/* 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";

/* exported ExtensionShortcuts */
const EXPORTED_SYMBOLS = ["ExtensionShortcuts"];

const { XPCOMUtils } = ChromeUtils.import(
  "resource://gre/modules/XPCOMUtils.jsm"
);
const { ExtensionCommon } = ChromeUtils.import(
  "resource://gre/modules/ExtensionCommon.jsm"
);
const { ExtensionUtils } = ChromeUtils.import(
  "resource://gre/modules/ExtensionUtils.jsm"
);
const { ShortcutUtils } = ChromeUtils.import(
  "resource://gre/modules/ShortcutUtils.jsm"
);

ChromeUtils.defineModuleGetter(
  this,
  "ExtensionParent",
  "resource://gre/modules/ExtensionParent.jsm"
);
ChromeUtils.defineModuleGetter(
  this,
  "ExtensionSettingsStore",
  "resource://gre/modules/ExtensionSettingsStore.jsm"
);
ChromeUtils.defineModuleGetter(
  this,
  "PrivateBrowsingUtils",
  "resource://gre/modules/PrivateBrowsingUtils.jsm"
);

XPCOMUtils.defineLazyGetter(this, "windowTracker", () => {
  return ExtensionParent.apiManager.global.windowTracker;
});
XPCOMUtils.defineLazyGetter(this, "browserActionFor", () => {
  return ExtensionParent.apiManager.global.browserActionFor;
});
XPCOMUtils.defineLazyGetter(this, "pageActionFor", () => {
  return ExtensionParent.apiManager.global.pageActionFor;
});
XPCOMUtils.defineLazyGetter(this, "sidebarActionFor", () => {
  return ExtensionParent.apiManager.global.sidebarActionFor;
});

const { ExtensionError } = ExtensionUtils;
const { makeWidgetId } = ExtensionCommon;

const EXECUTE_PAGE_ACTION = "_execute_page_action";
const EXECUTE_BROWSER_ACTION = "_execute_browser_action";
const EXECUTE_SIDEBAR_ACTION = "_execute_sidebar_action";

function normalizeShortcut(shortcut) {
  return shortcut ? shortcut.replace(/\s+/g, "") : "";
}

/**
 * An instance of this class is assigned to the shortcuts property of each
 * active webextension that has commands defined.
 *
 * It manages loading any updated shortcuts along with the ones defined in
 * the manifest and registering them to a browser window. It also provides
 * the list, update and reset APIs for the browser.commands interface and
 * the about:addons manage shortcuts page.
 */
class ExtensionShortcuts {
  static async removeCommandsFromStorage(extensionId) {
    // Cleanup the updated commands. In some cases the extension is installed
    // and uninstalled so quickly that `this.commands` hasn't loaded yet. To
    // handle that we need to make sure ExtensionSettingsStore is initialized
    // before we clean it up.
    await ExtensionSettingsStore.initialize();
    ExtensionSettingsStore.getAllForExtension(extensionId, "commands").forEach(
      key => {
        ExtensionSettingsStore.removeSetting(extensionId, "commands", key);
      }
    );
  }

  constructor({ extension, onCommand }) {
    this.keysetsMap = new WeakMap();
    this.windowOpenListener = null;
    this.extension = extension;
    this.onCommand = onCommand;
    this.id = makeWidgetId(extension.id);
  }

  async allCommands() {
    let commands = await this.commands;
    return Array.from(commands, ([name, command]) => {
      return {
        name,
        description: command.description,
        shortcut: command.shortcut,
      };
    });
  }

  async updateCommand({ name, description, shortcut }) {
    let { extension } = this;
    let commands = await this.commands;
    let command = commands.get(name);

    if (!command) {
      throw new ExtensionError(`Unknown command "${name}"`);
    }

