DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646
/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* vim: set sts=2 sw=2 et tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";

/**
 * This module contains code for managing APIs that need to run in the
 * parent process, and handles the parent side of operations that need
 * to be proxied from ExtensionChild.jsm.
 */

const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;

/* exported ExtensionParent */

this.EXPORTED_SYMBOLS = ["ExtensionParent"];

Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/XPCOMUtils.jsm");

XPCOMUtils.defineLazyModuleGetters(this, {
  AppConstants: "resource://gre/modules/AppConstants.jsm",
  AsyncShutdown: "resource://gre/modules/AsyncShutdown.jsm",
  DeferredTask: "resource://gre/modules/DeferredTask.jsm",
  E10SUtils: "resource://gre/modules/E10SUtils.jsm",
  ExtensionData: "resource://gre/modules/Extension.jsm",
  MessageChannel: "resource://gre/modules/MessageChannel.jsm",
  OS: "resource://gre/modules/osfile.jsm",
  NativeApp: "resource://gre/modules/NativeMessaging.jsm",
  PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
  Schemas: "resource://gre/modules/Schemas.jsm",
});

XPCOMUtils.defineLazyServiceGetters(this, {
  aomStartup: ["@mozilla.org/addons/addon-manager-startup;1", "amIAddonManagerStartup"],
});

Cu.import("resource://gre/modules/ExtensionCommon.jsm");
Cu.import("resource://gre/modules/ExtensionUtils.jsm");

var {
  BaseContext,
  CanOfAPIs,
  SchemaAPIManager,
  SpreadArgs,
} = ExtensionCommon;

var {
  DefaultMap,
  DefaultWeakMap,
  ExtensionError,
  MessageManagerProxy,
  defineLazyGetter,
  promiseDocumentLoaded,
  promiseEvent,
  promiseObserved,
} = ExtensionUtils;

const BASE_SCHEMA = "chrome://extensions/content/schemas/manifest.json";
const CATEGORY_EXTENSION_MODULES = "webextension-modules";
const CATEGORY_EXTENSION_SCHEMAS = "webextension-schemas";
const CATEGORY_EXTENSION_SCRIPTS = "webextension-scripts";

let schemaURLs = new Set();

schemaURLs.add("chrome://extensions/content/schemas/experiments.json");

let GlobalManager;
let ParentAPIManager;
let ProxyMessenger;
let StartupCache;

const global = this;

// This object loads the ext-*.js scripts that define the extension API.
let apiManager = new class extends SchemaAPIManager {
  constructor() {
    super("main");
    this.initialized = null;

    /* eslint-disable mozilla/balanced-listeners */
    this.on("startup", (e, extension) => {
      let promises = [];
      for (let apiName of this.eventModules.get("startup")) {
        promises.push(this.asyncGetAPI(apiName, extension).then(api => {
          if (api) {
            api.onStartup();
          }
        }));
      }

      return Promise.all(promises);
    });

    this.on("update", async (e, {id, resourceURI}) => {
      let modules = this.eventModules.get("update");
      if (modules.size == 0) {
        return;
      }

      let extension = new ExtensionData(resourceURI);
      await extension.loadManifest();

      return Promise.all(Array.from(modules).map(async apiName => {
        let module = await this.asyncLoadModule(apiName);
        module.onUpdate(id, extension.manifest);
      }));
    });

    this.on("uninstall", (e, {id}) => {
      let modules = this.eventModules.get("uninstall");
      return Promise.all(Array.from(modules).map(async apiName => {
        let module = await this.asyncLoadModule(apiName);
        module.onUninstall(id);
      }));
    });
    /* eslint-enable mozilla/balanced-listeners */
  }

  getModuleJSONURLs() {
    return Array.from(XPCOMUtils.enumerateCategoryEntries(CATEGORY_EXTENSION_MODULES),
                      ([name, url]) => url);
  }

  // Loads all the ext-*.js scripts currently registered.
  lazyInit() {
    if (this.initialized) {
      return this.initialized;
    }

    let modulesPromise = StartupCache.other.get(
      ["parentModules"],
      () => this.loadModuleJSON(this.getModuleJSONURLs()));

    let scriptURLs = [];
    for (let [/* name */, value] of XPCOMUtils.enumerateCategoryEntries(CATEGORY_EXTENSION_SCRIPTS)) {
      scriptURLs.push(value);
    }

    let promise = (async () => {
      let scripts = await Promise.all(scriptURLs.map(url => ChromeUtils.compileScript(url)));

      this.initModuleData(await modulesPromise);

      for (let script of scripts) {
        script.executeInGlobal(this.global);
      }

      // Load order matters here. The base manifest defines types which are
      // extended by other schemas, so needs to be loaded first.
      return Schemas.load(BASE_SCHEMA, AppConstants.DEBUG).then(() => {
        let promises = [];
        for (let [/* name */, url] of XPCOMUtils.enumerateCategoryEntries(CATEGORY_EXTENSION_SCHEMAS)) {
          promises.push(Schemas.load(url));
        }
        for (let [url, {content}] of this.schemaURLs) {
          promises.push(Schemas.load(url, content));
        }
        for (let url of schemaURLs) {
          promises.push(Schemas.load(url));
        }
        return Promise.all(promises);
      });
    })();

    /* eslint-disable mozilla/balanced-listeners */
    Services.mm.addMessageListener("Extension:GetTabAndWindowId", this);
    /* eslint-enable mozilla/balanced-listeners */

    this.initialized = promise;
    return this.initialized;
  }

  receiveMessage({name, target, sync}) {
    if (name === "Extension:GetTabAndWindowId") {
      let result = this.global.tabTracker.getBrowserData(target);

      if (result.tabId) {
        if (sync) {
          return result;
        }
        target.messageManager.sendAsyncMessage("Extension:SetFrameData", result);
      }
    }
  }
}();

// Subscribes to messages related to the extension messaging API and forwards it
// to the relevant message manager. The "sender" field for the `onMessage` and
// `onConnect` events are updated if needed.
ProxyMessenger = {
  _initialized: false,

  init() {
    if (this._initialized) {
      return;
    }
    this._initialized = true;

