<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

namespace repository_nextcloud;

use testable_access_controlled_link_manager;

defined('MOODLE_INTERNAL') || die();

global $CFG;
require_once($CFG->libdir . '/webdavlib.php');
require_once($CFG->dirroot . '/repository/nextcloud/tests/fixtures/testable_access_controlled_link_manager.php');

/**
 * Class repository_nextcloud_testcase
 *
 * @package repository_nextcloud
 * @group repository_nextcloud
 * @copyright  2017 Project seminar (Learnweb, University of Münster)
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class access_controlled_link_manager_test extends \advanced_testcase {

    /** @var null|testable_access_controlled_link_manager a malleable variant of the access_controlled_link_manager. */
    public $linkmanager = null;

    /** @var null|\repository_nextcloud\ocs_client The ocs_client used to send requests. */
    public $ocsmockclient = null;

    /** @var null|\core\oauth2\client Mock oauth client for the system account. */
    private $oauthsystemmock = null;

    /** @var null|\core\oauth2\issuer which belongs to the repository_nextcloud object. */
    public $issuer = null;

    /** @var string system account username. */
    public $systemaccountusername;

    /**
     * SetUp to create an repository instance.
     */
    protected function setUp(): void {
        $this->resetAfterTest(true);

        // Admin is necessary to create issuer object.
        $this->setAdminUser();

        $generator = $this->getDataGenerator()->get_plugin_generator('repository_nextcloud');
        $this->issuer = $generator->test_create_issuer();
        $generator->test_create_endpoints($this->issuer->get('id'));

        // Mock clients.
        $this->ocsmockclient = $this->getMockBuilder(ocs_client::class
        )->disableOriginalConstructor()->disableOriginalClone()->getMock();
        $this->oauthsystemmock = $this->getMockBuilder(\core\oauth2\client::class
        )->disableOriginalConstructor()->disableOriginalClone()->getMock();
        $systemwebdavclient = $this->getMockBuilder(\webdav_client::class
        )->disableOriginalConstructor()->disableOriginalClone()->getMock();
        $systemocsclient = $systemocsclient = $this->getMockBuilder(ocs_client::class
        )->disableOriginalConstructor()->disableOriginalClone()->getMock();

        // Pseudo system account user.
        $this->systemaccountusername = 'pseudouser';
        $record = new \stdClass();
        $record->issuerid = $this->issuer->get('id');
        $record->refreshtoken = 'pseudotoken';
        $record->grantedscopes = 'scopes';
        $record->email = '';
        $record->username = $this->systemaccountusername;
        $systemaccount = new \core\oauth2\system_account(0, $record);
        $systemaccount->create();

        $this->linkmanager = new testable_access_controlled_link_manager($this->ocsmockclient,
            $this->oauthsystemmock, $systemocsclient,
            $this->issuer, 'Nextcloud', $systemwebdavclient);

    }

    /**
     * Function to test the private function create_share_user_sysaccount.
     */
    public function test_create_share_user_sysaccount_user_shares() {
        $params = [
            'path' => "/ambient.txt",
            'shareType' => \repository_nextcloud\ocs_client::SHARE_TYPE_USER,
            'publicUpload' => false,
            'shareWith' => $this->systemaccountusername,
            'permissions' => \repository_nextcloud\ocs_client::SHARE_PERMISSION_READ,
        ];
        $expectedresponse = <<<XML
<?xml version="1.0"?>
<ocs>
 <meta>
  <status>ok</status>
  <statuscode>100</statuscode>
  <message/>
 </meta>
 <data>
  <id>207</id>
  <share_type>0</share_type>
  <uid_owner>user1</uid_owner>
  <displayname_owner>user1</displayname_owner>
  <permissions>19</permissions>
  <stime>1511532198</stime>
  <parent/>
  <expiration/>
  <token/>
  <uid_file_owner>user1</uid_file_owner>
  <displayname_file_owner>user1</displayname_file_owner>
  <path>/ambient.txt</path>
  <item_type>file</item_type>
  <mimetype>text/plain</mimetype>
  <storage_id>home::user1</storage_id>
  <storage>3</storage>
  <item_source>545</item_source>
  <file_source>545</file_source>
  <file_parent>20</file_parent>
  <file_target>/ambient.txt</file_target>
  <share_with>tech</share_with>
  <share_with_displayname>tech</share_with_displayname>
  <mail_send>0</mail_send>
 </data>
</ocs>
XML;
        $this->ocsmockclient->expects($this->once())->method('call')->with('create_share', $params)->will(
            $this->returnValue($expectedresponse));

