Proyectos de Subversion Moodle

<?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 tool_courserating\local\models;

use tool_courserating\constants;

use tool_courserating\helper;

/**

 * Model for summary table

 *

 * @package     tool_courserating

 * @copyright   2022 Marina Glancy <marina.glancy@gmail.com>

 * @license     https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class summary extends \core\persistent {

    /** @var string Table name */

    public const TABLE = 'tool_courserating_summary';

    /**

     * Return the definition of the properties of this model.

     *

     * @return array

     */

    protected static function define_properties(): array {

        $props = [

            'courseid' => [

                'type' => PARAM_INT,

            ],

            'cntall' => [

                'type' => PARAM_INT,

                'default' => 0,

            ],

            'avgrating' => [

                'type' => PARAM_FLOAT,

                'null' => NULL_ALLOWED,

                'default' => null,

            ],

            'sumrating' => [

                'type' => PARAM_INT,

                'default' => 0,

            ],

            'cntreviews' => [

                'type' => PARAM_INT,

                'default' => 0,

            ],

            'ratingmode' => [

                'type' => PARAM_INT,

                'default' => 0,

            ],

        ];

        for ($i = 1; $i <= 10; $i++) {

            $props[self::cntkey($i)] = [

                'type' => PARAM_INT,

                'default' => 0,

            ];

        }

        return $props;

    }

    /**

     * Retrieve summary for the specified course, insert in DB if does not exist

     *

     * @param int $courseid

     * @return summary

     */

    public static function get_for_course(int $courseid): summary {

        if ($summary = self::get_record(['courseid' => $courseid])) {

            return $summary;

        } else {

            $summary = new static(0, (object)[

                'courseid' => $courseid,

                'ratingmode' => helper::get_course_rating_mode($courseid),

            ]);

            $summary->save();

            return $summary;

        }

    }

    /**

     * Field name for the counter of rating $i

     *

     * @param int $i

     * @return string

     */

    protected static function cntkey(int $i) {

        $i = min(max(1, $i), 10);

        return 'cnt' . str_pad($i, 2, "0", STR_PAD_LEFT);

    }

    /**

     * Update summary after a rating was added

     *

     * @param int $courseid

     * @param rating $rating

     * @return static

     */

    public static function add_rating(int $courseid, rating $rating): self {

        if (!$record = self::get_record(['courseid' => $courseid])) {

            $record = new self(0, (object)['courseid' => $courseid]);

        }

        $record->set('cntall', $record->get('cntall') + 1);

        $record->set('sumrating', $record->get('sumrating') + $rating->get('rating'));

        $record->set('avgrating', 1.0 * $record->get('sumrating') / $record->get('cntall'));

        if ($rating->get('hasreview')) {

            $record->set('cntreviews', $record->get('cntreviews') + 1);

        }

        $record->set(self::cntkey($rating->get('rating')), $record->get(self::cntkey($rating->get('rating'))) + 1);

        $record->save();

        return $record;

    }

    /**

     * Update summary after a rating was updated

     *

     * @param int $courseid

     * @param rating $rating

     * @param \stdClass $oldrecord

     * @return static|null

     */

    public static function update_rating(int $courseid, rating $rating, \stdClass $oldrecord): ?self {

        $ratingold = $oldrecord->rating;

        $summary = self::get_for_course($courseid);

        if (!$summary->get('cntall') || !$summary->get(self::cntkey($ratingold))) {

            // Sanity check, did not pass, recalculate all.

            return $summary->recalculate();

        }

        if ($rating == $ratingold && $rating->get('hasreview') == $oldrecord->hasreview) {

            // Rating did not change.

            return null;

        }

        $summary->set('cntreviews', $summary->get('cntreviews') + $rating->get('hasreview') - $oldrecord->hasreview);

        if ($rating != $ratingold) {

            $summary->set('sumrating', $summary->get('sumrating') + $rating->get('rating') - $ratingold);

            $summary->set(self::cntkey($ratingold), $summary->get(self::cntkey($ratingold)) - 1);