    // Listen on the global frame message manager because content scripts send
    // and receive extension messages via their frame.
    // Listen on the parent process message manager because `runtime.connect`
    // and `runtime.sendMessage` requests must be delivered to all frames in an
    // addon process (by the API contract).
    // And legacy addons are not associated with a frame, so that is another
    // reason for having a parent process manager here.
    let messageManagers = [Services.mm, Services.ppmm];

    MessageChannel.addListener(messageManagers, "Extension:Connect", this);
    MessageChannel.addListener(messageManagers, "Extension:Message", this);
    MessageChannel.addListener(messageManagers, "Extension:Port:Disconnect", this);
    MessageChannel.addListener(messageManagers, "Extension:Port:PostMessage", this);
  },

  async receiveMessage({target, messageName, channelId, sender, recipient, data, responseType}) {
    if (recipient.toNativeApp) {
      let {childId, toNativeApp} = recipient;
      if (messageName == "Extension:Message") {
        let context = ParentAPIManager.getContextById(childId);
        return new NativeApp(context, toNativeApp).sendMessage(data);
      }
      if (messageName == "Extension:Connect") {
        let context = ParentAPIManager.getContextById(childId);
        NativeApp.onConnectNative(context, target.messageManager, data.portId, sender, toNativeApp);
        return true;
      }
      // "Extension:Port:Disconnect" and "Extension:Port:PostMessage" for
      // native messages are handled by NativeApp.
      return;
    }

    const noHandlerError = {
      result: MessageChannel.RESULT_NO_HANDLER,
      message: "No matching message handler for the given recipient.",
    };

    let extension = GlobalManager.extensionMap.get(sender.extensionId);
    let receiverMM = this.getMessageManagerForRecipient(recipient);
    if (!extension || !receiverMM) {
      return Promise.reject(noHandlerError);
    }

    if ((messageName == "Extension:Message" ||
         messageName == "Extension:Connect") &&
        apiManager.global.tabGetSender) {
      // From ext-tabs.js, undefined on Android.
      apiManager.global.tabGetSender(extension, target, sender);
    }

    let promise1 = MessageChannel.sendMessage(receiverMM, messageName, data, {
      sender,
      recipient,
      responseType,
    });

    if (!(extension.isEmbedded || recipient.toProxyScript) || !extension.remote) {
      return promise1;
    }

    // If we have a proxy script sandbox or a remote, embedded extension, where
    // the legacy side is running in a different process than the WebExtension
    // side. As a result, we need to dispatch the message to both the parent and
    // extension processes, and manually merge the results.
    let promise2 = MessageChannel.sendMessage(Services.ppmm.getChildAt(0), messageName, data, {
      sender,
      recipient,
      responseType,
    });

    let result = undefined;
    let failures = 0;
    let tryPromise = async promise => {
      try {
        let res = await promise;
        if (result === undefined) {
          result = res;
        }
      } catch (e) {
        if (e.result === MessageChannel.RESULT_NO_RESPONSE) {
          // Ignore.
        } else if (e.result === MessageChannel.RESULT_NO_HANDLER) {
          failures++;
        } else {
          throw e;
        }
      }
    };

    await Promise.all([tryPromise(promise1), tryPromise(promise2)]);
    if (failures == 2) {
      return Promise.reject(noHandlerError);
    }
    return result;
  },

  /**
   * @param {object} recipient An object that was passed to
   *     `MessageChannel.sendMessage`.
   * @param {Extension} extension
   * @returns {object|null} The message manager matching the recipient if found.
   */
  getMessageManagerForRecipient(recipient) {
    // tabs.sendMessage / tabs.connect
    if ("tabId" in recipient) {
      // `tabId` being set implies that the tabs API is supported, so we don't
      // need to check whether `tabTracker` exists.
      let tab = apiManager.global.tabTracker.getTab(recipient.tabId, null);
      if (!tab) {
        return null;
      }

      // There can be no recipients in a tab pending restore,
      // So we bail early to avoid instantiating the lazy browser.
      let node = tab.browser || tab;
      if (node.getAttribute("pending") === "true") {
        return null;
      }

      let browser = tab.linkedBrowser || tab.browser;

      // Options panels in the add-on manager currently require
      // special-casing, since their message managers aren't currently
      // connected to the tab's top-level message manager. To deal with
      // this, we find the options <browser> for the tab, and use that
      // directly, insteead.
      if (browser.currentURI.cloneIgnoringRef().spec === "about:addons") {
        let optionsBrowser = browser.contentDocument.querySelector(".inline-options-browser");
        if (optionsBrowser) {
          browser = optionsBrowser;
        }
      }

      return browser.messageManager;
    }

    // runtime.sendMessage / runtime.connect
    let extension = GlobalManager.extensionMap.get(recipient.extensionId);
    if (extension) {
      return extension.parentMessageManager;
    }

    return null;
  },
};

// Responsible for loading extension APIs into the right globals.
GlobalManager = {
  // Map[extension ID -> Extension]. Determines which extension is
  // responsible for content under a particular extension ID.
  extensionMap: new Map(),
  initialized: false,

  init(extension) {
    if (this.extensionMap.size == 0) {
      ProxyMessenger.init();
      apiManager.on("extension-browser-inserted", this._onExtensionBrowser);
      this.initialized = true;
    }

    this.extensionMap.set(extension.id, extension);
  },

  uninit(extension) {
    this.extensionMap.delete(extension.id);

    if (this.extensionMap.size == 0 && this.initialized) {
      apiManager.off("extension-browser-inserted", this._onExtensionBrowser);
      this.initialized = false;
    }
  },

  _onExtensionBrowser(type, browser, additionalData = {}) {
    browser.messageManager.loadFrameScript(`data:,
      Components.utils.import("resource://gre/modules/Services.jsm");

