smtech / grading-analytics

src/Snapshots/History.php

<?php
/** History class */

namespace smtech\GradingAnalytics\Snapshots;

use smtech\GradingAnalytics\Snapshots\Exception\SnapshotException;

/**
 * A class to query and cache the history of a course's statistics
 *
 * @author Seth Battis <SethBattis@stmarksschool.org>
 */
class History extends CacheableDatabase
{
    /**
     * The Canvas ID of the course
     * @var string|integer
     */
    protected $courseId;

    /**
     * The course history
     * @var array
     */
    protected static $data;

    /**
     * Construct a history object
     *
     * Note that the actual history will be queried and/or cached just in time
     * when needed, not during instantiation.
     *
     * @param \mysqli|\smtech\ReflexiveCanvasLTI\Toolbox|CacheableDatabase $databaseProvider
     *        An object containing a reusable mysqli access object
     * @param string|integer $courseId Canvas ID of the course
     *
     * @throws SnapshotException `SnapshotException::COURSE_ID` If `$courseId`
     *         does not appear to be a valid (numeric) Canvas course ID.
     */
    public function __construct($databaseProvider, $courseId)
    {
        parent::__construct($databaseProvider);

        if (is_numeric($courseId)) {
            $this->courseId = $courseId;
        } else {
            throw new SnapshotException(
                'Numeric Course ID required',
                SnapshotException::COURSE_ID
            );
        }
    }

    /**
     * Get the numeric Canvas course ID
     *
     * @return string|integer
     */
    public function getCourseId()
    {
        return $this->courseId;
    }

    /**
     * Get the numeric Canvas account ID of the course's parent department
     *
     * @return string|integer|false Returns `FALSE` if no parent department is
     *         included in the most recent collected course statistics
     */
    public function getDepartmentId()
    {
        if ($this->cacheHistory()) {
            return (integer) static::$data[$this->getCourseID()][0]['course[account_id]'];
        }
        return false;
    }

    /**
     * Get the date of the most recently collected course statistics
     *
     * @return string|false The date in `YYYY-MM-DD` format or `FALSE` if no
     *                          timestamp is available.
     */
    public function getCurrentTimestamp()
    {
        if ($this->cacheHistory()) {
            return substr(static::$data[$this->getCourseId()][0]['timestamp'], 0, 10);
        }
        return false;
    }

    /**
     * Trigger a caching of the course history, if not already cached
     *
     * @return boolean `TRUE` if there is a non-empty cache of course
     *                        statistics to work with, `FALSE` otherwise
     */
    public function cacheHistory()
    {
        $courseId = $this->getCourseId();
        if (empty(static::$data[$courseId])) {
            static::$data = $this->getCache()->getCache($courseId);

It seems like $this->getCache()->getCache($courseId) of type boolean is incompatible with the declared type array of property $data.

            if (empty($this->data)) {
                if ($response = $this->sql->query("
                    SELECT * FROM `course_statistics`
                        WHERE
                            `course[id]` = '$courseId'
                        ORDER BY
                            `timestamp` DESC
                ")) {
                    while ($row = $response->fetch_assoc()) {
                        static::$data[$courseId][] = $row;
                    }
                    $this->getCache()->setCache($courseId, static::$data[$courseId]);
                }
            }
        }
        return (is_array(static::$data) &&
            is_array(static::$data[$courseId]) &&
            count(static::$data[$courseId]) > 0
        );
    }

    /**
     * Get the course's history of statistics
     *
     * @link https://smtech.github.io/grading-analytics/definitions.html Online
     *       documentation of course statistic fields
     *
     * @return array|false One row per course statistic collected daily, as
     *                         described in the documentation, or `FALSE` if no
     *                         statistics are available
     */
    public function getHistory()
    {
        if ($this->cacheHistory()) {
            return static::$data[$this->getCourseId()];
        }
        return false;
    }
}