/**
 * 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.
 */

import {helper, assert} from './helper';
import {Target} from './Target';
import * as EventEmitter from 'events';
import {TaskQueue} from './TaskQueue';
import {Events} from './Events';
import {Connection} from './Connection';

type BrowserCloseCallback = () => Promise<void> | void;

/* TODO(jacktfranklin): once Target is migrated to TS
 * we can import + use its type here. But right now Target
 * is implemented in JS so we can't import the type and have to use
 * Puppeteer.Target
 */

export class Browser extends EventEmitter {
  static async create(connection: Connection, contextIds: string[], ignoreHTTPSErrors: boolean, defaultViewport?: Puppeteer.Viewport, process?: Puppeteer.ChildProcess, closeCallback?: BrowserCloseCallback): Promise<Browser> {
    const browser = new Browser(connection, contextIds, ignoreHTTPSErrors, defaultViewport, process, closeCallback);
    await connection.send('Target.setDiscoverTargets', {discover: true});
    return browser;
  }
   _ignoreHTTPSErrors: boolean;
   _defaultViewport?: Puppeteer.Viewport;
   _process?: Puppeteer.ChildProcess;
   _screenshotTaskQueue = new TaskQueue();
   _connection: Connection;
   _closeCallback: BrowserCloseCallback;
   _defaultContext: BrowserContext;
   _contexts: Map<string, BrowserContext>;
   // TODO: once Target is in TypeScript we can type this properly.
   _targets: Map<string, Puppeteer.Target>;

   constructor(connection: Connection, contextIds: string[], ignoreHTTPSErrors: boolean, defaultViewport?: Puppeteer.Viewport, process?: Puppeteer.ChildProcess, closeCallback?: BrowserCloseCallback) {
     super();
     this._ignoreHTTPSErrors = ignoreHTTPSErrors;
     this._defaultViewport = defaultViewport;
     this._process = process;
     this._screenshotTaskQueue = new TaskQueue();
     this._connection = connection;
     this._closeCallback = closeCallback || function(): void {};

     this._defaultContext = new BrowserContext(this._connection, this, null);
     this._contexts = new Map();
     for (const contextId of contextIds)
       this._contexts.set(contextId, new BrowserContext(this._connection, this, contextId));

     this._targets = new Map();
     this._connection.on(Events.Connection.Disconnected, () => this.emit(Events.Browser.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));
   }

   process(): Puppeteer.ChildProcess | null {
     return this._process;
   }

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

   browserContexts(): BrowserContext[] {
     return [this._defaultContext, ...Array.from(this._contexts.values())];
   }

   defaultBrowserContext(): BrowserContext {
     return this._defaultContext;
   }

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

   async _targetCreated(event: Protocol.Target.targetCreatedPayload): Promise<void> {
     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(Events.Browser.TargetCreated, target);
       context.emit(Events.BrowserContext.TargetCreated, target);
     }
   }

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

   /**
   * @param {!Protocol.Target.targetInfoChangedPayload} event
   */
   _targetInfoChanged(event: Protocol.Target.targetInfoChangedPayload): void {
     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(Events.Browser.TargetChanged, target);
       target.browserContext().emit(Events.BrowserContext.TargetChanged, target);
     }
   }

   wsEndpoint(): string {
     return this._connection.url();
   }

   async newPage(): Promise<Puppeteer.Page> {
     return this._defaultContext.newPage();
   }

   async _createPageInContext(contextId?: string): Promise<Puppeteer.Page> {
     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;
   }

   targets(): Puppeteer.Target[] {
     return Array.from(this._targets.values()).filter(target => target._isInitialized);
   }

   target(): Puppeteer.Target {
     return this.targets().find(target => target.type() === 'browser');
   }

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

     function check(target: Puppeteer.Target): void  {
       if (predicate(target))
         resolve(target);
     }
   }

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

   async version(): Promise<string> {
     const version = await this._getVersion();
     return version.product;
   }

   async userAgent(): Promise<string> {
     const version = await this._getVersion();
     return version.userAgent;
   }

   async close(): Promise<void> {
     await this._closeCallback.call(null);
     this.disconnect();
   }

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

   isConnected(): boolean {
     return !this._connection._closed;
   }

   _getVersion(): Promise<Protocol.Browser.getVersionReturnValue> {
     return this._connection.send('Browser.getVersion');
   }
}

export class BrowserContext extends EventEmitter {
  _connection: Connection;
  _browser: Browser;
  _id?: string;

  constructor(connection: Connection, browser: Browser, contextId?: string) {
    super();
    this._connection = connection;
    this._browser = browser;
    this._id = contextId;
  }

  targets(): Puppeteer.Target[] {
    return this._browser.targets().filter(target => target.browserContext() === this);
  }

  waitForTarget(predicate: (x: Puppeteer.Target) => boolean, options: { timeout?: number}): Promise<Puppeteer.Target> {
    return this._browser.waitForTarget(target => target.browserContext() === this && predicate(target), options);
  }

  async pages(): Promise<Puppeteer.Page[]> {
    const pages = await Promise.all(
        this.targets()
            .filter(target => target.type() === 'page')
            .map(target => target.page())
    );
    return pages.filter(page => !!page);
  }

  isIncognito(): boolean {
    return !!this._id;
  }

  async overridePermissions(origin: string, permissions: Protocol.Browser.PermissionType[]): Promise<void> {
    const webPermissionToProtocol = new Map<string, Protocol.Browser.PermissionType>([
      ['geolocation', 'geolocation'],
      ['midi', 'midi'],
      ['notifications', 'notifications'],
      // TODO: push isn't a valid type?
      // ['push', 'push'],
      ['camera', 'videoCapture'],
      ['microphone', 'audioCapture'],
      ['background-sync', 'backgroundSync'],
      ['ambient-light-sensor', 'sensors'],
      ['accelerometer', 'sensors'],
      ['gyroscope', 'sensors'],
      ['magnetometer', 'sensors'],
      ['accessibility-events', 'accessibilityEvents'],
      ['clipboard-read', 'clipboardReadWrite'],
      ['clipboard-write', 'clipboardReadWrite'],
      ['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(): Promise<void> {
    await this._connection.send('Browser.resetPermissions', {browserContextId: this._id || undefined});
  }

  newPage(): Promise<Puppeteer.Page> {
    return this._browser._createPageInContext(this._id);
  }

  browser(): Browser {
    return this._browser;
  }

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