public function videoRecommendationsAction($scope = 'all', $groupingId = 'all', $debug = false)
{
$this->view->disable();
// Get our context (this takes care of starting the session, too)
$context = $this->getDI()->getShared('ltiContext');
if (!$context->valid) {
echo '[{"error":"Invalid lti context"}]';
return;
}
if (!isset($groupingId)) {
echo '[{"error":"No scope grouping ID specified"}]';
return;
}
// Get the list of videos associated with concepts for the given scope and grouping ID
$videos = [];
switch ($scope) {
case "concept":
// Filter based on concept
$videos = MappingHelper::videosForConcept($groupingId);
break;
case "unit":
// Filter based on unit
$videos = MappingHelper::videosForConcepts(MappingHelper::conceptsInUnit($groupingId));
break;
default:
// All videos
$videos = MappingHelper::videosForConcepts(MappingHelper::allConcepts());
break;
}
// Find percentage watched for each video
foreach ($videos as $key => $video) {
$percentageWatched = MasteryHelper::calculateUniqueVideoPercentageForVideo($context->getUserName(), $video, $debug);
// Add the percentage to the video
$video["percentageWatched"] = $percentageWatched;
// Add the modified video back to the original array
$videos[$key] = $video;
}
// Format each video for the frontend
$formatted = [];
foreach ($videos as $video) {
$formatted[] = $video;
}
if ($debug) {
echo "<pre>Getting information for these video IDs in scope {$scope} and ID {$groupingId}\n";
foreach ($videos as $video) {
echo $video["Video ID"] . "\n";
}
}
echo json_encode($formatted);
}
public static function calculateUniqueVideoPercentageForConcepts($studentId, $conceptArray, $debug = false)
{
// Length of each statement in video seconds
$watchedStatementLength = 10;
// Find the videos related to this concept
$relatedVideos = MappingHelper::videosForConcepts($conceptArray);
$possibleWatchedStatementCount = 0;
$userWatchedStatementCount = 0;
$videoIds = array();
foreach ($relatedVideos as $video) {
// Length of video divided by 10 rounded down will be the total number of possible unique watched statements for that video
$possibleWatchedStatementCount += floor($video["Video Length"] / $watchedStatementLength);
// Add its ID to a list that we'll fetch watched statements for
$videoIds[] = 'https://ayamel.byu.edu/content/' . $video["Video ID"];
}
// Calculate how much time these videos were watched
// This is more efficient by using an $in query for all videos, rather than querying for each individual video as previously done
$statementHelper = new StatementHelper();
$statements = $statementHelper->getStatements("ayamel", ['statement.actor.name' => $studentId, 'statement.verb.id' => 'https://ayamel.byu.edu/watched', 'statement.object.id' => array('$in' => $videoIds)], ['statement.object.id' => true, 'statement.object.definition.extensions' => true]);
if ($statements["error"]) {
$userWatchedStatementCount = 0;
if ($debug) {
echo "Error in fetching watched statements for concept {$conceptId} and videos: \n";
print_r($videoIds);
}
} else {
// We need to track unique statements, so student can't get 100% video watched by watching the first half twice
$videoTrackers = [];
$watchStatementCount = $statements["cursor"]->count();
foreach ($statements["cursor"] as $statement) {
// We need to get rid of encoded "."s in extension names
$statement = StatementHelper::replaceHtmlEntity($statement["statement"], true);
// Set a flag for each rounded timestamp for each video
$videoId = $statement["object"]["id"];
$roundedTime = round($statement["object"]["definition"]["extensions"]["https://ayamel.byu.edu/playerTime"] / $watchedStatementLength);
if (!isset($videoTrackers[$videoId])) {
$videoTrackers[$videoId] = [];
}
// See if a statement with the same rounded timestamp was already tracked
if (isset($videoTrackers[$videoId][$roundedTime]) && $videoTrackers[$videoId][$roundedTime] == true) {
$isUnique = false;
} else {
$isUnique = true;
$userWatchedStatementCount++;
// Track this statement
$videoTrackers[$videoId][$roundedTime] = true;
}
if ($debug) {
print_r($statement);
echo "Video id: {$videoId}, rounded time: {$roundedTime}, unique: {$isUnique} \n<hr>";
}
}
}
if ($debug) {
echo "Videos for concept {$conceptId} : {$userWatchedStatementCount} unique watched statements out of {$possibleWatchedStatementCount} possible for the following videos: \n";
print_r($videoIds);
}
// Return percentage (0-100) of videos watched, avoiding division by 0
$percentage = $possibleWatchedStatementCount != 0 ? $userWatchedStatementCount / $possibleWatchedStatementCount : 0;
$percentage = round($percentage * 100);
return min($percentage, 100);
}
