Add opt-out setting for Gravatar integration

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

24 files changed, 730 insertions, 37 deletions

diff --git a/appinfo/routes.php b/appinfo/routes.php
index 678482081..0bcdb712c 100644
--- a/appinfo/routes.php
+++ b/appinfo/routes.php
@@ -96,11 +96,12 @@ $app->registerRoutes($this,
 		],
 	],
 	'resources' => [
-		'autoComplete' => ['url' => '/api/autoComplete'],
-		'localAttachments' => ['url' => '/api/attachments'],
 		'accounts' => ['url' => '/api/accounts'],
+		'aliases' => ['url' => '/api/accounts/{accountId}/aliases'],
+		'autoComplete' => ['url' => '/api/autoComplete'],
 		'folders' => ['url' => '/api/accounts/{accountId}/folders'],
+		'localAttachments' => ['url' => '/api/attachments'],
 		'messages' => ['url' => '/api/accounts/{accountId}/folders/{folderId}/messages'],
-		'aliases' => ['url' => '/api/accounts/{accountId}/aliases'],
+		'preferences' => ['url' => '/api/preferences'],
 	]
 ]);
diff --git a/js/app.js b/js/app.js
index 1bb329f49..89a363ddc 100644
--- a/js/app.js
+++ b/js/app.js
@@ -42,26 +42,33 @@ define(function(require) {
 	require('service/accountservice');
 	require('service/aliasesservice');
 	require('service/attachmentservice');
+	require('service/backgroundsyncservice');
 	require('service/davservice');
 	require('service/folderservice');
 	require('service/foldersyncservice');
 	require('service/messageservice');
-	require('service/backgroundsyncservice');
+	require('service/preferenceservice');
 	require('util/notificationhandler');
 
 	var Mail = Marionette.Application.extend({
 
+		_useExternalAvatars: false,
+
+		getUseExternalAvatars: function() {
+			return this._useExternalAvatars;
+		},
+
 		/**
 		 * Register the mailto protocol handler
 		 */
 		registerProtocolHandler: function() {
 			if (window.navigator.registerProtocolHandler) {
 				var url = window.location.protocol + '//' +
-					window.location.host +
-					OC.generateUrl('apps/mail/compose?uri=%s');
+						window.location.host +
+						OC.generateUrl('apps/mail/compose?uri=%s');
 				try {
 					window.navigator
-						.registerProtocolHandler('mailto', url, OC.theme.name + ' Mail');
+							.registerProtocolHandler('mailto', url, OC.theme.name + ' Mail');
 				} catch (e) {
 				}
 			}
@@ -91,6 +98,8 @@ define(function(require) {
 	Mail = new Mail();
 
 	Mail.on('start', function() {
+		this._useExternalAvatars = $('#external-avatars').val() === 'true';
+
 		this.view = new AppView();
 		Cache.init();
 
diff --git a/js/radio.js b/js/radio.js
index c26b06a1a..ff1592fef 100644
--- a/js/radio.js
+++ b/js/radio.js
@@ -24,6 +24,7 @@ define(function(require) {
 		'message',
 		'navigation',
 		'notification',
+		'preference',
 		'state',
 		'sync',
 		'ui'
diff --git a/js/service/preferenceservice.js b/js/service/preferenceservice.js
new file mode 100644
index 000000000..a73c18091
--- /dev/null
+++ b/js/service/preferenceservice.js
@@ -0,0 +1,74 @@
+/* global Promise */
+
+/**
+ * @copyright 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+define(function(require) {
+	'use strict';
+
+	var $ = require('jquery');
+	var OC = require('OC');
+	var Radio = require('radio');
+
+	Radio.preference.reply('save', savePreference);
+	Radio.preference.reply('get', savePreference);
+
+	function savePreference(key, value) {
+		var url = OC.generateUrl('/apps/mail/api/preferences/{key}', {
+			key: key
+		});
+
+		return new Promise(function(resolve, reject) {
+			return $.ajax(url, {
+				method: 'PUT',
+				data: {
+					key: key,
+					value: value
+				},
+				success: resolve,
+				error: reject
+			});
+		}).then(function(data) {
+			return data.value;
+		});
+	}
+
+	function getPreference(key) {
+		var url = OC.generateUrl('/apps/mail/api/preferences/{key}', {
+			key: key
+		});
+
+		return new Promise(function(resolve, reject) {
+			return $.ajax(url, {
+				success: resolve,
+				error: reject
+			});
+		}).then(function(data) {
+			return data.value;
+		});
+	}
+
+	return {
+		savePreference: savePreference,
+		getPreference: getPreference
+	};
+});
diff --git a/js/templates/settings.html b/js/templates/settings.html
index fb6f9a51c..e46c639fa 100644
--- a/js/templates/settings.html
+++ b/js/templates/settings.html
@@ -6,11 +6,20 @@
 	   class="button new-button"
 	   href="{{addAccountUrl}}">{{ t 'Add mail account' }}</a>
 
