/* 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 {ExtensionPreferencesManager} = ChromeUtils.import("resource://gre/modules/ExtensionPreferencesManager.jsm");
var {ExtensionParent} = ChromeUtils.import("resource://gre/modules/ExtensionParent.jsm");

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

const DEFAULT_SEARCH_STORE_TYPE = "default_search";
const DEFAULT_SEARCH_SETTING_NAME = "defaultSearch";
const ENGINE_ADDED_SETTING_NAME = "engineAdded";

const HOMEPAGE_PREF = "browser.startup.homepage";
const HOMEPAGE_PRIVATE_ALLOWED = "browser.startup.homepage_override.privateAllowed";
const HOMEPAGE_EXTENSION_CONTROLLED = "browser.startup.homepage_override.extensionControlled";
const HOMEPAGE_CONFIRMED_TYPE = "homepageNotification";
const HOMEPAGE_SETTING_TYPE = "prefs";
const HOMEPAGE_SETTING_NAME = "homepage_override";

XPCOMUtils.defineLazyGetter(this, "homepagePopup", () => {
  return new ExtensionControlledPopup({
    confirmedType: HOMEPAGE_CONFIRMED_TYPE,
    observerTopic: "browser-open-homepage-start",
    popupnotificationId: "extension-homepage-notification",
    settingType: HOMEPAGE_SETTING_TYPE,
    settingKey: HOMEPAGE_SETTING_NAME,
    descriptionId: "extension-homepage-notification-description",
    descriptionMessageId: "homepageControlled.message",
    learnMoreMessageId: "homepageControlled.learnMore",
    learnMoreLink: "extension-home",
    async beforeDisableAddon(popup, win) {
      // Disabling an add-on should remove the tabs that it has open, but we want
      // to open the new homepage in this tab (which might get closed).
      //   1. Replace the tab's URL with about:blank, wait for it to change
      //   2. Now that this tab isn't associated with the add-on, disable the add-on
      //   3. Trigger the browser's homepage method
      let gBrowser = win.gBrowser;
      let tab = gBrowser.selectedTab;
      await replaceUrlInTab(gBrowser, tab, "about:blank");
      Services.prefs.addObserver(HOMEPAGE_PREF, async function prefObserver() {
        Services.prefs.removeObserver(HOMEPAGE_PREF, prefObserver);
        let loaded = waitForTabLoaded(tab);
        win.BrowserHome();
        await loaded;
        // Manually trigger an event in case this is controlled again.
        popup.open();
      });
    },
  });
});

// When the browser starts up it will trigger the observer topic we're expecting
// but that happens before our observer has been registered. To handle the
// startup case we need to check if the preferences are set to load the homepage
// and check if the homepage is active, then show the doorhanger in that case.
async function handleInitialHomepagePopup(extensionId, homepageUrl) {
  // browser.startup.page == 1 is show homepage.
  if (Services.prefs.getIntPref("browser.startup.page") == 1) {
    let {gBrowser} = windowTracker.topWindow;
    let tab = gBrowser.selectedTab;
    let currentUrl = gBrowser.currentURI.spec;
    // When the first window is still loading the URL might be about:blank.
    // Wait for that the actual page to load before checking the URL, unless
    // the homepage is set to about:blank.
    if (currentUrl != homepageUrl && currentUrl == "about:blank") {
      await waitForTabLoaded(tab);
      currentUrl = gBrowser.currentURI.spec;
    }
    // Once the page has loaded, if necessary and the active tab hasn't changed,
    // then show the popup now.
    if (currentUrl == homepageUrl && gBrowser.selectedTab == tab) {
      homepagePopup.open();
      return;
    }
  }
  homepagePopup.addObserver(extensionId);
}

