<?php
// This file is part of Moodle - http://moodle.org/
//
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// 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.
//
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
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// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Testing the service layer within core_favourites.
 *
 * @package    core_favourites
 * @category   test
 * @copyright  2018 Jake Dallimore <jrhdallimore@gmail.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

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

/**
 * Test class covering the user_favourites_service within the service layer of favourites.
 *
 * @copyright  2018 Jake Dallimore <jrhdallimore@gmail.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class user_favourites_service_testcase extends advanced_testcase {

    public function setUp() {
        $this->resetAfterTest();
    }

    // Basic setup stuff to be reused in most tests.
    protected function setup_users_and_courses() {
        $user1 = self::getDataGenerator()->create_user();
        $user1context = \context_user::instance($user1->id);
        $user2 = self::getDataGenerator()->create_user();
        $user2context = \context_user::instance($user2->id);
        $course1 = self::getDataGenerator()->create_course();
        $course2 = self::getDataGenerator()->create_course();
        $course1context = context_course::instance($course1->id);
        $course2context = context_course::instance($course2->id);
        return [$user1context, $user2context, $course1context, $course2context];
    }

    /**
     * Generates an in-memory repository for testing, using an array store for CRUD stuff.
     *
     * @param array $mockstore
     * @return \PHPUnit\Framework\MockObject\MockObject
     */
    protected function get_mock_repository(array $mockstore) {
        // This mock will just store data in an array.
        $mockrepo = $this->getMockBuilder(\core_favourites\local\repository\ifavourites_repository::class)
            ->setMethods([])
            ->getMock();
        $mockrepo->expects($this->any())
            ->method('add')
            ->will($this->returnCallback(function(\stdclass $favourite) use (&$mockstore) {
                // Mock implementation of repository->add(), where an array is used instead of the DB.
                // Duplicates are confirmed via the unique key, and exceptions thrown just like a real repo.
                $key = $favourite->userid . $favourite->component . $favourite->itemtype . $favourite->itemid
                    . $favourite->contextid;

                // Check the objects for the unique key.
                foreach ($mockstore as $item) {
                    if ($item->uniquekey == $key) {
                        throw new \moodle_exception('Favourite already exists');
                    }
                }
                $index = count($mockstore);     // Integer index.
                $favourite->uniquekey = $key;   // Simulate the unique key constraint.
                $favourite->id = $index;
                $mockstore[$index] = $favourite;
                return $mockstore[$index];
            })
        );
        $mockrepo->expects($this->any())
            ->method('find_by')
            ->will($this->returnCallback(function(array $criteria, int $limitfrom = 0, int $limitnum = 0) use (&$mockstore) {
                // Check the mockstore for all objects with properties matching the key => val pairs in $criteria.
                foreach ($mockstore as $index => $mockrow) {
                    $mockrowarr = (array)$mockrow;
                    if (array_diff($criteria, $mockrowarr) == []) {
                        $returns[$index] = $mockrow;
                    }
                }
                // Return a subset of the records, according to the paging options, if set.
                if ($limitnum != 0) {
                    return array_slice($returns, $limitfrom, $limitnum);
                }
                // Otherwise, just return the full set.
                return $returns;
            })
        );
        $mockrepo->expects($this->any())
            ->method('find_favourite')
            ->will($this->returnCallback(function(int $userid, string $comp, string $type, int $id, int $ctxid) use (&$mockstore) {
                // Check the mockstore for all objects with properties matching the key => val pairs in $criteria.
                $crit = ['userid' => $userid, 'component' => $comp, 'itemtype' => $type, 'itemid' => $id, 'contextid' => $ctxid];
                foreach ($mockstore as $fakerow) {
                    $fakerowarr = (array)$fakerow;
                    if (array_diff($crit, $fakerowarr) == []) {
                        return $fakerow;
                    }
                }
                throw new \moodle_exception("Item not found");
            })
        );
        $mockrepo->expects($this->any())
            ->method('find')
            ->will($this->returnCallback(function(int $id) use (&$mockstore) {
                return $mockstore[$id];
            })
        );
        $mockrepo->expects($this->any())
            ->method('exists')
            ->will($this->returnCallback(function(int $id) use (&$mockstore) {
                return array_key_exists($id, $mockstore);
            })
        );
        $mockrepo->expects($this->any())
            ->method('delete')
            ->will($this->returnCallback(function(int $id) use (&$mockstore) {
                foreach ($mockstore as $mockrow) {
                    if ($mockrow->id == $id) {
                        unset($mockstore[$id]);
                    }
                }
            })
        );
        return $mockrepo;
    }

