/* 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";
/* global frame */

const {WebElementEventTarget} = ChromeUtils.import("chrome://marionette/content/dom.js", {});
ChromeUtils.import("chrome://marionette/content/element.js");
const {
  NoSuchWindowError,
  UnsupportedOperationError,
} = ChromeUtils.import("chrome://marionette/content/error.js", {});
const {
  MessageManagerDestroyedPromise,
} = ChromeUtils.import("chrome://marionette/content/sync.js", {});

this.EXPORTED_SYMBOLS = ["browser", "Context", "WindowState"];

/** @namespace */
this.browser = {};

const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";

/**
 * Variations of Marionette contexts.
 *
 * Choosing a context through the <tt>Marionette:SetContext</tt>
 * command directs all subsequent browsing context scoped commands
 * to that context.
 */
class Context {
  /**
   * Gets the correct context from a string.
   *
   * @param {string} s
   *     Context string serialisation.
   *
   * @return {Context}
   *     Context.
   *
   * @throws {TypeError}
   *     If <var>s</var> is not a context.
   */
  static fromString(s) {
    switch (s) {
      case "chrome":
        return Context.Chrome;

      case "content":
        return Context.Content;

      default:
        throw new TypeError(`Unknown context: ${s}`);
    }
  }
}
Context.Chrome = "chrome";
Context.Content = "content";
this.Context = Context;

/**
 * Get the <code>&lt;xul:browser&gt;</code> for the specified tab.
 *
 * @param {Tab} tab
 *     The tab whose browser needs to be returned.
 *
 * @return {Browser}
 *     The linked browser for the tab or null if no browser can be found.
 */
browser.getBrowserForTab = function(tab) {
  // Fennec
  if ("browser" in tab) {
    return tab.browser;

  // Firefox
  } else if ("linkedBrowser" in tab) {
    return tab.linkedBrowser;
  }

  return null;
};

/**
 * Return the tab browser for the specified chrome window.
 *
 * @param {ChromeWindow} win
 *     Window whose <code>tabbrowser</code> needs to be accessed.
 *
 * @return {Tab}
 *     Tab browser or null if it's not a browser window.
 */
browser.getTabBrowser = function(window) {
  // Fennec
  if ("BrowserApp" in window) {
    return window.BrowserApp;

  // Firefox
  } else if ("gBrowser" in window) {
    return window.gBrowser;

  // Thunderbird
  } else if (window.document.getElementById("tabmail")) {
    return window.document.getElementById("tabmail");
  }

  return null;
};

/**
 * Creates a browsing context wrapper.
 *
 * Browsing contexts handle interactions with the browser, according to
 * the current environment (Firefox, Fennec).
 */
browser.Context = class {

  /**
   * @param {ChromeWindow} win
   *     ChromeWindow that contains the top-level browsing context.
   * @param {GeckoDriver} driver
   *     Reference to driver instance.
   */
  constructor(window, driver) {
    this.window = window;
    this.driver = driver;

    // In Firefox this is <xul:tabbrowser> (not <xul:browser>!)
    // and BrowserApp in Fennec
    this.tabBrowser = browser.getTabBrowser(this.window);

    this.knownFrames = [];

    // Used to set curFrameId upon new session
    this.newSession = true;

    this.seenEls = new element.Store();

    // A reference to the tab corresponding to the current window handle,
    // if any.  Specifically, this.tab refers to the last tab that Marionette
    // switched to in this browser window. Note that this may not equal the
    // currently selected tab.  For example, if Marionette switches to tab
    // A, and then clicks on a button that opens a new tab B in the same
    // browser window, this.tab will still point to tab A, despite tab B
    // being the currently selected tab.
    this.tab = null;

    // Commands which trigger a navigation can cause the frame script to be
    // moved to a different process. To not loose the currently active
    // command, or any other already pushed following command, store them as
    // long as they haven't been fully processed. The commands get flushed
    // after a new browser has been registered.
    this.pendingCommands = [];
    this._needsFlushPendingCommands = false;

    this.frameRegsPending = 0;

    this.getIdForBrowser = driver.getIdForBrowser.bind(driver);
    this.updateIdForBrowser = driver.updateIdForBrowser.bind(driver);
  }

  /**
   * Returns the content browser for the currently selected tab.
   * If there is no tab selected, null will be returned.
   */
  get contentBrowser() {
    if (this.tab) {
      return browser.getBrowserForTab(this.tab);
    } else if (this.tabBrowser &&
        this.driver.isReftestBrowser(this.tabBrowser)) {
      return this.tabBrowser;
    }

    return null;
  }

  get messageManager() {
    if (this.contentBrowser) {
      return this.contentBrowser.messageManager;
    }

    return null;
  }

  /**
   * Checks if the browsing context has been discarded.
   *
   * The browsing context will have been discarded if the content
   * browser, represented by the <code>&lt;xul:browser&gt;</code>,
   * has been detached.
   *
   * @return {boolean}
   *     True if browsing context has been discarded, false otherwise.
   */
  get closed() {
    return this.contentBrowser === null;
  }

