type is audio/mpeg (was audio/wav for an .mp3)
* - audio path is absolute (no dependence on the working directory)
* - user escaped in SQL; `e107.` database name replaced by MPREFIX
* - falls back to any word when nothing exists at the user's level, and
* shows a message instead of crashing when the word list is empty
* - previous tkLastQuestion row removed before inserting the new one
*/
class spelling2 {
// Text-to-speech server (OpenAI-compatible /v1/audio/speech endpoint).
const TTS_URL = 'http://192.168.1.252:8880/v1/audio/speech';
const TTS_TIMEOUT = 20; // seconds
private $user;
/**
* @param string $user User to supply the question for.
*/
public function __construct($user) {
$this->user = $user;
}
public function getSpellingWord() {
$year = max(1, (int) ceil($this->difficulty()));
$question = $this->pickWord($year);
if ($question === null) {
$question = $this->pickWord(13); // nothing at this level: fall back to any word
}
if ($question === null) {
e107::getRender()->tablerender('Spelling', 'No spelling words are available yet.');
return;
}
$questionHtml = $this->spellingHtml($question);
$db = e107::getDb();
$db->delete('tkLastQuestion', "user = '" . $db->escape($this->user) . "'");
$db->insert('tkLastQuestion', ['user' => $this->user, 'LastQuestionHtml' => base64_encode($questionHtml)]);
e107::getRender()->tablerender('Spelling', $questionHtml);
}
/**
* Pick a word at or below $year, preferring words this user has answered
* least in the last month.
*
* @return array|null Row with `word` and `usage`, or null when none found.
*/
private function pickWord($year) {
$db = e107::getDb();
$row = $db->retrieve(
"SELECT `word`, `usage`, IFNULL(`cnt`, 0) AS Ncnt FROM
(SELECT `word`, `usage` FROM `" . MPREFIX . "tk_wordList`
WHERE `year` <= " . (int) $year . " AND `usage` != '') AS wList
LEFT JOIN
(SELECT `answer`, COUNT(`answer`) AS `cnt` FROM `" . MPREFIX . "tkReport`
WHERE `answereddatestamp` > UNIX_TIMESTAMP(NOW() - INTERVAL 1 MONTH)
AND `username` = '" . $db->escape($this->user) . "'
AND `subject` = 'spelling' GROUP BY `answer`) AS Ans
ON wList.`word` = Ans.`answer`
ORDER BY IFNULL(`cnt`, 0), RAND() LIMIT 1"
);
return (is_array($row) && !empty($row['word'])) ? $row : null;
}
/**
* Build the spelling form. The expected answer is stored server-side;
* the form only carries a token.
*
* @param array $data ['word' => .., 'usage' => ..]
*/
private function spellingHtml($data) {
$frm = e107::getForm();
$token = TkAnswerStore::issue($this->user, ['word' => $data['word'], 'usage' => $data['usage']]);
$fString = $frm->open('questionForm', 'post', '', ['autocomplete' => 'off', 'class' => 'formclass']);
$fString .= $frm->label('
Spelling
') . "\n";
$fString .= $frm->label('Spell the word in the sentence.') . "\n";
$fString .= '';
if ($this->ensureAudio($data)) {
$fString .= "\n";
} else {
// No audio available: show the sentence with the word hidden.
$blanked = preg_replace('/' . preg_quote($data['word'], '/') . '/iu', '_____', $data['usage']);
$fString .= '
Audio is unavailable right now.
' . htmlspecialchars((string) $blanked) . "
\n";
}
$fString .= '';
$fString .= $frm->text('a1', '', 80, ['placeholder' => 'Write answer here!', 'autocomplete' => "off", 'spellcheck' => "false"]) . "\n";
$fString .= $frm->hidden('checkerData', $token, ['id' => 'checkerData']);
$fString .= $frm->hidden('subject', 'spelling', ['id' => 'subject']);
$fString .= '' . "\n";
$fString .= $frm->button('Answer', 'Check answer') . "\n";
$fString .= $frm->close();
$fString .= '';
return $fString;
}
/**
* Make sure ../../audio/.mp3 exists, generating it through the
* TTS server if needed.
*
* @return bool True when a usable audio file is in place.
*/
private function ensureAudio($data) {
$dir = dirname(__DIR__, 2) . '/audio';
$file = $dir . '/' . md5($data['word']) . '.mp3';
if (is_file($file) && filesize($file) > 0) {
return true;
}
if (!is_dir($dir) || !is_writable($dir)) {
return false;
}
$voices = ['bf_emma', 'bf_isabella', 'bf_alice', 'bf_lily', 'bm_george', 'bm_lewis', 'bm_daniel', 'bm_fable'];
$body = json_encode([
'model' => 'tts-1',
'input' => 'Spell the word, ' . $data['word'] . '. ' . $data['usage'] . '.',
'voice' => $voices[array_rand($voices)],
]);
$context = stream_context_create(['http' => [
'method' => 'POST',
'header' => "Content-Type: application/json\r\n",
'content' => $body,
'timeout' => self::TTS_TIMEOUT,
'ignore_errors' => true,
]]);
$audio = @file_get_contents(self::TTS_URL, false, $context);
$status = isset($http_response_header[0]) ? $http_response_header[0] : '';
if ($audio === false || strlen($audio) < 100 || !preg_match('#^HTTP/\S+\s+200\b#', $status)) {
return false;
}
// Write to a temp file and rename so a half-written file is never served.
$tmp = $file . '.' . bin2hex(random_bytes(4)) . '.tmp';
if (file_put_contents($tmp, $audio) === false) {
return false;
}
if (!rename($tmp, $file)) {
@unlink($tmp);
return false;
}
return true;
}
/**
* Difficulty (word year level 1-13) from the last month of answers.
* Capped while the user has few answers.
*
* @return float
*/
private function difficulty() {
$db = e107::getDb();
$stats = $db->retrieve(
"SELECT (SUM(correct)/COUNT(correct)*13) AS percent, COUNT(correct) AS count
FROM `" . MPREFIX . "tkReport`
WHERE answereddatestamp >= UNIX_TIMESTAMP(NOW() - INTERVAL 1 MONTH)
AND `username` = '" . $db->escape($this->user) . "' AND `subject` = 'spelling'"
);
if (!is_array($stats)) {
return 1;
}
$count = (int) $stats['count'];
$percent = (float) $stats['percent'];
if ($count >= 300) {
return $percent;
} elseif ($count >= 250) {
return min($percent, 7);
} elseif ($count >= 200) {
return min($percent, 5);
} elseif ($count >= 100) {
return min($percent, 3);
}
return 1;
}
}