package ru.soune.nocopy.service.register;

import jakarta.persistence.EntityNotFoundException;
import lombok.RequiredArgsConstructor;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import ru.soune.nocopy.dto.*;
import ru.soune.nocopy.dto.register.AccountType;
import ru.soune.nocopy.dto.register.LoginAnswer;
import ru.soune.nocopy.dto.register.LoginRequest;
import ru.soune.nocopy.dto.register.RegRequest;
import ru.soune.nocopy.entity.company.Company;
import ru.soune.nocopy.entity.tarif.TariffInfo;
import ru.soune.nocopy.entity.tarif.TariffType;
import ru.soune.nocopy.entity.user.AuthToken;
import ru.soune.nocopy.entity.user.Permission;
import ru.soune.nocopy.entity.user.User;
import ru.soune.nocopy.entity.user.UserNotActive;
import ru.soune.nocopy.exception.CompanyAlreadyExist;
import ru.soune.nocopy.exception.NotFoundAuthToken;
import ru.soune.nocopy.exception.NotValidFieldException;
import ru.soune.nocopy.repository.*;
import ru.soune.nocopy.service.file.CheckCounterService;
import ru.soune.nocopy.service.tariff.TariffInfoService;

import java.security.SecureRandom;
import java.time.LocalDateTime;
import java.util.*;

@Service
@RequiredArgsConstructor
public class AuthService {

    private final UserRepository userRepository;

    private final AuthTokenRepository authTokenRepository;

    private final PasswordEncoder passwordEncoder;

    private final CompanyRepository companyRepository;

    private final CheckCounterService checkCounterService;

    private final TariffInfoRepository tariffInfoRepository;

    private final TariffInfoService tariffInfoService;

    private final UserNotActiveRepository userNotActiveRepository;

    private final SecureRandom secureRandom = new SecureRandom();

    @Transactional
    public AuthToken register(RegRequest registerRequest, boolean verified) {
        User user = new User();
        user.setFullName(registerRequest.getFullName());
        user.setEmail(registerRequest.getEmail());
        user.setPassword(passwordEncoder.encode(registerRequest.getPassword()));
        user.setActive(!verified);
        user.setEmailVerified(!verified);

        AccountType accountType = AccountType.valueOf(registerRequest.getAccountType().toUpperCase());

        if (accountType == AccountType.B2B && registerRequest.getCompanyName() != null) {
            try {
                createCompanyAccount(registerRequest, user);
            } catch (CompanyAlreadyExist exist) {
                throw new CompanyAlreadyExist("Company already exist");
            }
        } else if (accountType == AccountType.B2C && registerRequest.getCompanyName() == null) {
            createIndividualAccount(user);
        } else {
            createIndividualCompanyAccount(registerRequest, user);
        }

        if (registerRequest.getPhone() != null) {
            user.setPhone(registerRequest.getPhone());
        }

        User savedUser = userRepository.save(user);

        AuthToken authToken = genereateAuthToken(savedUser);

        checkCounterService.initProtectCheckLimit(user, 0);

        return authTokenRepository.save(authToken);
    }

    @Transactional
    public Long useUserAuthToken(String token) {
        if (token == null || token.isBlank()) {
            throw new NotFoundAuthToken("Token is required");
        }

        if (token.startsWith("Bearer ")) {
            token = token.replace("Bearer ", "");
        }

        AuthToken authToken = authTokenRepository.findByToken(token)
                .orElseThrow(() -> new NotFoundAuthToken("Token not found"));
        authToken.setLastUsedAt(LocalDateTime.now());
        authToken.setExpiresAt(LocalDateTime.now().plusHours(1));

        authTokenRepository.save(authToken);

        return authToken.getUser().getId();
    }

    public AuthToken login(LoginRequest request) {
        User user = userRepository.findByEmail(request.getEmail());

        if (!user.isActive()) {
            throw new NotValidFieldException("User not active", new BaseResponse(20003,
                    MessageCode.USER_NOT_ACTIVE.getCode(),
                    MessageCode.USER_NOT_ACTIVE.getDescription(), Map.of("userId", user.getId())));
        }

        if (!passwordEncoder.matches(request.getPassword(), user.getPassword())) {
            LoginAnswer loginAnswer = new LoginAnswer();
            loginAnswer.setFieldErrors(Arrays.asList(Map.of("password", request.getPassword())));
            loginAnswer.setVerified(user.isEmailVerified());
            loginAnswer.setActive(user.isActive());

