path: root/browser/components/BrowserContentHandler.sys.mjs

/* 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/. */

import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";

const lazy = {};

ChromeUtils.defineESModuleGetters(lazy, {
  BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.sys.mjs",
  FirstStartup: "resource://gre/modules/FirstStartup.sys.mjs",
  HeadlessShell: "resource:///modules/HeadlessShell.sys.mjs",
  HomePage: "resource:///modules/HomePage.sys.mjs",
  LaterRun: "resource:///modules/LaterRun.sys.mjs",
  NimbusFeatures: "resource://nimbus/ExperimentAPI.sys.mjs",
  PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.sys.mjs",
  SessionStartup: "resource:///modules/sessionstore/SessionStartup.sys.mjs",
  ShellService: "resource:///modules/ShellService.sys.mjs",
  SpecialMessageActions:
    "resource://messaging-system/lib/SpecialMessageActions.sys.mjs",
  UpdatePing: "resource://gre/modules/UpdatePing.sys.mjs",
});

XPCOMUtils.defineLazyServiceGetters(lazy, {
  UpdateManager: ["@mozilla.org/updates/update-manager;1", "nsIUpdateManager"],
  WinTaskbar: ["@mozilla.org/windows-taskbar;1", "nsIWinTaskbar"],
  WindowsUIUtils: ["@mozilla.org/windows-ui-utils;1", "nsIWindowsUIUtils"],
});

ChromeUtils.defineLazyGetter(lazy, "gSystemPrincipal", () =>
  Services.scriptSecurityManager.getSystemPrincipal()
);

ChromeUtils.defineLazyGetter(lazy, "gWindowsAlertsService", () => {
  // We might not have the Windows alerts service: e.g., on Windows 7 and Windows 8.
  if (!("nsIWindowsAlertsService" in Ci)) {
    return null;
  }
  return Cc["@mozilla.org/system-alerts-service;1"]
    ?.getService(Ci.nsIAlertsService)
    ?.QueryInterface(Ci.nsIWindowsAlertsService);
});

// One-time startup homepage override configurations
const ONCE_DOMAINS = ["mozilla.org", "firefox.com"];
const ONCE_PREF = "browser.startup.homepage_override.once";

// Index of Private Browsing icon in firefox.exe
// Must line up with the one in nsNativeAppSupportWin.h.
const PRIVATE_BROWSING_ICON_INDEX = 5;

function shouldLoadURI(aURI) {
  if (aURI && !aURI.schemeIs("chrome")) {
    return true;
  }

  dump("*** Preventing external load of chrome: URI into browser window\n");
  dump("    Use --chrome <uri> instead\n");
  return false;
}

function validateFirefoxProtocol(aCmdLine, launchedWithArg_osint) {
  let paramCount = 0;
  // Only accept one parameter when we're handling the protocol.
  for (let i = 0; i < aCmdLine.length; i++) {
    if (!aCmdLine.getArgument(i).startsWith("-")) {
      paramCount++;
    }
    if (paramCount > 1) {
      return false;
    }
  }
  // `-osint` and handling registered file types and protocols is Windows-only.
  return AppConstants.platform != "win" || launchedWithArg_osint;
}

function resolveURIInternal(
  aCmdLine,
  aArgument,
  launchedWithArg_osint = false
) {
  let principal = lazy.gSystemPrincipal;

  // If using Firefox protocol handler remove it from URI
  // at this stage. This is before we would otherwise
  // record telemetry so do that here.
  let handleFirefoxProtocol = protocol => {
    let protocolWithColon = protocol + ":";
    if (aArgument.startsWith(protocolWithColon)) {
      if (!validateFirefoxProtocol(aCmdLine, launchedWithArg_osint)) {
        throw new Error(
          "Invalid use of Firefox and Firefox-private protocols."
        );
      }
      aArgument = aArgument.substring(protocolWithColon.length);

      if (
        !aArgument.startsWith("http://") &&
        !aArgument.startsWith("https://")
      ) {
        throw new Error(
          "Firefox and Firefox-private protocols can only be used in conjunction with http and https urls."
        );
      }

      principal = Services.scriptSecurityManager.createNullPrincipal({});
      Services.telemetry.keyedScalarAdd(
        "os.environment.launched_to_handle",
        protocol,
        1
      );
    }
  };

  handleFirefoxProtocol("firefox");
  handleFirefoxProtocol("firefox-private");

  var uri = aCmdLine.resolveURI(aArgument);
  var uriFixup = Services.uriFixup;

  if (!(uri instanceof Ci.nsIFileURL)) {
    let prefURI = Services.uriFixup.getFixupURIInfo(
      aArgument,
      uriFixup.FIXUP_FLAG_FIX_SCHEME_TYPOS
    ).preferredURI;
    return { uri: prefURI, principal };
  }

  try {
    if (uri.file.exists()) {
      return { uri, principal };
    }
  } catch (e) {
    console.error(e);
  }

  // We have interpreted the argument as a relative file URI, but the file
  // doesn't exist. Try URI fixup heuristics: see bug 290782.

  try {
    uri = Services.uriFixup.getFixupURIInfo(aArgument).preferredURI;
  } catch (e) {
    console.error(e);
  }

  return { uri, principal };
}

let gKiosk = false;
let gMajorUpgrade = false;
let gFirstRunProfile = false;
var gFirstWindow = false;

const OVERRIDE_NONE = 0;
const OVERRIDE_NEW_PROFILE = 1;
const OVERRIDE_NEW_MSTONE = 2;
const OVERRIDE_NEW_BUILD_ID = 3;
/**
 * Determines whether a home page override is needed.
 * @param {boolean} [updateMilestones=true]
 *   True if we should update the milestone prefs after comparing those prefs
 *   with the current platform version and build ID.
 *
 *   If updateMilestones is false, then this function has no side-effects.
 *
 * @returns {number}
 *   One of the following constants:
 *     OVERRIDE_NEW_PROFILE
 *       if this is the first run with a new profile.
 *     OVERRIDE_NEW_MSTONE
 *       if this is the first run with a build with a different Gecko milestone
 *       (i.e. right after an upgrade).
 *     OVERRIDE_NEW_BUILD_ID
 *       if this is the first run with a new build ID of the same Gecko
 *       milestone (i.e. after a nightly upgrade).
 *     OVERRIDE_NONE
 *       otherwise.
 */
function needHomepageOverride(updateMilestones = true) {
  var savedmstone = Services.prefs.getCharPref(
    "browser.startup.homepage_override.mstone",
    ""
  );

  if (savedmstone == "ignore") {
    return OVERRIDE_NONE;
  }

  var mstone = Services.appinfo.platformVersion;

  var savedBuildID = Services.prefs.getCharPref(
    "browser.startup.homepage_override.buildID",
    ""
  );

  var buildID = Services.appinfo.platformBuildID;

  if (mstone != savedmstone) {
    // Bug 462254. Previous releases had a default pref to suppress the EULA
    // agreement if the platform's installer had already shown one. Now with
    // about:rights we've removed the EULA stuff and default pref, but we need
    // a way to make existing profiles retain the default that we removed.
    if (savedmstone) {
      Services.prefs.setBoolPref("browser.rights.3.shown", true);