        $result = $this->linkmanager->create_share_user_sysaccount("/ambient.txt");
        $xml = simplexml_load_string($expectedresponse);
        $expected = array();
        $expected['statuscode'] = (int)$xml->meta->statuscode;
        $expected['shareid'] = (int)$xml->data->id;
        $expected['filetarget'] = (string)$xml->data[0]->file_target;
        $this->assertEquals($expected, $result);
    }
    /**
     * Test the delete_share_function. In case the request fails, the function throws an exception, however this
     * can not be tested in phpUnit since it is javascript.
     */
    public function test_delete_share_dataowner_sysaccount() {
        $shareid = 5;
        $deleteshareparams = [
            'share_id' => $shareid
        ];
        $returnxml = <<<XML
<?xml version="1.0"?>
<ocs>
    <meta>
    <status>ok</status>
    <statuscode>100</statuscode>
    <message/>
    </meta>
    <data/>
</ocs>
XML;
        $this->ocsmockclient->expects($this->once())->method('call')->with('delete_share', $deleteshareparams)->will(
            $this->returnValue($returnxml));
        $this->linkmanager->delete_share_dataowner_sysaccount($shareid, 'repository_nextcloud');

    }

    /**
     * Function which test that create folder path does return the adequate results (path and success).
     * Additionally mock checks whether the right params are passed to the corresponding functions.
     */
    public function test_create_folder_path_folders_are_not_created() {

        $mocks = $this->set_up_mocks_for_create_folder_path(true, 'somename');
        $this->set_private_property($mocks['mockclient'], 'systemwebdavclient', $this->linkmanager);
        $result = $this->linkmanager->create_folder_path_access_controlled_links($mocks['mockcontext'], "mod_resource",
            'content', 0);
        $this->assertEquals('/somename (ctx )/mod_resource/content/0', $result);
    }
    /**
     * Function which test that create folder path does return the adequate results (path and success).
     * Additionally mock checks whether the right params are passed to the corresponding functions.
     */
    public function test_create_folder_path_folders_are_created() {

        // In Context is okay, number of context counts for number of iterations.
        $mocks = $this->set_up_mocks_for_create_folder_path(false, 'somename/withslash', true, 201);
        $this->set_private_property($mocks['mockclient'], 'systemwebdavclient', $this->linkmanager);
        $result = $this->linkmanager->create_folder_path_access_controlled_links($mocks['mockcontext'], "mod_resource",
            'content', 0);
        $this->assertEquals('/somenamewithslash (ctx )/mod_resource/content/0', $result);
    }
    /**
     * Test whether the create_folder_path methode throws exception.
     */
    public function test_create_folder_path_folder_creation_fails() {

        $mocks = $this->set_up_mocks_for_create_folder_path(false, 'somename', true, 400);
        $this->set_private_property($mocks['mockclient'], 'systemwebdavclient', $this->linkmanager);
        $this->expectException(\repository_nextcloud\request_exception::class);
        $this->linkmanager->create_folder_path_access_controlled_links($mocks['mockcontext'], "mod_resource",
            'content', 0);
    }

