<?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/>.

/**
 * Tests for tour.
 *
 * @package    tool_usertours
 * @copyright  2016 Andrew Nicols <andrew@nicols.co.uk>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

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

global $CFG;
require_once($CFG->libdir . '/formslib.php');

use tool_usertours\tour;

/**
 * Tests for tour.
 *
 * @package    tool_usertours
 * @copyright  2016 Andrew Nicols <andrew@nicols.co.uk>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class tour_testcase extends advanced_testcase {

    /**
     * @var moodle_database
     */
    protected $db;

    /**
     * Setup to store the DB reference.
     */
    public function setUp() {
        global $DB;

        $this->db = $DB;
    }

    /**
     * Tear down to restore the original DB reference.
     */
    public function tearDown() {
        global $DB;

        $DB = $this->db;
    }

    /**
     * Helper to mock the database.
     *
     * @return moodle_database
     */
    public function mock_database() {
        global $DB;

        $DB = $this->getMockBuilder(\moodle_database::class)
            ->getMock()
            ;

        return $DB;
    }

    /**
     * Data provider for the dirty value tester.
     *
     * @return array
     */
    public function dirty_value_provider() {
        return [
                'name' => [
                        'name',
                        ['Lorem'],
                    ],
                'description' => [
                        'description',
                        ['Lorem'],
                    ],
                'pathmatch' => [
                        'pathmatch',
                        ['Lorem'],
                    ],
                'enabled' => [
                        'enabled',
                        ['Lorem'],
                    ],
                'sortorder' => [
                        'sortorder',
                        [1],
                    ],
                'config' => [
                        'config',
                        ['key', 'value'],
                    ],
            ];
    }

    /**
     * Test that setters mark things as dirty.
     *
     * @dataProvider dirty_value_provider
     * @param   string  $name           The name of the key being tested
     * @param   mixed   $value          The value being set
     */
    public function test_dirty_values($name, $value) {
        $tour = new \tool_usertours\tour();
        $method = 'set_' . $name;
        call_user_func_array([$tour, $method], $value);

        $rc = new \ReflectionClass(\tool_usertours\tour::class);
        $rcp = $rc->getProperty('dirty');
        $rcp->setAccessible(true);

        $this->assertTrue($rcp->getValue($tour));
    }

    /**
     * Data provider for the get_ tests.
     *
     * @return array
     */
    public function getter_provider() {
        return [
                'id' => [
                        'id',
                        rand(1, 100),
                    ],
                'name' => [
                        'name',
                        'Lorem',
                    ],
                'description' => [
                        'description',
                        'Lorem',
                    ],
                'pathmatch' => [
                        'pathmatch',
                        'Lorem',
                    ],
                'enabled' => [
                        'enabled',
                        'Lorem',
                    ],
                'sortorder' => [
                        'sortorder',
                        rand(1, 100),
                    ],
                'config' => [
                        'config',
                        ['key', 'value'],
                    ],
            ];
    }

    /**
     * Test that getters return the configured value.
     *
     * @dataProvider getter_provider
     * @param   string  $key            The name of the key being tested
     * @param   mixed   $value          The value being set
     */
    public function test_getters($key, $value) {
        $tour = new \tool_usertours\tour();

        $rc = new \ReflectionClass(tour::class);

        $rcp = $rc->getProperty($key);
        $rcp->setAccessible(true);
        $rcp->setValue($tour, $value);

        $getter = 'get_' . $key;

        $this->assertEquals($value, $tour->$getter());
    }

    /**
     * Ensure that non-dirty tours are not persisted.
     */
    public function test_persist_non_dirty() {
        $tour = $this->getMockBuilder(tour::class)
            ->setMethods(['to_record'])
            ->getMock()
            ;

        $tour->expects($this->never())
            ->method('to_record')
            ;

        $this->assertSame($tour, $tour->persist());
    }

    /**
     * Ensure that new dirty tours are persisted.
     */
    public function test_persist_dirty_new() {
        // Mock the database.
        $DB = $this->mock_database();

        $DB->expects($this->never())
            ->method('update_record')
            ;

        $id = rand(1, 100);
        $DB->expects($this->once())
            ->method('insert_record')
            ->willReturn($id)
            ;

        // Mock the tour.
        $tour = $this->getMockBuilder(tour::class)
            ->setMethods([
                    'to_record',
                    'reload',
                ])
            ->getMock()
            ;