      // Remember that we saw a major version change.
      gMajorUpgrade = true;
    }

    if (updateMilestones) {
      Services.prefs.setCharPref(
        "browser.startup.homepage_override.mstone",
        mstone
      );
      Services.prefs.setCharPref(
        "browser.startup.homepage_override.buildID",
        buildID
      );
    }
    return savedmstone ? OVERRIDE_NEW_MSTONE : OVERRIDE_NEW_PROFILE;
  }

  if (buildID != savedBuildID) {
    if (updateMilestones) {
      Services.prefs.setCharPref(
        "browser.startup.homepage_override.buildID",
        buildID
      );
    }
    return OVERRIDE_NEW_BUILD_ID;
  }

  return OVERRIDE_NONE;
}

/**
 * Gets the override page for the first run after the application has been
 * updated.
 * @param  update
 *         The nsIUpdate for the update that has been applied.
 * @param  defaultOverridePage
 *         The default override page.
 * @return The override page.
 */
function getPostUpdateOverridePage(update, defaultOverridePage) {
  update = update.QueryInterface(Ci.nsIWritablePropertyBag);
  let actions = update.getProperty("actions");
  // When the update doesn't specify actions fallback to the original behavior
  // of displaying the default override page.
  if (!actions) {
    return defaultOverridePage;
  }

  // The existence of silent or the non-existence of showURL in the actions both
  // mean that an override page should not be displayed.
  if (actions.includes("silent") || !actions.includes("showURL")) {
    return "";
  }

  // If a policy was set to not allow the update.xml-provided
  // URL to be used, use the default fallback (which will also
  // be provided by the policy).
  if (!Services.policies.isAllowed("postUpdateCustomPage")) {
    return defaultOverridePage;
  }

  return update.getProperty("openURL") || defaultOverridePage;
}

/**
 * Open a browser window. If this is the initial launch, this function will
 * attempt to use the navigator:blank window opened by BrowserGlue.sys.mjs during
 * early startup.
 *
 * @param cmdLine
 *        The nsICommandLine object given to nsICommandLineHandler's handle
 *        method.
 *        Used to check if we are processing the command line for the initial launch.
 * @param triggeringPrincipal
 *        The nsIPrincipal to use as triggering principal for the page load(s).
 * @param urlOrUrlList (optional)
 *        When omitted, the browser window will be opened with the default
 *        arguments, which will usually load the homepage.
 *        This can be a JS array of urls provided as strings, each url will be
 *        loaded in a tab. postData will be ignored in this case.
 *        This can be a single url to load in the new window, provided as a string.
 *        postData will be used in this case if provided.
 * @param postData (optional)
 *        An nsIInputStream object to use as POST data when loading the provided
 *        url, or null.
 * @param forcePrivate (optional)
 *        Boolean. If set to true, the new window will be a private browsing one.
 *
 * @returns {ChromeWindow}
 *          Returns the top level window opened.
 */
function openBrowserWindow(
  cmdLine,
  triggeringPrincipal,
  urlOrUrlList,
  postData = null,
  forcePrivate = false
) {
  const isStartup =
    cmdLine && cmdLine.state == Ci.nsICommandLine.STATE_INITIAL_LAUNCH;

  let args;
  if (!urlOrUrlList) {
    // Just pass in the defaultArgs directly. We'll use system principal on the other end.
    args = [gBrowserContentHandler.getArgs(isStartup)];
  } else if (Array.isArray(urlOrUrlList)) {
    // There isn't an explicit way to pass a principal here, so we load multiple URLs
    // with system principal when we get to actually loading them.
    if (
      !triggeringPrincipal ||
      !triggeringPrincipal.equals(lazy.gSystemPrincipal)
    ) {
      throw new Error(
        "Can't open multiple URLs with something other than system principal."
      );
    }
    // Passing an nsIArray for the url disables the "|"-splitting behavior.
    let uriArray = Cc["@mozilla.org/array;1"].createInstance(
      Ci.nsIMutableArray
    );
    urlOrUrlList.forEach(function (uri) {
      var sstring = Cc["@mozilla.org/supports-string;1"].createInstance(
        Ci.nsISupportsString
      );
      sstring.data = uri;
      uriArray.appendElement(sstring);
    });
    args = [uriArray];
  } else {
    let extraOptions = Cc["@mozilla.org/hash-property-bag;1"].createInstance(
      Ci.nsIWritablePropertyBag2
    );
    extraOptions.setPropertyAsBool("fromExternal", true);

    // Always pass at least 3 arguments to avoid the "|"-splitting behavior,
    // ie. avoid the loadOneOrMoreURIs function.
    // Also, we need to pass the triggering principal.
    args = [
      urlOrUrlList,
      extraOptions,
      null, // refererInfo
      postData,
      undefined, // allowThirdPartyFixup; this would be `false` but that
      // needs a conversion. Hopefully bug 1485961 will fix.
      undefined, // user context id
      null, // origin principal
      null, // origin storage principal
      triggeringPrincipal,
    ];
  }

  if (isStartup) {
    let win = Services.wm.getMostRecentWindow("navigator:blank");
    if (win) {
      // Remove the windowtype of our blank window so that we don't close it
      // later on when seeing cmdLine.preventDefault is true.
      win.document.documentElement.removeAttribute("windowtype");

      if (forcePrivate) {
        win.docShell.QueryInterface(
          Ci.nsILoadContext
        ).usePrivateBrowsing = true;

        if (
          AppConstants.platform == "win" &&
          lazy.NimbusFeatures.majorRelease2022.getVariable(
            "feltPrivacyWindowSeparation"
          )
        ) {
          lazy.WinTaskbar.setGroupIdForWindow(
            win,
            lazy.WinTaskbar.defaultPrivateGroupId
          );
          lazy.WindowsUIUtils.setWindowIconFromExe(
            win,
            Services.dirsvc.get("XREExeF", Ci.nsIFile).path,
            // This corresponds to the definitions in
            // nsNativeAppSupportWin.h
            PRIVATE_BROWSING_ICON_INDEX
          );
        }
      }

      let openTime = win.openTime;
      win.location = AppConstants.BROWSER_CHROME_URL;
      win.arguments = args; // <-- needs to be a plain JS array here.