    /**
     * Helper function to generate mocks for testing create folder path.
     * @param bool $returnisdir Return value mocking the result of invoking is_dir
     * @param bool $returnestedcontext Name of the folder that is simulated to be checked/created
     * @param bool $callmkcol Also mock creation of the folder
     * @param int $returnmkcol Return value mocking the result of invoking mkcol
     * @return array ['mockcontext' context_module mock, 'mockclient' => webdav client mock]
     */
    protected function set_up_mocks_for_create_folder_path($returnisdir, $returnestedcontext, $callmkcol = false,
                                                           $returnmkcol = 201) {
        $mockcontext = $this->createMock(\context_module::class);
        $mockclient = $this->getMockBuilder(\webdav_client::class
        )->disableOriginalConstructor()->disableOriginalClone()->getMock();
        $parsedwebdavurl = parse_url($this->issuer->get_endpoint_url('webdav'));
        $webdavprefix = $parsedwebdavurl['path'];
        // Empty ctx 'id' expected because using code will not be able to access $ctx->id.
        $cleanedcontextname = clean_param($returnestedcontext, PARAM_FILE);
        $dirstring = $webdavprefix . '/' . $cleanedcontextname . ' (ctx )';
        $mockclient->expects($this->atMost(4))->method('is_dir')->with($this->logicalOr(
            $dirstring, $dirstring . '/mod_resource', $dirstring . '/mod_resource/content',
            $dirstring . '/mod_resource/content/0'))->willReturn($returnisdir);
        if ($callmkcol == true) {
            $mockclient->expects($this->atMost(4))->method('mkcol')->willReturn($returnmkcol);
        }
        $mockcontext->method('get_parent_contexts')->willReturn(array('1' => $mockcontext));
        $mockcontext->method('get_context_name')->willReturn($returnestedcontext);

        return array('mockcontext' => $mockcontext, 'mockclient' => $mockclient);
    }

    /**
     * Test whether the right methods from the webdavclient are called when the storage_folder is created.
     * 1. Directory already exist -> no further action needed.
     */
    public function test_create_storage_folder_success() {
        $mockwebdavclient = $this->createMock(\webdav_client::class);
        $url = $this->issuer->get_endpoint_url('webdav');
        $parsedwebdavurl = parse_url($url);
        $webdavprefix = $parsedwebdavurl['path'];
        $mockwebdavclient->expects($this->once())->method('open')->willReturn(true);
        $mockwebdavclient->expects($this->once())->method('is_dir')->with($webdavprefix . 'myname')->willReturn(true);
        $mockwebdavclient->expects($this->once())->method('close');
        $this->linkmanager->create_storage_folder('myname', $mockwebdavclient);

    }
    /**
     * Test whether the right methods from the webdavclient are called when the storage_folder is created.
     * 2. Directory does not exist. It is created with mkcol and returns a success.
     *
     */
    public function test_create_storage_folder_success_mkcol() {
        $mockwebdavclient = $this->createMock(\webdav_client::class);
        $url = $this->issuer->get_endpoint_url('webdav');
        $parsedwebdavurl = parse_url($url);
        $webdavprefix = $parsedwebdavurl['path'];
        $mockwebdavclient->expects($this->once())->method('open')->willReturn(true);
        $mockwebdavclient->expects($this->once())->method('is_dir')->with($webdavprefix . 'myname')->willReturn(false);
        $mockwebdavclient->expects($this->once())->method('mkcol')->with($webdavprefix . 'myname')->willReturn(201);
        $mockwebdavclient->expects($this->once())->method('close');

        $this->linkmanager->create_storage_folder('myname', $mockwebdavclient);
    }
    /**
     * Test whether the right methods from the webdavclient are called when the storage_folder is created.
     * 3. Request to create Folder fails.
     */
    public function test_create_storage_folder_failure() {
        $mockwebdavclient = $this->createMock(\webdav_client::class);
        $url = $this->issuer->get_endpoint_url('webdav');
        $parsedwebdavurl = parse_url($url);
        $webdavprefix = $parsedwebdavurl['path'];
        $mockwebdavclient->expects($this->once())->method('open')->willReturn(true);
        $mockwebdavclient->expects($this->once())->method('is_dir')->with($webdavprefix . 'myname')->willReturn(false);
        $mockwebdavclient->expects($this->once())->method('mkcol')->with($webdavprefix . 'myname')->willReturn(400);