// When an extension starts up, a search engine may asynchronously be
// registered, without blocking the startup. When an extension is
// uninstalled, we need to wait for this registration to finish
// before running the uninstallation handler.
// Map[extension id -> Promise]
var pendingSearchSetupTasks = new Map();

this.chrome_settings_overrides = class extends ExtensionAPI {
  static async processDefaultSearchSetting(action, id) {
    await ExtensionSettingsStore.initialize();
    let item = ExtensionSettingsStore.getSetting(DEFAULT_SEARCH_STORE_TYPE, DEFAULT_SEARCH_SETTING_NAME);
    if (!item) {
      return;
    }
    if (Services.search.defaultEngine.name != item.value &&
        Services.search.defaultEngine.name != item.initialValue) {
      // The current engine is not the same as the value that the ExtensionSettingsStore has.
      // This means that the user changed the engine, so we shouldn't control it anymore.
      // Do nothing and remove our entry from the ExtensionSettingsStore.
      ExtensionSettingsStore.removeSetting(id, DEFAULT_SEARCH_STORE_TYPE, DEFAULT_SEARCH_SETTING_NAME);
      return;
    }
    item = ExtensionSettingsStore[action](id, DEFAULT_SEARCH_STORE_TYPE, DEFAULT_SEARCH_SETTING_NAME);
    if (item) {
      try {
        let engine = Services.search.getEngineByName(item.value || item.initialValue);
        if (engine) {
          Services.search.defaultEngine = engine;
        }
      } catch (e) {
        Cu.reportError(e);
      }
    }
  }

  static async removeEngine(id) {
    await ExtensionSettingsStore.initialize();
    let item = await ExtensionSettingsStore.getSetting(
      DEFAULT_SEARCH_STORE_TYPE, ENGINE_ADDED_SETTING_NAME, id);
    if (item) {
      ExtensionSettingsStore.removeSetting(
        id, DEFAULT_SEARCH_STORE_TYPE, ENGINE_ADDED_SETTING_NAME);
    }
    // We can call removeEngine in nsSearchService startup, if so we dont
    // need to reforward the call, just disable the web extension.
    if (!Services.search.isInitialized) {
      return;
    }

    try {
      let engines = await Services.search.getEnginesByExtensionID(id);
      if (engines.length > 0) {
        await Services.search.removeWebExtensionEngine(id);
      }
    } catch (e) {
      Cu.reportError(e);
    }
  }

  static removeSearchSettings(id) {
    return Promise.all([
      this.processDefaultSearchSetting("removeSetting", id),
      this.removeEngine(id),
    ]);
  }

  static async onUninstall(id) {
    let searchStartupPromise = pendingSearchSetupTasks.get(id);
    if (searchStartupPromise) {
      await searchStartupPromise;
    }
    // Note: We do not have to deal with homepage here as it is managed by
    // the ExtensionPreferencesManager.
    return Promise.all([
      this.removeSearchSettings(id),
      homepagePopup.clearConfirmation(id),
    ]);
  }

  static onUpdate(id, manifest) {
    let haveHomepage = manifest && manifest.chrome_settings_overrides &&
                       manifest.chrome_settings_overrides.homepage;
    if (!haveHomepage) {
      ExtensionPreferencesManager.removeSetting(id, "homepage_override");
    }

    let haveSearchProvider = manifest && manifest.chrome_settings_overrides &&
                             manifest.chrome_settings_overrides.search_provider;
    if (!haveSearchProvider) {
      this.removeSearchSettings(id);
    }
  }

  async onManifestEntry(entryName) {
    let {extension} = this;
    let {manifest} = extension;

    await ExtensionSettingsStore.initialize();

    let homepageUrl = manifest.chrome_settings_overrides.homepage;

    if (homepageUrl) {
      let inControl;
      if (extension.startupReason == "ADDON_INSTALL" ||
          extension.startupReason == "ADDON_ENABLE") {
        inControl = await ExtensionPreferencesManager.setSetting(
          extension.id, "homepage_override", homepageUrl);
      } else {
        let item = await ExtensionPreferencesManager.getSetting("homepage_override");
        inControl = item.id == extension.id;
      }
      // We need to add the listener here too since onPrefsChanged won't trigger on a
      // restart (the prefs are already set).
      if (inControl) {
        Services.prefs.setBoolPref(HOMEPAGE_PRIVATE_ALLOWED, extension.privateBrowsingAllowed);
        // Also set this now as an upgraded browser will need this.
        Services.prefs.setBoolPref(HOMEPAGE_EXTENSION_CONTROLLED, true);
        if (extension.startupReason == "APP_STARTUP") {
          handleInitialHomepagePopup(extension.id, homepageUrl);
        } else {
          homepagePopup.addObserver(extension.id);
        }
      }