-	<p class="app-settings-hint">
-	<a id="keyboard-shortcuts"
-		  href="{{keyboardShortcutUrl}}">{{ t 'Keyboard shortcuts' }}</a></p>
+	<p>
+		<input class="checkbox"
+		       id="gravatar-enabled"
+		       {{#if useExternalAvatars}}checked="checked"{{/if}}
+		       type="checkbox">
+		<label for="gravatar-enabled">{{ t 'Use Gravatar and favicon avatars' }}</label>
+	</p>
 
 	<p class="app-settings-hint">
-		{{{ t 'Looking to encrypt your emails? Install the <a href="https://www.mailvelope.com/" target="_blank">Mailvelope browser extension</a>!' }}}
-	</p>
-</div>
\ No newline at end of file
+		<a id="keyboard-shortcuts"
+		   href="{{keyboardShortcutUrl}}">{{ t 'Keyboard shortcuts' }}</a>
+		</p>
+
+		<p class="app-settings-hint">
+			{{{ t 'Looking to encrypt your emails? Install the <a href="https://www.mailvelope.com/" target="_blank">Mailvelope browser extension</a>!' }}}
+		</p>
+	</div>
diff --git a/js/tests/service/preferenceservice_spec.js b/js/tests/service/preferenceservice_spec.js
new file mode 100644
index 000000000..d982b1af7
--- /dev/null
+++ b/js/tests/service/preferenceservice_spec.js
@@ -0,0 +1,92 @@
+/* global sinon, expect */
+
+/**
+ * @copyright 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+define([
+	'service/preferenceservice'
+], function(PreferenceService) {
+	'use strict';
+
+	describe('PreferenceService', function() {
+		var server;
+
+		beforeEach(function() {
+			server = sinon.fakeServer.create();
+		});
+
+		afterEach(function() {
+			server.restore();
+		});
+
+		it('retrieves a preference from the back-end', function(done) {
+			var retrieving = PreferenceService.getPreference('test');
+
+			expect(server.requests.length).toBe(1);
+			server.requests[0].respond(
+					200,
+					{
+						'Content-Type': 'application/json'
+					},
+					JSON.stringify({
+						value: '123'
+					})
+					);
+
+			retrieving.then(function(value) {
+				expect(value).toBe('123');
+
+				done();
+			}).catch(done.fail);
+		});
+
+		it('retrieves an error from the back-end', function(done) {
+			var retrieving = PreferenceService.getPreference('test');
+
+			expect(server.requests.length).toBe(1);
+			server.requests[0].respond(500, null, null);
+
+			retrieving.then(done.fail).catch(done);
+		});
+
+		it('stores a preference on the back-end', function(done) {
+			var storing = PreferenceService.savePreference('test', '123');
+
+			expect(server.requests.length).toBe(1);
+			server.requests[0].respond(
+					200,
+					{
+						'Content-Type': 'application/json'
+					},
+					JSON.stringify({
+						value: '123'
+					})
+					);
+
+			storing.then(function(value) {
+				expect(value).toBe('123');
+
+				done();
+			}).catch(done.fail);
+		});
+	});
+});
diff --git a/js/views/settings.js b/js/views/settings.js
index ec15056fc..12eca1e21 100644
--- a/js/views/settings.js
+++ b/js/views/settings.js
@@ -17,28 +17,44 @@ define(function(require) {
 	var SettingsTemplate = require('templates/settings.html');
 
 	return Marionette.View.extend({
+
 		accounts: null,
+
 		template: SettingsTemplate,
+
 		templateContext: function() {
+			var app = require('app');
 			return {
 				addAccountUrl: OC.generateUrl('apps/mail/#setup'),
+				useExternalAvatars: app.getUseExternalAvatars(),
 				keyboardShortcutUrl: OC.generateUrl('apps/mail/#shortcuts')
 			};
 		},
+
 		regions: {
 			accountsList: '#settings-accounts'
 		},
+
 		events: {
 			'click #new-mail-account': 'addAccount',
+			'change #gravatar-enabled': 'toggleExternalAvatars',
 			'click #keyboard-shortcuts': 'showKeyboardShortcuts'
 		},
+
 		addAccount: function(e) {
 			e.preventDefault();
 			Radio.navigation.trigger('setup');
 		},
+
+		toggleExternalAvatars: function() {
+			var enabled = this.$('#gravatar-enabled').attr('checked') === 'checked';
+			Radio.preference.request('save', 'external-avatars', enabled ? 'true' : 'false');
+		},
+
 		showKeyboardShortcuts: function(e) {
 			e.preventDefault();
 			Radio.navigation.trigger('keyboardshortcuts');
 		}
+
 	});
 });
diff --git a/lib/AppInfo/Application.php b/lib/AppInfo/Application.php
index 3ef9e3d81..15229fab6 100644
--- a/lib/AppInfo/Application.php
+++ b/lib/AppInfo/Application.php
@@ -26,10 +26,12 @@ use OCA\Mail\Contracts\IAttachmentService;
 use OCA\Mail\Contracts\IAvatarService;
 use OCA\Mail\Contracts\IMailManager;
 use OCA\Mail\Contracts\IMailTransmission;
+use OCA\Mail\Contracts\IUserPreferences;
 use OCA\Mail\Service\Attachment\AttachmentService;
 use OCA\Mail\Service\AvatarService;
 use OCA\Mail\Service\MailManager;
 use OCA\Mail\Service\MailTransmission;
+use OCA\Mail\Service\UserPreferenceSevice;
 use OCP\AppFramework\App;
 use OCP\Util;
 