      Services.obs.notifyObservers(this, "tab-content-frameloader-created", "");
    `, false);

    let viewType = browser.getAttribute("webextension-view-type");
    if (viewType) {
      let data = {viewType};

      let {tabTracker} = apiManager.global;
      Object.assign(data, tabTracker.getBrowserData(browser), additionalData);

      browser.messageManager.sendAsyncMessage("Extension:SetFrameData",
                                              data);
    }
  },

  getExtension(extensionId) {
    return this.extensionMap.get(extensionId);
  },

  injectInObject(context, isChromeCompat, dest) {
    SchemaAPIManager.generateAPIs(context, context.extension.apis, dest);
  },
};

/**
 * The proxied parent side of a context in ExtensionChild.jsm, for the
 * parent side of a proxied API.
 */
class ProxyContextParent extends BaseContext {
  constructor(envType, extension, params, xulBrowser, principal) {
    super(envType, extension);

    this.uri = Services.io.newURI(params.url);

    this.incognito = params.incognito;

    this.listenerPromises = new Set();

    // This message manager is used by ParentAPIManager to send messages and to
    // close the ProxyContext if the underlying message manager closes. This
    // message manager object may change when `xulBrowser` swaps docshells, e.g.
    // when a tab is moved to a different window.
    this.messageManagerProxy = new MessageManagerProxy(xulBrowser);

    Object.defineProperty(this, "principal", {
      value: principal, enumerable: true, configurable: true,
    });

    this.listenerProxies = new Map();

    this.pendingEventBrowser = null;

    apiManager.emit("proxy-context-load", this);
  }

  async withPendingBrowser(browser, callable) {
    let savedBrowser = this.pendingEventBrowser;
    this.pendingEventBrowser = browser;
    try {
      let result = await callable();
      return result;
    } finally {
      this.pendingEventBrowser = savedBrowser;
    }
  }

  get cloneScope() {
    return this.sandbox;
  }

  applySafe(callback, args) {
    // There's no need to clone when calling listeners for a proxied
    // context.
    return this.applySafeWithoutClone(callback, args);
  }

  get xulBrowser() {
    return this.messageManagerProxy.eventTarget;
  }

  get parentMessageManager() {
    return this.messageManagerProxy.messageManager;
  }

  shutdown() {
    this.unload();
  }

  unload() {
    if (this.unloaded) {
      return;
    }
    this.messageManagerProxy.dispose();
    super.unload();
    apiManager.emit("proxy-context-unload", this);
  }
}

defineLazyGetter(ProxyContextParent.prototype, "apiCan", function() {
  let obj = {};
  let can = new CanOfAPIs(this, apiManager, obj);
  GlobalManager.injectInObject(this, false, obj);
  return can;
});

defineLazyGetter(ProxyContextParent.prototype, "apiObj", function() {
  return this.apiCan.root;
});

defineLazyGetter(ProxyContextParent.prototype, "sandbox", function() {
  // NOTE: the required Blob and URL globals are used in the ext-registerContentScript.js
  // API module to convert JS and CSS data into blob URLs.
  return Cu.Sandbox(this.principal, {
    sandboxName: this.uri.spec,
    wantGlobalProperties: ["Blob", "URL"],
  });
});

/**
 * The parent side of proxied API context for extension content script
 * running in ExtensionContent.jsm.
 */
class ContentScriptContextParent extends ProxyContextParent {
}

/**
 * The parent side of proxied API context for extension page, such as a
 * background script, a tab page, or a popup, running in
 * ExtensionChild.jsm.
 */
class ExtensionPageContextParent extends ProxyContextParent {
  constructor(envType, extension, params, xulBrowser) {
    super(envType, extension, params, xulBrowser, extension.principal);

    this.viewType = params.viewType;

    this.extension.views.add(this);

    extension.emit("extension-proxy-context-load", this);
  }

  // The window that contains this context. This may change due to moving tabs.
  get xulWindow() {
    let win = this.xulBrowser.ownerGlobal;
    return win.document.docShell.rootTreeItem
              .QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindow);
  }

  get currentWindow() {
    if (this.viewType !== "background") {
      return this.xulWindow;
    }
  }

  get windowId() {
    let {currentWindow} = this;
    let {windowTracker} = apiManager.global;

    if (currentWindow && windowTracker) {
      return windowTracker.getId(currentWindow);
    }
  }

  get tabId() {
    let {tabTracker} = apiManager.global;
    let data = tabTracker.getBrowserData(this.xulBrowser);
    if (data.tabId >= 0) {
      return data.tabId;
    }
  }

  onBrowserChange(browser) {
    super.onBrowserChange(browser);
    this.xulBrowser = browser;
  }

  shutdown() {
    apiManager.emit("page-shutdown", this);
    this.extension.views.delete(this);
    super.shutdown();
  }
}

/**
 * The parent side of proxied API context for devtools extension page, such as a
 * devtools pages and panels running in ExtensionChild.jsm.
 */
class DevToolsExtensionPageContextParent extends ExtensionPageContextParent {
  set devToolsToolbox(toolbox) {
    if (this._devToolsToolbox) {
      throw new Error("Cannot set the context DevTools toolbox twice");
    }

    this._devToolsToolbox = toolbox;

    return toolbox;
  }

  get devToolsToolbox() {
    return this._devToolsToolbox;
  }

  set devToolsTarget(contextDevToolsTarget) {
    if (this._devToolsTarget) {
      throw new Error("Cannot set the context DevTools target twice");
    }

    this._devToolsTarget = contextDevToolsTarget;

    return contextDevToolsTarget;
  }

  get devToolsTarget() {
    return this._devToolsTarget;
  }

  shutdown() {
    if (this._devToolsTarget) {
      this._devToolsTarget.destroy();
      this._devToolsTarget = null;
    }

    this._devToolsToolbox = null;

    super.shutdown();
  }
}

ParentAPIManager = {
  proxyContexts: new Map(),

  parentMessageManagers: new Set(),

  init() {
    Services.obs.addObserver(this, "message-manager-close");
    Services.obs.addObserver(this, "ipc:content-created");