            $summary->set(self::cntkey($rating->get('rating')), (int)$summary->get(self::cntkey($rating->get('rating'))) + 1);

            $summary->set('avgrating', 1.0 * $summary->get('sumrating') / $summary->get('cntall'));

        }

        $summary->save();

        return $summary;

    }

    /**

     * Update summary when it has to be empty - reset all counter fields

     *

     * @return void

     * @throws \coding_exception

     */

    public function reset_all_counters() {

        foreach (['cntall', 'sumrating', 'cntreviews'] as $key) {

            $this->set($key, 0);

        }

        $this->set('avgrating', null);

        for ($i = 1; $i <= 10; $i++) {

            $this->set(self::cntkey($i), 0);

        }

    }

    /**

     * Recalculate summary for the specific course

     *

     * @return $this|null

     */

    public function recalculate(): ?self {

        global $DB;

        if ($this->get('ratingmode') == constants::RATEBY_NOONE) {

            $this->reset_all_counters();

            $this->save();

            return $this;

        }

        $isempty = $DB->sql_isempty('', 'review', false, true);

        $sql = 'SELECT COUNT(id) AS cntall,

               SUM(rating) AS sumrating,

               SUM(CASE WHEN '.$isempty.' THEN 0 ELSE 1 END) as cntreviews,

               SUM(CASE WHEN rating = 1 THEN 1 ELSE 0 END) as cnt01,

               SUM(CASE WHEN rating = 2 THEN 1 ELSE 0 END) as cnt02,

               SUM(CASE WHEN rating = 3 THEN 1 ELSE 0 END) as cnt03,

               SUM(CASE WHEN rating = 4 THEN 1 ELSE 0 END) as cnt04,

               SUM(CASE WHEN rating = 5 THEN 1 ELSE 0 END) as cnt05,

               SUM(CASE WHEN rating = 6 THEN 1 ELSE 0 END) as cnt06,

               SUM(CASE WHEN rating = 7 THEN 1 ELSE 0 END) as cnt07,

               SUM(CASE WHEN rating = 8 THEN 1 ELSE 0 END) as cnt08,

               SUM(CASE WHEN rating = 9 THEN 1 ELSE 0 END) as cnt09,

               SUM(CASE WHEN rating = 10 THEN 1 ELSE 0 END) as cnt10

            FROM {tool_courserating_rating} r

            WHERE r.courseid = :courseid

        ';

        $params = ['courseid' => $this->get('courseid')];

        $result = $DB->get_record_sql($sql, $params);

        if (!$result->cntall) {

            $this->reset_all_counters();

        } else {

            $keys = ['cntall', 'sumrating', 'cntreviews'];

            for ($i = 1; $i <= 10; $i++) {

                $keys[] = self::cntkey($i);

            }

            foreach ($keys as $key) {

                $this->set($key, $result->$key ?? 0);

            }

            $this->set('avgrating', 1.0 * $this->get('sumrating') / $this->get('cntall'));

        }

        $this->save();

        return $this;

    }

    /**

     * Recalculate summary after an individual rating was deleted

     *

     * @param \stdClass $rating snapshot of the rating record before it was deleted

     * @return static|null

     */

    public static function delete_rating(\stdClass $rating): ?self {

        $ratingold = $rating->rating;

        $hasreviewold = $rating->hasreview;

        $record = self::get_for_course($rating->courseid);

        if ($record->get('cntall') <= 1 || !$record->get(self::cntkey($ratingold))) {

            // Sanity check did not pass or no more ratings left, recalculate all.

            return $record->recalculate();

        }

        if ($hasreviewold && $record->get('cntreviews') > 0) {

            $record->set('cntreviews', $record->get('cntreviews') - 1);

        }

        $record->set('cntall', $record->get('cntall') - 1);

        $record->set('sumrating', $record->get('sumrating') - $ratingold);

        $record->set(self::cntkey($ratingold), $record->get(self::cntkey($ratingold)) - 1);

        $record->set('avgrating', 1.0 * $record->get('sumrating') / $record->get('cntall'));

        $record->save();

        return $record;

    }

}