/**
 * Copyright 2017 Google Inc. All rights reserved.
 *
 * 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.
 */

const { helper, assert } = require('./helper');
const {Target} = require('./Target');
const EventEmitter = require('events');
const {TaskQueue} = require('./TaskQueue');
const {Connection} = require('./Connection');

class Browser extends EventEmitter {
  /**
   * @param {!Puppeteer.Connection} connection
   * @param {!Array<string>} contextIds
   * @param {boolean} ignoreHTTPSErrors
   * @param {?Puppeteer.Viewport} defaultViewport
   * @param {?Puppeteer.ChildProcess} process
   * @param {(function():Promise)=} closeCallback
   */
  constructor(connection, contextIds, ignoreHTTPSErrors, defaultViewport, process, closeCallback) {
    super();
    this._ignoreHTTPSErrors = ignoreHTTPSErrors;
    this._defaultViewport = defaultViewport;
    this._process = process;
    this._screenshotTaskQueue = new TaskQueue();
    this._connection = connection;
    this._closeCallback = closeCallback || new Function();

    this._defaultContext = new BrowserContext(this._connection, this, null);
    /** @type {Map<string, BrowserContext>} */
    this._contexts = new Map();
    for (const contextId of contextIds)
      this._contexts.set(contextId, new BrowserContext(this._connection, this, contextId));

    /** @type {Map<string, Target>} */
    this._targets = new Map();
    this._connection.on(Connection.Events.Disconnected, () => this.emit(Browser.Events.Disconnected));
    this._connection.on('Target.targetCreated', this._targetCreated.bind(this));
    this._connection.on('Target.targetDestroyed', this._targetDestroyed.bind(this));
    this._connection.on('Target.targetInfoChanged', this._targetInfoChanged.bind(this));
  }

  /**
   * @return {?Puppeteer.ChildProcess}
   */
  process() {
    return this._process;
  }

  /**
   * @return {!Promise<!BrowserContext>}
   */
  async createIncognitoBrowserContext() {
    const {browserContextId} = await this._connection.send('Target.createBrowserContext');
    const context = new BrowserContext(this._connection, this, browserContextId);
    this._contexts.set(browserContextId, context);
    return context;
  }

  /**
   * @return {!Array<!BrowserContext>}
   */
  browserContexts() {
    return [this._defaultContext, ...Array.from(this._contexts.values())];
  }

  /**
   * @return {!BrowserContext}
   */
  defaultBrowserContext() {
    return this._defaultContext;
  }

  /**
   * @param {?string} contextId
   */
  async _disposeContext(contextId) {
    await this._connection.send('Target.disposeBrowserContext', {browserContextId: contextId || undefined});
    this._contexts.delete(contextId);
  }

  /**
   * @param {!Puppeteer.Connection} connection
   * @param {!Array<string>} contextIds
   * @param {boolean} ignoreHTTPSErrors
   * @param {?Puppeteer.Viewport} defaultViewport
   * @param {?Puppeteer.ChildProcess} process
   * @param {function()=} closeCallback
   */
  static async create(connection, contextIds, ignoreHTTPSErrors, defaultViewport, process, closeCallback) {
    const browser = new Browser(connection, contextIds, ignoreHTTPSErrors, defaultViewport, process, closeCallback);
    await connection.send('Target.setDiscoverTargets', {discover: true});
    return browser;
  }

  /**
   * @param {!Protocol.Target.targetCreatedPayload} event
   */
  async _targetCreated(event) {
    const targetInfo = event.targetInfo;
    const {browserContextId} = targetInfo;
    const context = (browserContextId && this._contexts.has(browserContextId)) ? this._contexts.get(browserContextId) : this._defaultContext;

    const target = new Target(targetInfo, context, () => this._connection.createSession(targetInfo), this._ignoreHTTPSErrors, this._defaultViewport, this._screenshotTaskQueue);
    assert(!this._targets.has(event.targetInfo.targetId), 'Target should not exist before targetCreated');
    this._targets.set(event.targetInfo.targetId, target);

    if (await target._initializedPromise) {
      this.emit(Browser.Events.TargetCreated, target);
      context.emit(BrowserContext.Events.TargetCreated, target);
    }
  }

  /**
   * @param {{targetId: string}} event
   */
  async _targetDestroyed(event) {
    const target = this._targets.get(event.targetId);
    target._initializedCallback(false);
    this._targets.delete(event.targetId);
    target._closedCallback();
    if (await target._initializedPromise) {
      this.emit(Browser.Events.TargetDestroyed, target);
      target.browserContext().emit(BrowserContext.Events.TargetDestroyed, target);
    }
  }

  /**
   * @param {!Protocol.Target.targetInfoChangedPayload} event
   */
  _targetInfoChanged(event) {
    const target = this._targets.get(event.targetInfo.targetId);
    assert(target, 'target should exist before targetInfoChanged');
    const previousURL = target.url();
    const wasInitialized = target._isInitialized;
    target._targetInfoChanged(event.targetInfo);
    if (wasInitialized && previousURL !== target.url()) {
      this.emit(Browser.Events.TargetChanged, target);
      target.browserContext().emit(BrowserContext.Events.TargetChanged, target);
    }
  }

  /**
   * @return {string}
   */
  wsEndpoint() {
    return this._connection.url();
  }

  /**
   * @return {!Promise<!Puppeteer.Page>}
   */
  async newPage() {
    return this._defaultContext.newPage();
  }

  /**
   * @param {?string} contextId
   * @return {!Promise<!Puppeteer.Page>}
   */
  async _createPageInContext(contextId) {
    const {targetId} = await this._connection.send('Target.createTarget', {url: 'about:blank', browserContextId: contextId || undefined});
    const target = await this._targets.get(targetId);
    assert(await target._initializedPromise, 'Failed to create target for page');
    const page = await target.page();
    return page;
  }

