<?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 the {@link core_question\engine\variants\least_used_strategy} class.
<  *
<  * @package   core_question
<  * @copyright 2015 The Open University
<  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  */



> namespace core_question;
> 
> use core_question\engine\variants\least_used_strategy;
> use qubaid_list;
> use question_bank;
> use question_engine;



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

global $CFG;
require_once($CFG->dirroot . '/question/engine/tests/helpers.php');


< 


/**
 * Tests for the {@link core_question\engine\variants\least_used_strategy} class.
 *

>  * @package    core_question


 * @copyright  2015 The Open University
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

< class least_used_variant_strategy_testcase extends advanced_testcase {



> class least_used_variant_strategy_test extends \advanced_testcase {



    public function test_question_with_one_variant_always_picks_that() {

<         $question = test_question_maker::make_question('shortanswer');
<         $quba = question_engine::make_questions_usage_by_activity('test', context_system::instance());



>         $question = \test_question_maker::make_question('shortanswer');
>         $quba = question_engine::make_questions_usage_by_activity('test', \context_system::instance());


        $quba->set_preferred_behaviour('deferredfeedback');
        $slot = $quba->add_question($question);

<         $quba->start_all_questions(new core_question\engine\variants\least_used_strategy(



>         $quba->start_all_questions(new least_used_strategy(


                $quba, new qubaid_list(array())));
        $this->assertEquals(1, $quba->get_variant($slot));
    }

    public function test_synchronised_question_should_use_the_same_dataset() {
        // Actually, we cheat here. We use the same question twice, not two different synchronised questions.

<         $question = test_question_maker::make_question('calculated');
<         $quba = question_engine::make_questions_usage_by_activity('test', context_system::instance());



>         $question = \test_question_maker::make_question('calculated');
>         $quba = question_engine::make_questions_usage_by_activity('test', \context_system::instance());


        $quba->set_preferred_behaviour('deferredfeedback');
        $slot1 = $quba->add_question($question);
        $slot2 = $quba->add_question($question);

<         $quba->start_all_questions(new core_question\engine\variants\least_used_strategy(



>         $quba->start_all_questions(new least_used_strategy(


                $quba, new qubaid_list(array())));
        $this->assertEquals($quba->get_variant($slot1), $quba->get_variant($slot2));
    }

    public function test_second_attempt_uses_other_dataset() {
        global $DB;
        $this->resetAfterTest();
        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');

        $cat = $generator->create_question_category();
        $questiondata = $generator->create_question('calculated', null, array('category' => $cat->id));

        // Create two dataset items.
        $adefinitionid = $DB->get_field_sql("
                    SELECT qdd.id
                      FROM {question_dataset_definitions} qdd
                      JOIN {question_datasets} qd ON qd.datasetdefinition = qdd.id
                     WHERE qd.question = ?
                       AND qdd.name = ?", array($questiondata->id, 'a'));
        $bdefinitionid = $DB->get_field_sql("
                    SELECT qdd.id
                      FROM {question_dataset_definitions} qdd
                      JOIN {question_datasets} qd ON qd.datasetdefinition = qdd.id
                     WHERE qd.question = ?
                       AND qdd.name = ?", array($questiondata->id, 'b'));
        $DB->set_field('question_dataset_definitions', 'itemcount', 2, array('id' => $adefinitionid));
        $DB->set_field('question_dataset_definitions', 'itemcount', 2, array('id' => $bdefinitionid));
        $DB->insert_record('question_dataset_items', array('definition' => $adefinitionid,
                'itemnumber' => 1, 'value' => 3));
        $DB->insert_record('question_dataset_items', array('definition' => $bdefinitionid,
                'itemnumber' => 1, 'value' => 7));
        $DB->insert_record('question_dataset_items', array('definition' => $adefinitionid,
                'itemnumber' => 2, 'value' => 6));
        $DB->insert_record('question_dataset_items', array('definition' => $bdefinitionid,
                'itemnumber' => 2, 'value' => 4));

        $question = question_bank::load_question($questiondata->id);


<         $quba1 = question_engine::make_questions_usage_by_activity('test', context_system::instance());



>         $quba1 = question_engine::make_questions_usage_by_activity('test', \context_system::instance());


        $quba1->set_preferred_behaviour('deferredfeedback');
        $slot1 = $quba1->add_question($question);

<         $quba1->start_all_questions(new core_question\engine\variants\least_used_strategy(



>         $quba1->start_all_questions(new least_used_strategy(


                $quba1, new qubaid_list(array())));
        question_engine::save_questions_usage_by_activity($quba1);
        $variant1 = $quba1->get_variant($slot1);

        // Second attempt should use the other variant.

<         $quba2 = question_engine::make_questions_usage_by_activity('test', context_system::instance());



>         $quba2 = question_engine::make_questions_usage_by_activity('test', \context_system::instance());


        $quba2->set_preferred_behaviour('deferredfeedback');
        $slot2 = $quba2->add_question($question);

<         $quba2->start_all_questions(new core_question\engine\variants\least_used_strategy(



>         $quba2->start_all_questions(new least_used_strategy(


                $quba1, new qubaid_list(array($quba1->get_id()))));
        question_engine::save_questions_usage_by_activity($quba2);
        $variant2 = $quba2->get_variant($slot2);

        $this->assertNotEquals($variant1, $variant2);

        // Third attempt uses either variant at random.

<         $quba3 = question_engine::make_questions_usage_by_activity('test', context_system::instance());



>         $quba3 = question_engine::make_questions_usage_by_activity('test', \context_system::instance());


        $quba3->set_preferred_behaviour('deferredfeedback');
        $slot3 = $quba3->add_question($question);

<         $quba3->start_all_questions(new core_question\engine\variants\least_used_strategy(



>         $quba3->start_all_questions(new least_used_strategy(


                $quba1, new qubaid_list(array($quba1->get_id(), $quba2->get_id()))));
        $variant3 = $quba3->get_variant($slot3);

        $this->assertTrue($variant3 == $variant1 || $variant3 == $variant2);
    }
}