package com.it_jaros.jscanner;

import java.util.List;
import java.util.regex.Pattern;

public class ServiceDetector {
    private static final List<ServicePattern> patterns = List.of(
            new ServicePattern(ServiceType.SSH, Pattern.compile("(?i)^SSH-")),

            new ServicePattern(ServiceType.HTTP, Pattern.compile("(?i)^HTTP/")),
            new ServicePattern(ServiceType.HTTP, Pattern.compile("(?i)\\bServer:\\s*")),

            new ServicePattern(ServiceType.FTP, Pattern.compile("(?i)^220.*\\bFTP\\b")),

            new ServicePattern(ServiceType.SMTP, Pattern.compile("(?i)^220.*\\bSMTP\\b")),
            new ServicePattern(ServiceType.SMTP, Pattern.compile("(?i)^220.*\\bESMTP\\b")),

            new ServicePattern(ServiceType.IMAP, Pattern.compile("(?i)^\\* OK.*\\bIMAP\\b")),

            new ServicePattern(ServiceType.POP3, Pattern.compile("(?i)^\\+OK.*\\bPOP3\\b"))
    );

    public static ServiceType detect(String banner) {
        if (banner == null || banner.isBlank()) {
            return ServiceType.UNKNOWN;
        }

        for (ServicePattern servicePattern : patterns) {
            if (servicePattern.matches(banner)) {
                return servicePattern.serviceType();
            }
        }

        return ServiceType.UNKNOWN;
    }

    private record ServicePattern(
            ServiceType serviceType,
            Pattern pattern
    ) {
        boolean matches(String banner) {
            return pattern.matcher(banner).find();
        }
    }
}