        $tour->expects($this->once())
            ->method('to_record')
            ;

        $tour->expects($this->once())
            ->method('reload')
            ;

        $rc = new \ReflectionClass(tour::class);

        $rcp = $rc->getProperty('dirty');
        $rcp->setAccessible(true);
        $rcp->setValue($tour, true);

        $this->assertSame($tour, $tour->persist());

        $rcp = $rc->getProperty('id');
        $rcp->setAccessible(true);
        $this->assertEquals($id, $rcp->getValue($tour));
    }

    /**
     * Ensure that non-dirty, forced tours are persisted.
     */
    public function test_persist_force_new() {
        global $DB;

        // Mock the database.
        $DB = $this->mock_database();

        $DB->expects($this->never())
            ->method('update_record')
            ;

        $id = rand(1, 100);
        $DB->expects($this->once())
            ->method('insert_record')
            ->willReturn($id)
            ;

        // Mock the tour.
        $tour = $this->getMockBuilder(tour::class)
            ->setMethods([
                    'to_record',
                    'reload',
                ])
            ->getMock()
            ;

        $tour->expects($this->once())
            ->method('to_record')
            ;

        $tour->expects($this->once())
            ->method('reload')
            ;

        $this->assertSame($tour, $tour->persist(true));

        $rc = new \ReflectionClass(tour::class);
        $rcp = $rc->getProperty('id');
        $rcp->setAccessible(true);
        $this->assertEquals($id, $rcp->getValue($tour));
    }

    /**
     * Ensure that dirty tours are persisted.
     */
    public function test_persist_dirty_existing() {
        // Mock the database.
        $DB = $this->mock_database();
        $DB->expects($this->once())
            ->method('update_record')
            ->willReturn($this->returnSelf())
            ;

        $DB->expects($this->never())
            ->method('insert_record')
            ;

        // Mock the tour.
        $tour = $this->getMockBuilder(tour::class)
            ->setMethods([
                    'to_record',
                    'reload',
                ])
            ->getMock()
            ;

        $tour->expects($this->once())
            ->method('to_record')
            ;

        $tour->expects($this->once())
            ->method('reload')
            ;

        $rc = new \ReflectionClass(tour::class);

        $rcp = $rc->getProperty('id');
        $rcp->setAccessible(true);
        $rcp->setValue($tour, 42);

        $rcp = $rc->getProperty('dirty');
        $rcp->setAccessible(true);
        $rcp->setValue($tour, true);

        $this->assertSame($tour, $tour->persist());
    }

    /**
     * Ensure that non-dirty, forced tours are persisted.
     */
    public function test_persist_force() {
        global $DB;

        // Mock the database.
        $DB = $this->mock_database();

        $DB->expects($this->once())
            ->method('update_record')
            ->willReturn($this->returnSelf())
            ;

        $DB->expects($this->never())
            ->method('insert_record')
            ;

        // Mock the tour.
        $tour = $this->getMockBuilder(tour::class)
            ->setMethods([
                    'to_record',
                    'reload',
                ])
            ->getMock()
            ;

        $tour->expects($this->once())
            ->method('to_record')
            ;

        $tour->expects($this->once())
            ->method('reload')
            ;

        $rc = new \ReflectionClass(tour::class);

        $rcp = $rc->getProperty('id');
        $rcp->setAccessible(true);
        $rcp->setValue($tour, 42);

        $rcp = $rc->getProperty('dirty');
        $rcp->setAccessible(true);
        $rcp->setValue($tour, true);

        $this->assertSame($tour, $tour->persist(true));
    }

    /**
     * Test setting config.
     */
    public function test_set_config() {
        $tour = new \tool_usertours\tour();

        $tour->set_config('key', 'value');
        $tour->set_config('another', [
                'foo' => 'bar',
            ]);

        $rc = new \ReflectionClass(tour::class);
        $rcp = $rc->getProperty('config');
        $rcp->setAccessible(true);
        $this->assertEquals((object) [
                'key' => 'value',
                'another' => [
                    'foo' => 'bar',
                ],
            ], $rcp->getValue($tour));
    }

    /**
     * Test get_config with no keys provided.
     */
    public function test_get_config_no_keys() {
        $tour = new \tool_usertours\tour();

        $rc = new \ReflectionClass(tour::class);
        $rcp = $rc->getProperty('config');
        $rcp->setAccessible(true);

        $allvalues = (object) [
                'some' => 'value',
                'another' => 42,
                'key' => [
                    'somethingelse',
                ],
            ];