    // Only store the updates so manifest changes can take precedence
    // later.
    let previousUpdates = await ExtensionSettingsStore.getSetting(
      "commands",
      name,
      extension.id
    );
    let commandUpdates = (previousUpdates && previousUpdates.value) || {};

    if (description && description != command.description) {
      commandUpdates.description = description;
      command.description = description;
    }

    if (shortcut != null && shortcut != command.shortcut) {
      shortcut = normalizeShortcut(shortcut);
      commandUpdates.shortcut = shortcut;
      command.shortcut = shortcut;
    }

    await ExtensionSettingsStore.addSetting(
      extension.id,
      "commands",
      name,
      commandUpdates
    );

    this.registerKeys(commands);
  }

  async resetCommand(name) {
    let { extension, manifestCommands } = this;
    let commands = await this.commands;
    let command = commands.get(name);

    if (!command) {
      throw new ExtensionError(`Unknown command "${name}"`);
    }

    let storedCommand = ExtensionSettingsStore.getSetting(
      "commands",
      name,
      extension.id
    );

    if (storedCommand && storedCommand.value) {
      commands.set(name, { ...manifestCommands.get(name) });
      ExtensionSettingsStore.removeSetting(extension.id, "commands", name);
      this.registerKeys(commands);
    }
  }

  loadCommands() {
    let { extension } = this;

    // Map[{String} commandName -> {Object} commandProperties]
    this.manifestCommands = this.loadCommandsFromManifest(extension.manifest);

    this.commands = (async () => {
      // Deep copy the manifest commands to commands so we can keep the original
      // manifest commands and update commands as needed.
      let commands = new Map();
      this.manifestCommands.forEach((command, name) => {
        commands.set(name, { ...command });
      });

      // Update the manifest commands with the persisted updates from
      // browser.commands.update().
      let savedCommands = await this.loadCommandsFromStorage(extension.id);
      savedCommands.forEach((update, name) => {
        let command = commands.get(name);
        if (command) {
          // We will only update commands, not add them.
          Object.assign(command, update);
        }
      });

      return commands;
    })();
  }

  registerKeys(commands) {
    for (let window of windowTracker.browserWindows()) {
      this.registerKeysToDocument(window, commands);
    }
  }

  /**
   * Registers the commands to all open windows and to any which
   * are later created.
   */
  async register() {
    let commands = await this.commands;
    this.registerKeys(commands);

    this.windowOpenListener = window => {
      if (!this.keysetsMap.has(window)) {
        this.registerKeysToDocument(window, commands);
      }
    };

    windowTracker.addOpenListener(this.windowOpenListener);
  }

  /**
   * Unregisters the commands from all open windows and stops commands
   * from being registered to windows which are later created.
   */
  unregister() {
    for (let window of windowTracker.browserWindows()) {
      if (this.keysetsMap.has(window)) {
        this.keysetsMap.get(window).remove();
      }
    }

    windowTracker.removeOpenListener(this.windowOpenListener);
  }

  /**
   * Creates a Map from commands for each command in the manifest.commands object.
   *
   * @param {Object} manifest The manifest JSON object.
   * @returns {Map<string, object>}
   */
  loadCommandsFromManifest(manifest) {
    let commands = new Map();
    // For Windows, chrome.runtime expects 'win' while chrome.commands
    // expects 'windows'.  We can special case this for now.
    let { PlatformInfo } = ExtensionParent;
    let os = PlatformInfo.os == "win" ? "windows" : PlatformInfo.os;
    for (let [name, command] of Object.entries(manifest.commands)) {
      let suggested_key = command.suggested_key || {};
      let shortcut = normalizeShortcut(
        suggested_key[os] || suggested_key.default
      );
      commands.set(name, {
        description: command.description,
        shortcut,
      });
    }
    return commands;
  }

  async loadCommandsFromStorage(extensionId) {
    await ExtensionSettingsStore.initialize();
    let names = ExtensionSettingsStore.getAllForExtension(
      extensionId,
      "commands"
    );
    return names.reduce((map, name) => {
      let command = ExtensionSettingsStore.getSetting(
        "commands",
        name,
        extensionId
      ).value;
      return map.set(name, command);
    }, new Map());
  }

