<?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/>.
/**
 * Unit tests for export/import description (info) for question category in the Moodle XML format.
 *
 * @package    qformat_xml
 * @copyright  2014 Nikita Nikitsky, Volgograd State Technical University
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

use core_question\local\bank\question_edit_contexts;

defined('MOODLE_INTERNAL') || die();
global $CFG;
require_once($CFG->libdir . '/questionlib.php');
require_once($CFG->dirroot . '/question/format/xml/format.php');
require_once($CFG->dirroot . '/question/format.php');
require_once($CFG->dirroot . '/question/engine/tests/helpers.php');
require_once($CFG->dirroot . '/question/editlib.php');

/**
 * Unit tests for the XML question format import and export.
 *
 * @copyright  2014 Nikita Nikitsky, Volgograd State Technical University
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class qformat_xml_import_export_test extends advanced_testcase {
    /**
     * Create object qformat_xml for test.
     * @param string $filename with name for testing file.
     * @param stdClass $course
     * @return qformat_xml XML question format object.
     */
    public function create_qformat($filename, $course) {
        $qformat = new qformat_xml();
        $qformat->setContexts((new question_edit_contexts(context_course::instance($course->id)))->all());
        $qformat->setCourse($course);
        $qformat->setFilename(__DIR__ . '/fixtures/' . $filename);
        $qformat->setRealfilename($filename);
        $qformat->setMatchgrades('error');
        $qformat->setCatfromfile(1);
        $qformat->setContextfromfile(1);
        $qformat->setStoponerror(1);
        $qformat->setCattofile(1);
        $qformat->setContexttofile(1);
        $qformat->set_display_progress(false);

        return $qformat;
    }

    /**
     * Check xml for compliance.
     * @param string $expectedxml with correct string.
     * @param string $xml you want to check.
     */
    public function assert_same_xml($expectedxml, $xml) {
        $this->assertEquals($this->normalise_xml($expectedxml),
                $this->normalise_xml($xml));
    }

    /**
     * Clean up some XML to remove irrelevant differences, before it is compared.
     * @param string $xml some XML.
     * @return string cleaned-up XML.
     */
    protected function normalise_xml($xml) {
        // Normalise line endings.
        $xml = phpunit_util::normalise_line_endings($xml);
        $xml = preg_replace("~\n$~", "", $xml); // Strip final newline in file.

        // Replace all numbers in question id comments with 0.
        $xml = preg_replace('~(?<=<!-- question: )([0-9]+)(?=  -->)~', '0', $xml);

        // Deal with how different databases output numbers. Only match when only thing in a tag.
        $xml = preg_replace("~>.0000000<~", '>0<', $xml); // How Oracle outputs 0.0000000.
        $xml = preg_replace("~(\.(:?[0-9]*[1-9])?)0*<~", '$1<', $xml); // Other cases of trailing 0s
        $xml = preg_replace("~([0-9]).<~", '$1<', $xml); // Stray . in 1. after last step.

        return $xml;
    }

    /**
     * Check imported category.
     * @param string $name imported category name.
     * @param string $info imported category info field (description of category).
     * @param int $infoformat imported category info field format.
     */
    public function assert_category_imported($name, $info, $infoformat, $idnumber = null) {
        global $DB;
        $category = $DB->get_record('question_categories', ['name' => $name], '*', MUST_EXIST);
        $this->assertEquals($info, $category->info);
        $this->assertEquals($infoformat, $category->infoformat);
        $this->assertSame($idnumber, $category->idnumber);
    }

    /**
     * Check a question category has a given parent.
     * @param string $catname Name of the question category
     * @param string $parentname Name of the parent category
     * @throws dml_exception
     */
    public function assert_category_has_parent($catname, $parentname) {
        global $DB;
        $sql = 'SELECT qc1.*
                  FROM {question_categories} qc1
                  JOIN {question_categories} qc2 ON qc1.parent = qc2.id
                 WHERE qc1.name = ?
                   AND qc2.name = ?';
        $categories = $DB->get_records_sql($sql, [$catname, $parentname]);
        $this->assertTrue(count($categories) == 1);
    }