@@ -48,9 +50,10 @@ class Application extends App {
 		$testSmtp = $transport === 'smtp';
 
 		$container->registerAlias(IAvatarService::class, AvatarService::class);
-		$container->registerAlias(IMailManager::class, MailManager::class);
 		$container->registerAlias(IAttachmentService::class, AttachmentService::class);
+		$container->registerAlias(IMailManager::class, MailManager::class);
 		$container->registerAlias(IMailTransmission::class, MailTransmission::class);
+		$container->registerAlias(IUserPreferences::class, UserPreferenceSevice::class);
 		$container->registerService('OCP\ISession', function ($c) {
 			return $c->getServer()->getSession();
 		});
diff --git a/lib/Contracts/IUserPreferences.php b/lib/Contracts/IUserPreferences.php
new file mode 100644
index 000000000..55b0d93af
--- /dev/null
+++ b/lib/Contracts/IUserPreferences.php
@@ -0,0 +1,40 @@
+<?php
+
+/**
+ * @copyright 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Mail\Contracts;
+
+interface IUserPreferences {
+
+	/**
+	 * @param string $key
+	 * @param mixed $value
+	 */
+	public function setPreference($key, $value);
+
+	/**
+	 * @param string $key
+	 * @param mixed|null $default
+	 */
+	public function getPreference($key, $default = null);
+}
diff --git a/lib/Controller/PageController.php b/lib/Controller/PageController.php
index 086a5f164..10b2fea2a 100644
--- a/lib/Controller/PageController.php
+++ b/lib/Controller/PageController.php
@@ -24,6 +24,7 @@
 
 namespace OCA\Mail\Controller;
 
+use OCA\Mail\Contracts\IUserPreferences;
 use OCA\Mail\Service\AccountService;
 use OCA\Mail\Service\AliasesService;
 use OCP\AppFramework\Controller;
@@ -55,6 +56,9 @@ class PageController extends Controller {
 	/** @var IUserSession */
 	private $userSession;
 
+	/** @var IUserPreferences */
+	private $preferences;
+
 	/**
 	 * @param string $appName
 	 * @param IRequest $request
@@ -63,8 +67,12 @@ class PageController extends Controller {
 	 * @param AccountService $accountService
 	 * @param AliasesService $aliasesService
 	 * @param string $UserId
+	 * @param IUserPreferences
 	 */
-	public function __construct($appName, IRequest $request, IURLGenerator $urlGenerator, IConfig $config, AccountService $accountService, AliasesService $aliasesService, $UserId, IUserSession $userSession) {
+	public function __construct($appName, IRequest $request,
+		IURLGenerator $urlGenerator, IConfig $config, AccountService $accountService,
+		AliasesService $aliasesService, $UserId, IUserSession $userSession,
+		IUserPreferences $preferences) {
 		parent::__construct($appName, $request);
 		$this->urlGenerator = $urlGenerator;
 		$this->config = $config;
@@ -72,6 +80,7 @@ class PageController extends Controller {
 		$this->aliasesService = $aliasesService;
 		$this->currentUserId = $UserId;
 		$this->userSession = $userSession;
+		$this->preferences = $preferences;
 	}
 
 	/**
@@ -86,17 +95,21 @@ class PageController extends Controller {
 		$accountsJson = [];
 		foreach ($mailAccounts as $mailAccount) {
 			$json = $mailAccount->jsonSerialize();
-			$json['aliases'] = $this->aliasesService->findAll($mailAccount->getId(), $this->currentUserId);
+			$json['aliases'] = $this->aliasesService->findAll($mailAccount->getId(),
+				$this->currentUserId);
 			$accountsJson[] = $json;
 		}
 
 		$user = $this->userSession->getUser();
-		$response = new TemplateResponse($this->appName, 'index', [
+		$response = new TemplateResponse($this->appName, 'index',
+			[
 			'debug' => $this->config->getSystemValue('debug', false),
 			'app-version' => $this->config->getAppValue('mail', 'installed_version'),
 			'accounts' => base64_encode(json_encode($accountsJson)),
+			'external-avatars' => $this->preferences->getPreference('external-avatars', 'true'),
 			'prefill_displayName' => $user->getDisplayName(),
-			'prefill_email' => $this->config->getUserValue($user->getUID(), 'settings', 'email', ''),
+			'prefill_email' => $this->config->getUserValue($user->getUID(), 'settings',
+				'email', ''),
 		]);
 
 		$csp = new ContentSecurityPolicy();
@@ -124,7 +137,8 @@ class PageController extends Controller {
 			}
 		}
 