    /**
     * Test getting a user_favourites_service from the static locator.
     */
    public function test_get_service_for_user_context() {
        list($user1context, $user2context, $course1context, $course2context) = $this->setup_users_and_courses();
        $userservice = \core_favourites\services::get_service_for_user_context($user1context);
        $this->assertInstanceOf(\core_favourites\local\service\user_favourites_service::class, $userservice);
    }

    /**
     * Test confirming an item can be favourited only once.
     */
    public function test_create_favourite_basic() {
        list($user1context, $user2context, $course1context, $course2context) = $this->setup_users_and_courses();

        // Get a user_favourites_service for a user.
        $repo = $this->get_mock_repository([]); // Mock repository, using the array as a mock DB.
        $user1service = new \core_favourites\local\service\user_favourites_service($user1context, $repo);

        // Favourite a course.
        $favourite1 = $user1service->create_favourite('core_course', 'course', $course1context->instanceid, $course1context);
        $this->assertObjectHasAttribute('id', $favourite1);

        // Try to favourite the same course again.
        $this->expectException('moodle_exception');
        $user1service->create_favourite('core_course', 'course', $course1context->instanceid, $course1context);
    }

    /**
     * Test confirming that an exception is thrown if trying to favourite an item for a non-existent component.
     */
    public function test_create_favourite_nonexistent_component() {
        list($user1context, $user2context, $course1context, $course2context) = $this->setup_users_and_courses();

        // Get a user_favourites_service for the user.
        $repo = $this->get_mock_repository([]); // Mock repository, using the array as a mock DB.
        $user1service = new \core_favourites\local\service\user_favourites_service($user1context, $repo);

        // Try to favourite something in a non-existent component.
        $this->expectException('moodle_exception');
        $user1service->create_favourite('core_cccourse', 'my_area', $course1context->instanceid, $course1context);
    }

    /**
     * Test fetching favourites for single user, by area.
     */
    public function test_find_favourites_by_type_single_user() {
        list($user1context, $user2context, $course1context, $course2context) = $this->setup_users_and_courses();

        // Get a user_favourites_service for the user.
        $repo = $this->get_mock_repository([]); // Mock repository, using the array as a mock DB.
        $service = new \core_favourites\local\service\user_favourites_service($user1context, $repo);

        // Favourite 2 courses, in separate areas.
        $fav1 = $service->create_favourite('core_course', 'course', $course1context->instanceid, $course1context);
        $fav2 = $service->create_favourite('core_course', 'anothertype', $course2context->instanceid, $course2context);

        // Verify we can get favourites by area.
        $favourites = $service->find_favourites_by_type('core_course', 'course');
        $this->assertInternalType('array', $favourites);
        $this->assertCount(1, $favourites); // We only get favourites for the 'core_course/course' area.
        $this->assertAttributeEquals($fav1->id, 'id', $favourites[$fav1->id]);

        $favourites = $service->find_favourites_by_type('core_course', 'anothertype');
        $this->assertInternalType('array', $favourites);
        $this->assertCount(1, $favourites); // We only get favourites for the 'core_course/course' area.
        $this->assertAttributeEquals($fav2->id, 'id', $favourites[$fav2->id]);
    }

    /**
     * Make sure the find_favourites_by_type() method only returns favourites for the scoped user.
     */
    public function test_find_favourites_by_type_multiple_users() {
        list($user1context, $user2context, $course1context, $course2context) = $this->setup_users_and_courses();