      ChromeUtils.addProfilerMarker("earlyBlankWindowVisible", openTime);
      lazy.BrowserWindowTracker.registerOpeningWindow(win, forcePrivate);
      return win;
    }
  }

  // We can't provide arguments to openWindow as a JS array.
  if (!urlOrUrlList) {
    // If we have a single string guaranteed to not contain '|' we can simply
    // wrap it in an nsISupportsString object.
    let [url] = args;
    args = Cc["@mozilla.org/supports-string;1"].createInstance(
      Ci.nsISupportsString
    );
    args.data = url;
  } else {
    // Otherwise, pass an nsIArray.
    if (args.length > 1) {
      let string = Cc["@mozilla.org/supports-string;1"].createInstance(
        Ci.nsISupportsString
      );
      string.data = args[0];
      args[0] = string;
    }
    let array = Cc["@mozilla.org/array;1"].createInstance(Ci.nsIMutableArray);
    args.forEach(a => {
      array.appendElement(a);
    });
    args = array;
  }

  return lazy.BrowserWindowTracker.openWindow({
    args,
    features: gBrowserContentHandler.getFeatures(cmdLine),
    private: forcePrivate,
  });
}

function openPreferences(cmdLine, extraArgs) {
  openBrowserWindow(cmdLine, lazy.gSystemPrincipal, "about:preferences");
}

async function doSearch(searchTerm, cmdLine) {
  // XXXbsmedberg: use handURIToExistingBrowser to obey tabbed-browsing
  // preferences, but need nsIBrowserDOMWindow extensions
  // Open the window immediately as BrowserContentHandler needs to
  // be handled synchronously. Then load the search URI when the
  // SearchService has loaded.
  let win = openBrowserWindow(cmdLine, lazy.gSystemPrincipal, "about:blank");
  await new Promise(resolve => {
    Services.obs.addObserver(function observe(subject) {
      if (subject == win) {
        Services.obs.removeObserver(
          observe,
          "browser-delayed-startup-finished"
        );
        resolve();
      }
    }, "browser-delayed-startup-finished");
  });

  win.BrowserSearch.loadSearchFromCommandLine(
    searchTerm,
    lazy.PrivateBrowsingUtils.isInTemporaryAutoStartMode ||
      lazy.PrivateBrowsingUtils.isWindowPrivate(win),
    lazy.gSystemPrincipal,
    win.gBrowser.selectedBrowser.csp
  ).catch(console.error);
}

export function nsBrowserContentHandler() {
  if (!gBrowserContentHandler) {
    gBrowserContentHandler = this;
  }
  return gBrowserContentHandler;
}

nsBrowserContentHandler.prototype = {
  /* nsISupports */
  QueryInterface: ChromeUtils.generateQI([
    "nsICommandLineHandler",
    "nsIBrowserHandler",
    "nsIContentHandler",
    "nsICommandLineValidator",
  ]),

  /* nsICommandLineHandler */
  handle: function bch_handle(cmdLine) {
    if (
      cmdLine.handleFlag("kiosk", false) ||
      cmdLine.handleFlagWithParam("kiosk-monitor", false)
    ) {
      gKiosk = true;
    }
    if (cmdLine.handleFlag("disable-pinch", false)) {
      let defaults = Services.prefs.getDefaultBranch(null);
      defaults.setBoolPref("apz.allow_zooming", false);
      Services.prefs.lockPref("apz.allow_zooming");
      defaults.setCharPref("browser.gesture.pinch.in", "");
      Services.prefs.lockPref("browser.gesture.pinch.in");
      defaults.setCharPref("browser.gesture.pinch.in.shift", "");
      Services.prefs.lockPref("browser.gesture.pinch.in.shift");
      defaults.setCharPref("browser.gesture.pinch.out", "");
      Services.prefs.lockPref("browser.gesture.pinch.out");
      defaults.setCharPref("browser.gesture.pinch.out.shift", "");
      Services.prefs.lockPref("browser.gesture.pinch.out.shift");
    }
    if (cmdLine.handleFlag("browser", false)) {
      openBrowserWindow(cmdLine, lazy.gSystemPrincipal);
      cmdLine.preventDefault = true;
    }

    var uriparam;
    try {
      while ((uriparam = cmdLine.handleFlagWithParam("new-window", false))) {
        let { uri, principal } = resolveURIInternal(cmdLine, uriparam);
        if (!shouldLoadURI(uri)) {
          continue;
        }
        openBrowserWindow(cmdLine, principal, uri.spec);
        cmdLine.preventDefault = true;
      }
    } catch (e) {
      console.error(e);
    }

    try {
      while ((uriparam = cmdLine.handleFlagWithParam("new-tab", false))) {
        let { uri, principal } = resolveURIInternal(cmdLine, uriparam);
        handURIToExistingBrowser(
          uri,
          Ci.nsIBrowserDOMWindow.OPEN_NEWTAB,
          cmdLine,
          false,
          principal
        );
        cmdLine.preventDefault = true;
      }
    } catch (e) {
      console.error(e);
    }