    Services.mm.addMessageListener("API:CreateProxyContext", this);
    Services.mm.addMessageListener("API:CloseProxyContext", this, true);
    Services.mm.addMessageListener("API:Call", this);
    Services.mm.addMessageListener("API:AddListener", this);
    Services.mm.addMessageListener("API:RemoveListener", this);

    this.schemaHook = this.schemaHook.bind(this);
  },

  attachMessageManager(extension, processMessageManager) {
    extension.parentMessageManager = processMessageManager;
  },

  async observe(subject, topic, data) {
    if (topic === "message-manager-close") {
      let mm = subject;
      for (let [childId, context] of this.proxyContexts) {
        if (context.parentMessageManager === mm) {
          this.closeProxyContext(childId);
        }
      }

      // Reset extension message managers when their child processes shut down.
      for (let extension of GlobalManager.extensionMap.values()) {
        if (extension.parentMessageManager === mm) {
          extension.parentMessageManager = null;
        }
      }

      this.parentMessageManagers.delete(mm);
    } else if (topic === "ipc:content-created") {
      let mm = subject.QueryInterface(Ci.nsIInterfaceRequestor)
                      .getInterface(Ci.nsIMessageSender);
      if (mm.remoteType === E10SUtils.EXTENSION_REMOTE_TYPE) {
        this.parentMessageManagers.add(mm);
        mm.sendAsyncMessage("Schema:Add", Schemas.schemaJSON);

        Schemas.schemaHook = this.schemaHook;
      }
    }
  },

  schemaHook(schemas) {
    for (let mm of this.parentMessageManagers) {
      mm.sendAsyncMessage("Schema:Add", schemas);
    }
  },

  shutdownExtension(extensionId) {
    for (let [childId, context] of this.proxyContexts) {
      if (context.extension.id == extensionId) {
        context.shutdown();
        this.proxyContexts.delete(childId);
      }
    }
  },

  receiveMessage({name, data, target}) {
    try {
      switch (name) {
        case "API:CreateProxyContext":
          this.createProxyContext(data, target);
          break;

        case "API:CloseProxyContext":
          this.closeProxyContext(data.childId);
          break;

        case "API:Call":
          this.call(data, target);
          break;

        case "API:AddListener":
          this.addListener(data, target);
          break;

        case "API:RemoveListener":
          this.removeListener(data);
          break;
      }
    } catch (e) {
      Cu.reportError(e);
    }
  },

  createProxyContext(data, target) {
    let {envType, extensionId, childId, principal} = data;
    if (this.proxyContexts.has(childId)) {
      throw new Error("A WebExtension context with the given ID already exists!");
    }

    let extension = GlobalManager.getExtension(extensionId);
    if (!extension) {
      throw new Error(`No WebExtension found with ID ${extensionId}`);
    }

    let context;
    if (envType == "addon_parent" || envType == "devtools_parent") {
      let processMessageManager = (target.messageManager.processMessageManager ||
                                   Services.ppmm.getChildAt(0));

      if (!extension.parentMessageManager) {
        let expectedRemoteType = extension.remote ? E10SUtils.EXTENSION_REMOTE_TYPE : null;
        if (target.remoteType === expectedRemoteType) {
          this.attachMessageManager(extension, processMessageManager);
        }
      }

      if (processMessageManager !== extension.parentMessageManager) {
        throw new Error("Attempt to create privileged extension parent from incorrect child process");
      }

      if (envType == "addon_parent") {
        context = new ExtensionPageContextParent(envType, extension, data, target);
      } else if (envType == "devtools_parent") {
        context = new DevToolsExtensionPageContextParent(envType, extension, data, target);
      }
    } else if (envType == "content_parent") {
      context = new ContentScriptContextParent(envType, extension, data, target, principal);
    } else {
      throw new Error(`Invalid WebExtension context envType: ${envType}`);
    }
    this.proxyContexts.set(childId, context);
  },

  closeProxyContext(childId) {
    let context = this.proxyContexts.get(childId);
    if (context) {
      context.unload();
      this.proxyContexts.delete(childId);
    }
  },

  async call(data, target) {
    let context = this.getContextById(data.childId);
    if (context.parentMessageManager !== target.messageManager) {
      throw new Error("Got message on unexpected message manager");
    }

    let reply = result => {
      if (!context.parentMessageManager) {
        Services.console.logStringMessage("Cannot send function call result: other side closed connection " +
                                          `(call data: ${uneval({path: data.path, args: data.args})})`);
        return;
      }

      context.parentMessageManager.sendAsyncMessage(
        "API:CallResult",
        Object.assign({
          childId: data.childId,
          callId: data.callId,
        }, result));
    };

    try {
      let args = data.args;
      let pendingBrowser = context.pendingEventBrowser;
      let fun = await context.apiCan.asyncFindAPIPath(data.path);
      let result = context.withPendingBrowser(pendingBrowser,
                                              () => fun(...args));
      if (data.callId) {
        result = result || Promise.resolve();

        result.then(result => {
          result = result instanceof SpreadArgs ? [...result] : [result];

          let holder = new StructuredCloneHolder(result);

          reply({result: holder});
        }, error => {
          error = context.normalizeError(error);
          reply({error: {message: error.message, fileName: error.fileName}});
        });
      }
    } catch (e) {
      if (data.callId) {
        let error = context.normalizeError(e);
        reply({error: {message: error.message}});
      } else {
        Cu.reportError(e);
      }
    }
  },

  async addListener(data, target) {
    let context = this.getContextById(data.childId);
    if (context.parentMessageManager !== target.messageManager) {
      throw new Error("Got message on unexpected message manager");
    }

    let {childId} = data;
    let handlingUserInput = false;
    let lowPriority = data.path.startsWith("webRequest.");

    function listener(...listenerArgs) {
      return context.sendMessage(
        context.parentMessageManager,
        "API:RunListener",
        {
          childId,
          handlingUserInput,
          listenerId: data.listenerId,
          path: data.path,
          get args() {
            return new StructuredCloneHolder(listenerArgs);
          },
        },
        {
          lowPriority,
          recipient: {childId},
        })
        .then(result => {
          return result && result.deserialize(global);
        });
    }

    context.listenerProxies.set(data.listenerId, listener);

    let args = data.args;
    let promise = context.apiCan.asyncFindAPIPath(data.path);