-		array_walk($params, function (&$value, $key) {
+		array_walk($params,
+			function (&$value, $key) {
 			$value = "$key=" . urlencode($value);
 		});
 
diff --git a/lib/Controller/PreferencesController.php b/lib/Controller/PreferencesController.php
new file mode 100644
index 000000000..cdaa28bcc
--- /dev/null
+++ b/lib/Controller/PreferencesController.php
@@ -0,0 +1,76 @@
+<?php
+
+/**
+ * @copyright 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Mail\Controller;
+
+use OCA\Mail\Contracts\IUserPreferences;
+use OCA\Mail\Http\JSONResponse;
+use OCP\AppFramework\Controller;
+use OCP\AppFramework\Http;
+use OCP\IRequest;
+
+class PreferencesController extends Controller {
+
+	/** @var IUserPreferences */
+	private $userPreference;
+
+	/**
+	 * @param IRequest $request
+	 * @param IUserPreferences $userPreference
+	 */
+	public function __construct(IRequest $request, IUserPreferences $userPreference) {
+		parent::__construct('mail', $request);
+		$this->userPreference = $userPreference;
+	}
+
+	/**
+	 * @NoAdminRequired
+	 *
+	 * @param string $id
+	 * @return JSONResponse
+	 */
+	public function show($id) {
+		return new JSONResponse([
+			'value' => $this->userPreference->getPreference($id)
+		]);
+	}
+
+	/**
+	 * @NoAdminRequired
+	 *
+	 * @param string $key
+	 * @param string $value
+	 * @return JSONResponse
+	 */
+	public function update($key, $value) {
+		if (is_null($key) || is_null($value)) {
+			return new JSONResponse(null, Http::STATUS_BAD_REQUEST);
+		}
+
+		$this->userPreference->setPreference($key, $value);
+
+		return new JSONResponse();
+	}
+
+}
diff --git a/lib/Service/Avatar/AddressbookSource.php b/lib/Service/Avatar/AddressbookSource.php
index 44b920f92..b65cc69c6 100644
--- a/lib/Service/Avatar/AddressbookSource.php
+++ b/lib/Service/Avatar/AddressbookSource.php
@@ -41,6 +41,15 @@ class AddressbookSource implements IAvatarSource {
 	}
 
 	/**
+	 * Does this source query external services?
+	 *
+	 * @return bool
+	 */
+	public function isExternal() {
+		return false;
+	}
+
+	/**
 	 * @param string $email sender email address
 	 * @param AvatarFactory $factory
 	 * @return Avatar|null avatar URL if one can be found
diff --git a/lib/Service/Avatar/CompositeAvatarSource.php b/lib/Service/Avatar/CompositeAvatarSource.php
index 344e63c77..46e2b576f 100644
--- a/lib/Service/Avatar/CompositeAvatarSource.php
+++ b/lib/Service/Avatar/CompositeAvatarSource.php
@@ -27,7 +27,7 @@ namespace OCA\Mail\Service\Avatar;
 /**
  * Composition of all avatar sources for easier usage
  */
-class CompositeAvatarSource implements IAvatarSource {
+class CompositeAvatarSource {
 
 	/** @var IAvatarSource[] */
 	private $sources;
@@ -49,10 +49,16 @@ class CompositeAvatarSource implements IAvatarSource {
 	/**
 	 * @param string $email sender email address
 	 * @param AvatarFactory $factory
+	 * @param bool $queryExternal
 	 * @return Avatar|null avatar URL if one can be found
 	 */
-	public function fetch($email, AvatarFactory $factory) {
+	public function fetch($email, AvatarFactory $factory, $queryExternal) {
 		foreach ($this->sources as $source) {
+			if (!$queryExternal && $source->isExternal()) {
+				// Skip this one
+				continue;
+			}
+
 			$avatar = $source->fetch($email, $factory);
 
 			if (is_null($avatar)) {
diff --git a/lib/Service/Avatar/FaviconSource.php b/lib/Service/Avatar/FaviconSource.php
index 9861592dd..f5b02302a 100644
--- a/lib/Service/Avatar/FaviconSource.php
+++ b/lib/Service/Avatar/FaviconSource.php
@@ -50,6 +50,15 @@ class FaviconSource implements IAvatarSource {
 	}
 
 	/**
+	 * Does this source query external services?
+	 *
+	 * @return bool
+	 */
+	public function isExternal() {
+		return true;
+	}
+
+	/**
 	 * @param string $email sender email address
 	 * @param AvatarFactory $factory
 	 * @return Avatar|null avatar URL if one can be found
diff --git a/lib/Service/Avatar/GravatarSource.php b/lib/Service/Avatar/GravatarSource.php
index 1c4132597..a22ad13bc 100644
--- a/lib/Service/Avatar/GravatarSource.php
+++ b/lib/Service/Avatar/GravatarSource.php
@@ -39,6 +39,15 @@ class GravatarSource implements IAvatarSource {
 	}
 