    var chromeParam = cmdLine.handleFlagWithParam("chrome", false);
    if (chromeParam) {
      // Handle old preference dialog URLs.
      if (
        chromeParam == "chrome://browser/content/pref/pref.xul" ||
        chromeParam == "chrome://browser/content/preferences/preferences.xul"
      ) {
        openPreferences(cmdLine);
        cmdLine.preventDefault = true;
      } else {
        try {
          let { uri: resolvedURI } = resolveURIInternal(cmdLine, chromeParam);
          let isLocal = uri => {
            let localSchemes = new Set(["chrome", "file", "resource"]);
            if (uri instanceof Ci.nsINestedURI) {
              uri = uri.QueryInterface(Ci.nsINestedURI).innerMostURI;
            }
            return localSchemes.has(uri.scheme);
          };
          if (isLocal(resolvedURI)) {
            // If the URI is local, we are sure it won't wrongly inherit chrome privs
            let features = "chrome,dialog=no,all" + this.getFeatures(cmdLine);
            // Provide 1 null argument, as openWindow has a different behavior
            // when the arg count is 0.
            let argArray = Cc["@mozilla.org/array;1"].createInstance(
              Ci.nsIMutableArray
            );
            argArray.appendElement(null);
            Services.ww.openWindow(
              null,
              resolvedURI.spec,
              "_blank",
              features,
              argArray
            );
            cmdLine.preventDefault = true;
          } else {
            dump("*** Preventing load of web URI as chrome\n");
            dump(
              "    If you're trying to load a webpage, do not pass --chrome.\n"
            );
          }
        } catch (e) {
          console.error(e);
        }
      }
    }
    if (cmdLine.handleFlag("preferences", false)) {
      openPreferences(cmdLine);
      cmdLine.preventDefault = true;
    }
    if (cmdLine.handleFlag("silent", false)) {
      cmdLine.preventDefault = true;
    }

    try {
      var privateWindowParam = cmdLine.handleFlagWithParam(
        "private-window",
        false
      );
      // Check for Firefox private browsing protocol handler here.
      let url = null;
      let urlFlagIdx = cmdLine.findFlag("url", false);
      if (urlFlagIdx > -1 && cmdLine.length > 1) {
        url = cmdLine.getArgument(urlFlagIdx + 1);
      }
      if (privateWindowParam || url?.startsWith("firefox-private:")) {
        // Check if the osint flag is present on Windows
        let launchedWithArg_osint =
          AppConstants.platform == "win" &&
          cmdLine.findFlag("osint", false) == 0;
        let forcePrivate = true;
        let resolvedInfo;
        if (!lazy.PrivateBrowsingUtils.enabled) {
          // Load about:privatebrowsing in a normal tab, which will display an error indicating
          // access to private browsing has been disabled.
          forcePrivate = false;
          resolvedInfo = {
            uri: Services.io.newURI("about:privatebrowsing"),
            principal: lazy.gSystemPrincipal,
          };
        } else if (url?.startsWith("firefox-private:")) {
          cmdLine.removeArguments(urlFlagIdx, urlFlagIdx + 1);
          resolvedInfo = resolveURIInternal(
            cmdLine,
            url,
            launchedWithArg_osint
          );
        } else {
          resolvedInfo = resolveURIInternal(
            cmdLine,
            privateWindowParam,
            launchedWithArg_osint
          );
        }
        handURIToExistingBrowser(
          resolvedInfo.uri,
          Ci.nsIBrowserDOMWindow.OPEN_NEWTAB,
          cmdLine,
          forcePrivate,
          resolvedInfo.principal
        );
        cmdLine.preventDefault = true;
      }
    } catch (e) {
      if (e.result != Cr.NS_ERROR_INVALID_ARG) {
        throw e;
      }
      // NS_ERROR_INVALID_ARG is thrown when flag exists, but has no param.
      if (cmdLine.handleFlag("private-window", false)) {
        openBrowserWindow(
          cmdLine,
          lazy.gSystemPrincipal,
          "about:privatebrowsing",
          null,
          lazy.PrivateBrowsingUtils.enabled
        );
        cmdLine.preventDefault = true;
      }
    }

    var searchParam = cmdLine.handleFlagWithParam("search", false);
    if (searchParam) {
      doSearch(searchParam, cmdLine);
      cmdLine.preventDefault = true;
    }

    // The global PB Service consumes this flag, so only eat it in per-window
    // PB builds.
    if (
      cmdLine.handleFlag("private", false) &&
      lazy.PrivateBrowsingUtils.enabled
    ) {
      lazy.PrivateBrowsingUtils.enterTemporaryAutoStartMode();
      if (cmdLine.state == Ci.nsICommandLine.STATE_INITIAL_LAUNCH) {
        let win = Services.wm.getMostRecentWindow("navigator:blank");
        if (win) {
          win.docShell.QueryInterface(
            Ci.nsILoadContext
          ).usePrivateBrowsing = true;
        }
      }
    }
    if (cmdLine.handleFlag("setDefaultBrowser", false)) {
      // Note that setDefaultBrowser is an async function, but "handle" (the method being executed)
      // is an implementation of an interface method and changing it to be async would be complicated
      // and ultimately nothing here needs the result of setDefaultBrowser, so we do not bother doing
      // an await.
      lazy.ShellService.setDefaultBrowser(true).catch(e => {
        console.error("setDefaultBrowser failed:", e);
      });
    }

    if (cmdLine.handleFlag("first-startup", false)) {
      // We don't want subsequent calls to needHompageOverride to have different
      // values because the milestones in prefs got updated, so we intentionally
      // tell needHomepageOverride to leave the milestone prefs alone when doing
      // this check.
      let override = needHomepageOverride(false /* updateMilestones */);
      if (override == OVERRIDE_NEW_PROFILE) {
        lazy.FirstStartup.init();
      }
    }

    var fileParam = cmdLine.handleFlagWithParam("file", false);
    if (fileParam) {
      var file = cmdLine.resolveFile(fileParam);
      var fileURI = Services.io.newFileURI(file);
      openBrowserWindow(cmdLine, lazy.gSystemPrincipal, fileURI.spec);
      cmdLine.preventDefault = true;
    }

    if (AppConstants.platform == "win") {
      // Handle "? searchterm" for Windows Vista start menu integration
      for (var i = cmdLine.length - 1; i >= 0; --i) {
        var param = cmdLine.getArgument(i);
        if (param.match(/^\? /)) {
          cmdLine.removeArguments(i, i);
          cmdLine.preventDefault = true;

          searchParam = param.substr(2);
          doSearch(searchParam, cmdLine);
        }
      }
    }
  },

