package com.plannaplan.services;

import java.util.List;
import java.util.Optional;
import java.util.UUID;

import com.plannaplan.entities.User;
import com.plannaplan.exceptions.UserNotFoundException;
import com.plannaplan.models.UserApiResponse;
import com.plannaplan.repositories.UserRepository;
import com.plannaplan.types.UserRoles;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * Service of UserService which can get(By Email), login, save user.
 */
@Service
public class UserService {
    @Autowired
    private UserRepository repo;

    @Autowired
    private UsosApiService service;

    public UserService() {
        super();
    }

    /**
     * checks if user exist and return him or creates new one with student role
     * otherwise
     * 
     * @param email  user email in usos
     * @param usosId user id in usos
     * @return user entity instace containing changes saved in database
     */
    public User checkForUser(String email, String usosId) {
        return this.checkForUser(email, usosId, UserRoles.STUDENT);
    }

    /**
     * checks if user exist and creates new one if doesn't
     * 
     * @param email          user email in usos
     * @param usosId         user id in usos
     * @param roleIfNotExist role to be set in case user is not in database yet
     * @return user entity instace containing changes saved in database
     */
    public User checkForUser(String email, String usosId, UserRoles roleIfNotExist) {
        if (usosId == null) {
            Optional<User> user = this.repo.getByEmail(email.replace("\n", "").trim());
            if (user.isPresent()) {
                return user.get();
            } else {
                final User newUser = new User(null, null, email.replace("\n", "").trim(), roleIfNotExist);
                return this.repo.save(newUser);
            }
        } else {
            Optional<User> user = this.repo.getByUsosId(usosId.replace("\n", "").trim());
            if (user.isPresent()) {
                return user.get();
            } else {
                final User newUser = new User(null, null, email.replace("\n", "").trim(), usosId, roleIfNotExist);
                return this.repo.save(newUser);
            }
        }
    }

    /**
     * generates token for user and if user don't have name in database it will
     * attemp to obtain these from usos api and saves changes in database
     * 
     * @param authority user we want to login
     * @return user with changed values after save in db
     * @throws UserNotFoundException throwed if user doesn't exist
     */
    public User login(User authority) throws UserNotFoundException {
        final String token = UUID.randomUUID().toString();
        if ((authority.getName() == null || authority.getSurname() == null) && authority.getUsosId() != null) {
            final UserApiResponse resp = this.service.getUserData(authority.getUsosId());
            authority.updateWithUsosData(resp);
        }
        try {
            authority.setToken(token);
            this.repo.save(authority);
        } catch (Exception e) {
            throw new UserNotFoundException(e.getMessage());
        }
        return authority;
    }

    /**
     * sacves user to databse and return instatnce with id
     * 
     * @param user to be saved
     * @return instatnce with bd id
     */
    public User save(User user) {
        return this.repo.save(user);
    }

    /**
     * 
     * @param email of user to be find
     * @return user with given mail
     * @throws UserNotFoundException throwed if user doesn't exist
     */
    public User getUserByEmail(String email) throws UserNotFoundException {
        return this.repo.getByEmail(email.replace("\n", "").trim())
                .orElseThrow(() -> new UserNotFoundException("Cannot find user with given authority"));

    }

    /**
     * return user by given authority
     * 
     * @param authority user usosId or email
     * @return optional with user if found
     */
    public Optional<User> getByAuthority(String authority) {
        return this.repo.getByAuthority(authority);
    }

    public Optional<User> getByToken(String token) {
        return this.repo.getByToken(token);
    }

    /**
     * search for user with given query
     * 
     * @param query string that will be matched to users name and surname
     * @return list opf results
     */
    public List<User> searchForStudents(String query) {
        return this.repo.searchForUsers(query, UserRoles.STUDENT);
    }

    public Optional<User> getById(Long userId) {
        return this.repo.findById(userId);
    }

    public List<User> getAllStudents() {
        return this.repo.getAllByRole(UserRoles.STUDENT);
    }

    public Optional<User> getUserByRefreshToken(String refreshToken) {
        return this.repo.getByRefreshToken(refreshToken);
    }

    public boolean adminExists() {
        return this.repo.getAllByRole(UserRoles.ADMIN).size() > 0;
    }

}