        $rcp->setValue($tour, $allvalues);

        $this->assertEquals($allvalues, $tour->get_config());
    }

    /**
     * Data provider for get_config.
     *
     * @return array
     */
    public function get_config_provider() {
        $allvalues = (object) [
                'some' => 'value',
                'another' => 42,
                'key' => [
                    'somethingelse',
                ],
            ];

        return [
                'No nitial config' => [
                        null,
                        null,
                        null,
                        (object) [],
                    ],
                'All values' => [
                        $allvalues,
                        null,
                        null,
                        $allvalues,
                    ],
                'Valid string value' => [
                        $allvalues,
                        'some',
                        null,
                        'value',
                    ],
                'Valid array value' => [
                        $allvalues,
                        'key',
                        null,
                        ['somethingelse'],
                    ],
                'Invalid value' => [
                        $allvalues,
                        'notavalue',
                        null,
                        null,
                    ],
                'Configuration value' => [
                        $allvalues,
                        'placement',
                        null,
                        \tool_usertours\configuration::get_default_value('placement'),
                    ],
                'Invalid value with default' => [
                        $allvalues,
                        'notavalue',
                        'somedefault',
                        'somedefault',
                    ],
            ];
    }

    /**
     * Test get_config with valid keys provided.
     *
     * @dataProvider get_config_provider
     * @param   object  $values     The config values
     * @param   string  $key        The key
     * @param   mixed   $default    The default value
     * @param   mixed   $expected   The expected value
     */
    public function test_get_config_valid_keys($values, $key, $default, $expected) {
        $tour = new \tool_usertours\tour();

        $rc = new \ReflectionClass(tour::class);
        $rcp = $rc->getProperty('config');
        $rcp->setAccessible(true);
        $rcp->setValue($tour, $values);

        $this->assertEquals($expected, $tour->get_config($key, $default));
    }

    /**
     * Check that a tour which has never been persisted is removed correctly.
     */
    public function test_remove_non_persisted() {
        $tour = $this->getMockBuilder(tour::class)
            ->setMethods([
                    'get_steps',
                ])
            ->getMock()
            ;

        $tour->expects($this->never())
            ->method('get_steps')
            ;

        // Mock the database.
        $DB = $this->mock_database();
        $DB->expects($this->never())
            ->method('delete_records')
            ;

        $this->assertNull($tour->remove());
    }

    /**
     * Check that a tour which has been persisted is removed correctly.
     */
    public function test_remove_persisted() {
        $id = rand(1, 100);

        $tour = $this->getMockBuilder(tour::class)
            ->setMethods([
                    'get_steps',
                ])
            ->getMock()
            ;

        $rc = new \ReflectionClass(tour::class);
        $rcp = $rc->getProperty('id');
        $rcp->setAccessible(true);
        $rcp->setValue($tour, $id);

        $step = $this->getMockBuilder(\tool_usertours\step::class)
            ->setMethods([
                    'remove',
                ])
            ->getMock()
            ;

        $tour->expects($this->once())
            ->method('get_steps')
            ->willReturn([$step])
            ;

        // Mock the database.
        $DB = $this->mock_database();
        $DB->expects($this->once())
            ->method('delete_records')
            ->with($this->equalTo('tool_usertours_tours'), $this->equalTo(['id' => $id]))
            ->willReturn(null)
            ;

        $DB->expects($this->once())
            ->method('get_records')
            ->with($this->equalTo('tool_usertours_tours'), $this->equalTo(null))
            ->willReturn([])
            ;

        $this->assertNull($tour->remove());
    }

    /**
     * Teset that sortorder is reset according to sortorder with values from 0.
     */
    public function test_reset_step_sortorder() {
        $tour = new \tool_usertours\tour();

        $mockdata = [];
        for ($i = 4; $i >= 0; $i--) {
            $id = rand($i * 10, ($i * 10) + 9);
            $mockdata[] = (object) ['id' => $id];
            $expectations[] = [$this->equalTo('tool_usertours_steps'), $this->equalTo('sortorder'), 4 - $i, ['id' => $id]];
        }

        // Mock the database.
        $DB = $this->mock_database();
        $DB->expects($this->once())
            ->method('get_records')
            ->willReturn($mockdata)
            ;

        $setfield = $DB->expects($this->exactly(5))
            ->method('set_field')
            ;
        call_user_func_array([$setfield, 'withConsecutive'], $expectations);