            int attempts = user.getFailedLoginAttempts() + 1;
            user.setFailedLoginAttempts(attempts);

            if (attempts >= 5) {
                user.setActive(false);
                blockUser(user);
            }

            userRepository.save(user);

            throw new NotValidFieldException("Invalid password", new BaseResponse(20003,
                    MessageCode.AUTH_PASSWORD_NOT_MATCHES.getCode(),
                    MessageCode.AUTH_PASSWORD_NOT_MATCHES.getDescription(), loginAnswer));
        }

        user.setLastLoginAt(LocalDateTime.now());
        user.setFailedLoginAttempts(0);
        user.setActive(true);

        User savedUser = userRepository.save(user);

        AuthToken authToken = new AuthToken();
        authToken.setToken(generateAuthToken());
        authToken.setUser(savedUser);

        return authTokenRepository.save(authToken);
    }

    @Transactional
    public void logout(String token) {
        authTokenRepository.findByToken(token)
                .ifPresent(authTokenRepository::delete);
    }

    @Transactional
    public AuthToken generateAuthToken(User user) {
        return authTokenRepository.save(genereateAuthToken(user));
    }

    private AuthToken genereateAuthToken(User user) {
        AuthToken authToken = new AuthToken();
        authToken.setToken(generateAuthToken());
        authToken.setUser(user);

        return authToken;
    }

    private String generateAuthToken() {
        byte[] bytes = new byte[32];
        secureRandom.nextBytes(bytes);
        return Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
    }

    private void createCompanyAccount(RegRequest request, User user) {
        Optional<Company> byInn = companyRepository.findByInn(request.getInn());

        if (byInn.isPresent()) {
            throw new CompanyAlreadyExist("Company was already created");
        }

        Company company = new Company();
        company.setCompanyName(request.getCompanyName());
        company.setInn(request.getInn());

        TariffInfo companyTariff = tariffInfoService.createTariffInfo(TariffType.DEMO);
        company.setTariffInfo(companyTariff);

        companyRepository.save(company);
        tariffInfoService.addTariffInfo(companyTariff);

        user.setCompany(company);
        user.grantPermission(Permission.COMPANY_ADMIN_PERMISSIONS);
    }

    private void createIndividualAccount(User user) {
        TariffInfo personalTariff = tariffInfoService.createTariffInfo(TariffType.DEMO);

        tariffInfoService.addTariffInfo(personalTariff);

        user.setPersonalTariffInfo(personalTariff);
        user.grantPermission(Permission.DEFAULT_USER_PERMISSIONS);
    }


    private void createIndividualCompanyAccount(RegRequest request, User user) {
        String authToken = request.getAuthToken();
        Long userIdByToken = authTokenRepository.findUserIdByToken(authToken);
        User companyUser = userRepository.findById(userIdByToken)
                .orElseThrow(() -> new EntityNotFoundException("Not found token: " + authToken));

        Company company = companyUser.getCompany();
        if (company == null) {
            throw new IllegalStateException("Not have company");
        }

        TariffInfo tariffInfo = company.getTariffInfo();
        if (tariffInfo == null) {
            throw new IllegalStateException("Company not have tariff");
        }

//        Tariff tariff = tariffInfo.getTariff();
//        Long maxUsers = tariff.getMaxUsers();
//        long currentCountUsers = userRepository.countByCompanyId(company.getId());
//
//        if (currentCountUsers >= maxUsers) {
//            throw new NotValidFieldException("Max user is over.", new BaseResponse(20002,
//                    MessageCode.USER_LIMIT_IS_OVER.getCode(),
//                    MessageCode.USER_LIMIT_IS_OVER.getDescription(), Map.of(
//                    "limit", maxUsers, "countUser", currentCountUsers)));
//        }

        user.setCompany(company);
        user.grantPermission(Permission.DEFAULT_USER_PERMISSIONS);
    }

    public void blockUser(User user) {
        Optional<UserNotActive> existing = userNotActiveRepository.findByUserId(user.getId());
        if (existing.isEmpty()) {
            LocalDateTime now = LocalDateTime.now();

            UserNotActive notActive = UserNotActive.builder()
                    .user(user)
                    .createdAt(now)
                    .blockedUntil(now.plusMinutes(15))
                    .build();

            userNotActiveRepository.save(notActive);
        }
    }
}