/**
 * Copyright 2013-2015, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @providesModule UserAgent
 */

'use strict';

var UserAgentData = require('./UserAgentData');
var VersionRange = require('./VersionRange');

var mapObject = require('./mapObject');
var memoizeStringOnly = require('./memoizeStringOnly');

/**
 * Checks to see whether `name` and `version` satisfy `query`.
 *
 * @param {string} name Name of the browser, device, engine or platform
 * @param {?string} version Version of the browser, engine or platform
 * @param {string} query Query of form "Name [range expression]"
 * @param {?function} normalizer Optional pre-processor for range expression
 * @return {boolean}
 */
function compare(name, version, query, normalizer) {
  // check for exact match with no version
  if (name === query) {
    return true;
  }

  // check for non-matching names
  if (!query.startsWith(name)) {
    return false;
  }

  // full comparison with version
  var range = query.slice(name.length);
  if (version) {
    range = normalizer ? normalizer(range) : range;
    return VersionRange.contains(range, version);
  }

  return false;
}

/**
 * Normalizes `version` by stripping any "NT" prefix, but only on the Windows
 * platform.
 *
 * Mimics the stripping performed by the `UserAgentWindowsPlatform` PHP class.
 *
 * @param {string} version
 * @return {string}
 */
function normalizePlatformVersion(version) {
  if (UserAgentData.platformName === 'Windows') {
    return version.replace(/^\s*NT/, '');
  }

  return version;
}

/**
 * Provides client-side access to the authoritative PHP-generated User Agent
 * information supplied by the server.
 */
var UserAgent = {
  /**
   * Check if the User Agent browser matches `query`.
   *
   * `query` should be a string like "Chrome" or "Chrome > 33".
   *
   * Valid browser names include:
   *
   * - ACCESS NetFront
   * - AOL
   * - Amazon Silk
   * - Android
   * - BlackBerry
   * - BlackBerry PlayBook
   * - Chrome
   * - Chrome for iOS
   * - Chrome frame
   * - Facebook PHP SDK
   * - Facebook for iOS
   * - Firefox
   * - IE
   * - IE Mobile
   * - Mobile Safari
   * - Motorola Internet Browser
   * - Nokia
   * - Openwave Mobile Browser
   * - Opera
   * - Opera Mini
   * - Opera Mobile
   * - Safari
   * - UIWebView
   * - Unknown
   * - webOS
   * - etc...
   *
   * An authoritative list can be found in the PHP `BrowserDetector` class and
   * related classes in the same file (see calls to `new UserAgentBrowser` here:
   * https://fburl.com/50728104).
   *
   * @note Function results are memoized
   *
   * @param {string} query Query of the form "Name [range expression]"
   * @return {boolean}
   */
  isBrowser: function (query) {
    return compare(UserAgentData.browserName, UserAgentData.browserFullVersion, query);
  },

  /**
   * Check if the User Agent browser uses a 32 or 64 bit architecture.
   *
   * @note Function results are memoized
   *
   * @param {string} query Query of the form "32" or "64".
   * @return {boolean}
   */
  isBrowserArchitecture: function (query) {
    return compare(UserAgentData.browserArchitecture, null, query);
  },

  /**
   * Check if the User Agent device matches `query`.
   *
   * `query` should be a string like "iPhone" or "iPad".
   *
   * Valid device names include:
   *
   * - Kindle
   * - Kindle Fire
   * - Unknown
   * - iPad
   * - iPhone
   * - iPod
   * - etc...
   *
   * An authoritative list can be found in the PHP `DeviceDetector` class and
   * related classes in the same file (see calls to `new UserAgentDevice` here:
   * https://fburl.com/50728332).
   *
   * @note Function results are memoized
   *
   * @param {string} query Query of the form "Name"
   * @return {boolean}
   */
  isDevice: function (query) {
    return compare(UserAgentData.deviceName, null, query);
  },

  /**
   * Check if the User Agent rendering engine matches `query`.
   *
   * `query` should be a string like "WebKit" or "WebKit >= 537".
   *
   * Valid engine names include:
   *
   * - Gecko
   * - Presto
   * - Trident
   * - WebKit
   * - etc...
   *
   * An authoritative list can be found in the PHP `RenderingEngineDetector`
   * class related classes in the same file (see calls to `new
   * UserAgentRenderingEngine` here: https://fburl.com/50728617).
   *
   * @note Function results are memoized
   *
   * @param {string} query Query of the form "Name [range expression]"
   * @return {boolean}
   */
  isEngine: function (query) {
    return compare(UserAgentData.engineName, UserAgentData.engineVersion, query);
  },

  /**
   * Check if the User Agent platform matches `query`.
   *
   * `query` should be a string like "Windows" or "iOS 5 - 6".
   *
   * Valid platform names include:
   *
   * - Android
   * - BlackBerry OS
   * - Java ME
   * - Linux
   * - Mac OS X
   * - Mac OS X Calendar
   * - Mac OS X Internet Account
   * - Symbian
   * - SymbianOS
   * - Windows
   * - Windows Mobile
   * - Windows Phone
   * - iOS
   * - iOS Facebook Integration Account
   * - iOS Facebook Social Sharing UI
   * - webOS
   * - Chrome OS
   * - etc...
   *
   * An authoritative list can be found in the PHP `PlatformDetector` class and
   * related classes in the same file (see calls to `new UserAgentPlatform`
   * here: https://fburl.com/50729226).
   *
   * @note Function results are memoized
   *
   * @param {string} query Query of the form "Name [range expression]"
   * @return {boolean}
   */
  isPlatform: function (query) {
    return compare(UserAgentData.platformName, UserAgentData.platformFullVersion, query, normalizePlatformVersion);
  },

  /**
   * Check if the User Agent platform is a 32 or 64 bit architecture.
   *
   * @note Function results are memoized
   *
   * @param {string} query Query of the form "32" or "64".
   * @return {boolean}
   */
  isPlatformArchitecture: function (query) {
    return compare(UserAgentData.platformArchitecture, null, query);
  }

};

module.exports = mapObject(UserAgent, memoizeStringOnly);