    // Store pending listener additions so we can be sure they're all
    // fully initialize before we consider extension startup complete.
    if (context.viewType === "background" && context.listenerPromises) {
      const {listenerPromises} = context;
      listenerPromises.add(promise);
      let remove = () => { listenerPromises.delete(promise); };
      promise.then(remove, remove);
    }

    let handler = await promise;
    if (handler.setUserInput) {
      handlingUserInput = true;
    }
    handler.addListener(listener, ...args);
  },

  async removeListener(data) {
    let context = this.getContextById(data.childId);
    let listener = context.listenerProxies.get(data.listenerId);

    let handler = await context.apiCan.asyncFindAPIPath(data.path);
    handler.removeListener(listener);
  },

  getContextById(childId) {
    let context = this.proxyContexts.get(childId);
    if (!context) {
      throw new Error("WebExtension context not found!");
    }
    return context;
  },
};

ParentAPIManager.init();

/**
 * This utility class is used to create hidden XUL windows, which are used to
 * contains the extension pages that are not visible (e.g. the background page and
 * the devtools page), and it is also used by the ExtensionDebuggingUtils to
 * contains the browser elements that are used by the addon debugger to be able
 * to connect to the devtools actors running in the same process of the target
 * extension (and be able to stay connected across the addon reloads).
 */
class HiddenXULWindow {
  constructor() {
    this._windowlessBrowser = null;
    this.waitInitialized = this.initWindowlessBrowser();
  }

  shutdown() {
    if (this.unloaded) {
      throw new Error("Unable to shutdown an unloaded HiddenXULWindow instance");
    }

    this.unloaded = true;

    this.chromeShell = null;
    this.waitInitialized = null;

    this._windowlessBrowser.close();
    this._windowlessBrowser = null;
  }

  get chromeDocument() {
    return this._windowlessBrowser.document;
  }

  /**
   * Private helper that create a XULDocument in a windowless browser.
   *
   * @returns {Promise<XULDocument>}
   *          A promise which resolves to the newly created XULDocument.
   */
  async initWindowlessBrowser() {
    if (this.waitInitialized) {
      throw new Error("HiddenXULWindow already initialized");
    }

    // The invisible page is currently wrapped in a XUL window to fix an issue
    // with using the canvas API from a background page (See Bug 1274775).
    let windowlessBrowser = Services.appShell.createWindowlessBrowser(true);
    this._windowlessBrowser = windowlessBrowser;

    // The windowless browser is a thin wrapper around a docShell that keeps
    // its related resources alive. It implements nsIWebNavigation and
    // forwards its methods to the underlying docShell, but cannot act as a
    // docShell itself. Calling `getInterface(nsIDocShell)` gives us the
    // underlying docShell, and `QueryInterface(nsIWebNavigation)` gives us
    // access to the webNav methods that are already available on the
    // windowless browser, but contrary to appearances, they are not the same
    // object.
    this.chromeShell = this._windowlessBrowser
                           .QueryInterface(Ci.nsIInterfaceRequestor)
                           .getInterface(Ci.nsIDocShell)
                           .QueryInterface(Ci.nsIWebNavigation);

    if (PrivateBrowsingUtils.permanentPrivateBrowsing) {
      let attrs = this.chromeShell.getOriginAttributes();
      attrs.privateBrowsingId = 1;
      this.chromeShell.setOriginAttributes(attrs);
    }

    let system = Services.scriptSecurityManager.getSystemPrincipal();
    this.chromeShell.createAboutBlankContentViewer(system);
    this.chromeShell.useGlobalHistory = false;
    this.chromeShell.loadURI("chrome://extensions/content/dummy.xul", 0, null, null, null);

    await promiseObserved("chrome-document-global-created",
                          win => win.document == this.chromeShell.document);
    return promiseDocumentLoaded(windowlessBrowser.document);
  }

  /**
   * Creates the browser XUL element that will contain the WebExtension Page.
   *
   * @param {Object} xulAttributes
   *        An object that contains the xul attributes to set of the newly
   *        created browser XUL element.
   * @param {nsIFrameLoader} [groupFrameLoader]
   *        The frame loader to load this browser into the same process
   *        and tab group as.
   *
   * @returns {Promise<XULElement>}
   *          A Promise which resolves to the newly created browser XUL element.
   */
  async createBrowserElement(xulAttributes, groupFrameLoader = null) {
    if (!xulAttributes || Object.keys(xulAttributes).length === 0) {
      throw new Error("missing mandatory xulAttributes parameter");
    }

    await this.waitInitialized;

    const chromeDoc = this.chromeDocument;

    const browser = chromeDoc.createElement("browser");
    browser.setAttribute("type", "content");
    browser.setAttribute("disableglobalhistory", "true");
    browser.sameProcessAsFrameLoader = groupFrameLoader;

    for (const [name, value] of Object.entries(xulAttributes)) {
      if (value != null) {
        browser.setAttribute(name, value);
      }
    }

    let awaitFrameLoader = Promise.resolve();

    if (browser.getAttribute("remote") === "true") {
      awaitFrameLoader = promiseEvent(browser, "XULFrameLoaderCreated");
    }

    chromeDoc.documentElement.appendChild(browser);
    await awaitFrameLoader;

    return browser;
  }
}


/**
 * This is a base class used by the ext-backgroundPage and ext-devtools API implementations
 * to inherits the shared boilerplate code needed to create a parent document for the hidden
 * extension pages (e.g. the background page, the devtools page) in the BackgroundPage and
 * DevToolsPage classes.
 *
 * @param {Extension} extension
 *        The Extension which owns the hidden extension page created (used to decide
 *        if the hidden extension page parent doc is going to be a windowlessBrowser or
 *        a visible XUL window).
 * @param {string} viewType
 *        The viewType of the WebExtension page that is going to be loaded
 *        in the created browser element (e.g. "background" or "devtools_page").
 */
class HiddenExtensionPage extends HiddenXULWindow {
  constructor(extension, viewType) {
    if (!extension || !viewType) {
      throw new Error("extension and viewType parameters are mandatory");
    }

    super();
    this.extension = extension;
    this.viewType = viewType;
    this.browser = null;
  }

