package com.tailbet.util;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.security.Keys;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.crypto.SecretKey;
import java.nio.charset.StandardCharsets;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 * JWT工具类
 */
@Component
public class JwtUtil {

    @Value("${jwt.secret}")
    private String secret;

    @Value("${jwt.expiration}")
    private Long expiration;

    private SecretKey getSigningKey() {
        byte[] keyBytes = secret.getBytes(StandardCharsets.UTF_8);
        return Keys.hmacShaKeyFor(keyBytes);
    }

    /**
     * 生成Token
     */
    public String generateToken(Long userId, String username) {
        Map<String, Object> claims = new HashMap<>();
        claims.put("userId", userId);
        claims.put("username", username);
        return createToken(claims, username);
    }

    private String createToken(Map<String, Object> claims, String subject) {
        Date now = new Date();
        Date expirationDate = new Date(now.getTime() + expiration);

        return Jwts.builder()
                .claims(claims)
                .subject(subject)
                .issuedAt(now)
                .expiration(expirationDate)
                .signWith(getSigningKey())
                .compact();
    }

    /**
     * 解析Token
     */
    public Claims parseToken(String token) {
        return Jwts.parser()
                .verifyWith(getSigningKey())
                .build()
                .parseSignedClaims(token)
                .getPayload();
    }

    /**
     * 获取用户ID
     */
    public Long getUserId(String token) {
        Claims claims = parseToken(token);
        return claims.get("userId", Long.class);
    }

    /**
     * 获取用户名
     */
    public String getUsername(String token) {
        Claims claims = parseToken(token);
        return claims.getSubject();
    }

    /**
     * 验证Token是否过期
     */
    public boolean isTokenExpired(String token) {
        try {
            Claims claims = parseToken(token);
            return claims.getExpiration().before(new Date());
        } catch (Exception e) {
            return true;
        }
    }
}