        $this->expectException(\repository_nextcloud\request_exception::class);
        $this->linkmanager->create_storage_folder('myname', $mockwebdavclient);
    }
    /**
     * Test whether the webdav client gets the right params and whether function differentiates between move and copy.
     */
    public function test_transfer_file_to_path_copyfile() {
        // Initialize params.
        $parsedwebdavurl = parse_url($this->issuer->get_endpoint_url('webdav'));
        $webdavprefix = $parsedwebdavurl['path'];
        $srcpath = 'sourcepath';
        $dstpath = "destinationpath/another/path";

        // Mock the Webdavclient and set expected methods.
        $systemwebdavclientmock = $this->createMock(\webdav_client::class);
        $systemwebdavclientmock->expects($this->once())->method('open')->willReturn(true);
        $systemwebdavclientmock->expects($this->once())->method('copy_file')->with($webdavprefix . $srcpath,
            $webdavprefix . $dstpath . '/' . $srcpath, true)->willReturn(201);
        $this->set_private_property($systemwebdavclientmock, 'systemwebdavclient', $this->linkmanager);

        // Call of function.
        $result = $this->linkmanager->transfer_file_to_path($srcpath, $dstpath, 'copy');

        $this->assertEquals(201, $result);
    }
    /**
     * Test whether the webdav client gets the right params and whether function handles overwrite.
     *
     * @covers \repository_nextcloud\access_controlled_link_manager::transfer_file_to_path
     */
    public function test_transfer_file_to_path_overwritefile() {
        // Initialize params.
        $parsedwebdavurl = parse_url($this->issuer->get_endpoint_url('webdav'));
        $webdavprefix = $parsedwebdavurl['path'];
        $srcpath = 'sourcepath';
        $dstpath = "destinationpath/another/path";

        // Mock the Webdavclient and set expected methods.
        $systemwebdavclientmock = $this->createMock(\webdav_client::class);
        $systemwebdavclientmock->expects($this->once())->method('open')->willReturn(true);
        $systemwebdavclientmock->expects($this->once())->method('copy_file')->with($webdavprefix . $srcpath,
            $webdavprefix . $dstpath . '/' . $srcpath, true)->willReturn(204);
        $this->set_private_property($systemwebdavclientmock, 'systemwebdavclient', $this->linkmanager);

        // Call of function.
        $result = $this->linkmanager->transfer_file_to_path($srcpath, $dstpath, 'copy');

        $this->assertEquals(204, $result);
    }
    /**
     * This function tests whether the function transfer_file_to_path() moves or copies a given file to a given path
     * It tests whether the webdav_client gets the right parameter and whether function distinguishes between move and copy.
     *
     */
    public function test_transfer_file_to_path_copyfile_movefile() {
        // Initialize params.
        $parsedwebdavurl = parse_url($this->issuer->get_endpoint_url('webdav'));
        $webdavprefix = $parsedwebdavurl['path'];
        $srcpath = 'sourcepath';
        $dstpath = "destinationpath/another/path";

        $systemwebdavclientmock = $this->createMock(\webdav_client::class);

        $systemwebdavclientmock->expects($this->once())->method('open')->willReturn(true);
        $this->set_private_property($systemwebdavclientmock, 'systemwebdavclient', $this->linkmanager);
        $webdavclientmock = $this->createMock(\webdav_client::class);