  /**
   * Destroy the created parent document.
   */
  shutdown() {
    if (this.unloaded) {
      throw new Error("Unable to shutdown an unloaded HiddenExtensionPage instance");
    }

    if (this.browser) {
      this.browser.remove();
      this.browser = null;
    }

    super.shutdown();
  }

  /**
   * Creates the browser XUL element that will contain the WebExtension Page.
   *
   * @returns {Promise<XULElement>}
   *          A Promise which resolves to the newly created browser XUL element.
   */
  async createBrowserElement() {
    if (this.browser) {
      throw new Error("createBrowserElement called twice");
    }

    this.browser = await super.createBrowserElement({
      "webextension-view-type": this.viewType,
      "remote": this.extension.remote ? "true" : null,
      "remoteType": this.extension.remote ?
        E10SUtils.EXTENSION_REMOTE_TYPE : null,
    }, this.extension.groupFrameLoader);

    return this.browser;
  }
}

/**
 * This object provides utility functions needed by the devtools actors to
 * be able to connect and debug an extension (which can run in the main or in
 * a child extension process).
 */
const DebugUtils = {
  // A lazily created hidden XUL window, which contains the browser elements
  // which are used to connect the webextension patent actor to the extension process.
  hiddenXULWindow: null,

  // Map<extensionId, Promise<XULElement>>
  debugBrowserPromises: new Map(),
  // DefaultWeakMap<Promise<browser XULElement>, Set<WebExtensionParentActor>>
  debugActors: new DefaultWeakMap(() => new Set()),

  _extensionUpdatedWatcher: null,
  watchExtensionUpdated() {
    if (!this._extensionUpdatedWatcher) {
      // Watch the updated extension objects.
      this._extensionUpdatedWatcher = async (evt, extension) => {
        const browserPromise = this.debugBrowserPromises.get(extension.id);
        if (browserPromise) {
          const browser = await browserPromise;
          if (browser.isRemoteBrowser !== extension.remote &&
              this.debugBrowserPromises.get(extension.id) === browserPromise) {
            // If the cached browser element is not anymore of the same
            // remote type of the extension, remove it.
            this.debugBrowserPromises.delete(extension.id);
            browser.remove();
          }
        }
      };

      apiManager.on("ready", this._extensionUpdatedWatcher);
    }
  },

  unwatchExtensionUpdated() {
    if (this._extensionUpdatedWatcher) {
      apiManager.off("ready", this._extensionUpdatedWatcher);
      delete this._extensionUpdatedWatcher;
    }
  },

  getExtensionManifestWarnings(id) {
    const addon = GlobalManager.extensionMap.get(id);
    if (addon) {
      return addon.warnings;
    }
    return [];
  },


  /**
   * Retrieve a XUL browser element which has been configured to be able to connect
   * the devtools actor with the process where the extension is running.
   *
   * @param {WebExtensionParentActor} webExtensionParentActor
   *        The devtools actor that is retrieving the browser element.
   *
   * @returns {Promise<XULElement>}
   *          A promise which resolves to the configured browser XUL element.
   */
  async getExtensionProcessBrowser(webExtensionParentActor) {
    const extensionId = webExtensionParentActor.addonId;
    const extension = GlobalManager.getExtension(extensionId);
    if (!extension) {
      throw new Error(`Extension not found: ${extensionId}`);
    }

    const createBrowser = () => {
      if (!this.hiddenXULWindow) {
        this.hiddenXULWindow = new HiddenXULWindow();
        this.watchExtensionUpdated();
      }

      return this.hiddenXULWindow.createBrowserElement({
        "webextension-addon-debug-target": extensionId,
        "remote": extension.remote ? "true" : null,
        "remoteType": extension.remote ?
          E10SUtils.EXTENSION_REMOTE_TYPE : null,
      }, extension.groupFrameLoader);
    };

    let browserPromise = this.debugBrowserPromises.get(extensionId);

    // Create a new promise if there is no cached one in the map.
    if (!browserPromise) {
      browserPromise = createBrowser();
      this.debugBrowserPromises.set(extensionId, browserPromise);
      browserPromise.then(browser => {
        browserPromise.browser = browser;
      });
      browserPromise.catch(e => {
        Cu.reportError(e);
        this.debugBrowserPromises.delete(extensionId);
      });
    }

    this.debugActors.get(browserPromise).add(webExtensionParentActor);

    return browserPromise;
  },

  getFrameLoader(extensionId) {
    let promise = this.debugBrowserPromises.get(extensionId);
    return promise && promise.browser && promise.browser.frameLoader;
  },

  /**
   * Given the devtools actor that has retrieved an addon debug browser element,
   * it destroys the XUL browser element, and it also destroy the hidden XUL window
   * if it is not currently needed.
   *
   * @param {WebExtensionParentActor} webExtensionParentActor
   *        The devtools actor that has retrieved an addon debug browser element.
   */
  async releaseExtensionProcessBrowser(webExtensionParentActor) {
    const extensionId = webExtensionParentActor.addonId;
    const browserPromise = this.debugBrowserPromises.get(extensionId);

    if (browserPromise) {
      const actorsSet = this.debugActors.get(browserPromise);
      actorsSet.delete(webExtensionParentActor);
      if (actorsSet.size === 0) {
        this.debugActors.delete(browserPromise);
        this.debugBrowserPromises.delete(extensionId);
        await browserPromise.then((browser) => browser.remove());
      }
    }

    if (this.debugBrowserPromises.size === 0 && this.hiddenXULWindow) {
      this.hiddenXULWindow.shutdown();
      this.hiddenXULWindow = null;
      this.unwatchExtensionUpdated();
    }
  },
};


function promiseExtensionViewLoaded(browser) {
  return new Promise(resolve => {
    browser.messageManager.addMessageListener("Extension:ExtensionViewLoaded", function onLoad({data}) {
      browser.messageManager.removeMessageListener("Extension:ExtensionViewLoaded", onLoad);
      resolve(data.childId && ParentAPIManager.getContextById(data.childId));
    });
  });
}