        $tour->reset_step_sortorder();
    }

    /**
     * Test that a disabled tour should never be shown to users.
     */
    public function test_should_show_for_user_disabled() {
        $tour = new \tool_usertours\tour();
        $tour->set_enabled(false);

        $this->assertFalse($tour->should_show_for_user());
    }

    /**
     * Provider for should_show_for_user.
     *
     * @return array
     */
    public function should_show_for_user_provider() {
        $time = time();
        return [
                'Not seen by user at all' => [
                        null,
                        null,
                        null,
                        true,
                    ],
                'Completed by user before majorupdatetime' => [
                        $time - DAYSECS,
                        null,
                        $time,
                        true,
                    ],
                'Completed by user since majorupdatetime' => [
                        $time,
                        null,
                        $time - DAYSECS,
                        false,
                    ],
                'Requested by user before current completion' => [
                        $time,
                        $time - DAYSECS,
                        null,
                        false,
                    ],
                'Requested by user since completion' => [
                        $time - DAYSECS,
                        $time,
                        null,
                        true,
                    ],
            ];
    }

    /**
     * Test that a disabled tour should never be shown to users.
     *
     * @dataProvider should_show_for_user_provider
     * @param   mixed   $completiondate The user's completion date for this tour
     * @param   mixed   $requesteddate  The user's last requested date for this tour
     * @param   mixed   $updateddate    The date this tour was last updated
     * @param   string  $expectation    The expected tour key
     */
    public function test_should_show_for_user($completiondate, $requesteddate, $updateddate, $expectation) {
        // Uses user preferences so we must be in a user context.
        $this->resetAfterTest();
        $this->setAdminUser();

        $tour = $this->getMockBuilder(tour::class)
            ->setMethods([
                    'get_id',
                    'get_config',
                    'is_enabled',
                ])
            ->getMock()
            ;

        $tour->method('is_enabled')
            ->willReturn(true)
            ;

        $id = rand(1, 100);
        $tour->method('get_id')
            ->willReturn($id)
            ;

        if ($completiondate !== null) {
            set_user_preference(\tool_usertours\tour::TOUR_LAST_COMPLETED_BY_USER . $id, $completiondate);
        }

        if ($requesteddate !== null) {
            set_user_preference(\tool_usertours\tour::TOUR_REQUESTED_BY_USER . $id, $requesteddate);
        }

        if ($updateddate !== null) {
            $tour->expects($this->once())
                ->method('get_config')
                ->willReturn($updateddate)
                ;
        }

        $this->assertEquals($expectation, $tour->should_show_for_user());
    }

    /**
     * Provider for get_tour_key.
     *
     * @return array
     */
    public function get_tour_key_provider() {
        $id = rand(1, 100);
        $time = time();

        return [
            'No initial values' => [
                    $id,
                    [null, $time],
                    $this->greaterThanOrEqual($time),
                    true,
                    null,
                    sprintf('tool_usertours_\d_%d_%s', $id, $time),
                ],

            'Initial tour time, no user pref' => [
                    $id,
                    [$time],
                    null,
                    false,
                    null,
                    sprintf('tool_usertours_\d_%d_%s', $id, $time),
                ],
            'Initial tour time, with user reset lower' => [
                    $id,
                    [$time],
                    null,
                    false,
                    $time - DAYSECS,
                    sprintf('tool_usertours_\d_%d_%s', $id, $time),
                ],
            'Initial tour time, with user reset higher' => [
                    $id,
                    [$time],
                    null,
                    false,
                    $time + DAYSECS,
                    sprintf('tool_usertours_\d_%d_%s', $id, $time + DAYSECS),
                ],
        ];
    }

    /**
     * Test that get_tour_key provides the anticipated unique keys.
     *
     * @dataProvider get_tour_key_provider
     * @param   int     $id             The tour ID
     * @param   array   $getconfig      The mocked values for get_config calls
     * @param   array   $setconfig      The mocked values for set_config calls
     * @param   bool    $willpersist    Whether a persist is expected
     * @param   mixed   $userpref       The value to set for the user preference
     * @param   string  $expectation    The expected tour key
     */
    public function test_get_tour_key($id, $getconfig, $setconfig, $willpersist, $userpref, $expectation) {
        // Uses user preferences so we must be in a user context.
        $this->resetAfterTest();
        $this->setAdminUser();

