+
+/**
+ * Marks all courses that require rounded grade items be updated.
+ *
+ * Used during upgrade and in course restore process.
+ *
+ * This upgrade script is needed because it has been decided that if a grade is rounded up, and it will changed a letter
+ * grade or satisfy a course completion grade criteria, then it should be set as so, and the letter will be awarded and or
+ * the course completion grade will be awarded.
+ *
+ * @param int $courseid Specify a course ID to run this script on just one course.
+ */
+function upgrade_course_letter_boundary($courseid = null) {
+ global $DB, $CFG;
+
+ $coursesql = '';
+ $params = array('contextlevel' => CONTEXT_COURSE);
+ if (!empty($courseid)) {
+ $coursesql = 'AND c.id = :courseid';
+ $params['courseid'] = $courseid;
+ }
+
+ $contextselect = context_helper::get_preload_record_columns_sql('ctx');
+
+ // 3, 13, 23, 31, and 32 are the grade display types that incorporate showing letters. See lib/grade/constants/php.
+ if (isset($CFG->grade_displaytype) && in_array($CFG->grade_displaytype, array(3, 13, 23, 31, 32))) {
+ // Check to see if the system letter boundaries are borked.
+ $systemcontext = context_system::instance();
+ if (upgrade_letter_boundary_needs_freeze($systemcontext)) {
+ // Select courses with no grade setting for display and a grade item that is using the default display,
+ // but have not altered the course letter boundary configuration. These courses are definitely affected.
+ $sql = "SELECT DISTINCT c.id AS courseid
+ FROM {grade_items} gi
+ JOIN {course} c ON c.id = gi.courseid
+ LEFT JOIN {grade_settings} gs ON gs.courseid = c.id AND name = 'displaytype'
+ LEFT JOIN (SELECT DISTINCT c.id
+ FROM {grade_letters} gl
+ JOIN {context} ctx ON gl.contextid = ctx.id
+ JOIN {course} c ON ctx.instanceid = c.id
+ WHERE ctx.contextlevel = :contextlevel) gl ON gl.id = c.id
+ WHERE (gi.display = 0 AND (gs.value is NULL))
+ AND gl.id is NULL $coursesql";
+ $affectedcourseids = $DB->get_recordset_sql($sql, $params);
+ foreach ($affectedcourseids as $courseid) {
+ set_config('gradebook_calculations_freeze_' . $courseid->courseid, 20160511);
+ }
+ $affectedcourseids->close();
+ }
+ // If the system letter boundary is okay proceed to check grade item and course grade display settings.
+ $params['contextlevel2'] = CONTEXT_COURSE;
+ $sql = "SELECT DISTINCT c.id AS courseid, $contextselect
+ FROM {course} c
+ JOIN {context} ctx ON ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel
+ JOIN {grade_items} gi ON c.id = gi.courseid
+ LEFT JOIN {grade_settings} gs ON c.id = gs.courseid AND name = 'displaytype'
+ LEFT JOIN (SELECT DISTINCT c.id
+ FROM {grade_letters} gl
+ JOIN {context} ctx ON gl.contextid = ctx.id
+ JOIN {course} c ON ctx.instanceid = c.id
+ WHERE ctx.contextlevel = :contextlevel2) gl ON gl.id = c.id
+ WHERE (gi.display IN (3, 13, 23, 31, 32)
+ OR (" . $DB->sql_compare_text('gs.value') . " IN ('3', '13', '23', '31', '32'))
+ OR gl.id is NOT NULL)
+ $coursesql";
+ } else {
+ // There is no site setting for letter grades. Just check the modified letter boundaries.
+ $sql = "SELECT DISTINCT c.id AS courseid, $contextselect
+ FROM {grade_letters} l, {course} c
+ JOIN {context} ctx ON ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel
+ WHERE l.contextid = ctx.id
+ AND ctx.instanceid = c.id
+ $coursesql";
+ }
+
+ $potentialcourses = $DB->get_recordset_sql($sql, $params);
+
+ foreach ($potentialcourses as $value) {
+ $gradebookfreeze = 'gradebook_calculations_freeze_' . $value->courseid;
+
+ // Check also if this course id has already been frozen.
+ // If we already have this course ID then move on to the next record.
+ if (!property_exists($CFG, $gradebookfreeze)) {
+ // Check for 57 letter grade issue.
+ context_helper::preload_from_record($value);
+ $coursecontext = context_course::instance($value->courseid);
+ if (upgrade_letter_boundary_needs_freeze($coursecontext)) {
+ // We have a course with a possible score standardisation problem. Flag for freeze.
+ // Flag this course as being frozen.
+ set_config('gradebook_calculations_freeze_' . $value->courseid, 20160511);
+ }
+ }
+ }
+ $potentialcourses->close();
+}
+
+/**
+ * Checks the letter boundary of the provided context to see if it needs freezing.
+ * Each letter boundary is tested to see if receiving that boundary number will
+ * result in achieving the cosponsoring letter.
+ *
+ * @param object $context Context object
+ * @return bool if the letter boundary for this context should be frozen.
+ */
+function upgrade_letter_boundary_needs_freeze($context) {
+ global $DB;
+
+ $contexts = $context->get_parent_context_ids();
+ array_unshift($contexts, $context->id);
+
+ foreach ($contexts as $ctxid) {
+
+ $letters = $DB->get_records_menu('grade_letters', array('contextid' => $ctxid), 'lowerboundary DESC',
+ 'lowerboundary, letter');
+
+ if (!empty($letters)) {
+ foreach ($letters as $boundary => $notused) {
+ $standardisedboundary = upgrade_standardise_score($boundary, 0, 100, 0, 100);
+ if ($boundary != $standardisedboundary) {
+ return true;
+ }
+ }
+ // We found letters but we have no boundary problem.
+ return false;
+ }
+ }
+ return false;
+}
+
+/**
+ * Given a float value situated between a source minimum and a source maximum, converts it to the
+ * corresponding value situated between a target minimum and a target maximum. Thanks to Darlene
+ * for the formula :-)
+ *
+ * @param float $rawgrade
+ * @param float $sourcemin
+ * @param float $sourcemax
+ * @param float $targetmin
+ * @param float $targetmax
+ * @return float Converted value
+ */
+function upgrade_standardise_score($rawgrade, $sourcemin, $sourcemax, $targetmin, $targetmax) {
+ if (is_null($rawgrade)) {
+ return null;
+ }
+
+ if ($sourcemax == $sourcemin or $targetmin == $targetmax) {
+ // Prevent division by 0.
+ return $targetmax;
+ }
+
+ $factor = ($rawgrade - $sourcemin) / ($sourcemax - $sourcemin);
+ $diff = $targetmax - $targetmin;
+ $standardisedvalue = $factor * $diff + $targetmin;
+ return $standardisedvalue;
+}
