Add storage priority support

Each storage backend has a default priority, assigned to any system mounts
created in ownCloud. mount.json can be manually modified to change these
priorities.

The priority order is as follows:
 * Personal
 * User
 * Group
 * Global

Within each mount type, the mount with the highest priority is active.

The storage backend defaults were chosen to be the following:
 * Local - 150
 * Remote storage - 100
 * SMB / CIFS with OC login - 90

2 files changed, 60 insertions, 4 deletions

diff --git a/apps/files_external/appinfo/app.php b/apps/files_external/appinfo/app.php
index e8ed8950c3a..ca164784fb0 100644
--- a/apps/files_external/appinfo/app.php
+++ b/apps/files_external/appinfo/app.php
@@ -32,11 +32,13 @@ OCP\Util::connectHook('OC_User', 'post_login', 'OC\Files\Storage\SMB_OC', 'login
 
 OC_Mount_Config::registerBackend('\OC\Files\Storage\Local', array(
 	'backend' => (string)$l->t('Local'),
+	'priority' => 150,
 	'configuration' => array(
 		'datadir' => (string)$l->t('Location'))));
 
 OC_Mount_Config::registerBackend('\OC\Files\Storage\AmazonS3', array(
 	'backend' => (string)$l->t('Amazon S3'),
+	'priority' => 100,
 	'configuration' => array(
 		'key' => (string)$l->t('Key'),
 		'secret' => '*'.$l->t('Secret'),
@@ -45,6 +47,7 @@ OC_Mount_Config::registerBackend('\OC\Files\Storage\AmazonS3', array(
 
 OC_Mount_Config::registerBackend('\OC\Files\Storage\AmazonS3', array(
 	'backend' => (string)$l->t('Amazon S3 and compliant'),
+	'priority' => 100,
 	'configuration' => array(
 		'key' => (string)$l->t('Access Key'),
 		'secret' => '*'.$l->t('Secret Key'),
@@ -58,6 +61,7 @@ OC_Mount_Config::registerBackend('\OC\Files\Storage\AmazonS3', array(
 
 OC_Mount_Config::registerBackend('\OC\Files\Storage\Dropbox', array(
 	'backend' => 'Dropbox',
+	'priority' => 100,
 	'configuration' => array(
 		'configured' => '#configured',
 		'app_key' => (string)$l->t('App key'),
@@ -69,6 +73,7 @@ OC_Mount_Config::registerBackend('\OC\Files\Storage\Dropbox', array(
 
 OC_Mount_Config::registerBackend('\OC\Files\Storage\FTP', array(
 	'backend' => 'FTP',
+	'priority' => 100,
 	'configuration' => array(
 		'host' => (string)$l->t('Host'),
 		'user' => (string)$l->t('Username'),
@@ -79,6 +84,7 @@ OC_Mount_Config::registerBackend('\OC\Files\Storage\FTP', array(
 
 OC_Mount_Config::registerBackend('\OC\Files\Storage\Google', array(
 	'backend' => 'Google Drive',
+	'priority' => 100,
 	'configuration' => array(
 		'configured' => '#configured',
 		'client_id' => (string)$l->t('Client ID'),
@@ -90,6 +96,7 @@ OC_Mount_Config::registerBackend('\OC\Files\Storage\Google', array(
 
 OC_Mount_Config::registerBackend('\OC\Files\Storage\Swift', array(
 	'backend' => (string)$l->t('OpenStack Object Storage'),
+	'priority' => 100,
 	'configuration' => array(
 		'user' => (string)$l->t('Username (required)'),
 		'bucket' => (string)$l->t('Bucket (required)'),
@@ -107,6 +114,7 @@ OC_Mount_Config::registerBackend('\OC\Files\Storage\Swift', array(
 if (!OC_Util::runningOnWindows()) {
 	OC_Mount_Config::registerBackend('\OC\Files\Storage\SMB', array(
 		'backend' => 'SMB / CIFS',
+		'priority' => 100,
 		'configuration' => array(
 			'host' => (string)$l->t('Host'),
 			'user' => (string)$l->t('Username'),
@@ -117,6 +125,7 @@ if (!OC_Util::runningOnWindows()) {
 
