<?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 core;

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

global $CFG;
require_once("$CFG->libdir/graphlib.php");

/**
 * Tests for Graphlib.
 *
 * @coversDefaultClass \graph
 * @package    core
 * @copyright  2023 Meirza (meirza.arson@moodle.com)
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class graphlib_test extends \basic_testcase {

    /**
     * Data provider for test_graphlib.
     *
     * @return array
     */
    public function create_data(): array {
        return [
            'data' =>
            [
                'mock' => [
                    'survey_name' => 'Survey 101',
                    'names' => [
                        'Relevance', 'Reflective thinking', 'Interactivity', 'Tutor support', 'Peer support', 'Interpretation'
                    ],
                    'buckets1' => [
                        0.75, 2.5, 1.5, 1.5, 2.5, 2.5
                    ],
                    'stractual' => 'Actual',
                    'buckets2' => [
                        -1, -1, -1, -1, -1, -1
                    ],
                    'strpreferred' => 'Preferred',
                    'stdev1' => [
                        0.82915619758885, 1.1180339887499, 1.1180339887499, 1.1180339887499, 1.1180339887499, 1.1180339887499
                    ],
                    'stdev2' => [
                        0, 0, 0, 0, 0, 0
                    ],
                    'options' => [
                        'Almost never', 'Seldom', 'Sometimes', 'Often', 'Almost always'
                    ],
                    'maxbuckets1' => 2.5,
                    'maxbuckets2' => -1
                ]
            ]
        ];
    }

    /**
     * Test graphlib.
     *
     * @dataProvider create_data
     * @covers ::output
     * @param array $mock
     * @return void
     */
    public function test_graphlib($mock): void {
        $graph = new \graph(300, 200);
        ob_start();
        $graph->parameter['title'] = strip_tags(format_string($mock['survey_name'], true));
        $graph->x_data = $mock['names'];
        $graph->y_data['answers1'] = $mock['buckets1'];
        $graph->y_format['answers1'] = array('colour' => 'ltblue', 'line' => 'line', 'point' => 'square',
                'shadow_offset' => 4, 'legend' => $mock['stractual']);
        $graph->y_data['answers2'] = $mock['buckets2'];
        $graph->y_format['answers2'] = array('colour' => 'ltorange', 'line' => 'line', 'point' => 'square',
                'shadow_offset' => 4, 'legend' => $mock['strpreferred']);
        $graph->y_data['stdev1'] = $mock['stdev1'];
        $graph->y_format['stdev1'] = array('colour' => 'ltltblue', 'bar' => 'fill',
                'shadow_offset' => '4', 'legend' => 'none', 'bar_size' => 0.3);
        $graph->y_data['stdev2'] = $mock['stdev2'];
        $graph->y_format['stdev2'] = array('colour' => 'ltltorange', 'bar' => 'fill',
                'shadow_offset' => '4', 'legend' => 'none', 'bar_size' => 0.2);
        $graph->offset_relation['stdev1'] = 'answers1';
        $graph->offset_relation['stdev2'] = 'answers2';
        $graph->parameter['legend'] = 'outside-top';
        $graph->parameter['legend_border'] = 'black';
        $graph->parameter['legend_offset'] = 4;
        $graph->y_tick_labels = $mock['options'];
        if (($mock['maxbuckets1'] > 0.0) && ($mock['maxbuckets2'] > 0.0)) {
            $graph->y_order = array('stdev1', 'answers1', 'stdev2', 'answers2');
        } else if ($mock['maxbuckets1'] > 0.0) {
            $graph->y_order = array('stdev1', 'answers1');
        } else {
            $graph->y_order = array('stdev2', 'answers2');
        }
        $graph->parameter['y_max_left'] = 4;
        $graph->parameter['y_axis_gridlines'] = 5;
        $graph->parameter['y_resolution_left'] = 1;
        $graph->parameter['y_decimal_left'] = 1;
        $graph->parameter['x_axis_angle'] = 0;
        $graph->parameter['x_inner_padding'] = 6;
        @$graph->draw();
        $res = ob_end_clean();

        $this->assertTrue($res);
    }
}