/**
 * This helper is used to subscribe a listener (e.g. in the ext-devtools API implementation)
 * to be called for every ExtensionProxyContext created for an extension page given
 * its related extension, viewType and browser element (both the top level context and any context
 * created for the extension urls running into its iframe descendants).
 *
 * @param {object} params.extension
 *        The Extension on which we are going to listen for the newly created ExtensionProxyContext.
 * @param {string} params.viewType
 *        The viewType of the WebExtension page that we are watching (e.g. "background" or
 *        "devtools_page").
 * @param {XULElement} params.browser
 *        The browser element of the WebExtension page that we are watching.
 * @param {function} onExtensionProxyContextLoaded
 *        The callback that is called when a new context has been loaded (as `callback(context)`);
 *
 * @returns {function}
 *          Unsubscribe the listener.
 */
function watchExtensionProxyContextLoad({extension, viewType, browser}, onExtensionProxyContextLoaded) {
  if (typeof onExtensionProxyContextLoaded !== "function") {
    throw new Error("Missing onExtensionProxyContextLoaded handler");
  }

  const listener = (event, context) => {
    if (context.viewType == viewType && context.xulBrowser == browser) {
      onExtensionProxyContextLoaded(context);
    }
  };

  extension.on("extension-proxy-context-load", listener);

  return () => {
    extension.off("extension-proxy-context-load", listener);
  };
}

// Used to cache the list of WebExtensionManifest properties defined in the BASE_SCHEMA.
let gBaseManifestProperties = null;

// Manages icon details for toolbar buttons in the |pageAction| and
// |browserAction| APIs.
let IconDetails = {
  // WeakMap<Extension -> Map<url-string -> Map<iconType-string -> object>>>
  iconCache: new DefaultWeakMap(() => {
    return new DefaultMap(() => new DefaultMap(() => new Map()));
  }),

  // Normalizes the various acceptable input formats into an object
  // with icon size as key and icon URL as value.
  //
  // If a context is specified (function is called from an extension):
  // Throws an error if an invalid icon size was provided or the
  // extension is not allowed to load the specified resources.
  //
  // If no context is specified, instead of throwing an error, this
  // function simply logs a warning message.
  normalize(details, extension, context = null) {
    if (!details.imageData && details.path != null) {
      // Pick a cache key for the icon paths. If the path is a string,
      // use it directly. Otherwise, stringify the path object.
      let key = details.path;
      if (typeof key !== "string") {
        key = uneval(key);
      }

      let icons = this.iconCache.get(extension)
                      .get(context && context.uri.spec)
                      .get(details.iconType);

      let icon = icons.get(key);
      if (!icon) {
        icon = this._normalize(details, extension, context);
        icons.set(key, icon);
      }
      return icon;
    }

    return this._normalize(details, extension, context);
  },

  _normalize(details, extension, context = null) {
    let result = {};

    try {
      let {imageData, path, themeIcons} = details;

      if (imageData) {
        if (typeof imageData == "string") {
          imageData = {"19": imageData};
        }

        for (let size of Object.keys(imageData)) {
          result[size] = imageData[size];
        }
      }

      let baseURI = context ? context.uri : extension.baseURI;

      if (path != null) {
        if (typeof path != "object") {
          path = {"19": path};
        }

        for (let size of Object.keys(path)) {
          let url = baseURI.resolve(path[size]);

          // The Chrome documentation specifies these parameters as
          // relative paths. We currently accept absolute URLs as well,
          // which means we need to check that the extension is allowed
          // to load them. This will throw an error if it's not allowed.
          this._checkURL(url, extension);

          result[size] = url;
        }
      }

      if (themeIcons) {
        themeIcons.forEach(({size, light, dark}) => {
          let lightURL = baseURI.resolve(light);
          let darkURL = baseURI.resolve(dark);

          this._checkURL(lightURL, extension);
          this._checkURL(darkURL, extension);

          let defaultURL = result[size] || result[19]; // always fallback to default first
          result[size] = {
            "default": defaultURL || darkURL, // Fallback to the dark url if no default is specified.
            "light": lightURL,
            "dark": darkURL,
          };
        });
      }
    } catch (e) {
      // Function is called from extension code, delegate error.
      if (context) {
        throw e;
      }
      // If there's no context, it's because we're handling this
      // as a manifest directive. Log a warning rather than
      // raising an error.
      extension.manifestError(`Invalid icon data: ${e}`);
    }

    return result;
  },

  // Checks if the extension is allowed to load the given URL with the specified principal.
  // This will throw an error if the URL is not allowed.
  _checkURL(url, extension) {
    if (!extension.checkLoadURL(url, {allowInheritsPrincipal: true})) {
      throw new ExtensionError(`Illegal URL ${url}`);
    }
  },

  // Returns the appropriate icon URL for the given icons object and the
  // screen resolution of the given window.
  getPreferredIcon(icons, extension = null, size = 16) {
    const DEFAULT = "chrome://browser/content/extension.svg";

    let bestSize = null;
    if (icons[size]) {
      bestSize = size;
    } else if (icons[2 * size]) {
      bestSize = 2 * size;
    } else {
      let sizes = Object.keys(icons)
                        .map(key => parseInt(key, 10))
                        .sort((a, b) => a - b);

      bestSize = sizes.find(candidate => candidate > size) || sizes.pop();
    }

    if (bestSize) {
      return {size: bestSize, icon: icons[bestSize]};
    }

    return {size, icon: DEFAULT};
  },

  convertImageURLToDataURL(imageURL, contentWindow, browserWindow, size = 18) {
    return new Promise((resolve, reject) => {
      let image = new contentWindow.Image();
      image.onload = function() {
        let canvas = contentWindow.document.createElement("canvas");
        let ctx = canvas.getContext("2d");
        let dSize = size * browserWindow.devicePixelRatio;

