content: package com.alibou.security.config;
  
  import io.jsonwebtoken.Claims;
  import io.jsonwebtoken.Jwts;
  import io.jsonwebtoken.SignatureAlgorithm;
  import io.jsonwebtoken.io.Decoders;
  import io.jsonwebtoken.security.Keys;
  import java.security.Key;
  import java.util.Date;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.function.Function;
  
  import org.springframework.beans.factory.annotation.Value;
  import org.springframework.security.core.userdetails.UserDetails;
  import org.springframework.stereotype.Service;
  
  @Service
  public class JwtService {
  
    @Value("${application.security.jwt.secret-key}")
    private String secretKey;
    @Value("${application.security.jwt.expiration}")
    private long jwtExpiration;
    @Value("${application.security.jwt.refresh-token.expiration}")
    private long refreshExpiration;
  
    public String extractUsername(String token) {
      return extractClaim(token, Claims::getSubject);
    }
  
    public <T> T extractClaim(String token, Function<Claims, T> claimsResolver) {
      final Claims claims = extractAllClaims(token);
      return claimsResolver.apply(claims);
    }
  
    public String generateToken(UserDetails userDetails) {
      return generateToken(new HashMap<>(), userDetails);
    }
  
    public String generateToken(
        Map<String, Object> extraClaims,
        UserDetails userDetails
    ) {
      return buildToken(extraClaims, userDetails, jwtExpiration);
    }
  
    public String generateRefreshToken(
        UserDetails userDetails
    ) {
      return buildToken(new HashMap<>(), userDetails, refreshExpiration);
    }
  
    private String buildToken(
            Map<String, Object> extraClaims,
            UserDetails userDetails,
            long expiration
    ) {
      return Jwts
              .builder()
              .setClaims(extraClaims)
              .setSubject(userDetails.getUsername())
              .setIssuedAt(new Date(System.currentTimeMillis()))
              .setExpiration(new Date(System.currentTimeMillis() + expiration))
              .signWith(getSignInKey(), SignatureAlgorithm.HS256)
              .compact();
    }
  
    public boolean isTokenValid(String token, UserDetails userDetails) {
      final String username = extractUsername(token);
      return (username.equals(userDetails.getUsername())) && !isTokenExpired(token);
    }
  
    private boolean isTokenExpired(String token) {
      return extractExpiration(token).before(new Date());
    }
  
    private Date extractExpiration(String token) {
      return extractClaim(token, Claims::getExpiration);
    }
  
    private Claims extractAllClaims(String token) {
      return Jwts
          .parserBuilder()
          .setSigningKey(getSignInKey())
          .build()
          .parseClaimsJws(token)
          .getBody();
    }
  
    private Key getSignInKey() {
      byte[] keyBytes = Decoders.BASE64.decode(secretKey);
      return Keys.hmacShaKeyFor(keyBytes);
    }
  }
  