        $tour = $this->getMockBuilder(tour::class)
            ->setMethods([
                    'get_config',
                    'set_config',
                    'get_id',
                    'persist',
                ])
            ->getMock()
            ;

        if ($getconfig) {
            $tour->expects($this->exactly(count($getconfig)))
                ->method('get_config')
                ->will(call_user_func_array([$this, 'onConsecutiveCalls'], $getconfig))
                ;
        }

        if ($setconfig) {
            $tour->expects($this->once())
                ->method('set_config')
                ->with($this->equalTo('majorupdatetime'), $setconfig)
                ->will($this->returnSelf())
                ;
        } else {
            $tour->expects($this->never())
                ->method('set_config')
                ;
        }

        if ($willpersist) {
            $tour->expects($this->once())
                ->method('persist')
                ;
        } else {
            $tour->expects($this->never())
                ->method('persist')
                ;
        }

        $tour->expects($this->any())
            ->method('get_id')
            ->willReturn($id)
            ;

        if ($userpref !== null) {
            set_user_preference(\tool_usertours\tour::TOUR_REQUESTED_BY_USER . $id, $userpref);
        }

        $this->assertRegExp(
                '/' . $expectation . '/',
                $tour->get_tour_key()
            );
    }

    /**
     * Ensure that the request_user_reset function sets an appropriate value for the tour.
     */
    public function test_requested_user_reset() {
        $tour = $this->getMockBuilder(tour::class)
            ->setMethods([
                    'get_id',
                ])
            ->getMock()
            ;

        $id = rand(1, 100);
        $time = time();

        $tour->expects($this->once())
            ->method('get_id')
            ->willReturn($id)
            ;

        $tour->request_user_reset();

        $this->assertGreaterThanOrEqual($time, get_user_preferences(\tool_usertours\tour::TOUR_REQUESTED_BY_USER . $id));
    }

    /**
     * Ensure that the request_user_reset function sets an appropriate value for the tour.
     */
    public function test_mark_user_completed() {
        $tour = $this->getMockBuilder(tour::class)
            ->setMethods([
                    'get_id',
                ])
            ->getMock()
            ;

        $id = rand(1, 100);
        $time = time();

        $tour->expects($this->once())
            ->method('get_id')
            ->willReturn($id)
            ;

        $tour->mark_user_completed();

        $this->assertGreaterThanOrEqual($time, get_user_preferences(\tool_usertours\tour::TOUR_LAST_COMPLETED_BY_USER . $id));
    }

    /**
     * Provider for the is_first_tour and is_last_tour tests.
     *
     * @return array
     */
    public function sortorder_first_last_provider() {
        $topcount = rand(10, 100);
        return [
                'Only tour => first + last' => [
                        0,
                        true,
                        1,
                        true,
                    ],
                'First tour of many' => [
                        0,
                        true,
                        $topcount,
                        false,
                    ],
                'Last tour of many' => [
                        $topcount - 1,
                        false,
                        $topcount,
                        true,
                    ],
                'Middle tour of many' => [
                        5,
                        false,
                        $topcount,
                        false,
                    ],
            ];
    }

    /**
     * Test the is_first_tour() function.
     *
     * @dataProvider sortorder_first_last_provider
     * @param   int     $sortorder      The new sort order
     * @param   bool    $isfirst        Whether this is the first tour
     * @param   int     $total          The number of tours
     * @param   bool    $islast         Whether this is the last tour
     */
    public function test_is_first_tour($sortorder, $isfirst, $total, $islast) {
        $tour = new \tool_usertours\tour();

        $rc = new \ReflectionClass(tour::class);
        $rcp = $rc->getProperty('sortorder');
        $rcp->setAccessible(true);
        $rcp->setValue($tour, $sortorder);

        $this->assertEquals($isfirst, $tour->is_first_tour());
    }

    /**
     * Test the is_last_tour() function.
     *
     * @dataProvider sortorder_first_last_provider
     * @param   int     $sortorder      The new sort order
     * @param   bool    $isfirst        Whether this is the first tour
     * @param   int     $total          The number of tours
     * @param   bool    $islast         Whether this is the last tour
     */
    public function test_is_last_tour_calculated($sortorder, $isfirst, $total, $islast) {
        $tour = new \tool_usertours\tour();

        $rc = new \ReflectionClass(tour::class);
        $rcp = $rc->getProperty('sortorder');
        $rcp->setAccessible(true);
        $rcp->setValue($tour, $sortorder);