    /**
     * Check a question exists in a category.
     * @param string $qname The name of the question
     * @param string $catname The name of the category
     * @throws dml_exception
     */
    public function assert_question_in_category($qname, $catname) {
        global $DB;

        $sql = "SELECT q.*, qbe.questioncategoryid AS category
                  FROM {question} q
                  JOIN {question_versions} qv ON qv.questionid = q.id
                  JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
                 WHERE q.name = :name";
        $question = $DB->get_record_sql($sql, ['name' => $qname], MUST_EXIST);
        $category = $DB->get_record('question_categories', ['name' => $catname], '*', MUST_EXIST);
        $this->assertEquals($category->id, $question->category);
    }

    /**
     * Simple check for importing a category with a description.
     */
    public function test_import_category(): void {
        $this->resetAfterTest();
        $course = $this->getDataGenerator()->create_course();
        $this->setAdminUser();
        $qformat = $this->create_qformat('category_with_description.xml', $course);
        $imported = $qformat->importprocess();
        $this->assertTrue($imported);
        $this->assert_category_imported('Alpha',
                'This is Alpha category for test', FORMAT_MOODLE, 'alpha-idnumber');
        $this->assert_category_has_parent('Alpha', 'top');
    }

    /**
     * Check importing nested categories.
     */
    public function test_import_nested_categories(): void {
        $this->resetAfterTest();
        $course = $this->getDataGenerator()->create_course();
        $this->setAdminUser();
        $qformat = $this->create_qformat('nested_categories.xml', $course);
        $imported = $qformat->importprocess();
        $this->assertTrue($imported);
        $this->assert_category_imported('Delta', 'This is Delta category for test', FORMAT_PLAIN);
        $this->assert_category_imported('Epsilon', 'This is Epsilon category for test', FORMAT_MARKDOWN);
        $this->assert_category_imported('Zeta', 'This is Zeta category for test', FORMAT_MOODLE);
        $this->assert_category_has_parent('Delta', 'top');
        $this->assert_category_has_parent('Epsilon', 'Delta');
        $this->assert_category_has_parent('Zeta', 'Epsilon');
    }

    /**
     * Check importing nested categories contain the right questions.
     */
    public function test_import_nested_categories_with_questions(): void {
        $this->resetAfterTest();
        $course = $this->getDataGenerator()->create_course();
        $this->setAdminUser();
        $qformat = $this->create_qformat('nested_categories_with_questions.xml', $course);
        $imported = $qformat->importprocess();
        $this->assertTrue($imported);
        $this->assert_category_imported('Iota', 'This is Iota category for test', FORMAT_PLAIN);
        $this->assert_category_imported('Kappa', 'This is Kappa category for test', FORMAT_MARKDOWN);
        $this->assert_category_imported('Lambda', 'This is Lambda category for test', FORMAT_MOODLE);
        $this->assert_category_imported('Mu', 'This is Mu category for test', FORMAT_MOODLE);
        $this->assert_question_in_category('Iota Question', 'Iota');
        $this->assert_question_in_category('Kappa Question', 'Kappa');
        $this->assert_question_in_category('Lambda Question', 'Lambda');
        $this->assert_question_in_category('Mu Question', 'Mu');
        $this->assert_category_has_parent('Iota', 'top');
        $this->assert_category_has_parent('Kappa', 'Iota');
        $this->assert_category_has_parent('Lambda', 'Kappa');
        $this->assert_category_has_parent('Mu', 'Iota');
    }

    /**
     * Check import of an old file (without format), for backward compatability.
     */
    public function test_import_old_format(): void {
        $this->resetAfterTest();
        $course = $this->getDataGenerator()->create_course();
        $this->setAdminUser();
        $qformat = $this->create_qformat('old_format_file.xml', $course);
        $imported = $qformat->importprocess();
        $this->assertTrue($imported);
        $this->assert_category_imported('Pi', '', FORMAT_MOODLE);
        $this->assert_category_imported('Rho', '', FORMAT_MOODLE);
        $this->assert_question_in_category('Pi Question', 'Pi');
        $this->assert_question_in_category('Rho Question', 'Rho');
        $this->assert_category_has_parent('Pi', 'top');
        $this->assert_category_has_parent('Rho', 'Pi');
    }

