package com.rongyichuang.auth.util;

import io.jsonwebtoken.*;
import io.jsonwebtoken.security.Keys;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.crypto.SecretKey;
import java.util.Date;

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

    private static final Logger logger = LoggerFactory.getLogger(JwtUtil.class);

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

    @Value("${app.jwt.expiration:86400000}") // 默认24小时
    private long jwtExpiration;

    /**
     * 生成JWT token
     */
    public String generateToken(Long userId, String phone) {
        Date now = new Date();
        Date expiryDate = new Date(now.getTime() + jwtExpiration);

        SecretKey key = Keys.hmacShaKeyFor(jwtSecret.getBytes());

        return Jwts.builder()
                .setSubject(userId.toString())
                .claim("phone", phone)
                .setIssuedAt(now)
                .setExpiration(expiryDate)
                .signWith(key, SignatureAlgorithm.HS256)
                .compact();
    }

    /**
     * 从token中获取用户ID
     */
    public Long getUserIdFromToken(String token) {
        Claims claims = getClaimsFromToken(token);
        return Long.parseLong(claims.getSubject());
    }

    /**
     * 从token中获取手机号
     */
    public String getPhoneFromToken(String token) {
        Claims claims = getClaimsFromToken(token);
        return claims.get("phone", String.class);
    }

    /**
     * 验证token是否有效
     */
    public boolean validateToken(String token) {
        try {
            getClaimsFromToken(token);
            return true;
        } catch (JwtException | IllegalArgumentException e) {
            logger.error("JWT token验证失败: {}", e.getMessage());
            return false;
        }
    }

    /**
     * 检查token是否过期
     */
    public boolean isTokenExpired(String token) {
        try {
            Claims claims = getClaimsFromToken(token);
            return claims.getExpiration().before(new Date());
        } catch (JwtException | IllegalArgumentException e) {
            return true;
        }
    }

    /**
     * 从token中解析Claims
     */
    private Claims getClaimsFromToken(String token) {
        SecretKey key = Keys.hmacShaKeyFor(jwtSecret.getBytes());
        return Jwts.parserBuilder()
                .setSigningKey(key)
                .build()
                .parseClaimsJws(token)
                .getBody();
    }
}