  /**
   * The current frame ID is managed per browser element on desktop in
   * case the ID needs to be refreshed. The currently selected window is
   * identified by a tab.
   */
  get curFrameId() {
    let rv = null;
    if (this.tab || this.driver.isReftestBrowser(this.contentBrowser)) {
      rv = this.getIdForBrowser(this.contentBrowser);
    }
    return rv;
  }

  /**
   * Returns the current title of the content browser.
   *
   * @return {string}
   *     Read-only property containing the current title.
   *
   * @throws {NoSuchWindowError}
   *     If the current ChromeWindow does not have a content browser.
   */
  get currentTitle() {
    // Bug 1363368 - contentBrowser could be null until we wait for its
    // initialization been finished
    if (this.contentBrowser) {
      return this.contentBrowser.contentTitle;
    }
    throw new NoSuchWindowError(
        "Current window does not have a content browser");
  }

  /**
   * Returns the current URI of the content browser.
   *
   * @return {nsIURI}
   *     Read-only property containing the currently loaded URL.
   *
   * @throws {NoSuchWindowError}
   *     If the current ChromeWindow does not have a content browser.
   */
  get currentURI() {
    // Bug 1363368 - contentBrowser could be null until we wait for its
    // initialization been finished
    if (this.contentBrowser) {
      return this.contentBrowser.currentURI;
    }
    throw new NoSuchWindowError(
        "Current window does not have a content browser");
  }

  /**
   * Gets the position and dimensions of the top-level browsing context.
   *
   * @return {Map.<string, number>}
   *     Object with |x|, |y|, |width|, and |height| properties.
   */
  get rect() {
    return {
      x: this.window.screenX,
      y: this.window.screenY,
      width: this.window.outerWidth,
      height: this.window.outerHeight,
    };
  }

  /**
   * Retrieves the current tabmodal UI object.  According to the browser
   * associated with the currently selected tab.
   */
  getTabModalUI() {
    let br = this.contentBrowser;
    if (!br.hasAttribute("tabmodalPromptShowing")) {
      return null;
    }

    // The modal is a direct sibling of the browser element.
    // See tabbrowser.xml's getTabModalPromptBox.
    let modalElements = br.parentNode.getElementsByTagNameNS(
        XUL_NS, "tabmodalprompt");

    return br.tabModalPromptBox.prompts.get(modalElements[0]).ui;
  }

  /**
   * Close the current window.
   *
   * @return {Promise}
   *     A promise which is resolved when the current window has been closed.
   */
  closeWindow() {
    return new Promise(resolve => {
      // Wait for the window message manager to be destroyed
      let destroyed = new MessageManagerDestroyedPromise(
          this.window.messageManager);

      this.window.addEventListener("unload", async () => {
        await destroyed;
        resolve();
      }, {once: true});
      this.window.close();
    });
  }

  /**
   * Close the current tab.
   *
   * @return {Promise}
   *     A promise which is resolved when the current tab has been closed.
   *
   * @throws UnsupportedOperationError
   *     If tab handling for the current application isn't supported.
   */
  closeTab() {
    // If the current window is not a browser then close it directly. Do the
    // same if only one remaining tab is open, or no tab selected at all.
    if (!this.tabBrowser ||
        !this.tabBrowser.tabs ||
        this.tabBrowser.tabs.length === 1 ||
        !this.tab) {
      return this.closeWindow();
    }

    return new Promise((resolve, reject) => {
      // Wait for the browser message manager to be destroyed
      let browserDetached = async () => {
        await new MessageManagerDestroyedPromise(this.messageManager);
        resolve();
      };

      if (this.tabBrowser.closeTab) {
        // Fennec
        this.tabBrowser.deck.addEventListener(
            "TabClose", browserDetached, {once: true});
        this.tabBrowser.closeTab(this.tab);

      } else if (this.tabBrowser.removeTab) {
        // Firefox
        this.tab.addEventListener(
            "TabClose", browserDetached, {once: true});
        this.tabBrowser.removeTab(this.tab);

      } else {
        reject(new UnsupportedOperationError(
            `closeTab() not supported in ${this.driver.appName}`));
      }
    });
  }

  /**
   * Opens a tab with given URI.
   *
   * @param {string} uri
   *      URI to open.
   */
  addTab(uri) {
    return this.tabBrowser.addTab(uri, true);
  }