  /**
   * @return {!Array<!Target>}
   */
  targets() {
    return Array.from(this._targets.values()).filter(target => target._isInitialized);
  }

  /**
   * @return {!Target}
   */
  target() {
    return this.targets().find(target => target.type() === 'browser');
  }

  /**
   * @param {function(!Target):boolean} predicate
   * @param {{timeout?: number}=} options
   * @return {!Promise<!Target>}
   */
  async waitForTarget(predicate, options = {}) {
    const {
      timeout = 30000
    } = options;
    const existingTarget = this.targets().find(predicate);
    if (existingTarget)
      return existingTarget;
    let resolve;
    const targetPromise = new Promise(x => resolve = x);
    this.on(Browser.Events.TargetCreated, check);
    this.on(Browser.Events.TargetChanged, check);
    try {
      if (!timeout)
        return await targetPromise;
      return await helper.waitWithTimeout(targetPromise, 'target', timeout);
    } finally {
      this.removeListener(Browser.Events.TargetCreated, check);
      this.removeListener(Browser.Events.TargetChanged, check);
    }

    /**
     * @param {!Target} target
     */
    function check(target) {
      if (predicate(target))
        resolve(target);
    }
  }

  /**
   * @return {!Promise<!Array<!Puppeteer.Page>>}
   */
  async pages() {
    const contextPages = await Promise.all(this.browserContexts().map(context => context.pages()));
    // Flatten array.
    return contextPages.reduce((acc, x) => acc.concat(x), []);
  }

  /**
   * @return {!Promise<string>}
   */
  async version() {
    const version = await this._getVersion();
    return version.product;
  }

  /**
   * @return {!Promise<string>}
   */
  async userAgent() {
    const version = await this._getVersion();
    return version.userAgent;
  }

  async close() {
    await this._closeCallback.call(null);
    this.disconnect();
  }

  disconnect() {
    this._connection.dispose();
  }

  /**
   * @return {!Promise<!Object>}
   */
  _getVersion() {
    return this._connection.send('Browser.getVersion');
  }
}

/** @enum {string} */
Browser.Events = {
  TargetCreated: 'targetcreated',
  TargetDestroyed: 'targetdestroyed',
  TargetChanged: 'targetchanged',
  Disconnected: 'disconnected'
};

class BrowserContext extends EventEmitter {
  /**
   * @param {!Puppeteer.Connection} connection
   * @param {!Browser} browser
   * @param {?string} contextId
   */
  constructor(connection, browser, contextId) {
    super();
    this._connection = connection;
    this._browser = browser;
    this._id = contextId;
  }

  /**
   * @return {!Array<!Target>} target
   */
  targets() {
    return this._browser.targets().filter(target => target.browserContext() === this);
  }

  /**
   * @param {function(!Target):boolean} predicate
   * @param {{timeout?: number}=} options
   * @return {!Promise<!Target>}
   */
  waitForTarget(predicate, options) {
    return this._browser.waitForTarget(target => target.browserContext() === this && predicate(target), options);
  }

  /**
   * @return {!Promise<!Array<!Puppeteer.Page>>}
   */
  async pages() {
    const pages = await Promise.all(
        this.targets()
            .filter(target => target.type() === 'page')
            .map(target => target.page())
    );
    return pages.filter(page => !!page);
  }

  /**
   * @return {boolean}
   */
  isIncognito() {
    return !!this._id;
  }

  /**
   * @param {string} origin
   * @param {!Array<string>} permissions
   */
  async overridePermissions(origin, permissions) {
    const webPermissionToProtocol = new Map([
      ['geolocation', 'geolocation'],
      ['midi', 'midi'],
      ['notifications', 'notifications'],
      ['push', 'push'],
      ['camera', 'videoCapture'],
      ['microphone', 'audioCapture'],
      ['background-sync', 'backgroundSync'],
      ['ambient-light-sensor', 'sensors'],
      ['accelerometer', 'sensors'],
      ['gyroscope', 'sensors'],
      ['magnetometer', 'sensors'],
      ['accessibility-events', 'accessibilityEvents'],
      ['clipboard-read', 'clipboardRead'],
      ['clipboard-write', 'clipboardWrite'],
      ['payment-handler', 'paymentHandler'],
      // chrome-specific permissions we have.
      ['midi-sysex', 'midiSysex'],
    ]);
    permissions = permissions.map(permission => {
      const protocolPermission = webPermissionToProtocol.get(permission);
      if (!protocolPermission)
        throw new Error('Unknown permission: ' + permission);
      return protocolPermission;
    });
    await this._connection.send('Browser.grantPermissions', {origin, browserContextId: this._id || undefined, permissions});
  }

  async clearPermissionOverrides() {
    await this._connection.send('Browser.resetPermissions', {browserContextId: this._id || undefined});
  }

  /**
   * @return {!Promise<!Puppeteer.Page>}
   */
  newPage() {
    return this._browser._createPageInContext(this._id);
  }

  /**
   * @return {!Browser}
   */
  browser() {
    return this._browser;
  }

  async close() {
    assert(this._id, 'Non-incognito profiles cannot be closed!');
    await this._browser._disposeContext(this._id);
  }
}

/** @enum {string} */
BrowserContext.Events = {
  TargetCreated: 'targetcreated',
  TargetDestroyed: 'targetdestroyed',
  TargetChanged: 'targetchanged',
};

helper.tracePublicAPI(BrowserContext);
helper.tracePublicAPI(Browser);

module.exports = {Browser, BrowserContext};