/* 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";

var EXPORTED_SYMBOLS = ["ShellService"];

const { AppConstants } = ChromeUtils.import(
  "resource://gre/modules/AppConstants.jsm"
);
const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
const { XPCOMUtils } = ChromeUtils.import(
  "resource://gre/modules/XPCOMUtils.jsm"
);
ChromeUtils.defineModuleGetter(
  this,
  "WindowsRegistry",
  "resource://gre/modules/WindowsRegistry.jsm"
);

XPCOMUtils.defineLazyModuleGetters(this, {
  Subprocess: "resource://gre/modules/Subprocess.jsm",
  setTimeout: "resource://gre/modules/Timer.jsm",
});

XPCOMUtils.defineLazyServiceGetter(
  this,
  "XreDirProvider",
  "@mozilla.org/xre/directory-provider;1",
  "nsIXREDirProvider"
);

/**
 * Internal functionality to save and restore the docShell.allow* properties.
 */
let ShellServiceInternal = {
  /**
   * Used to determine whether or not to offer "Set as desktop background"
   * functionality. Even if shell service is available it is not
   * guaranteed that it is able to set the background for every desktop
   * which is especially true for Linux with its many different desktop
   * environments.
   */
  get canSetDesktopBackground() {
    if (AppConstants.platform == "win" || AppConstants.platform == "macosx") {
      return true;
    }

    if (AppConstants.platform == "linux") {
      if (this.shellService) {
        let linuxShellService = this.shellService.QueryInterface(
          Ci.nsIGNOMEShellService
        );
        return linuxShellService.canSetDesktopBackground;
      }
    }

    return false;
  },

  isDefaultBrowserOptOut() {
    if (AppConstants.platform == "win") {
      let optOutValue = WindowsRegistry.readRegKey(
        Ci.nsIWindowsRegKey.ROOT_KEY_CURRENT_USER,
        "Software\\Mozilla\\Firefox",
        "DefaultBrowserOptOut"
      );
      WindowsRegistry.removeRegKey(
        Ci.nsIWindowsRegKey.ROOT_KEY_CURRENT_USER,
        "Software\\Mozilla\\Firefox",
        "DefaultBrowserOptOut"
      );
      if (optOutValue == "True") {
        Services.prefs.setBoolPref("browser.shell.checkDefaultBrowser", false);
        return true;
      }
    }
    return false;
  },

  /**
   * Used to determine whether or not to show a "Set Default Browser"
   * query dialog. This attribute is true if the application is starting
   * up and "browser.shell.checkDefaultBrowser" is true, otherwise it
   * is false.
   */
  _checkedThisSession: false,
  get shouldCheckDefaultBrowser() {
    // If we've already checked, the browser has been started and this is a
    // new window open, and we don't want to check again.
    if (this._checkedThisSession) {
      return false;
    }

    if (!Services.prefs.getBoolPref("browser.shell.checkDefaultBrowser")) {
      return false;
    }

    if (this.isDefaultBrowserOptOut()) {
      return false;
    }

    return true;
  },

  set shouldCheckDefaultBrowser(shouldCheck) {
    Services.prefs.setBoolPref(
      "browser.shell.checkDefaultBrowser",
      !!shouldCheck
    );
  },

  isDefaultBrowser(startupCheck, forAllTypes) {
    // If this is the first browser window, maintain internal state that we've
    // checked this session (so that subsequent window opens don't show the
    // default browser dialog).
    if (startupCheck) {
      this._checkedThisSession = true;
    }
    if (this.shellService) {
      return this.shellService.isDefaultBrowser(forAllTypes);
    }
    return false;
  },

  /*
   * Set the default browser through the UserChoice registry keys on Windows.
   *
   * NOTE: This does NOT open the System Settings app for manual selection
   * in case of failure. If that is desired, catch the exception and call
   * setDefaultBrowser().
   *
   * @return Promise, resolves when successful, rejects with Error on failure.
   */
  async setAsDefaultUserChoice() {
    if (AppConstants.platform != "win") {
      throw new Error("Windows-only");
    }

    // We launch the WDBA to handle the registry writes, see
    // SetDefaultBrowserUserChoice() in
    // toolkit/mozapps/defaultagent/SetDefaultBrowser.cpp.
    // This is external in case an overzealous antimalware product decides to
    // quarrantine any program that writes UserChoice, though this has not
    // occurred during extensive testing.