  get helpInfo() {
    let info =
      "  --browser          Open a browser window.\n" +
      "  --new-window <url> Open <url> in a new window.\n" +
      "  --new-tab <url>    Open <url> in a new tab.\n" +
      "  --private-window <url> Open <url> in a new private window.\n";
    if (AppConstants.platform == "win") {
      info += "  --preferences      Open Options dialog.\n";
    } else {
      info += "  --preferences      Open Preferences dialog.\n";
    }
    info +=
      "  --screenshot [<path>] Save screenshot to <path> or in working directory.\n";
    info +=
      "  --window-size width[,height] Width and optionally height of screenshot.\n";
    info +=
      "  --search <term>    Search <term> with your default search engine.\n";
    info += "  --setDefaultBrowser Set this app as the default browser.\n";
    info +=
      "  --first-startup    Run post-install actions before opening a new window.\n";
    info += "  --kiosk            Start the browser in kiosk mode.\n";
    info +=
      "  --kiosk-monitor <num> Place kiosk browser window on given monitor.\n";
    info +=
      "  --disable-pinch    Disable touch-screen and touch-pad pinch gestures.\n";
    return info;
  },

  /* nsIBrowserHandler */

  get defaultArgs() {
    return this.getArgs();
  },

  getArgs(isStartup = false) {
    var prefb = Services.prefs;

    if (!gFirstWindow) {
      gFirstWindow = true;
      if (lazy.PrivateBrowsingUtils.isInTemporaryAutoStartMode) {
        return "about:privatebrowsing";
      }
    }

    var override;
    var overridePage = "";
    var additionalPage = "";
    var willRestoreSession = false;
    try {
      // Read the old value of homepage_override.mstone before
      // needHomepageOverride updates it, so that we can later add it to the
      // URL if we do end up showing an overridePage. This makes it possible
      // to have the overridePage's content vary depending on the version we're
      // upgrading from.
      let old_mstone = Services.prefs.getCharPref(
        "browser.startup.homepage_override.mstone",
        "unknown"
      );
      let old_buildId = Services.prefs.getCharPref(
        "browser.startup.homepage_override.buildID",
        "unknown"
      );
      override = needHomepageOverride();
      if (override != OVERRIDE_NONE) {
        switch (override) {
          case OVERRIDE_NEW_PROFILE:
            // New profile.
            gFirstRunProfile = true;
            if (lazy.NimbusFeatures.aboutwelcome.getVariable("showModal")) {
              break;
            }
            overridePage = Services.urlFormatter.formatURLPref(
              "startup.homepage_welcome_url"
            );
            additionalPage = Services.urlFormatter.formatURLPref(
              "startup.homepage_welcome_url.additional"
            );
            // Turn on 'later run' pages for new profiles.
            lazy.LaterRun.enable(lazy.LaterRun.ENABLE_REASON_NEW_PROFILE);
            break;
          case OVERRIDE_NEW_MSTONE:
            // Check whether we will restore a session. If we will, we assume
            // that this is an "update" session. This does not take crashes
            // into account because that requires waiting for the session file
            // to be read. If a crash occurs after updating, before restarting,
            // we may open the startPage in addition to restoring the session.
            willRestoreSession =
              lazy.SessionStartup.isAutomaticRestoreEnabled();

            overridePage = Services.urlFormatter.formatURLPref(
              "startup.homepage_override_url"
            );
            let update = lazy.UpdateManager.readyUpdate;
            if (
              update &&
              Services.vc.compare(update.appVersion, old_mstone) > 0
            ) {
              overridePage = getPostUpdateOverridePage(update, overridePage);
              // Send the update ping to signal that the update was successful.
              lazy.UpdatePing.handleUpdateSuccess(old_mstone, old_buildId);
              lazy.LaterRun.enable(lazy.LaterRun.ENABLE_REASON_UPDATE_APPLIED);
            }

            overridePage = overridePage.replace("%OLD_VERSION%", old_mstone);
            break;
          case OVERRIDE_NEW_BUILD_ID:
            if (lazy.UpdateManager.readyUpdate) {
              // Send the update ping to signal that the update was successful.
              lazy.UpdatePing.handleUpdateSuccess(old_mstone, old_buildId);
              lazy.LaterRun.enable(lazy.LaterRun.ENABLE_REASON_UPDATE_APPLIED);
            }
            break;
        }
      }
    } catch (ex) {}

    // formatURLPref might return "about:blank" if getting the pref fails
    if (overridePage == "about:blank") {
      overridePage = "";
    }

    // Allow showing a one-time startup override if we're not showing one
    if (isStartup && overridePage == "" && prefb.prefHasUserValue(ONCE_PREF)) {
      try {
        // Show if we haven't passed the expiration or there's no expiration
        const { expire, url } = JSON.parse(
          Services.urlFormatter.formatURLPref(ONCE_PREF)
        );
        if (!(Date.now() > expire)) {
          // Only set allowed urls as override pages
          overridePage = url
            .split("|")
            .map(val => {
              try {
                return new URL(val);
              } catch (ex) {
                // Invalid URL, so filter out below
                console.error("Invalid once url:", ex);
                return null;
              }
            })
            .filter(
              parsed =>
                parsed &&
                parsed.protocol == "https:" &&
                // Only accept exact hostname or subdomain; without port
                ONCE_DOMAINS.includes(
                  Services.eTLD.getBaseDomainFromHost(parsed.host)
                )
            )
            .join("|");

          // Be noisy as properly configured urls should be unchanged
          if (overridePage != url) {
            console.error(`Mismatched once urls: ${url}`);
          }
        }
      } catch (ex) {
        // Invalid json pref, so ignore (and clear below)
        console.error("Invalid once pref:", ex);
      } finally {
        prefb.clearUserPref(ONCE_PREF);
      }
    }

    if (!additionalPage) {
      additionalPage = lazy.LaterRun.getURL() || "";
    }

    if (additionalPage && additionalPage != "about:blank") {
      if (overridePage) {
        overridePage += "|" + additionalPage;
      } else {
        overridePage = additionalPage;
      }
    }

    var startPage = "";
    try {
      var choice = prefb.getIntPref("browser.startup.page");
      if (choice == 1 || choice == 3) {
        startPage = lazy.HomePage.get();
      }
    } catch (e) {
      console.error(e);
    }