      // We need to monitor permission change and update the preferences.
      // eslint-disable-next-line mozilla/balanced-listeners
      extension.on("add-permissions", async (ignoreEvent, permissions) => {
        if (permissions.permissions.includes("internal:privateBrowsingAllowed")) {
          let item = await ExtensionPreferencesManager.getSetting("homepage_override");
          if (item.id == extension.id) {
            Services.prefs.setBoolPref(HOMEPAGE_PRIVATE_ALLOWED, true);
          }
        }
      });
      // eslint-disable-next-line mozilla/balanced-listeners
      extension.on("remove-permissions", async (ignoreEvent, permissions) => {
        if (permissions.permissions.includes("internal:privateBrowsingAllowed")) {
          let item = await ExtensionPreferencesManager.getSetting("homepage_override");
          if (item.id == extension.id) {
            Services.prefs.setBoolPref(HOMEPAGE_PRIVATE_ALLOWED, false);
          }
        }
      });

      extension.callOnClose({
        close: () => {
          if (extension.shutdownReason == "ADDON_DISABLE") {
            homepagePopup.clearConfirmation(extension.id);
          }
        },
      });
    }
    if (manifest.chrome_settings_overrides.search_provider) {
      // Registering a search engine can potentially take a long while,
      // or not complete at all (when searchInitialized is never resolved),
      // so we are deliberately not awaiting the returned promise here.
      let searchStartupPromise =
        this.processSearchProviderManifestEntry().finally(() => {
          if (pendingSearchSetupTasks.get(extension.id) === searchStartupPromise) {
            pendingSearchSetupTasks.delete(extension.id);
          }
        });

      // Save the promise so we can await at onUninstall.
      pendingSearchSetupTasks.set(extension.id, searchStartupPromise);
    }
  }

  async processSearchProviderManifestEntry() {
    let {extension} = this;
    let {manifest} = extension;
    let searchProvider = manifest.chrome_settings_overrides.search_provider;
    if (searchProvider.is_default) {
      await searchInitialized;
      if (!this.extension) {
        Cu.reportError(`Extension shut down before search provider was registered`);
        return;
      }
    }
    extension.callOnClose({
      close: () => {
        if (extension.shutdownReason == "ADDON_DISABLE") {
          chrome_settings_overrides.processDefaultSearchSetting("disable", extension.id);
          chrome_settings_overrides.removeEngine(extension.id);
        }
      },
    });

    let engineName = searchProvider.name.trim();
    if (searchProvider.is_default) {
      let engine = Services.search.getEngineByName(engineName);
      let defaultEngines = await Services.search.getDefaultEngines();
      if (engine && defaultEngines.some(defaultEngine => defaultEngine.name == engineName)) {
        // Needs to be called every time to handle reenabling, but
        // only sets default for install or enable.
        await this.setDefault(engineName);
        // For built in search engines, we don't do anything further
        return;
      }
    }
    await this.addSearchEngine();
    if (searchProvider.is_default) {
      if (extension.startupReason === "ADDON_INSTALL") {
        // Don't ask if it already the current engine
        let engine = Services.search.getEngineByName(engineName);
        let defaultEngine = await Services.search.getDefault();
        if (defaultEngine.name != engine.name) {
          let subject = {
            wrappedJSObject: {
              // This is a hack because we don't have the browser of
              // the actual install. This means the popup might show
              // in a different window. Will be addressed in a followup bug.
              browser: windowTracker.topWindow.gBrowser.selectedBrowser,
              name: this.extension.name,
              icon: this.extension.iconURL,
              currentEngine: defaultEngine.name,
              newEngine: engineName,
              respond(allow) {
                if (allow) {
                  ExtensionSettingsStore.addSetting(
                    extension.id, DEFAULT_SEARCH_STORE_TYPE, DEFAULT_SEARCH_SETTING_NAME, engineName, () => defaultEngine.name);
                  Services.search.defaultEngine = Services.search.getEngineByName(engineName);
                }
              },
            },
          };
          Services.obs.notifyObservers(subject, "webextension-defaultsearch-prompt");
        }
      } else {
        // Needs to be called every time to handle reenabling, but
        // only sets default for install or enable.
        this.setDefault(engineName);
      }
    } else if (ExtensionSettingsStore.hasSetting(extension.id,
                                                 DEFAULT_SEARCH_STORE_TYPE,
                                                 DEFAULT_SEARCH_SETTING_NAME)) {
      // is_default has been removed, but we still have a setting. Remove it.
      chrome_settings_overrides.processDefaultSearchSetting("removeSetting", extension.id);
    }
  }

