📄 register_training.php

<?php
// File: web/mobile/Flutter/register_training.php

// Enable error reporting for debugging
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

// Enable CORS headers
header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Methods: POST");
header("Access-Control-Allow-Headers: Content-Type");
header("Content-Type: application/json; charset=UTF-8");

require_once 'db.php';

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    // Start a database transaction
    $pdo->beginTransaction();

    try {
        // Validate required fields
        $requiredFields = ['training_id', 'user_id', 'full_name', 'mobile_number', 'payment_status'];
        foreach ($requiredFields as $field) {
            if (!isset($_POST[$field]) || empty($_POST[$field])) {
                throw new Exception("Missing required field: $field");
            }
        }

        // Sanitize and prepare input data
        $trainingId = intval($_POST['training_id']);
        $userId = intval($_POST['user_id']);
        $fullName = $_POST['full_name'];
        $mobileNumber = $_POST['mobile_number'];
        $paymentStatus = $_POST['payment_status'];
        $razorpayPaymentId = $_POST['razorpay_payment_id'] ?? null;

        // Check if user is already registered for this training
        $checkRegistrationStmt = $pdo->prepare("
            SELECT COUNT(*) as registration_count 
            FROM training_participants 
            WHERE training_id = :training_id AND user_id = :user_id
        ");
        $checkRegistrationStmt->execute([
            'training_id' => $trainingId,
            'user_id' => $userId
        ]);
        $registrationCheck = $checkRegistrationStmt->fetch(PDO::FETCH_ASSOC);

        if ($registrationCheck['registration_count'] > 0) {
            throw new Exception("You are already registered for this training");
        }

        // Prepare and execute registration insert
        $insertStmt = $pdo->prepare("
            INSERT INTO training_participants 
            (training_id, user_id, full_name, mobile_number, registration_date, payment_status, razorpay_payment_id) 
            VALUES 
            (:training_id, :user_id, :full_name, :mobile_number, NOW(), :payment_status, :razorpay_payment_id)
        ");
        $insertStmt->execute([
            'training_id' => $trainingId,
            'user_id' => $userId,
            'full_name' => $fullName,
            'mobile_number' => $mobileNumber,
            'payment_status' => $paymentStatus,
            'razorpay_payment_id' => $razorpayPaymentId
        ]);

        // Commit the transaction
        $pdo->commit();

        // Prepare success response
        $response = [
            'status' => 'success',
            'message' => 'Training registration successful',
            'registrationDetails' => [
                'trainingId' => $trainingId,
                'userId' => $userId,
                'fullName' => $fullName,
                'paymentStatus' => $paymentStatus
            ]
        ];

        echo json_encode($response);
    } catch (Exception $e) {
        // Rollback the transaction in case of error
        $pdo->rollBack();

        // Prepare error response
        $response = [
            'status' => 'error',
            'message' => $e->getMessage()
        ];

        echo json_encode($response);
        exit;
    }
} else {
    // Method not allowed
    http_response_code(405);
    echo json_encode([
        'status' => 'error',
        'message' => 'Method Not Allowed'
    ]);
}
?>