AppUserDetailService.java

package com.codecool.bytebattlers.service;

import com.codecool.bytebattlers.model.AppUser;
import com.codecool.bytebattlers.repository.AppUserRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.stereotype.Service;

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

@RequiredArgsConstructor
@Service
public class AppUserDetailService implements UserDetailsService {
    private final AppUserRepository repository;

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        Optional<AppUser> appUser = repository.findByEmail(username);

        if (appUser.isEmpty()) {
            throw new UsernameNotFoundException("User not found!");
        }

        AppUser user = appUser.get();
        List<SimpleGrantedAuthority> authorities = List.of(new SimpleGrantedAuthority(user.getRole().name()));

        return new User(user.getEmail(), user.getPassword(), authorities);
    }
}