 	/**
+	 * Does this source query external services?
+	 *
+	 * @return bool
+	 */
+	public function isExternal() {
+		return true;
+	}
+
+	/**
 	 * @param string $email sender email address
 	 * @param AvatarFactory $factory
 	 * @return Avatar|null avatar URL if one can be found
diff --git a/lib/Service/Avatar/IAvatarSource.php b/lib/Service/Avatar/IAvatarSource.php
index 4be65d597..98e1930f7 100644
--- a/lib/Service/Avatar/IAvatarSource.php
+++ b/lib/Service/Avatar/IAvatarSource.php
@@ -24,11 +24,16 @@
 
 namespace OCA\Mail\Service\Avatar;
 
-use OCP\Files\IMimeTypeDetector;
-
 interface IAvatarSource {
 
 	/**
+	 * Does this source query external services?
+	 *
+	 * @return bool
+	 */
+	public function isExternal();
+
+	/**
 	 * @param string $email sender email address
 	 * @param AvatarFactory $factory
 	 * @return Avatar|null avatar URL if one can be found
diff --git a/lib/Service/AvatarService.php b/lib/Service/AvatarService.php
index d3d5656fc..f9236a879 100644
--- a/lib/Service/AvatarService.php
+++ b/lib/Service/AvatarService.php
@@ -22,12 +22,12 @@
 namespace OCA\Mail\Service;
 
 use OCA\Mail\Contracts\IAvatarService;
+use OCA\Mail\Contracts\IUserPreferences;
 use OCA\Mail\Service\Avatar\Avatar;
 use OCA\Mail\Service\Avatar\AvatarFactory;
 use OCA\Mail\Service\Avatar\Cache as AvatarCache;
 use OCA\Mail\Service\Avatar\CompositeAvatarSource;
 use OCA\Mail\Service\Avatar\Downloader;
-use OCA\Mail\Service\Avatar\IAvatarSource;
 use OCP\IURLGenerator;
 
 class AvatarService implements IAvatarService {
@@ -38,7 +38,7 @@ class AvatarService implements IAvatarService {
 	/** @var Downloader */
 	private $downloader;
 
-	/** @var IAvatarSource */
+	/** @var CompositeAvatarSource */
 	private $source;
 
 	/** @var IURLGenerator */
@@ -47,19 +47,33 @@ class AvatarService implements IAvatarService {
 	/** @var AvatarFactory */
 	private $avatarFactory;
 
+	/** @var IUserPreferences */
+	private $preferences;
+
 	/**
 	 * @param CompositeAvatarSource $source
 	 * @param Downloader $downloader
 	 * @param AvatarCache $cache
 	 * @param IURLGenerator $urlGenerator
 	 * @param AvatarFactory $avatarFactory
+	 * @param IUserPreferences $preferences
 	 */
-	public function __construct(CompositeAvatarSource $source, Downloader $downloader, AvatarCache $cache, IURLGenerator $urlGenerator, AvatarFactory $avatarFactory) {
+	public function __construct(CompositeAvatarSource $source,
+		Downloader $downloader, AvatarCache $cache, IURLGenerator $urlGenerator,
+		AvatarFactory $avatarFactory, IUserPreferences $preferences) {
 		$this->source = $source;
 		$this->cache = $cache;
 		$this->urlGenerator = $urlGenerator;
 		$this->downloader = $downloader;
 		$this->avatarFactory = $avatarFactory;
+		$this->preferences = $preferences;
+	}
+
+	/**
+	 * @return bool
+	 */
+	private function externalAvatarsAllowed() {
+		return $this->preferences->getPreference('external-avatars', 'true') === 'true';
 	}
 
 	/**
@@ -69,7 +83,8 @@ class AvatarService implements IAvatarService {
 		if ($avatar->isExternal()) {
 			$mime = $avatar->getMime();
 
-			return in_array($mime, [
+			return in_array($mime,
+				[
 				'image/jpeg',
 				'image/png',
 				'image/x-icon',
@@ -91,7 +106,7 @@ class AvatarService implements IAvatarService {
 			return $cachedAvatar;
 		}
 
-		$avatar = $this->source->fetch($email, $this->avatarFactory);
+		$avatar = $this->source->fetch($email, $this->avatarFactory, $this->externalAvatarsAllowed());
 		if (is_null($avatar) || !$this->hasAllowedMime($avatar)) {
 			// Cannot locate any avatar -> nothing to do here
 			return null;
diff --git a/lib/Service/UserPreferenceSevice.php b/lib/Service/UserPreferenceSevice.php
new file mode 100644
index 000000000..5f45c8438
--- /dev/null
+++ b/lib/Service/UserPreferenceSevice.php
@@ -0,0 +1,63 @@
+<?php
+
+/**
+ * @copyright 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Mail\Service;
+
+use OCA\Mail\Contracts\IUserPreferences;
+use OCP\IConfig;
+
+class UserPreferenceSevice implements IUserPreferences {
+
+	/** @var IConfig */
+	private $config;
+
+	/** @var string */
+	private $UserId;
+
+	/**
+	 * @param IConfig $config
+	 * @param string $UserId
+	 */
+	public function __construct(IConfig $config, $UserId) {
+		$this->UserId = $UserId;
+		$this->config = $config;
+	}
+
+	/**
+	 * @param string $key
+	 * @param mixed $value
+	 */
+	public function setPreference($key, $value) {
+		$this->config->setUserValue($this->UserId, 'mail', $key, $value);
+	}
+
+	/**
+	 * @param string $key
+	 * @param mixed|null $default
+	 */
+	public function getPreference($key, $default = null) {
+		return $this->config->getUserValue($this->UserId, 'mail', $key, $default);
+	}
+
+}
diff --git a/templates/index.php b/templates/index.php
index 0e78e1236..0ca81710a 100644
--- a/templates/index.php
+++ b/templates/index.php
@@ -31,6 +31,7 @@ script('mail', 'build/build');
 