    /**
     * Check the import of an xml file where the child category exists before the parent category.
     */
    public function test_import_categories_in_reverse_order(): void {
        $this->resetAfterTest();
        $course = $this->getDataGenerator()->create_course();
        $this->setAdminUser();
        $qformat = $this->create_qformat('categories_reverse_order.xml', $course);
        $imported = $qformat->importprocess();
        $this->assertTrue($imported);
        $this->assert_category_imported('Sigma', 'This is Sigma category for test', FORMAT_HTML);
        $this->assert_category_imported('Tau', 'This is Tau category for test', FORMAT_HTML);
        $this->assert_question_in_category('Sigma Question', 'Sigma');
        $this->assert_question_in_category('Tau Question', 'Tau');
        $this->assert_category_has_parent('Sigma', 'top');
        $this->assert_category_has_parent('Tau', 'Sigma');
    }

    /**
     * Check exception when importing questions with invalid grades.
     *
     * @covers \qformat_default::importprocess
     */
    public function test_import_invalid_grades(): void {
        global $OUTPUT;

        $this->resetAfterTest(true);
        $course = $this->getDataGenerator()->create_course();
        $this->setAdminUser();
        $qformat = $this->create_qformat('error_invalid_grades.xml', $course);

        ob_start();
        $imported = $qformat->importprocess();
        $output = ob_get_clean();

        $a = ['grades' => '0.33', 'question' => 'Question with invalid grades : x > 1 & x < 2'];
        $expectedoutput = $OUTPUT->notification(get_string('invalidgradequestion', 'question', $a));
        $expectedoutput .= $OUTPUT->notification(get_string('importparseerror', 'question'));

        $this->assertFalse($imported);
        $this->assertEquals($expectedoutput, $output);
    }

    /**
     * Simple check for exporting a category.
     */
    public function test_export_category(): void {
        global $SITE;

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');
        $this->resetAfterTest();
        $this->setAdminUser();
        // Note while this loads $qformat with all the 'right' data from the xml file,
        // the call to setCategory, followed by exportprocess will actually only export data
        // from the database (created by the generator).
        $qformat = $this->create_qformat('export_category.xml', $SITE);

        $category = $generator->create_question_category([
                'name' => 'Alpha',
                'contextid' => context_course::instance($SITE->id)->id,
                'info' => 'This is Alpha category for test',
                'infoformat' => '0',
                'idnumber' => 'alpha-idnumber',
                'stamp' => make_unique_id_code(),
                'parent' => '0',
                'sortorder' => '999']);
        $question = $generator->create_question('truefalse', null, [
                'category' => $category->id,
                'name' => 'Alpha Question',
                'questiontext' => ['format' => '1', 'text' => '<p>Testing Alpha Question</p>'],
                'generalfeedback' => ['format' => '1', 'text' => ''],
                'correctanswer' => '1',
                'feedbacktrue' => ['format' => '1', 'text' => ''],
                'feedbackfalse' => ['format' => '1', 'text' => ''],
                'penalty' => '1']);
        $qformat->setCategory($category);

        $expectedxml = file_get_contents(__DIR__ . '/fixtures/export_category.xml');
        $this->assert_same_xml($expectedxml, $qformat->exportprocess());
    }

    /**
     * Check exporting nested categories.
     */
    public function test_export_nested_categories(): void {
        global $SITE;

        $this->resetAfterTest();
        $this->setAdminUser();
        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');
        $qformat = $this->create_qformat('nested_categories.zml', $SITE);

