added notification and cancellation mail

public/fetch_available_dates.php

@@ -0,0 +1,35 @@
+<?php
+require_once('include/headscript.php');
+
+$conn = mysqli_connect($servername, $username, $password, $dbname);
+
+if (!$conn) {
+    die(json_encode(['error' => 'Connessione al database fallita']));
+}
+
+$class_id = isset($_POST['class_id']) ? intval($_POST['class_id']) : 0;
+
+if ($class_id <= 0) {
+    die(json_encode(['error' => 'ID classe non valido']));
+}
+
+// Query per ottenere le date disponibili per la classe specificata
+// Supponiamo che ci sia una tabella 'class_schedule' con le date disponibili
+$sql = "SELECT DISTINCT DATE(bookingstart) as available_date 
+        FROM class_schedule 
+        WHERE class_id = ? 
+        ORDER BY available_date";
+$stmt = mysqli_prepare($conn, $sql);
+mysqli_stmt_bind_param($stmt, 'i', $class_id);
+mysqli_stmt_execute($stmt);
+$result = mysqli_stmt_get_result($stmt);
+
+$availableDates = [];
+while ($row = mysqli_fetch_assoc($result)) {
+    $availableDates[] = $row['available_date'];
+}
+
+mysqli_stmt_close($stmt);
+mysqli_close($conn);
+header('Content-Type: application/json');
+echo json_encode(['availableDates' => $availableDates]);