

  screenshot(options: types.ScreenshotOptions = {}): Promise<Buffer> {
    return this._screenshotter.screenshotPage(options);
  }

  evaluate: types.Evaluate = (pageFunction, ...args) => {
    return this.mainFrame().evaluate(pageFunction, ...args as any);
  }

  addScriptTag(options: { content?: string; path?: string; type?: string; url?: string; }): Promise<dom.ElementHandle> {
    return this.mainFrame().addScriptTag(options);
  }

  addStyleTag(options: { content?: string; path?: string; url?: string; }): Promise<dom.ElementHandle> {
    return this.mainFrame().addStyleTag(options);
  }

  click(selector: string | types.Selector, options?: input.ClickOptions) {
    return this.mainFrame().click(selector, options);
  }

  dblclick(selector: string | types.Selector, options?: input.MultiClickOptions) {
    return this.mainFrame().dblclick(selector, options);
  }

  tripleclick(selector: string | types.Selector, options?: input.MultiClickOptions) {
    return this.mainFrame().tripleclick(selector, options);
  }

  fill(selector: string | types.Selector, value: string) {
    return this.mainFrame().fill(selector, value);
  }

  select(selector: string | types.Selector, ...values: Array<string>): Promise<Array<string>> {
    return this._frameManager.mainFrame().select(selector, ...values);
  }

  type(selector: string | types.Selector, text: string, options: { delay: (number | undefined); } | undefined) {
    return this._frameManager.mainFrame().type(selector, text, options);
  }

  focus(selector: string | types.Selector) {
    return this._frameManager.mainFrame().focus(selector);
  }

  hover(selector: string | types.Selector) {
    return this._frameManager.mainFrame().hover(selector);
  }

  waitFor(selectorOrFunctionOrTimeout: (string | number | Function), options: { polling?: string | number; timeout?: number; visible?: boolean; hidden?: boolean; } | undefined = {}, ...args: Array<any>): Promise<js.JSHandle> {
    return this._frameManager.mainFrame().waitFor(selectorOrFunctionOrTimeout, options, ...args);
  }

  waitForFunction(pageFunction: Function | string, options: types.WaitForFunctionOptions, ...args): Promise<js.JSHandle> {
    return this._frameManager.mainFrame().waitForFunction(pageFunction, options, ...args);
  }

  waitForSelector(selector: string | types.Selector, options?: types.TimeoutOptions): Promise<dom.ElementHandle> {
    return this._frameManager.mainFrame().waitForSelector(selector, options);
  }

  waitForXPath(xpath: string, options?: types.TimeoutOptions): Promise<dom.ElementHandle> {
    return this._frameManager.mainFrame().waitForXPath(xpath, options);
  }

  title(): Promise<string> {
    return this._frameManager.mainFrame().title();
  }

  $(selector: string | types.Selector): Promise<dom.ElementHandle | null> {
    return this._frameManager.mainFrame().$(selector);
  }

  $$(selector: string | types.Selector): Promise<Array<dom.ElementHandle>> {
    return this._frameManager.mainFrame().$$(selector);
  }

  $eval: types.$Eval = (selector, pageFunction, ...args) => {
    return this._frameManager.mainFrame().$eval(selector, pageFunction, ...args as any);
  }

  $$eval: types.$$Eval = (selector, pageFunction, ...args) => {
    return this._frameManager.mainFrame().$$eval(selector, pageFunction, ...args as any);
  }

  $x(expression: string): Promise<Array<dom.ElementHandle>> {
    return this._frameManager.mainFrame().$x(expression);
  }

  evaluateHandle: types.EvaluateHandle = async (pageFunction, ...args) => {
    return this._frameManager.mainFrame().evaluateHandle(pageFunction, ...args as any);
  }

  async close(options: any = {}) {
    assert(!this._disconnected, 'Protocol error: Connection closed. Most likely the page has been closed.');
    const {
      runBeforeUnload = false,
    } = options;
    await this._session.send('Page.close', { runBeforeUnload });
    if (!runBeforeUnload)
      await this._closedPromise;
  }

  async content() {
    return await this._frameManager.mainFrame().content();
  }

  async setContent(html: string) {
    return await this._frameManager.mainFrame().setContent(html);
  }

  _addConsoleMessage(type: string, args: js.JSHandle[], location: console.ConsoleMessageLocation) {
    if (!this.listenerCount(Events.Page.Console)) {
      args.forEach(arg => arg.dispose());
      return;
    }
    this.emit(Events.Page.Console, new console.ConsoleMessage(type, undefined, args, location));
  }

  isClosed(): boolean {
    return this._closed;
  }

  async waitForFileChooser(options: { timeout?: number; } = {}): Promise<FileChooser> {
    const {
      timeout = this._timeoutSettings.timeout(),
    } = options;
    let callback;
    const promise = new Promise<FileChooser>(x => callback = x);
    this._fileChooserInterceptors.add(callback);
    return helper.waitWithTimeout<FileChooser>(promise, 'waiting for file chooser', timeout).catch(e => {
      this._fileChooserInterceptors.delete(callback);
      throw e;
    });
  }

  async _onFileChooserOpened(handle: dom.ElementHandle) {
    if (!this._fileChooserInterceptors.size) {
      await handle.dispose();
      return;
    }
    const interceptors = Array.from(this._fileChooserInterceptors);
    this._fileChooserInterceptors.clear();
    const multiple = await handle.evaluate((element: HTMLInputElement) => !!element.multiple);
    const fileChooser = { element: handle, multiple };
    for (const interceptor of interceptors)
      interceptor.call(null, fileChooser);
    this.emit(Events.Page.FileChooser, fileChooser);
  }
}

type FileChooser = {
  element: dom.ElementHandle,
  multiple: boolean
};