  async setDefault(engineName) {
    let {extension} = this;
    if (extension.startupReason === "ADDON_INSTALL") {
      let defaultEngine = await Services.search.getDefault();
      let item = await ExtensionSettingsStore.addSetting(
        extension.id, DEFAULT_SEARCH_STORE_TYPE, DEFAULT_SEARCH_SETTING_NAME, engineName, () => defaultEngine.name);
      await Services.search.setDefault(Services.search.getEngineByName(item.value));
    } else if (extension.startupReason === "ADDON_ENABLE") {
      chrome_settings_overrides.processDefaultSearchSetting("enable", extension.id);
    }
  }

  async addSearchEngine() {
    let {extension} = this;
    let isCurrent = false;
    let index = -1;
    if (extension.startupReason === "ADDON_UPGRADE") {
      let engines = await Services.search.getEnginesByExtensionID(extension.id);
      if (engines.length > 0) {
        let firstEngine = engines[0];
        let firstEngineName = firstEngine.name;
        // There can be only one engine right now
        isCurrent = (await Services.search.getDefault()).name == firstEngineName;
        // Get position of engine and store it
        index = (await Services.search.getEngines()).map(engine => engine.name).indexOf(firstEngineName);
        await Services.search.removeEngine(firstEngine);
      }
    }
    try {
      let engines = await Services.search.addEnginesFromExtension(extension);
      if (engines.length > 0) {
        await ExtensionSettingsStore.addSetting(
          extension.id, DEFAULT_SEARCH_STORE_TYPE, ENGINE_ADDED_SETTING_NAME,
          engines[0].name);
      }
      if (extension.startupReason === "ADDON_UPGRADE") {
        let engines = await Services.search.getEnginesByExtensionID(extension.id);
        let engine = Services.search.getEngineByName(engines[0].name);
        if (isCurrent) {
          await Services.search.setDefault(engine);
        }
        if (index != -1) {
          await Services.search.moveEngine(engine, index);
        }
      }
    } catch (e) {
      Cu.reportError(e);
      return false;
    }
    return true;
  }
};

ExtensionPreferencesManager.addSetting("homepage_override", {
  prefNames: [
    HOMEPAGE_PREF,
    HOMEPAGE_EXTENSION_CONTROLLED,
  ],
  // ExtensionPreferencesManager will call onPrefsChanged when control changes
  // and it updates the preferences. We are passed the item from
  // ExtensionSettingsStore that details what is in control. If there is an id
  // then control has changed to an extension, if there is no id then control
  // has been returned to the user.
  onPrefsChanged(item) {
    if (item.id) {
      homepagePopup.addObserver(item.id);

      let policy = ExtensionParent.WebExtensionPolicy.getByID(item.id);
      Services.prefs.setBoolPref(HOMEPAGE_PRIVATE_ALLOWED, policy && policy.privateBrowsingAllowed);
      Services.prefs.setBoolPref(HOMEPAGE_EXTENSION_CONTROLLED, true);
    } else {
      homepagePopup.removeObserver();

      Services.prefs.clearUserPref(HOMEPAGE_PRIVATE_ALLOWED);
      Services.prefs.clearUserPref(HOMEPAGE_EXTENSION_CONTROLLED);
    }
  },
  setCallback(value) {
    return {
      [HOMEPAGE_PREF]: value,
      [HOMEPAGE_EXTENSION_CONTROLLED]: !!value,
    };
  },
});