generateDiagnosticMessage static method

String generateDiagnosticMessage(SmtpDiagnosticReport report)

Generates a detailed diagnostic message.

Implementation

static String generateDiagnosticMessage(SmtpDiagnosticReport report) {
  final buffer = StringBuffer();
  buffer.writeln('=== SMTP Diagnostic Report ===');
  buffer.writeln('Host: ${report.config.host}');
  buffer.writeln('Port: ${report.config.port}');
  buffer.writeln('Encryption: ${report.config.encryption}');
  buffer.writeln('Timeout: ${report.config.timeout}s');
  buffer.writeln();

  if (report.hostResolved) {
    buffer.writeln('✓ Host resolved: ${report.resolvedAddresses.join(', ')}');
  } else {
    buffer.writeln('✗ Host resolution failed');
  }

  if (report.portOpen) {
    buffer.writeln('✓ Port ${report.config.port} is open');
    buffer.writeln('  Connection time: ${report.connectionTime}ms');
  } else {
    buffer.writeln('✗ Port ${report.config.port} is closed or unreachable');
  }

  if (report.sslSupported) {
    buffer.writeln('✓ SSL/TLS connection successful');
  }

  if (report.error != null) {
    buffer.writeln();
    buffer.writeln('Error: ${report.error}');
  }

  buffer.writeln();
  buffer.writeln('Recommendations:');

  if (!report.hostResolved) {
    buffer.writeln('• Check that the SMTP hostname is correct');
    buffer.writeln('• Verify your DNS settings');
    buffer.writeln('• Check your internet connection');
  } else if (!report.portOpen) {
    buffer.writeln('• Verify the SMTP port is correct');
    buffer.writeln('  - Common ports: 25 (plain), 587 (TLS), 465 (SSL)');
    buffer.writeln(
      '• Check firewall settings (allow outbound on port ${report.config.port})',
    );
    buffer.writeln('• Verify the SMTP server is running');
    buffer.writeln('• Try increasing the timeout value');
  } else if (report.success) {
    buffer.writeln('• Connection successful! The SMTP server is reachable.');
    buffer.writeln(
      '• If authentication still fails, check username/password',
    );
  }

  buffer.writeln();
  buffer.writeln('Total diagnostic time: ${report.totalTime}ms');

  return buffer.toString();
}