 	OC_Mount_Config::registerBackend('\OC\Files\Storage\SMB_OC', array(
 			'backend' => (string)$l->t('SMB / CIFS using OC login'),
+			'priority' => 90,
 			'configuration' => array(
 				'host' => (string)$l->t('Host'),
 				'username_as_share' => '!'.$l->t('Username as share'),
@@ -127,6 +136,7 @@ if (!OC_Util::runningOnWindows()) {
 
 OC_Mount_Config::registerBackend('\OC\Files\Storage\DAV', array(
 	'backend' => 'WebDAV',
+	'priority' => 100,
 	'configuration' => array(
 		'host' => (string)$l->t('URL'),
 		'user' => (string)$l->t('Username'),
@@ -137,6 +147,7 @@ OC_Mount_Config::registerBackend('\OC\Files\Storage\DAV', array(
 
 OC_Mount_Config::registerBackend('\OC\Files\Storage\OwnCloud', array(
 	'backend' => 'ownCloud',
+	'priority' => 100,
 	'configuration' => array(
 		'host' => (string)$l->t('URL'),
 		'user' => (string)$l->t('Username'),
@@ -147,6 +158,7 @@ OC_Mount_Config::registerBackend('\OC\Files\Storage\OwnCloud', array(
 
 OC_Mount_Config::registerBackend('\OC\Files\Storage\SFTP', array(
 	'backend' => 'SFTP',
+	'priority' => 100,
 	'configuration' => array(
 		'host' => (string)$l->t('Host'),
 		'user' => (string)$l->t('Username'),
diff --git a/apps/files_external/lib/config.php b/apps/files_external/lib/config.php
index 7a651239cb4..e23a72b56f1 100755
--- a/apps/files_external/lib/config.php
+++ b/apps/files_external/lib/config.php
@@ -126,6 +126,8 @@ class OC_Mount_Config {
 		$datadir = \OC_Config::getValue("datadirectory", \OC::$SERVERROOT . "/data");
 		$mount_file = \OC_Config::getValue("mount_file", $datadir . "/mount.json");
 