 <input type="hidden" id="config-installed-version" value="<?php p($_['app-version']); ?>">
 <input type="hidden" id="serialized-accounts" value="<?php p($_['accounts']); ?>">
+<input type="hidden" id="external-avatars" value="<?php p($_['external-avatars']); ?>">
 
 <div id="user-displayname"
      style="display: none"><?php p($_['prefill_displayName']); ?></div>
diff --git a/tests/Controller/PageControllerTest.php b/tests/Controller/PageControllerTest.php
index 1d0ffca8e..468a6c5f4 100644
--- a/tests/Controller/PageControllerTest.php
+++ b/tests/Controller/PageControllerTest.php
@@ -21,6 +21,7 @@
 
 namespace OCA\Mail\Tests\Controller;
 
+use OCA\Mail\Contracts\IUserPreferences;
 use OCA\Mail\Controller\PageController;
 use OCA\Mail\Service\AccountService;
 use OCA\Mail\Service\AliasesService;
@@ -62,6 +63,9 @@ class PageControllerTest extends PHPUnit_Framework_TestCase {
 	/** @var IUserSession|PHPUnit_Framework_MockObject_MockObject */
 	private $userSession;
 
+	/** @var IUserPreferences|PHPUnit_Framework_MockObject_MockObject */
+	private $preferences;
+
 	/** @var PageController */
 	private $controller;
 
@@ -76,13 +80,21 @@ class PageControllerTest extends PHPUnit_Framework_TestCase {
 		$this->accountService = $this->createMock(AccountService::class);
 		$this->aliasesService = $this->createMock(AliasesService::class);
 		$this->userSession = $this->createMock(IUserSession::class);
-		$this->controller = new PageController($this->appName, $this->request, $this->urlGenerator, $this->config, $this->accountService, $this->aliasesService, $this->userId, $this->userSession);
+		$this->preferences = $this->createMock(IUserPreferences::class);
+
+		$this->controller = new PageController($this->appName, $this->request,
+			$this->urlGenerator, $this->config, $this->accountService,
+			$this->aliasesService, $this->userId, $this->userSession, $this->preferences);
 	}
 
 	public function testIndex() {
 		$account1 = $this->createMock(IAccount::class);
 		$account2 = $this->createMock(IAccount::class);
 
+		$this->preferences->expects($this->once())
+			->method('getPreference')
+			->with('external-avatars', 'true')
+			->willReturn('true');
 		$this->accountService->expects($this->once())
 			->method('findByUserId')
 			->with($this->userId)
@@ -149,11 +161,14 @@ class PageControllerTest extends PHPUnit_Framework_TestCase {
 			->will($this->returnValue('jane'));
 		$this->config->expects($this->once())
 			->method('getUserValue')
-			->with($this->equalTo('jane'), $this->equalTo('settings'), $this->equalTo('email'), $this->equalTo(''))
+			->with($this->equalTo('jane'), $this->equalTo('settings'),
+				$this->equalTo('email'), $this->equalTo(''))
 			->will($this->returnValue('jane@doe.cz'));
 