    if (startPage == "about:blank") {
      startPage = "";
    }

    let skipStartPage =
      override == OVERRIDE_NEW_PROFILE &&
      prefb.getBoolPref("browser.startup.firstrunSkipsHomepage");
    // Only show the startPage if we're not restoring an update session and are
    // not set to skip the start page on this profile
    if (overridePage && startPage && !willRestoreSession && !skipStartPage) {
      return overridePage + "|" + startPage;
    }

    return overridePage || startPage || "about:blank";
  },

  mFeatures: null,

  getFeatures: function bch_features(cmdLine) {
    if (this.mFeatures === null) {
      this.mFeatures = "";

      if (cmdLine) {
        try {
          var width = cmdLine.handleFlagWithParam("width", false);
          var height = cmdLine.handleFlagWithParam("height", false);
          var left = cmdLine.handleFlagWithParam("left", false);
          var top = cmdLine.handleFlagWithParam("top", false);

          if (width) {
            this.mFeatures += ",width=" + width;
          }
          if (height) {
            this.mFeatures += ",height=" + height;
          }
          if (left) {
            this.mFeatures += ",left=" + left;
          }
          if (top) {
            this.mFeatures += ",top=" + top;
          }
        } catch (e) {}
      }

      // The global PB Service consumes this flag, so only eat it in per-window
      // PB builds.
      if (lazy.PrivateBrowsingUtils.isInTemporaryAutoStartMode) {
        this.mFeatures += ",private";
      }

      if (
        Services.prefs.getBoolPref("browser.suppress_first_window_animation") &&
        !Services.wm.getMostRecentWindow("navigator:browser")
      ) {
        this.mFeatures += ",suppressanimation";
      }
    }

    return this.mFeatures;
  },

  get kiosk() {
    return gKiosk;
  },

  get majorUpgrade() {
    return gMajorUpgrade;
  },

  set majorUpgrade(val) {
    gMajorUpgrade = val;
  },

  get firstRunProfile() {
    return gFirstRunProfile;
  },

  set firstRunProfile(val) {
    gFirstRunProfile = val;
  },

  /* nsIContentHandler */

  handleContent: function bch_handleContent(contentType, context, request) {
    const NS_ERROR_WONT_HANDLE_CONTENT = 0x805d0001;

    try {
      var webNavInfo = Cc["@mozilla.org/webnavigation-info;1"].getService(
        Ci.nsIWebNavigationInfo
      );
      if (!webNavInfo.isTypeSupported(contentType)) {
        throw NS_ERROR_WONT_HANDLE_CONTENT;
      }
    } catch (e) {
      throw NS_ERROR_WONT_HANDLE_CONTENT;
    }

    request.QueryInterface(Ci.nsIChannel);
    handURIToExistingBrowser(
      request.URI,
      Ci.nsIBrowserDOMWindow.OPEN_DEFAULTWINDOW,
      null,
      false,
      request.loadInfo.triggeringPrincipal
    );
    request.cancel(Cr.NS_BINDING_ABORTED);
  },

  /* nsICommandLineValidator */
  validate: function bch_validate(cmdLine) {
    var urlFlagIdx = cmdLine.findFlag("url", false);
    if (
      urlFlagIdx > -1 &&
      cmdLine.state == Ci.nsICommandLine.STATE_REMOTE_EXPLICIT
    ) {
      var urlParam = cmdLine.getArgument(urlFlagIdx + 1);
      if (
        cmdLine.length != urlFlagIdx + 2 ||
        /firefoxurl(-[a-f0-9]+)?:/i.test(urlParam)
      ) {
        throw Components.Exception("", Cr.NS_ERROR_ABORT);
      }
    }
  },
};
var gBrowserContentHandler = new nsBrowserContentHandler();

function handURIToExistingBrowser(
  uri,
  location,
  cmdLine,
  forcePrivate,
  triggeringPrincipal
) {
  if (!shouldLoadURI(uri)) {
    return;
  }

  let openInWindow = ({ browserDOMWindow }) => {
    browserDOMWindow.openURI(
      uri,
      null,
      location,
      Ci.nsIBrowserDOMWindow.OPEN_EXTERNAL,
      triggeringPrincipal
    );
  };

  // Unless using a private window is forced, open external links in private
  // windows only if we're in perma-private mode.
  let allowPrivate =
    forcePrivate || lazy.PrivateBrowsingUtils.permanentPrivateBrowsing;
  let navWin = lazy.BrowserWindowTracker.getTopWindow({
    private: allowPrivate,
  });

  if (navWin) {
    openInWindow(navWin);
    return;
  }

  let pending = lazy.BrowserWindowTracker.getPendingWindow({
    private: allowPrivate,
  });
  if (pending) {
    // Note that we cannot make this function async as some callers rely on
    // catching exceptions it can throw in some cases and some of those callers
    // cannot be made async.
    pending.then(openInWindow);
    return;
  }

  // if we couldn't load it in an existing window, open a new one
  openBrowserWindow(cmdLine, triggeringPrincipal, uri.spec, null, forcePrivate);
}

/**
 * If given URI is a file type or a protocol, record telemetry that
 * Firefox was invoked or launched (if `isLaunch` is truth-y).  If the
 * file type or protocol is not registered by default, record it as
 * ".<other extension>" or "<other protocol>".
 *
 * @param uri
 *        The URI Firefox was asked to handle.
 * @param isLaunch
 *        truth-y if Firefox was launched/started rather than running and invoked.
 */
function maybeRecordToHandleTelemetry(uri, isLaunch) {
  let scalar = isLaunch
    ? "os.environment.launched_to_handle"
    : "os.environment.invoked_to_handle";

  if (uri instanceof Ci.nsIFileURL) {
    let extension = "." + uri.fileExtension.toLowerCase();
    // Keep synchronized with https://searchfox.org/mozilla-central/source/browser/installer/windows/nsis/shared.nsh
    // and https://searchfox.org/mozilla-central/source/browser/installer/windows/msix/AppxManifest.xml.in.
    let registeredExtensions = new Set([
      ".avif",
      ".htm",
      ".html",
      ".pdf",
      ".shtml",
      ".xht",
      ".xhtml",
      ".svg",
      ".webp",
    ]);
    if (registeredExtensions.has(extension)) {
      Services.telemetry.keyedScalarAdd(scalar, extension, 1);
    } else {
      Services.telemetry.keyedScalarAdd(scalar, ".<other extension>", 1);
    }
  } else if (uri) {
    let scheme = uri.scheme.toLowerCase();
    let registeredSchemes = new Set(["about", "http", "https", "mailto"]);
    if (registeredSchemes.has(scheme)) {
      Services.telemetry.keyedScalarAdd(scalar, scheme, 1);
    } else {
      Services.telemetry.keyedScalarAdd(scalar, "<other protocol>", 1);
    }
  }
}

export function nsDefaultCommandLineHandler() {}

nsDefaultCommandLineHandler.prototype = {
  /* nsISupports */
  QueryInterface: ChromeUtils.generateQI(["nsICommandLineHandler"]),