  /**
   * Set the current tab.
   *
   * @param {number=} index
   *     Tab index to switch to. If the parameter is undefined,
   *     the currently selected tab will be used.
   * @param {ChromeWindow=} window
   *     Switch to this window before selecting the tab.
   * @param {boolean=} focus
   *      A boolean value which determins whether to focus
   *      the window. Defaults to true.
   *
   * @throws UnsupportedOperationError
   *     If tab handling for the current application isn't supported.
   */
  switchToTab(index, window = undefined, focus = true) {
    if (window) {
      this.window = window;
      this.tabBrowser = browser.getTabBrowser(this.window);
    }

    if (!this.tabBrowser) {
      return;
    }

    if (typeof index == "undefined") {
      this.tab = this.tabBrowser.selectedTab;
    } else {
      this.tab = this.tabBrowser.tabs[index];

      if (focus) {
        if (this.tabBrowser.selectTab) {
          // Fennec
          this.tabBrowser.selectTab(this.tab);

        } else if ("selectedTab" in this.tabBrowser) {
          // Firefox
          this.tabBrowser.selectedTab = this.tab;

        } else {
          throw new UnsupportedOperationError("switchToTab() not supported");
        }
      }
    }

    // TODO(ato): Currently tied to curBrowser, but should be moved to
    // WebElement when introduced by https://bugzil.la/1400256.
    this.eventObserver = new WebElementEventTarget(this.messageManager);
  }

  /**
   * Registers a new frame, and sets its current frame id to this frame
   * if it is not already assigned, and if a) we already have a session
   * or b) we're starting a new session and it is the right start frame.
   *
   * @param {string} uid
   *     Frame uid for use by Marionette.
   * @param {xul:browser} target
   *     The <xul:browser> that was the target of the originating message.
   */
  register(uid, target) {
    if (this.tabBrowser) {
      // If we're setting up a new session on Firefox, we only process the
      // registration for this frame if it belongs to the current tab.
      if (!this.tab) {
        this.switchToTab();
      }

      if (target === this.contentBrowser) {
        this.updateIdForBrowser(this.contentBrowser, uid);
        this._needsFlushPendingCommands = true;
      }
    }

    // used to delete sessions
    this.knownFrames.push(uid);
  }

  /**
   * Flush any queued pending commands.
   *
   * Needs to be run after a process change for the frame script.
   */
  flushPendingCommands() {
    if (!this._needsFlushPendingCommands) {
      return;
    }

    this.pendingCommands.forEach(cb => cb());
    this._needsFlushPendingCommands = false;
  }

  /**
    * This function intercepts commands interacting with content and queues
    * or executes them as needed.
    *
    * No commands interacting with content are safe to process until
    * the new listener script is loaded and registered itself.
    * This occurs when a command whose effect is asynchronous (such
    * as goBack) results in process change of the frame script and new
    * commands are subsequently posted to the server.
    */
  executeWhenReady(cb) {
    if (this._needsFlushPendingCommands) {
      this.pendingCommands.push(cb);
    } else {
      cb();
    }
  }

};

/**
 * The window storage is used to save outer window IDs mapped to weak
 * references of Window objects.
 *
 * Usage:
 *
 *     let wins = new browser.Windows();
 *     wins.set(browser.outerWindowID, window);
 *
 *     ...
 *
 *     let win = wins.get(browser.outerWindowID);
 *
 */
browser.Windows = class extends Map {

  /**
   * Save a weak reference to the Window object.
   *
   * @param {string} id
   *     Outer window ID.
   * @param {Window} win
   *     Window object to save.
   *
   * @return {browser.Windows}
   *     Instance of self.
   */
  set(id, win) {
    let wref = Cu.getWeakReference(win);
    super.set(id, wref);
    return this;
  }

  /**
   * Get the window object stored by provided |id|.
   *
   * @param {string} id
   *     Outer window ID.
   *
   * @return {Window}
   *     Saved window object.
   *
   * @throws {RangeError}
   *     If |id| is not in the store.
   */
  get(id) {
    let wref = super.get(id);
    if (!wref) {
      throw new RangeError();
    }
    return wref.get();
  }

};

/**
 * Marionette representation of the {@link ChromeWindow} window state.
 *
 * @enum {string}
 */
const WindowState = {
  Maximized: "maximized",
  Minimized: "minimized",
  Normal: "normal",
  Fullscreen: "fullscreen",

  /**
   * Converts {@link nsIDOMChromeWindow.windowState} to WindowState.
   *
   * @param {number} windowState
   *     Attribute from {@link nsIDOMChromeWindow.windowState}.
   *
   * @return {WindowState}
   *     JSON representation.
   *
   * @throws {TypeError}
   *     If <var>windowState</var> was unknown.
   */
  from(windowState) {
    switch (windowState) {
      case 1:
        return WindowState.Maximized;

      case 2:
        return WindowState.Minimized;

      case 3:
        return WindowState.Normal;

      case 4:
        return WindowState.Fullscreen;

      default:
        throw new TypeError(`Unknown window state: ${windowState}`);
    }
  },
};
this.WindowState = WindowState;