-		$expected = new TemplateResponse($this->appName, 'index', [
+		$expected = new TemplateResponse($this->appName, 'index',
+			[
 			'debug' => true,
+			'external-avatars' => 'true',
 			'app-version' => '1.2.3',
 			'accounts' => base64_encode(json_encode($accountsJson)),
 			'prefill_displayName' => 'Jane Doe',
diff --git a/tests/Controller/PreferencesControllerTest.php b/tests/Controller/PreferencesControllerTest.php
new file mode 100644
index 000000000..a8bd9845c
--- /dev/null
+++ b/tests/Controller/PreferencesControllerTest.php
@@ -0,0 +1,74 @@
+<?php
+
+/**
+ * @copyright 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Mail\Tests\Controller;
+
+use OCA\Mail\Contracts\IUserPreferences;
+use OCA\Mail\Controller\PreferencesController;
+use OCA\Mail\Http\JSONResponse;
+use OCA\Mail\Tests\TestCase;
+use OCP\IRequest;
+use PHPUnit_Framework_MockObject_MockObject;
+
+class PreferencesControllerTest extends TestCase {
+
+	/** @var IUserPreferences|PHPUnit_Framework_MockObject_MockObject */
+	private $preferences;
+
+	/** @var PreferencesController */
+	private $controller;
+
+	protected function setUp() {
+		parent::setUp();
+
+		$request = $this->createMock(IRequest::class);
+		$this->preferences = $this->createMock(IUserPreferences::class);
+
+		$this->controller = new PreferencesController($request, $this->preferences);
+	}
+
+	public function testGetPreference() {
+		$this->preferences->expects($this->once())
+			->method('getPreference')
+			->with('test')
+			->willReturn(123);
+		$expected = new JSONResponse(['value' => 123]);
+
+		$actual = $this->controller->show('test');
+
+		$this->assertEquals($expected, $actual);
+	}
+
+	public function testSetPreference() {
+		$this->preferences->expects($this->once())
+			->method('setPreference')
+			->with('test');
+		$expected = new JSONResponse();
+
+		$actual = $this->controller->update('test', 123);
+
+		$this->assertEquals($expected, $actual);
+	}
+
+}
diff --git a/tests/Service/Avatar/CompositeAvatarSourceTest.php b/tests/Service/Avatar/CompositeAvatarSourceTest.php
index e3511c5ee..37088b20d 100644
--- a/tests/Service/Avatar/CompositeAvatarSourceTest.php
+++ b/tests/Service/Avatar/CompositeAvatarSourceTest.php
@@ -60,20 +60,59 @@ class CompositeAvatarSourceTest extends TestCase {
 	public function testFetchNoneFound() {
 		$email = 'jane@doe.com';
 		$avatarFactory = $this->createMock(AvatarFactory::class);
+		$this->addressbookSource->expects($this->any())
+			->method('isExternal')
+			->willReturn(false);
 		$this->addressbookSource->expects($this->once())
 			->method('fetch')
 			->with($email, $avatarFactory)
 			->willReturn(null);
+		$this->gravatarSource->expects($this->any())
+			->method('isExternal')
+			->willReturn(true);
 		$this->gravatarSource->expects($this->once())
 			->method('fetch')
 			->with($email, $avatarFactory)
 			->willReturn(null);
+		$this->faviconSource->expects($this->any())
+			->method('isExternal')
+			->willReturn(true);
 		$this->faviconSource->expects($this->once())
 			->method('fetch')
 			->with($email, $avatarFactory)
 			->willReturn(null);
 
-		$actualAvatar = $this->source->fetch($email, $avatarFactory);
+		$actualAvatar = $this->source->fetch($email, $avatarFactory, true);
+
+		$this->assertNull($actualAvatar);
+	}
+
+	public function testFetchNoneFoundQueryOnlyInternal() {
+		$email = 'jane@doe.com';
+		$avatarFactory = $this->createMock(AvatarFactory::class);
+		$this->addressbookSource->expects($this->once())
+			->method('isExternal')
+			->willReturn(false);
+		$this->addressbookSource->expects($this->once())
+			->method('fetch')
+			->with($email, $avatarFactory)
+			->willReturn(null);
+		$this->gravatarSource->expects($this->once())
+			->method('isExternal')
+			->willReturn(true);
+		$this->gravatarSource->expects($this->never())
+			->method('fetch')
+			->with($email, $avatarFactory)
+			->willReturn(null);
+		$this->faviconSource->expects($this->once())
+			->method('isExternal')
+			->willReturn(true);
+		$this->faviconSource->expects($this->never())
+			->method('fetch')
+			->with($email, $avatarFactory)
+			->willReturn(null);
+
+		$actualAvatar = $this->source->fetch($email, $avatarFactory, false);
 
 		$this->assertNull($actualAvatar);
 	}
@@ -91,7 +130,7 @@ class CompositeAvatarSourceTest extends TestCase {
 			->with($email, $avatarFactory)
 			->willReturn($avatar);
 
-		$actualAvatar = $this->source->fetch($email, $avatarFactory);
+		$actualAvatar = $this->source->fetch($email, $avatarFactory, true);
 
 		$this->assertEquals($avatar, $actualAvatar);
 	}
diff --git a/tests/Service/AvatarServiceTest.php b/tests/Service/AvatarServiceTest.php
index 6a642d628..348efe287 100644
--- a/tests/Service/AvatarServiceTest.php
+++ b/tests/Service/AvatarServiceTest.php
@@ -24,6 +24,7 @@
 
 namespace OCA\Mail\Tests\Service;
 
+use OCA\Mail\Contracts\IUserPreferences;
 use OCA\Mail\Service\Avatar\Avatar;
 use OCA\Mail\Service\Avatar\AvatarFactory;
 use OCA\Mail\Service\Avatar\Cache;
@@ -54,6 +55,9 @@ class AvatarServiceTest extends TestCase {
 	/** @var AvatarFactory|PHPUnit_Framework_MockObject_MockObject */
 	private $avatarFactory;
 
+	/** @var IUserPreferences */
+	private $preferences;
+
 	/** @var AvatarService */
 	private $avatarService;
 
@@ -65,8 +69,10 @@ class AvatarServiceTest extends TestCase {
 		$this->cache = $this->createMock(Cache::class);
 		$this->urlGenerator = $this->createMock(IURLGenerator::class);
 		$this->avatarFactory = $this->createMock(AvatarFactory::class);
+		$this->preferences = $this->createMock(IUserPreferences::class);
 
