<?php
// Enable error reporting for debugging purposes (remove in production)
error_reporting(E_ALL);
ini_set('display_errors', 1);

// Initialize variable for default email value
$defaultEmail = "";

// Define a function to send an email with comprehensive error handling
function sendEmail($to, $subject, $message) {
    // Validate email format
    if (!filter_var($to, FILTER_VALIDATE_EMAIL)) {
        error_log("Invalid email address: $to");
        return false;
    }
    
    // Basic email headers for better compatibility
    $headers = "From: webmaster@" . $_SERVER['HTTP_HOST'] . "\r\n";
    $headers .= "Reply-To: webmaster@" . $_SERVER['HTTP_HOST'] . "\r\n";
    $headers .= "MIME-Version: 1.0\r\n";
    $headers .= "Content-Type: text/plain; charset=UTF-8\r\n";
    $headers .= "X-Mailer: PHP/" . phpversion();
    
    // Sanitize subject to prevent header injection
    $subject = preg_replace("/[\r\n]/", "", $subject);
    
    // Try to send email
    if (mail($to, $subject, $message, $headers)) {
        return true;
    } else {
        // Log the error for debugging
        error_log("Failed to send email to: $to");
        return false;
    }
}

// Function to check if mail() function is available
function isMailAvailable() {
    return function_exists('mail');
}

?>

<!-- Display a message indicating that upload is working -->
Upload is <b><span style="color: green">WORKING</span></b><br>

<!-- Display mail function status -->
Check Mailing ..<br>
<?php
if (!isMailAvailable()) {
    echo '<b><span style="color: red">MAIL FUNCTION NOT AVAILABLE ON THIS SERVER</span></b><br>';
} else {
    echo '<b><span style="color: green">MAIL FUNCTION IS AVAILABLE</span></b><br>';
}
?>

<!-- Display server information for debugging -->
<div style="background: #f0f0f0; padding: 10px; margin: 10px 0; font-size: 12px;">
    <strong>Server Info:</strong><br>
    PHP Version: <?php echo phpversion(); ?><br>
    Server: <?php echo $_SERVER['SERVER_SOFTWARE'] ?? 'Unknown'; ?><br>
    OS: <?php echo PHP_OS; ?><br>
    Mail Function: <?php echo isMailAvailable() ? 'Available' : 'Not Available'; ?>
</div>

<!-- Create a form for users to input email address -->
<form method="post">
    <label for="email">Email Address:</label>
    <input type="email" name="email" id="email" value="<?php echo htmlspecialchars($defaultEmail); ?>" placeholder="Enter your email" required>
    <br><br>
    <input type="submit" value="Send Test Email >>">
</form>
<br>

<?php
// Check if the form has been submitted and email field is filled
if ($_SERVER['REQUEST_METHOD'] === 'POST' && !empty($_POST['email'])) {
    
    // Sanitize email input
    $email = filter_var(trim($_POST['email']), FILTER_SANITIZE_EMAIL);
    
    // Validate email
    if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
        echo '<b style="color: red;">Please enter a valid email address</b>';
    } elseif (!isMailAvailable()) {
        echo '<b style="color: red;">Mail function is not available on this server. Contact your hosting provider.</b>';
    } else {
        $xx = mt_rand(); // Generate a random number
        
        // Create message with more details
        $message = "EMAIL TEST WORKING!\n\n";
        $message .= "Test ID: " . $xx . "\n";
        $message .= "Server: " . ($_SERVER['SERVER_SOFTWARE'] ?? 'Unknown') . "\n";
        $message .= "PHP Version: " . phpversion() . "\n";
        $message .= "Timestamp: " . date('Y-m-d H:i:s') . "\n";
        $message .= "This is a test email to verify that the PHP mail system is working correctly.";
        
        $subject = "PHP Mail Test - " . $xx;
        
        // Send email and handle result
        $result = sendEmail($email, $subject, $message);
        
        if ($result) {
            // Display a success message
            echo "<b style='color: green;'>✓ Successfully sent test email to " . htmlspecialchars($email) . " (Test ID: $xx)</b>";
            echo "<br><small>Please check your inbox and spam folder for the test email.</small>";
        } else {
            // Display a failure message
            echo "<b style='color: red;'>✗ Failed to send test email to " . htmlspecialchars($email) . "</b>";
            
            // Additional troubleshooting info
            echo "<div style='background: #fff0f0; padding: 10px; margin: 10px 0; font-size: 11px;'>";
            echo "<strong>Troubleshooting Tips:</strong><br>";
            echo "1. Verify the email address is correct<br>";
            echo "2. Check your spam folder<br>";
            echo "3. Contact your hosting provider to check mail server configuration<br>";
            echo "4. Verify PHP mail() function is enabled on the server";
            echo "</div>";
        }
    }
}
?>