        $categorydelta = $generator->create_question_category([
                'name' => 'Delta',
                'contextid' => context_course::instance($SITE->id)->id,
                'info' => 'This is Delta category for test',
                'infoformat' => '2',
                'stamp' => make_unique_id_code(),
                'parent' => '0',
                'sortorder' => '999']);
        $categoryepsilon = $generator->create_question_category([
                'name' => 'Epsilon',
                'contextid' => context_course::instance($SITE->id)->id,
                'info' => 'This is Epsilon category for test',
                'infoformat' => '4',
                'stamp' => make_unique_id_code(),
                'parent' => $categorydelta->id,
                'sortorder' => '999']);
        $categoryzeta = $generator->create_question_category([
                'name' => 'Zeta',
                'contextid' => context_course::instance($SITE->id)->id,
                'info' => 'This is Zeta category for test',
                'infoformat' => '0',
                'stamp' => make_unique_id_code(),
                'parent' => $categoryepsilon->id,
                'sortorder' => '999']);
        $question  = $generator->create_question('truefalse', null, [
                'category' => $categoryzeta->id,
                'name' => 'Zeta Question',
                'questiontext' => [
                                'format' => '1',
                                'text' => '<p>Testing Zeta Question</p>'],
                'generalfeedback' => ['format' => '1', 'text' => ''],
                'correctanswer' => '1',
                'feedbacktrue' => ['format' => '1', 'text' => ''],
                'feedbackfalse' => ['format' => '1', 'text' => ''],
                'penalty' => '1']);
        $qformat->setCategory($categorydelta);
        $qformat->setCategory($categoryepsilon);
        $qformat->setCategory($categoryzeta);

        $expectedxml = file_get_contents(__DIR__ . '/fixtures/nested_categories.xml');
        $this->assert_same_xml($expectedxml, $qformat->exportprocess());
    }

    /**
     * Check exporting nested categories contain the right questions.
     */
    public function test_export_nested_categories_with_questions(): void {
        global $SITE;

        $this->resetAfterTest();
        $this->setAdminUser();
        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');
        $qformat = $this->create_qformat('nested_categories_with_questions.xml', $SITE);

        $categoryiota = $generator->create_question_category([
                'name' => 'Iota',
                'contextid' => context_course::instance($SITE->id)->id,
                'info' => 'This is Iota category for test',
                'infoformat' => '2',
                'stamp' => make_unique_id_code(),
                'parent' => '0',
                'sortorder' => '999']);
        $iotaquestion  = $generator->create_question('truefalse', null, [
                'category' => $categoryiota->id,
                'name' => 'Iota Question',
                'questiontext' => [
                        'format' => '1',
                        'text' => '<p>Testing Iota Question</p>'],
                'generalfeedback' => ['format' => '1', 'text' => ''],
                'correctanswer' => '1',
                'feedbacktrue' => ['format' => '1', 'text' => ''],
                'feedbackfalse' => ['format' => '1', 'text' => ''],
                'penalty' => '1']);
        $categorykappa = $generator->create_question_category([
                'name' => 'Kappa',
                'contextid' => context_course::instance($SITE->id)->id,
                'info' => 'This is Kappa category for test',
                'infoformat' => '4',
                'stamp' => make_unique_id_code(),
                'parent' => $categoryiota->id,
                'sortorder' => '999']);
        $kappaquestion  = $generator->create_question('essay', null, [
                'category' => $categorykappa->id,
                'name' => 'Kappa Essay Question',
                'questiontext' => ['text' => 'Testing Kappa Essay Question'],
                'generalfeedback' => '',
                'responseformat' => 'editor',
                'responserequired' => 1,
                'responsefieldlines' => 10,
                'attachments' => 0,
                'attachmentsrequired' => 0,
                'graderinfo' => ['format' => '1', 'text' => ''],
                'responsetemplate' => ['format' => '1', 'text' => ''],
                'idnumber' => '']);
        $kappaquestion1  = $generator->create_question('truefalse', null, [
                'category' => $categorykappa->id,
                'name' => 'Kappa Question',
                'questiontext' => [
                        'format' => '1',
                        'text' => '<p>Testing Kappa Question</p>'],
                'generalfeedback' => ['format' => '1', 'text' => ''],
                'correctanswer' => '1',
                'feedbacktrue' => ['format' => '1', 'text' => ''],
                'feedbackfalse' => ['format' => '1', 'text' => ''],
                'penalty' => '1',
                'idnumber' => '']);
        $categorylambda = $generator->create_question_category([
                'name' => 'Lambda',
                'contextid' => context_course::instance($SITE->id)->id,
                'info' => 'This is Lambda category for test',
                'infoformat' => '0',
                'stamp' => make_unique_id_code(),
                'parent' => $categorykappa->id,
                'sortorder' => '999']);
        $lambdaquestion  = $generator->create_question('truefalse', null, [
                'category' => $categorylambda->id,
                'name' => 'Lambda Question',
                'questiontext' => [
                        'format' => '1',
                        'text' => '<p>Testing Lambda Question</p>'],
                'generalfeedback' => ['format' => '1', 'text' => ''],
                'correctanswer' => '1',
                'feedbacktrue' => ['format' => '1', 'text' => ''],
                'feedbackfalse' => ['format' => '1', 'text' => ''],
                'penalty' => '1']);
        $categorymu = $generator->create_question_category([
                'name' => 'Mu',
                'contextid' => context_course::instance($SITE->id)->id,
                'info' => 'This is Mu category for test',
                'infoformat' => '0',
                'stamp' => make_unique_id_code(),
                'parent' => $categoryiota->id,
                'sortorder' => '999']);
        $muquestion  = $generator->create_question('truefalse', null, [
                'category' => $categorymu->id,
                'name' => 'Mu Question',
                'questiontext' => [
                        'format' => '1',
                        'text' => '<p>Testing Mu Question</p>'],
                'generalfeedback' => ['format' => '1', 'text' => ''],
                'correctanswer' => '1',
                'feedbacktrue' => ['format' => '1', 'text' => ''],
                'feedbackfalse' => ['format' => '1', 'text' => ''],
                'penalty' => '1']);
        $qformat->setCategory($categoryiota);