        // The total will be calculated.
        $DB = $this->mock_database();
        $DB->expects($this->once())
            ->method('count_records')
            ->willReturn($total)
            ;
        $this->assertEquals($islast, $tour->is_last_tour());
    }

    /**
     * Test the is_last_tour() function.
     *
     * @dataProvider sortorder_first_last_provider
     * @param   int     $sortorder      The new sort order
     * @param   bool    $isfirst        Whether this is the first tour
     * @param   int     $total          The number of tours
     * @param   bool    $islast         Whether this is the last tour
     */
    public function test_is_last_tour_provided($sortorder, $isfirst, $total, $islast) {
        $tour = new \tool_usertours\tour();

        $rc = new \ReflectionClass(tour::class);
        $rcp = $rc->getProperty('sortorder');
        $rcp->setAccessible(true);
        $rcp->setValue($tour, $sortorder);

        // The total is provided.
        // No DB calls expected.
        $DB = $this->mock_database();
        $DB->expects($this->never())
            ->method('count_records')
            ->willReturn(0)
            ;
        $this->assertEquals($islast, $tour->is_last_tour($total));
    }

    /**
     * Data provider for the get_filter_values tests.
     *
     * @return array
     */
    public function get_filter_values_provider() {
        $cheese = ['cheddar', 'boursin', 'mozzarella'];
        $horses = ['coolie', 'dakota', 'leo', 'twiggy'];
        return [
            'No config' => [
                [],
                'cheese',
                [],
            ],
            'Some config for another filter' => [
                [
                    'horses' => $horses,
                ],
                'cheese',
                [],
            ],
            'Some config for this filter' => [
                [
                    'horses' => $horses,
                ],
                'horses',
                $horses,
            ],
            'Some config for several filters' => [
                [
                    'horses' => $horses,
                    'cheese' => $cheese
                ],
                'horses',
                $horses,
            ],
        ];
    }

    /**
     * Tests for the get_filter_values function.
     *
     * @dataProvider get_filter_values_provider
     * @param   array       $fullconfig     The config value being tested
     * @param   string      $filtername     The name of the filter being tested
     * @param   array       $expectedvalues The expected result
     */
    public function test_get_filter_values($fullconfig, $filtername, $expectedvalues) {
        $tour = $this->getMockBuilder(tour::class)
            ->setMethods(['get_config'])
            ->getMock();

        $tour->expects($this->once())
            ->method('get_config')
            ->will($this->returnValue($fullconfig));

        $this->assertEquals($expectedvalues, $tour->get_filter_values($filtername));
    }

    /**
     * Data provider for set_filter_values tests.
     *
     * @return  array
     */
    public function set_filter_values_provider() {
        $cheese = ['cheddar', 'boursin', 'mozzarella'];
        $horses = ['coolie', 'dakota', 'leo', 'twiggy'];

        return [
            'No initial value' => [
                [],
                'cheese',
                $cheese,
                ['cheese' => $cheese],
            ],
            'Existing filter merged' => [
                ['horses' => $horses],
                'cheese',
                $cheese,
                ['horses' => $horses, 'cheese' => $cheese],
            ],
            'Existing filter updated' => [
                ['cheese' => $cheese],
                'cheese',
                ['cheddar'],
                ['cheese' => ['cheddar']],
            ],
            'Existing filter updated with merge' => [
                ['horses' => $horses, 'cheese' => $cheese],
                'cheese',
                ['cheddar'],
                ['horses' => $horses, 'cheese' => ['cheddar']],
            ],
        ];
    }

    /**
     * Base tests for set_filter_values.
     *
     * @dataProvider set_filter_values_provider
     * @param   array       $currentvalues  The current value
     * @param   string      $filtername     The name of the filter to add to
     * @param   array       $newvalues      The new values to store
     * @param   array       $expectedvalues The combined values
     */
    public function test_set_filter_values_merge($currentvalues, $filtername, $newvalues, $expectedvalues) {
        $tour = $this->getMockBuilder(tour::class)
            ->setMethods(['get_config', 'set_config'])
            ->getMock();

        $tour->expects($this->once())
            ->method('get_config')
            ->will($this->returnValue($currentvalues));

        $tour->expects($this->once())
            ->method('set_config')
            ->with(
                $this->equalTo('filtervalues'),
                $this->equalTo($expectedvalues)
            );

        $tour->set_filter_values($filtername, $newvalues);
    }
}