-		$this->avatarService = new AvatarService($this->source, $this->downloader, $this->cache, $this->urlGenerator, $this->avatarFactory);
+		$this->avatarService = new AvatarService($this->source, $this->downloader,
+			$this->cache, $this->urlGenerator, $this->avatarFactory, $this->preferences);
 	}
 
 	public function testGetCachedAvatarUrl() {
@@ -85,13 +91,17 @@ class AvatarServiceTest extends TestCase {
 	public function testGetAvatarNoAvatarFound() {
 		$email = 'jane@doe.com';
 		$uid = 'john';
+		$this->preferences->expects($this->once())
+			->method('getPreference')
+			->with('external-avatars', 'true')
+			->willReturn('true');
 		$this->cache->expects($this->once())
 			->method('get')
 			->with($email)
 			->willReturn(null);
 		$this->source->expects($this->once())
 			->method('fetch')
-			->with($email, $this->avatarFactory)
+			->with($email, $this->avatarFactory, true)
 			->willReturn(null);
 		$this->cache->expects($this->never())
 			->method('add');
@@ -104,6 +114,10 @@ class AvatarServiceTest extends TestCase {
 	public function testGetAvatarMimeNotAllowed() {
 		$email = 'jane@doe.com';
 		$uid = 'john';
+		$this->preferences->expects($this->once())
+			->method('getPreference')
+			->with('external-avatars', 'true')
+			->willReturn('true');
 		$this->cache->expects($this->once())
 			->method('get')
 			->with($email)
@@ -111,7 +125,7 @@ class AvatarServiceTest extends TestCase {
 		$avatar = new Avatar('http://…', 'application/xml');
 		$this->source->expects($this->once())
 			->method('fetch')
-			->with($email, $this->avatarFactory)
+			->with($email, $this->avatarFactory, true)
 			->willReturn($avatar);
 		$this->cache->expects($this->never())
 			->method('add');
@@ -121,17 +135,46 @@ class AvatarServiceTest extends TestCase {
 		$this->assertNull($url);
 	}
 
+	public function testGetAvatarOnlyInternalAllowed() {
+		$email = 'jane@doe.com';
+		$uid = 'john';
+		$avatar = new Avatar('https://doe.com/favicon.ico', 'image/png');
+		$this->preferences->expects($this->once())
+			->method('getPreference')
+			->with('external-avatars', 'true')
+			->willReturn('false');
+		$this->cache->expects($this->once())
+			->method('get')
+			->with($email)
+			->willReturn(null);
+		$this->source->expects($this->once())
+			->method('fetch')
+			->with($email, $this->avatarFactory, false)
+			->willReturn($avatar);
+		$this->cache->expects($this->once())
+			->method('add')
+			->with($email, $uid, $avatar);
+
+		$actualAvatar = $this->avatarService->getAvatar($email, $uid);
+
+		$this->assertEquals($avatar, $actualAvatar);
+	}
+
 	public function testGetAvatar() {
 		$email = 'jane@doe.com';
 		$uid = 'john';
 		$avatar = new Avatar('https://doe.com/favicon.ico', 'image/png');
+		$this->preferences->expects($this->once())
+			->method('getPreference')
+			->with('external-avatars', 'true')
+			->willReturn('true');
 		$this->cache->expects($this->once())
 			->method('get')
 			->with($email)
 			->willReturn(null);
 		$this->source->expects($this->once())
 			->method('fetch')
-			->with($email, $this->avatarFactory)
+			->with($email, $this->avatarFactory, true)
 			->willReturn($avatar);
 		$this->cache->expects($this->once())
 			->method('add')
diff --git a/tests/Service/UserPreferenceServiceTest.php b/tests/Service/UserPreferenceServiceTest.php
new file mode 100644
index 000000000..4e5a0e079
--- /dev/null
+++ b/tests/Service/UserPreferenceServiceTest.php
@@ -0,0 +1,70 @@
+<?php
+
+/**
+ * @copyright 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Mail\Tests\Service;
+
+use OCA\Mail\Service\UserPreferenceSevice;
+use OCA\Mail\Tests\TestCase;
+use OCP\IConfig;
+
+class UserPreferenceServiceTest extends TestCase {
+
+	/** @var IConfig */
+	private $config;
+
+	/** @var string */
+	private $userId = 'claire';
+
+	/** @var UserPreferenceSevice */
+	private $service;
+
+	protected function setUp() {
+		parent::setUp();
+
+		$this->config = $this->createMock(IConfig::class);
+		$this->service = new UserPreferenceSevice($this->config, $this->userId);
+	}
+
+	public function testGetPreference() {
+		$this->config->expects($this->once())
+			->method('getUserValue')
+			->with($this->userId, 'mail', 'test', null)
+			->willReturn('123');
+		$expected = '123';
+
+		$actual = $this->service->getPreference('test');
+
+		$this->assertEquals($expected, $actual);
+	}
+
+	public function testSetPreference() {
+		$this->config->expects($this->once())
+			->method('setUserValue')
+			->with($this->userId, 'mail', 'test', '123')
+			->willReturn('123');
+
+		$this->service->setPreference('test', '123');
+	}
+
+}