  /**
   * Registers the commands to a document.
   * @param {ChromeWindow} window The XUL window to insert the Keyset.
   * @param {Map} commands The commands to be set.
   */
  registerKeysToDocument(window, commands) {
    if (
      !this.extension.privateBrowsingAllowed &&
      PrivateBrowsingUtils.isWindowPrivate(window)
    ) {
      return;
    }

    let doc = window.document;
    let keyset = doc.createXULElement("keyset");
    keyset.id = `ext-keyset-id-${this.id}`;
    if (this.keysetsMap.has(window)) {
      this.keysetsMap.get(window).remove();
    }
    let sidebarKey;
    commands.forEach((command, name) => {
      if (command.shortcut) {
        let parts = command.shortcut.split("+");

        // The key is always the last element.
        let key = parts.pop();

        if (/^[0-9]$/.test(key)) {
          let shortcutWithNumpad = command.shortcut.replace(
            /[0-9]$/,
            "Numpad$&"
          );
          let numpadKeyElement = this.buildKey(doc, name, shortcutWithNumpad);
          keyset.appendChild(numpadKeyElement);
        }

        let keyElement = this.buildKey(doc, name, command.shortcut);
        keyset.appendChild(keyElement);
        if (name == EXECUTE_SIDEBAR_ACTION) {
          sidebarKey = keyElement;
        }
      }
    });
    doc.documentElement.appendChild(keyset);
    if (sidebarKey) {
      window.SidebarUI.updateShortcut({ key: sidebarKey });
    }
    this.keysetsMap.set(window, keyset);
  }

  /**
   * Builds a XUL Key element and attaches an onCommand listener which
   * emits a command event with the provided name when fired.
   *
   * @param {Document} doc The XUL document.
   * @param {string} name The name of the command.
   * @param {string} shortcut The shortcut provided in the manifest.
   * @see https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/key
   *
   * @returns {Document} The newly created Key element.
   */
  buildKey(doc, name, shortcut) {
    let keyElement = this.buildKeyFromShortcut(doc, name, shortcut);

    // We need to have the attribute "oncommand" for the "command" listener to fire,
    // and it is currently ignored when set to the empty string.
    keyElement.setAttribute("oncommand", "//");

    /* eslint-disable mozilla/balanced-listeners */
    // We remove all references to the key elements when the extension is shutdown,
    // therefore the listeners for these elements will be garbage collected.
    keyElement.addEventListener("command", event => {
      let action;
      if (name == EXECUTE_PAGE_ACTION) {
        action = pageActionFor(this.extension);
      } else if (name == EXECUTE_BROWSER_ACTION) {
        action = browserActionFor(this.extension);
      } else if (name == EXECUTE_SIDEBAR_ACTION) {
        action = sidebarActionFor(this.extension);
      } else {
        this.extension.tabManager.addActiveTabPermission();
        this.onCommand(name);
        return;
      }
      if (action) {
        let win = event.target.ownerGlobal;
        action.triggerAction(win);
      }
    });
    /* eslint-enable mozilla/balanced-listeners */

    return keyElement;
  }

  /**
   * Builds a XUL Key element from the provided shortcut.
   *
   * @param {Document} doc The XUL document.
   * @param {string} name The name of the shortcut.
   * @param {string} shortcut The shortcut provided in the manifest.
   *
   * @see https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/key
   * @returns {Document} The newly created Key element.
   */
  buildKeyFromShortcut(doc, name, shortcut) {
    let keyElement = doc.createXULElement("key");

    let parts = shortcut.split("+");

    // The key is always the last element.
    let chromeKey = parts.pop();

    // The modifiers are the remaining elements.
    keyElement.setAttribute(
      "modifiers",
      ShortcutUtils.getModifiersAttribute(parts)
    );

    // A keyElement with key "NumpadX" is created above and isn't from the
    // manifest. The id will be set on the keyElement with key "X" only.
    if (name == EXECUTE_SIDEBAR_ACTION && !chromeKey.startsWith("Numpad")) {
      let id = `ext-key-id-${this.id}-sidebar-action`;
      keyElement.setAttribute("id", id);
    }

    let [attribute, value] = ShortcutUtils.getKeyAttribute(chromeKey);
    keyElement.setAttribute(attribute, value);
    if (attribute == "keycode") {
      keyElement.setAttribute("event", "keydown");
    }

    return keyElement;
  }
}