        // Scales the image while maintaing width to height ratio.
        // If the width and height differ, the image is centered using the
        // smaller of the two dimensions.
        let dWidth, dHeight, dx, dy;
        if (this.width > this.height) {
          dWidth = dSize;
          dHeight = image.height * (dSize / image.width);
          dx = 0;
          dy = (dSize - dHeight) / 2;
        } else {
          dWidth = image.width * (dSize / image.height);
          dHeight = dSize;
          dx = (dSize - dWidth) / 2;
          dy = 0;
        }

        canvas.width = dSize;
        canvas.height = dSize;
        ctx.drawImage(this, 0, 0, this.width, this.height, dx, dy, dWidth, dHeight);
        resolve(canvas.toDataURL("image/png"));
      };
      image.onerror = reject;
      image.src = imageURL;
    });
  },

  // These URLs should already be properly escaped, but make doubly sure CSS
  // string escape characters are escaped here, since they could lead to a
  // sandbox break.
  escapeUrl(url) {
    return url.replace(/[\\\s"]/g, encodeURIComponent);
  },
};

StartupCache = {
  DB_NAME: "ExtensionStartupCache",

  STORE_NAMES: Object.freeze(["general", "locales", "manifests", "other", "permissions", "schemas"]),

  file: OS.Path.join(OS.Constants.Path.localProfileDir, "startupCache", "webext.sc.lz4"),

  async _saveNow() {
    let data = new Uint8Array(aomStartup.encodeBlob(this._data));
    await OS.File.writeAtomic(this.file, data, {tmpPath: `${this.file}.tmp`});
  },

  async save() {
    if (!this._saveTask) {
      OS.File.makeDir(OS.Path.dirname(this.file), {
        ignoreExisting: true,
        from: OS.Constants.Path.localProfileDir,
      });

      this._saveTask = new DeferredTask(() => this._saveNow(), 5000);

      AsyncShutdown.profileBeforeChange.addBlocker(
        "Flush WebExtension StartupCache",
        async () => {
          await this._saveTask.finalize();
          this._saveTask = null;
        });
    }
    return this._saveTask.arm();
  },

  _data: null,
  async _readData() {
    let result = new Map();
    try {
      let {buffer} = await OS.File.read(this.file);

      result = aomStartup.decodeBlob(buffer);
    } catch (e) {
      if (!e.becauseNoSuchFile) {
        Cu.reportError(e);
      }
    }

    this._data = result;
    return result;
  },

  get dataPromise() {
    if (!this._dataPromise) {
      this._dataPromise = this._readData();
    }
    return this._dataPromise;
  },

  clearAddonData(id) {
    return Promise.all([
      this.general.delete(id),
      this.locales.delete(id),
      this.manifests.delete(id),
      this.permissions.delete(id),
    ]).catch(e => {
      // Ignore the error. It happens when we try to flush the add-on
      // data after the AddonManager has flushed the entire startup cache.
    });
  },

  observe(subject, topic, data) {
    if (topic === "startupcache-invalidate") {
      this._data = new Map();
      this._dataPromise = Promise.resolve(this._data);
    }
  },

  get(extension, path, createFunc) {
    return this.general.get([extension.id, extension.version, ...path],
                            createFunc);
  },

  delete(extension, path) {
    return this.general.delete([extension.id, extension.version, ...path]);
  },
};

Services.obs.addObserver(StartupCache, "startupcache-invalidate");

class CacheStore {
  constructor(storeName) {
    this.storeName = storeName;
  }

  async getStore(path = null) {
    let data = await StartupCache.dataPromise;

    let store = data.get(this.storeName);
    if (!store) {
      store = new Map();
      data.set(this.storeName, store);
    }

    let key = path;
    if (Array.isArray(path)) {
      for (let elem of path.slice(0, -1)) {
        let next = store.get(elem);
        if (!next) {
          next = new Map();
          store.set(elem, next);
        }
        store = next;
      }
      key = path[path.length - 1];
    }

    return [store, key];
  }

  async get(path, createFunc) {
    let [store, key] = await this.getStore(path);

    let result = store.get(key);

    if (result === undefined) {
      result = await createFunc(path);
      store.set(key, result);
      StartupCache.save();
    }

    return result;
  }

  async set(path, value) {
    let [store, key] = await this.getStore(path);

    store.set(key, value);
    StartupCache.save();
  }

  async getAll() {
    let [store] = await this.getStore();

    return new Map(store);
  }

  async delete(path) {
    let [store, key] = await this.getStore(path);

    store.delete(key);
    StartupCache.save();
  }
}

for (let name of StartupCache.STORE_NAMES) {
  StartupCache[name] = new CacheStore(name);
}

var ExtensionParent = {
  GlobalManager,
  HiddenExtensionPage,
  IconDetails,
  ParentAPIManager,
  StartupCache,
  WebExtensionPolicy,
  apiManager,
  get baseManifestProperties() {
    if (gBaseManifestProperties) {
      return gBaseManifestProperties;
    }

    let types = Schemas.schemaJSON.get(BASE_SCHEMA).deserialize({})[0].types;
    let manifest = types.find(type => type.id === "WebExtensionManifest");
    if (!manifest) {
      throw new Error("Unable to find base manifest properties");
    }

    gBaseManifestProperties = Object.getOwnPropertyNames(manifest.properties);
    return gBaseManifestProperties;
  },
  promiseExtensionViewLoaded,
  watchExtensionProxyContextLoad,
  DebugUtils,
};

XPCOMUtils.defineLazyGetter(ExtensionParent, "PlatformInfo", () => {
  return Object.freeze({
    os: (function() {
      let os = AppConstants.platform;
      if (os == "macosx") {
        os = "mac";
      }
      return os;
    })(),
    arch: (function() {
      let abi = Services.appinfo.XPCOMABI;
      let [arch] = abi.split("-");
      if (arch == "x86") {
        arch = "x86-32";
      } else if (arch == "x86_64") {
        arch = "x86-64";
      }
      return arch;
    })(),
  });
});

/**
 * Retreives the browser_style stylesheets needed for extension popups and sidebars.
 * @returns {Array<string>} an array of stylesheets needed for the current platform.
 */
XPCOMUtils.defineLazyGetter(ExtensionParent, "extensionStylesheets", () => {
  let stylesheets = ["chrome://browser/content/extension.css"];

  if (AppConstants.platform === "macosx") {
    stylesheets.push("chrome://browser/content/extension-mac.css");
  }

  return stylesheets;
});