        $webdavclientmock->expects($this->once())->method('move')->with($webdavprefix . $srcpath,
            $webdavprefix . $dstpath . '/' . $srcpath, false)->willReturn(201);
        $result = $this->linkmanager->transfer_file_to_path($srcpath, $dstpath, 'move', $webdavclientmock);
        $this->assertEquals(201, $result);
    }

    /**
     * Test the get_shares_from path() function. This function extracts from an list of shares the share of a given user
     * (the username is a parameter in the function call) and returns the id. The test firstly test whether the right fileid
     * for user1 is extracted then for user2 and last but least whether an error is thrown if the user does not have a share.
     * @throws moodle_exception
     */
    public function test_get_shares_from_path() {
        $params = [
            'path' => '/Kernsystem/Kursbereich Miscellaneous/Kurs Example Course/Datei zet/mod_resource/content/0/picture.png',
            'reshares' => true
        ];
        $reference = new \stdClass();
        $reference->link = "/Kernsystem/Kursbereich Miscellaneous/Kurs Example Course/Datei zet/mod_resource/content/0/picture.png";
        $reference->name = "f\u00fcrdennis.png";
        $reference->usesystem = true;
        $expectedresponse = <<<XML
<?xml version="1.0"?>
<ocs>
 <meta>
  <status>ok</status>
  <statuscode>100</statuscode>
  <message/>
 </meta>
 <data>
  <element>
   <id>292</id>
   <share_type>0</share_type>
   <uid_owner>tech</uid_owner>
   <displayname_owner>tech</displayname_owner>
   <permissions>19</permissions>
   <stime>1515752494</stime>
   <parent/>
   <expiration/>
   <token/>
   <uid_file_owner>tech</uid_file_owner>
   <displayname_file_owner>tech</displayname_file_owner>
   <path>some/path/of/some/file.pdf</path>
   <item_type>file</item_type>
   <mimetype>image/png</mimetype>
   <storage_id>home::tech</storage_id>
   <storage>4</storage>
   <item_source>1085</item_source>
   <file_source>1085</file_source>
   <file_parent>1084</file_parent>
   <file_target>/fehler (3).png</file_target>
   <share_with>user1</share_with>
   <share_with_displayname>user1</share_with_displayname>
   <mail_send>0</mail_send>
  </element>
  <element>
   <id>293</id>
   <share_type>0</share_type>
   <uid_owner>tech</uid_owner>
   <displayname_owner>tech</displayname_owner>
   <permissions>19</permissions>
   <stime>1515752494</stime>
   <parent/>
   <expiration/>
   <token/>
   <uid_file_owner>tech</uid_file_owner>
   <displayname_file_owner>tech</displayname_file_owner>
   <path>some/path/of/some/file.pdf</path>
   <item_type>file</item_type>
   <mimetype>image/png</mimetype>
   <storage_id>home::tech</storage_id>
   <storage>4</storage>
   <item_source>1085</item_source>
   <file_source>1085</file_source>
   <file_parent>1084</file_parent>
   <file_target>/fehler (3).png</file_target>
   <share_with>user2</share_with>
   <share_with_displayname>user2</share_with_displayname>
   <mail_send>0</mail_send>
  </element>
 </data>
</ocs>
XML;
        $this->set_private_property($this->ocsmockclient, 'systemocsclient', $this->linkmanager);

        $this->ocsmockclient->expects($this->exactly(3))->method('call')->with('get_shares', $params)->will(
            $this->returnValue($expectedresponse));
        $xmlobjuser1 = (int) $this->linkmanager->get_shares_from_path($reference->link, 'user2');
        $xmlobjuser2 = (int) $this->linkmanager->get_shares_from_path($reference->link, 'user1');

        $this->assertEquals(293, $xmlobjuser1);
        $this->assertEquals(292, $xmlobjuser2);

        $this->expectException(\repository_nextcloud\request_exception::class);

        $this->expectExceptionMessage('A request to Nextcloud has failed. The requested file could not be accessed. Please ' .
            'check whether you have chosen a valid file and you are authenticated with the right account.');
        $this->linkmanager->get_shares_from_path($reference->link, 'user3');

