package io.spring.api.security;

import io.spring.core.service.JwtService;
import io.spring.core.user.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
import org.springframework.web.filter.OncePerRequestFilter;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Collections;
import java.util.Optional;

@SuppressWarnings("SpringJavaAutowiringInspection")
public class JwtTokenFilter extends OncePerRequestFilter {
    @Autowired
    private UserRepository userRepository;

    @Autowired
    private JwtService jwtService;

    private String header = "Authorization";

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        getTokenString(request.getHeader(header)).ifPresent(token -> {
            jwtService.getSubFromToken(token).ifPresent(id -> {
                if (SecurityContextHolder.getContext().getAuthentication() == null) {
                    userRepository.findById(id).ifPresent(user -> {
                        UsernamePasswordAuthenticationToken authenticationToken = new UsernamePasswordAuthenticationToken(
                            user,
                            null,
                            Collections.emptyList()
                        );
                        authenticationToken.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));
                        SecurityContextHolder.getContext().setAuthentication(authenticationToken);
                    });
                }
            });
        });

        filterChain.doFilter(request, response);
    }

    private Optional<String> getTokenString(String header) {
        if (header == null) {
            return Optional.empty();
        } else {
            String[] split = header.split(" ");
            if (split.length < 2) {
                return Optional.empty();
            } else {
                return Optional.ofNullable(split[1]);
            }
        }
    }
}