  _haveProfile: false,

  /* nsICommandLineHandler */
  handle: function dch_handle(cmdLine) {
    var urilist = [];
    var principalList = [];

    if (AppConstants.platform == "win") {
      // Windows itself does disk I/O when the notification service is
      // initialized, so make sure that is lazy.
      while (true) {
        let tag = cmdLine.handleFlagWithParam("notification-windowsTag", false);
        if (!tag) {
          break;
        }

        // All notifications will invoke Firefox with an action.  Prior to Bug 1805514,
        // this data was extracted from the Windows toast object directly (keyed by the
        // notification ID) and not passed over the command line.  This is acceptable
        // because the data passed is chrome-controlled, but if we implement the `actions`
        // part of the DOM Web Notifications API, this will no longer be true:
        // content-controlled data might transit over the command line.  This could lead
        // to escaping bugs and overflows.  In the future, we intend to avoid any such
        // issue by once again extracting all such data from the Windows toast object.
        let notificationData = cmdLine.handleFlagWithParam(
          "notification-windowsAction",
          false
        );
        if (!notificationData) {
          break;
        }

        let alertService = lazy.gWindowsAlertsService;
        if (!alertService) {
          console.error("Windows alert service not available.");
          break;
        }

        async function handleNotification() {
          let { tagWasHandled } = await alertService.handleWindowsTag(tag);

          // If the tag was not handled via callback, then the notification was
          // from a prior instance of the application and we need to handle
          // fallback behavior.
          if (!tagWasHandled) {
            console.info(
              `Completing Windows notification (tag=${JSON.stringify(
                tag
              )}, notificationData=${notificationData})`
            );
            try {
              notificationData = JSON.parse(notificationData);
            } catch (e) {
              console.error(
                `Completing Windows notification (tag=${JSON.stringify(
                  tag
                )}, failed to parse (notificationData=${notificationData})`
              );
            }
          }

          // This is awkward: the relaunch data set by the caller is _wrapped_
          // into a compound object that includes additional notification data,
          // and everything is exchanged as strings.  Unwrap and parse here.
          let opaqueRelaunchData = null;
          if (notificationData?.opaqueRelaunchData) {
            try {
              opaqueRelaunchData = JSON.parse(
                notificationData.opaqueRelaunchData
              );
            } catch (e) {
              console.error(
                `Completing Windows notification (tag=${JSON.stringify(
                  tag
                )}, failed to parse (opaqueRelaunchData=${
                  notificationData.opaqueRelaunchData
                })`
              );
            }
          }

          if (notificationData?.privilegedName) {
            Services.telemetry.setEventRecordingEnabled(
              "browser.launched_to_handle",
              true
            );
            Glean.browserLaunchedToHandle.systemNotification.record({
              name: notificationData.privilegedName,
            });
          }

          // If we have an action in the notification data, this will be the
          // window to perform the action in.
          let winForAction;

          if (notificationData?.launchUrl && !opaqueRelaunchData) {
            // Unprivileged Web Notifications contain a launch URL and are handled
            // slightly differently than privileged notifications with actions.
            let { uri, principal } = resolveURIInternal(
              cmdLine,
              notificationData.launchUrl
            );
            if (cmdLine.state != Ci.nsICommandLine.STATE_INITIAL_LAUNCH) {
              // Try to find an existing window and load our URI into the current
              // tab, new tab, or new window as prefs determine.
              try {
                handURIToExistingBrowser(
                  uri,
                  Ci.nsIBrowserDOMWindow.OPEN_DEFAULTWINDOW,
                  cmdLine,
                  false,
                  principal
                );
                return;
              } catch (e) {}
            }

            if (shouldLoadURI(uri)) {
              openBrowserWindow(cmdLine, principal, [uri.spec]);
            }
          } else if (cmdLine.state == Ci.nsICommandLine.STATE_INITIAL_LAUNCH) {
            // No URL provided, but notification was interacted with while the
            // application was closed. Fall back to opening the browser without url.
            winForAction = openBrowserWindow(cmdLine, lazy.gSystemPrincipal);
            await new Promise(resolve => {
              Services.obs.addObserver(function observe(subject) {
                if (subject == winForAction) {
                  Services.obs.removeObserver(
                    observe,
                    "browser-delayed-startup-finished"
                  );
                  resolve();
                }
              }, "browser-delayed-startup-finished");
            });
          } else {
            // Relaunch in private windows only if we're in perma-private mode.
            let allowPrivate =
              lazy.PrivateBrowsingUtils.permanentPrivateBrowsing;
            winForAction = lazy.BrowserWindowTracker.getTopWindow({
              private: allowPrivate,
            });
          }

          if (opaqueRelaunchData && winForAction) {
            // Without dispatch, `OPEN_URL` with `where: "tab"` does not work on relaunch.
            Services.tm.dispatchToMainThread(() => {
              lazy.SpecialMessageActions.handleAction(
                opaqueRelaunchData,
                winForAction.gBrowser
              );
            });
          }
        }