    }
    /** Test whether the systemwebdav client is constructed correctly. Port is set to 443 in case of https, to 80 in
     * case of http and exception is thrown when endpoint does not exist.
     * @throws \repository_nextcloud\configuration_exception
     * @throws coding_exception
     */
    public function test_create_system_dav() {
        // Initialize mock and params.
        $fakeaccesstoken = new \stdClass();
        $fakeaccesstoken->token = "fake access token";
        // Use `atLeastOnce` instead of `exactly(2)` because it is only called a second time on dev systems that allow http://.
        $this->oauthsystemmock->expects($this->atLeastOnce())->method('get_accesstoken')->willReturn($fakeaccesstoken);
        $parsedwebdavurl = parse_url($this->issuer->get_endpoint_url('webdav'));

        // Call function and create own client.
        $dav = $this->linkmanager->create_system_dav();
        $mydav = new \webdav_client($parsedwebdavurl['host'], '', '', 'bearer', 'ssl://',
            "fake access token", $parsedwebdavurl['path']);
        $mydav->port = 443;
        $mydav->debug = false;
        $this->assertEquals($mydav, $dav);

        // Deletes the old webdav endpoint and ...
        $this->delete_endpoints('webdav_endpoint');
        // Creates a new one which requires different ports.
        try {
            $endpoint = new \stdClass();
            $endpoint->name = "webdav_endpoint";
            $endpoint->url = 'http://www.default.test/webdav/index.php';
            $endpoint->issuerid = $this->issuer->get('id');
            \core\oauth2\api::create_endpoint($endpoint);

            // Call function and create own client.
            $dav = $this->linkmanager->create_system_dav();
            $mydav = new \webdav_client($parsedwebdavurl['host'], '', '', 'bearer', '',
                "fake access token");
            $mydav->port = 80;
            $mydav->debug = false;
            $this->assertEquals($mydav, $dav);
        } catch (core\invalid_persistent_exception $e) {
            // In some cases Moodle does not allow to create http connections. In those cases the exception
            // is catched here and the test are executed.
            $this->expectException(\core\invalid_persistent_exception::class);
            $this->linkmanager->create_system_dav();
        } finally {

            // Delte endpoints and ...
            $this->delete_endpoints('webdav_endpoint');

            // Do not insert new ones, therefore exception is thrown.
            $this->expectException(\repository_nextcloud\configuration_exception::class);
            $this->linkmanager->create_system_dav();
        }
    }

    /**
     * Tests the function get_share_information_from_shareid(). From a response with two element it is tested
     * whether the right file_target is extracted and lastly it is checked whether an error is thrown in case no suitable
     * element exists.
     * @throws \repository_nextcloud\request_exception
     * @throws coding_exception
     */
    public function test_get_share_information_from_shareid() {
        $params303 = [
            'share_id' => 303,
        ];
        $params302 = [
            'share_id' => 302,
        ];
        $expectedresponse = <<<XML
<?xml version="1.0"?>
<ocs>
 <meta>
  <status>ok</status>
  <statuscode>100</statuscode>
  <message/>
 </meta>
 <data>
  <element>
   <id>302</id>
   <share_type>0</share_type>
   <uid_owner>tech</uid_owner>
   <displayname_owner>tech</displayname_owner>
   <permissions>19</permissions>
   <stime>1516096325</stime>
   <parent/>
   <expiration/>
   <token/>
   <uid_file_owner>tech</uid_file_owner>
   <displayname_file_owner>tech</displayname_file_owner>
     <path>/some/target (2).png</path>
   <item_type>file</item_type>
   <mimetype>image/png</mimetype>
   <storage_id>shared::/some/target.png</storage_id>
   <storage>4</storage>
   <item_source>1125</item_source>
   <file_source>1125</file_source>
   <file_parent>20</file_parent>
   <file_target>/some/target.png</file_target>
   <share_with>user1</share_with>
   <share_with_displayname>user1</share_with_displayname>
   <mail_send>0</mail_send>
  </element>
  <element>
   <id>303</id>
   <share_type>0</share_type>
   <uid_owner>tech</uid_owner>
   <displayname_owner>tech</displayname_owner>
   <permissions>19</permissions>
   <stime>1516096325</stime>
   <parent/>
   <expiration/>
   <token/>
   <uid_file_owner>tech</uid_file_owner>
   <displayname_file_owner>tech</displayname_file_owner>
   <path>/some/target (2).pdf</path>
   <item_type>file</item_type>
   <mimetype>image/png</mimetype>
   <storage_id>shared::/some/target.pdf</storage_id>
   <storage>4</storage>
   <item_source>1125</item_source>
   <file_source>1125</file_source>
   <file_parent>20</file_parent>
   <file_target>/some/target.pdf</file_target>
   <share_with>user2</share_with>
   <share_with_displayname>user1</share_with_displayname>
   <mail_send>0</mail_send>
  </element>
 </data>
</ocs>
XML;
        $this->set_private_property($this->ocsmockclient, 'systemocsclient', $this->linkmanager);