        // Get a user_favourites_service for 2 users.
        $repo = $this->get_mock_repository([]);
        $user1service = new \core_favourites\local\service\user_favourites_service($user1context, $repo);
        $user2service = new \core_favourites\local\service\user_favourites_service($user2context, $repo);

        // Now, as each user, favourite the same course.
        $fav1 = $user1service->create_favourite('core_course', 'course', $course1context->instanceid, $course1context);
        $fav2 = $user2service->create_favourite('core_course', 'course', $course1context->instanceid, $course1context);

        // Verify find_favourites_by_type only returns results for the user to which the service is scoped.
        $user1favourites = $user1service->find_favourites_by_type('core_course', 'course');
        $this->assertInternalType('array', $user1favourites);
        $this->assertCount(1, $user1favourites); // We only get favourites for the 'core_course/course' area for $user1.
        $this->assertAttributeEquals($fav1->id, 'id', $user1favourites[$fav1->id]);

        $user2favourites = $user2service->find_favourites_by_type('core_course', 'course');
        $this->assertInternalType('array', $user2favourites);
        $this->assertCount(1, $user2favourites); // We only get favourites for the 'core_course/course' area for $user2.
        $this->assertAttributeEquals($fav2->id, 'id', $user2favourites[$fav2->id]);
    }

    /**
     * Test confirming that an exception is thrown if trying to get favourites for a non-existent component.
     */
    public function test_find_favourites_by_type_nonexistent_component() {
        list($user1context, $user2context, $course1context, $course2context) = $this->setup_users_and_courses();

        // Get a user_favourites_service for the user.
        $repo = $this->get_mock_repository([]);
        $service = new \core_favourites\local\service\user_favourites_service($user1context, $repo);

        // Verify we get an exception if we try to search for favourites in an invalid component.
        $this->expectException('moodle_exception');
        $service->find_favourites_by_type('cccore_notreal', 'something');
    }

    /**
     * Test confirming the pagination support for the find_favourites_by_type() method.
     */
    public function test_find_favourites_by_type_pagination() {
        list($user1context, $user2context, $course1context, $course2context) = $this->setup_users_and_courses();

        // Get a user_favourites_service for the user.
        $repo = $this->get_mock_repository([]);
        $service = new \core_favourites\local\service\user_favourites_service($user1context, $repo);

        // Favourite 10 arbitrary items.
        foreach (range(1, 10) as $i) {
            $service->create_favourite('core_course', 'course', $i, $course1context);
        }

        // Verify we have 10 favourites.
        $this->assertCount(10, $service->find_favourites_by_type('core_course', 'course'));

        // Verify we get back 5 favourites for page 1.
        $favourites = $service->find_favourites_by_type('core_course', 'course', 0, 5);
        $this->assertCount(5, $favourites);

        // Verify we get back 5 favourites for page 2.
        $favourites = $service->find_favourites_by_type('core_course', 'course', 5, 5);
        $this->assertCount(5, $favourites);

        // Verify we get back an empty array if querying page 3.
        $favourites = $service->find_favourites_by_type('core_course', 'course', 10, 5);
        $this->assertCount(0, $favourites);
    }

    /**
     * Test confirming the basic deletion behaviour.
     */
    public function test_delete_favourite_basic() {
        list($user1context, $user2context, $course1context, $course2context) = $this->setup_users_and_courses();

        // Get a user_favourites_service for the user.
        $repo = $this->get_mock_repository([]);
        $service = new \core_favourites\local\service\user_favourites_service($user1context, $repo);

        // Favourite a course.
        $fav1 = $service->create_favourite('core_course', 'course', $course1context->instanceid, $course1context);
        $this->assertTrue($repo->exists($fav1->id));

        // Delete the favourite.
        $service->delete_favourite('core_course', 'course', $course1context->instanceid, $course1context);

        // Verify the favourite doesn't exist.
        $this->assertFalse($repo->exists($fav1->id));

        // Try to delete a favourite which we know doesn't exist.
        $this->expectException(\moodle_exception::class);
        $service->delete_favourite('core_course', 'course', $course1context->instanceid, $course1context);
    }
}