+		$backends = self::getBackends();
+
 		//move config file to it's new position
 		if (is_file(\OC::$SERVERROOT . '/config/mount.json')) {
 			rename(\OC::$SERVERROOT . '/config/mount.json', $mount_file);
@@ -136,7 +138,15 @@ class OC_Mount_Config {
 		if (isset($mountConfig[self::MOUNT_TYPE_GLOBAL])) {
 			foreach ($mountConfig[self::MOUNT_TYPE_GLOBAL] as $mountPoint => $options) {
 				$options['options'] = self::decryptPasswords($options['options']);
-				$mountPoints[$mountPoint] = $options;
+				if (!isset($options['priority'])) {
+					$options['priority'] = $backends[$options['class']]['priority'];
+				}
+
+				if ( (!isset($mountPoints[$mountPoint]))
+					|| ($options['priority'] >= $mountPoints[$mountPoint]['priority']) ) {
+					$options['priority_type'] = 'global';
+					$mountPoints[$mountPoint] = $options;
+				}
 			}
 		}
 		if (isset($mountConfig[self::MOUNT_TYPE_GROUP])) {
@@ -148,7 +158,16 @@ class OC_Mount_Config {
 							$option = self::setUserVars($user, $option);
 						}
 						$options['options'] = self::decryptPasswords($options['options']);
-						$mountPoints[$mountPoint] = $options;
+						if (!isset($options['priority'])) {
+							$options['priority'] = $backends[$options['class']]['priority'];
+						}
+
+						if ( (!isset($mountPoints[$mountPoint]))
+							|| ($options['priority'] >= $mountPoints[$mountPoint]['priority'])
+							|| ($mountPoints[$mountPoint]['priority_type'] != 'group') ) {
+							$options['priority_type'] = 'group';
+							$mountPoints[$mountPoint] = $options;
+						}
 					}
 				}
 			}
@@ -162,7 +181,16 @@ class OC_Mount_Config {
 							$option = self::setUserVars($user, $option);
 						}
 						$options['options'] = self::decryptPasswords($options['options']);
-						$mountPoints[$mountPoint] = $options;
+						if (!isset($options['priority'])) {
+							$options['priority'] = $backends[$options['class']]['priority'];
+						}
+
+						if ( (!isset($mountPoints[$mountPoint]))
+							|| ($options['priority'] >= $mountPoints[$mountPoint]['priority'])
+							|| ($mountPoints[$mountPoint]['priority_type'] != 'user') ) {
+							$options['priority_type'] = 'user';
+							$mountPoints[$mountPoint] = $options;
+						}
 					}
 				}
 			}
@@ -173,7 +201,12 @@ class OC_Mount_Config {
 		if (isset($mountConfig[self::MOUNT_TYPE_USER][$user])) {
 			foreach ($mountConfig[self::MOUNT_TYPE_USER][$user] as $mountPoint => $options) {
 				$options['options'] = self::decryptPasswords($options['options']);
-				$mountPoints[$mountPoint] = $options;
+
+				if ( (!isset($mountPoints[$mountPoint]))
+					|| ($mountPoints[$mountPoint]['priority_type'] != 'personal') ) {
+					$options['priority_type'] = 'personal';
+					$mountPoints[$mountPoint] = $options;
+				}
 			}
 		}
 
@@ -244,6 +277,9 @@ class OC_Mount_Config {
 						$mount['class'] = '\OC\Files\Storage\\'.substr($mount['class'], 15);
 					}
 					$mount['options'] = self::decryptPasswords($mount['options']);
+					if (!isset($mount['priority'])) {
+						$mount['priority'] = $backends[$mount['class']]['priority'];
+					}
 					// Remove '/$user/files/' from mount point
 					$mountPoint = substr($mountPoint, 13);
 
@@ -251,6 +287,7 @@ class OC_Mount_Config {
 						'class' => $mount['class'],
 						'mountpoint' => $mountPoint,
 						'backend' => $backends[$mount['class']]['backend'],
+						'priority' => $mount['priority'],
 						'options' => $mount['options'],
 						'applicable' => array('groups' => array($group), 'users' => array()),
 						'status' => self::getBackendStatus($mount['class'], $mount['options'], false)
@@ -275,12 +312,16 @@ class OC_Mount_Config {
 						$mount['class'] = '\OC\Files\Storage\\'.substr($mount['class'], 15);
 					}
 					$mount['options'] = self::decryptPasswords($mount['options']);
+					if (!isset($mount['priority'])) {
+						$mount['priority'] = $backends[$mount['class']]['priority'];
+					}
 					// Remove '/$user/files/' from mount point
 					$mountPoint = substr($mountPoint, 13);
 					$config = array(
 						'class' => $mount['class'],
 						'mountpoint' => $mountPoint,
 						'backend' => $backends[$mount['class']]['backend'],
+						'priority' => $mount['priority'],
 						'options' => $mount['options'],
 						'applicable' => array('groups' => array(), 'users' => array($user)),
 						'status' => self::getBackendStatus($mount['class'], $mount['options'], false)
@@ -400,6 +441,9 @@ class OC_Mount_Config {
 				'options' => self::encryptPasswords($classOptions))
 			)
 		);
+		if (! $isPersonal) {
+			$mount[$applicable][$mountPoint]['priority'] = $backends[$class]['priority'];
+		}
 
 		$mountPoints = self::readData($isPersonal ? OCP\User::getUser() : NULL);
 		$mountPoints = self::mergeMountPoints($mountPoints, $mount, $mountType);