        $this->ocsmockclient->expects($this->exactly(3))->method('call')->with('get_information_of_share',
            $this->logicalOr($params303, $params302))->will($this->returnValue($expectedresponse));

        // Test function for two different users. Setting the id is just a dummy value since always $expectedresponse ...
        // ... is returned.
        $filetarget = $this->linkmanager->get_share_information_from_shareid(303, 'user2');
        $this->assertEquals('/some/target.pdf', $filetarget);

        $filetarget = $this->linkmanager->get_share_information_from_shareid(302, 'user1');
        $this->assertEquals('/some/target.png', $filetarget);

        // Expect exception in case no suitable elemtn exist in the response.
        $this->expectException(\repository_nextcloud\request_exception::class);
        $this->expectExceptionMessage('A request to Nextcloud has failed. The requested file could not be accessed. Please ' .
            'check whether you have chosen a valid file and you are authenticated with the right account.');
        $this->linkmanager->get_share_information_from_shareid(302, 'user3');
    }

    /**
     * Helper method which inserts a value into a non-public field of an object.
     *
     * @param mixed $value mock value that will be inserted.
     * @param string $propertyname name of the private property.
     * @param object $class Instance that is being modified.
     * @return ReflectionProperty the resulting reflection property.
     */
    protected function set_private_property($value, $propertyname, $class) {
        $refclient = new \ReflectionClass($class);
        $private = $refclient->getProperty($propertyname);
        $private->setAccessible(true);
        $private->setValue($class, $value);
        return $private;
    }
    /**
     * Helper method which gets a value from a non-public field of an object.
     *
     * @param string $propertyname name of the private property.
     * @param object $class Instance that is being modified.
     * @return mixed the resulting value.
     */
    protected function get_private_property($propertyname, $class) {
        $refclient = new \ReflectionClass($class);
        $private = $refclient->getProperty($propertyname);
        $private->setAccessible(true);
        $property = $private->getValue($private);
        return $property;
    }
    /**
     * Deletes all endpoint with the given name.
     * @param string $endpointname
     * @return array|null
     * @throws moodle_exception
     */
    protected function delete_endpoints($endpointname) {
        $endpoints = \core\oauth2\api::get_endpoints($this->issuer);
        $arrayofids = array();
        foreach ($endpoints as $endpoint) {
            $name = $endpoint->get('name');
            if ($name === $endpointname) {
                $arrayofids[$endpoint->get('id')] = $endpoint->get('id');
            }
        }
        if (empty($arrayofids)) {
            return;
        }
        foreach ($arrayofids as $id) {
            \core\oauth2\api::delete_endpoint($id);
        }
    }

}
