package com.mailserver.config;

import com.mailserver.repository.UserRepository;
import com.mailserver.service.UserService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.CommandLineRunner;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.security.SecureRandom;
import java.util.Base64;

/**
 * First mailbox on an empty database: {@code mailserver.admin.email} (default admin@<first domain>) with
 * {@code mailserver.admin.password}; no password given — a random one, printed to the log once.
 */
@Configuration
public class DataInitializer {

    private static final Logger log = LoggerFactory.getLogger(DataInitializer.class);

    @Bean
    public CommandLineRunner initDatabase(UserService userService, UserRepository userRepository, MailDomains domains,
                                          @Value("${mailserver.admin.email:}") String email,
                                          @Value("${mailserver.admin.password:}") String password) {
        return args -> {
            if (userRepository.count().block() > 0) {
                return;
            }
            String address = email.isBlank() ? "admin@" + domains.domains().iterator().next() : email.trim().toLowerCase();
            boolean generated = password.isBlank();
            String secret = generated ? randomPassword() : password;
            userService.register(address, secret, "Administrator").block();
            if (generated) {
                log.warn("First mailbox created: {} — password: {} (shown once, change it)", address, secret);
            } else {
                log.info("First mailbox created: {}", address);
            }
        };
    }

    private static String randomPassword() {
        byte[] bytes = new byte[18];
        new SecureRandom().nextBytes(bytes);
        return Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
    }
}