    if (!ShellService.checkAllProgIDsExist()) {
      throw new Error("checkAllProgIDsExist() failed");
    }

    if (!ShellService.checkBrowserUserChoiceHashes()) {
      throw new Error("checkBrowserUserChoiceHashes() failed");
    }

    const wdba = Services.dirsvc.get("XREExeF", Ci.nsIFile);
    wdba.leafName = "default-browser-agent.exe";
    const aumi = XreDirProvider.getInstallHash();

    const exeProcess = await Subprocess.call({
      command: wdba.path,
      arguments: ["set-default-browser-user-choice", aumi],
    });

    // exit codes
    const S_OK = 0;
    const STILL_ACTIVE = 0x103;

    const exeWaitTimeoutMs = 2000; // 2 seconds
    const exeWaitPromise = exeProcess.wait();
    const timeoutPromise = new Promise(function(resolve, reject) {
      setTimeout(() => resolve({ exitCode: STILL_ACTIVE }), exeWaitTimeoutMs);
    });
    const { exitCode } = await Promise.race([exeWaitPromise, timeoutPromise]);

    if (exitCode != S_OK) {
      throw new Error(`WDBA nonzero exit code ${exitCode}`);
    }
  },

  // override nsIShellService.setDefaultBrowser() on the ShellService proxy.
  setDefaultBrowser(claimAllTypes, forAllUsers) {
    // On Windows 10, our best chance is to set UserChoice, so try that first.
    if (
      AppConstants.platform == "win" &&
      Services.prefs.getBoolPref(
        "browser.shell.setDefaultBrowserUserChoice",
        false
      ) &&
      Services.sysinfo.getProperty("version") == "10.0"
    ) {
      // nsWindowsShellService::SetDefaultBrowser() kicks off several
      // operations, but doesn't wait for their result. So we don't need to
      // await the result of setAsDefaultUserChoice() here, either, we just need
      // to fall back in case it fails.
      this.setAsDefaultUserChoice().catch(err => {
        Cu.reportError(err);
        this.shellService.setDefaultBrowser(claimAllTypes, forAllUsers);
      });
      return;
    }

    this.shellService.setDefaultBrowser(claimAllTypes, forAllUsers);
  },

  setAsDefault() {
    let claimAllTypes = true;
    let setAsDefaultError = false;
    if (AppConstants.platform == "win") {
      try {
        // In Windows 8+, the UI for selecting default protocol is much
        // nicer than the UI for setting file type associations. So we
        // only show the protocol association screen on Windows 8+.
        // Windows 8 is version 6.2.
        let version = Services.sysinfo.getProperty("version");
        claimAllTypes = parseFloat(version) < 6.2;
      } catch (ex) {}
    }
    try {
      ShellService.setDefaultBrowser(claimAllTypes, false);
    } catch (ex) {
      setAsDefaultError = true;
      Cu.reportError(ex);
    }
    // Here BROWSER_IS_USER_DEFAULT and BROWSER_SET_USER_DEFAULT_ERROR appear
    // to be inverse of each other, but that is only because this function is
    // called when the browser is set as the default. During startup we record
    // the BROWSER_IS_USER_DEFAULT value without recording BROWSER_SET_USER_DEFAULT_ERROR.
    Services.telemetry
      .getHistogramById("BROWSER_IS_USER_DEFAULT")
      .add(!setAsDefaultError);
    Services.telemetry
      .getHistogramById("BROWSER_SET_DEFAULT_ERROR")
      .add(setAsDefaultError);
  },

  async doesAppNeedPin() {
    // Currently this only works on certain Windows versions.
    try {
      // First check if we can even pin the app where an exception means no.
      this.shellService
        .QueryInterface(Ci.nsIWindowsShellService)
        .checkPinCurrentAppToTaskbar();

      // Then check if we're already pinned.
      return !(await this.shellService.isCurrentAppPinnedToTaskbarAsync());
    } catch (ex) {
      return false;
    }
  },

  async pinToTaskbar() {
    if (await this.doesAppNeedPin()) {
      try {
        this.shellService.pinCurrentAppToTaskbar();
      } catch (ex) {
        Cu.reportError(ex);
      }
    }
  },
};

XPCOMUtils.defineLazyServiceGetter(
  ShellServiceInternal,
  "shellService",
  "@mozilla.org/browser/shell-service;1",
  Ci.nsIShellService
);

/**
 * The external API exported by this module.
 */
var ShellService = new Proxy(ShellServiceInternal, {
  get(target, name) {
    if (name in target) {
      return target[name];
    }
    if (target.shellService) {
      return target.shellService[name];
    }
    Services.console.logStringMessage(
      `${name} not found in ShellService: ${target.shellService}`
    );
    return undefined;
  },
});