        // Notification handling occurs asynchronously to prevent blocking the
        // main thread. As a result we won't have the information we need to open
        // a new tab in the case of notification fallback handling before
        // returning. We call `enterLastWindowClosingSurvivalArea` to prevent
        // the browser from exiting in case early blank window is pref'd off.
        if (cmdLine.state == Ci.nsICommandLine.STATE_INITIAL_LAUNCH) {
          Services.startup.enterLastWindowClosingSurvivalArea();
        }
        handleNotification()
          .catch(e => {
            console.error(
              `Error handling Windows notification with tag '${tag}':`,
              e
            );
          })
          .finally(() => {
            if (cmdLine.state == Ci.nsICommandLine.STATE_INITIAL_LAUNCH) {
              Services.startup.exitLastWindowClosingSurvivalArea();
            }
          });

        return;
      }
    }

    if (
      cmdLine.state == Ci.nsICommandLine.STATE_INITIAL_LAUNCH &&
      Services.startup.wasSilentlyStarted
    ) {
      // If we are starting up in silent mode, don't open a window. We also need
      // to make sure that the application doesn't immediately exit, so stay in
      // a LastWindowClosingSurvivalArea until a window opens.
      Services.startup.enterLastWindowClosingSurvivalArea();
      Services.obs.addObserver(function windowOpenObserver() {
        Services.startup.exitLastWindowClosingSurvivalArea();
        Services.obs.removeObserver(windowOpenObserver, "domwindowopened");
      }, "domwindowopened");
      return;
    }

    if (AppConstants.platform == "win" || AppConstants.platform == "macosx") {
      // Handle the case where we don't have a profile selected yet (e.g. the
      // Profile Manager is displayed).
      // On Windows, we will crash if we open an url and then select a profile.
      // On macOS, if we open an url we don't experience a crash but a broken
      // window is opened.
      // To prevent this handle all url command line flags and set the
      // command line's preventDefault to true to prevent the display of the ui.
      // The initial command line will be retained when nsAppRunner calls
      // LaunchChild though urls launched after the initial launch will be lost.
      if (!this._haveProfile) {
        try {
          // This will throw when a profile has not been selected.
          Services.dirsvc.get("ProfD", Ci.nsIFile);
          this._haveProfile = true;
        } catch (e) {
          // eslint-disable-next-line no-empty
          while ((ar = cmdLine.handleFlagWithParam("url", false))) {}
          cmdLine.preventDefault = true;
        }
      }
    }

    // `-osint` and handling registered file types and protocols is Windows-only.
    let launchedWithArg_osint =
      AppConstants.platform == "win" && cmdLine.findFlag("osint", false) == 0;
    if (launchedWithArg_osint) {
      cmdLine.handleFlag("osint", false);
    }

    try {
      var ar;
      while ((ar = cmdLine.handleFlagWithParam("url", false))) {
        let { uri, principal } = resolveURIInternal(
          cmdLine,
          ar,
          launchedWithArg_osint
        );
        urilist.push(uri);
        principalList.push(principal);

        if (launchedWithArg_osint) {
          launchedWithArg_osint = false;

          // We use the resolved URI here, even though it can produce
          // surprising results where-by `-osint -url test.pdf` resolves to
          // a query with search parameter "test.pdf".  But that shouldn't
          // happen when Firefox is launched by Windows itself: files should
          // exist and be resolved to file URLs.
          const isLaunch =
            cmdLine && cmdLine.state == Ci.nsICommandLine.STATE_INITIAL_LAUNCH;

          maybeRecordToHandleTelemetry(uri, isLaunch);
        }
      }
    } catch (e) {
      console.error(e);
    }

    if (
      AppConstants.platform == "win" &&
      cmdLine.handleFlag("to-handle-default-browser-agent", false)
    ) {
      // The Default Browser Agent launches Firefox in response to a Windows
      // native notification, but it does so in a non-standard manner.
      Services.telemetry.setEventRecordingEnabled(
        "browser.launched_to_handle",
        true
      );
      Glean.browserLaunchedToHandle.systemNotification.record({
        name: "default-browser-agent",
      });

      let thanksURI = Services.io.newURI(
        Services.urlFormatter.formatURLPref(
          "browser.shell.defaultBrowserAgent.thanksURL"
        )
      );
      urilist.push(thanksURI);
      principalList.push(lazy.gSystemPrincipal);
    }

    if (cmdLine.findFlag("screenshot", true) != -1) {
      // Shouldn't have to push principal here with the screenshot flag
      lazy.HeadlessShell.handleCmdLineArgs(
        cmdLine,
        urilist.filter(shouldLoadURI).map(u => u.spec)
      );
      return;
    }

    for (let i = 0; i < cmdLine.length; ++i) {
      var curarg = cmdLine.getArgument(i);
      if (curarg.match(/^-/)) {
        console.error("Warning: unrecognized command line flag", curarg);
        // To emulate the pre-nsICommandLine behavior, we ignore
        // the argument after an unrecognized flag.
        ++i;
      } else {
        try {
          let { uri, principal } = resolveURIInternal(cmdLine, curarg);
          urilist.push(uri);
          principalList.push(principal);
        } catch (e) {
          console.error(
            `Error opening URI ${curarg} from the command line:`,
            e
          );
        }
      }
    }

    if (urilist.length) {
      if (
        cmdLine.state != Ci.nsICommandLine.STATE_INITIAL_LAUNCH &&
        urilist.length == 1
      ) {
        // Try to find an existing window and load our URI into the
        // current tab, new tab, or new window as prefs determine.
        try {
          handURIToExistingBrowser(
            urilist[0],
            Ci.nsIBrowserDOMWindow.OPEN_DEFAULTWINDOW,
            cmdLine,
            false,
            principalList[0] ?? lazy.gSystemPrincipal
          );
          return;
        } catch (e) {}
      }

      // Can't open multiple URLs without using system principal.
      // The firefox and firefox-private protocols should only
      // accept a single URL due to using the -osint option
      // so this isn't very relevant.
      var URLlist = urilist.filter(shouldLoadURI).map(u => u.spec);
      if (URLlist.length) {
        openBrowserWindow(cmdLine, lazy.gSystemPrincipal, URLlist);
      }
    } else if (!cmdLine.preventDefault) {
      if (
        AppConstants.platform == "win" &&
        cmdLine.state != Ci.nsICommandLine.STATE_INITIAL_LAUNCH &&
        lazy.WindowsUIUtils.inTabletMode
      ) {
        // In windows 10 tablet mode, do not create a new window, but reuse the existing one.
        let win = lazy.BrowserWindowTracker.getTopWindow();
        if (win) {
          win.focus();
          return;
        }
      }
      openBrowserWindow(cmdLine, lazy.gSystemPrincipal);
    } else {
      // Need a better solution in the future to avoid opening the blank window
      // when command line parameters say we are not going to show a browser
      // window, but for now the blank window getting closed quickly (and
      // causing only a slight flicker) is better than leaving it open.
      let win = Services.wm.getMostRecentWindow("navigator:blank");
      if (win) {
        win.close();
      }
    }
  },

  helpInfo: "",
};