        $expectedxml = file_get_contents(__DIR__ . '/fixtures/nested_categories_with_questions.xml');
        $this->assert_same_xml($expectedxml, $qformat->exportprocess());
    }

    /**
     * Simple check for exporting a category.
     */
    public function test_export_category_with_special_chars(): void {
        global $SITE;

        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');
        $this->resetAfterTest();
        $this->setAdminUser();
        // Note while this loads $qformat with all the 'right' data from the xml file,
        // the call to setCategory, followed by exportprocess will actually only export data
        // from the database (created by the generator).
        $qformat = $this->create_qformat('export_category.xml', $SITE);

        $category = $generator->create_question_category([
                'name' => 'Alpha',
                'contextid' => context_course::instance($SITE->id)->id,
                'info' => 'This is Alpha category for test',
                'infoformat' => '0',
                'idnumber' => 'The inequalities < & >',
                'stamp' => make_unique_id_code(),
                'parent' => '0',
                'sortorder' => '999']);
        $generator->create_question('truefalse', null, [
                'category' => $category->id,
                'name' => 'Alpha Question',
                'questiontext' => ['format' => '1', 'text' => '<p>Testing Alpha Question</p>'],
                'generalfeedback' => ['format' => '1', 'text' => ''],
                'idnumber' => 'T & F',
                'correctanswer' => '1',
                'feedbacktrue' => ['format' => '1', 'text' => ''],
                'feedbackfalse' => ['format' => '1', 'text' => ''],
                'penalty' => '1']);
        $qformat->setCategory($category);

        $expectedxml = file_get_contents(__DIR__ . '/fixtures/html_chars_in_idnumbers.xml');
        $this->assert_same_xml($expectedxml, $qformat->exportprocess());
    }

    /**
     * Test that bad multianswer questions are not imported.
     */
    public function test_import_broken_multianswer_questions(): void {
        $lines = file(__DIR__ . '/fixtures/broken_cloze_questions.xml');
        $importer = $qformat = new qformat_xml();

        // The importer echoes some errors, so we need to capture and check that.
        ob_start();
        $questions = $importer->readquestions($lines);
        $output = ob_get_contents();
        ob_end_clean();

        // Check that there were some expected errors.
        $this->assertStringContainsString('Error importing question', $output);
        $this->assertStringContainsString('Invalid embedded answers (Cloze) question', $output);
        $this->assertStringContainsString('This type of question requires at least 2 choices', $output);
        $this->assertStringContainsString('The answer must be a number, for example -1.234 or 3e8, or \'*\'.', $output);
        $this->assertStringContainsString('One of the answers should have a score of 100% so it is possible to get full marks for this question.',
                $output);
        $this->assertStringContainsString('The question text must include at least one embedded answer.', $output);

        // No question  have been imported.
        $this->assertCount(0, $questions);
    }
}
