package com.zhentao.tool;

import com.zhentao.enums.ApiServerException;
import com.zhentao.exception.AsynException;
import io.jsonwebtoken.Claims;
import io.jsonwebtoken.JwtBuilder;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import javax.crypto.spec.SecretKeySpec;
import javax.xml.bind.DatatypeConverter;
import java.security.Key;
import java.util.Date;

public class TokenUtils {

    public static final String SECRET = "cjyfutu1688";

    public static String createJwtToken(String id) {
        String issuer = "www.futureading.com";
        String subject = "65532781@qq.com";
        long ttlMillis = 3600000; // 例如，设置token有效期为1小时
        return createJwtToken(id, issuer, subject, ttlMillis);
    }

    public static String createJwtToken(String id, String issuer, String subject, long ttlMillis) {
        SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.HS256;
        long nowMillis = System.currentTimeMillis();
        Date now = new Date(nowMillis);

        byte[] apiKeySecretBytes = DatatypeConverter.parseBase64Binary(SECRET);
        Key signingKey = new SecretKeySpec(apiKeySecretBytes, signatureAlgorithm.getJcaName());

        JwtBuilder builder = Jwts.builder().setId(id)
                .setIssuedAt(now)
                .setSubject(subject)
                .setIssuer(issuer)
                .signWith(signatureAlgorithm, signingKey);

        if (ttlMillis >= 0) {
            long expMillis = nowMillis + ttlMillis;
            Date exp = new Date(expMillis);
            builder.setExpiration(exp);
        }

        return builder.compact();
    }

    public static Claims parseJWT(String jwt) {
        Claims claims = Jwts.parser()
                .setSigningKey(DatatypeConverter.parseBase64Binary(SECRET))
                .parseClaimsJws(jwt).getBody();
        return claims;
    }

    public static Long getUserId(String token) {
        Claims claims = null;
        try {
            claims = parseJWT(token);
        } catch (Exception e) {
            throw new AsynException(ApiServerException.TOKEN_ERR);
        }

        if (null == claims) {
            throw new AsynException(ApiServerException.TOKEN_ERR);
        }
        String id = claims.getId();
        Long userId = Long.valueOf(id);

        return userId;
    }

    /**
     * 检查token是否过期
     * @param jwt 要检查的token
     * @return 如果token过期返回true，否则返回false
     */
    public static boolean isTokenExpired(String jwt) {
        Claims claims = parseJWT(jwt);
        Date exp = claims.getExpiration();
        if (exp == null) {
            // 如果没有设置过期时间，可以认为token不过期
            return false;
        }
        return exp.before(new Date()); // 比较当前时间和过期时间
    }

    public static void main(String[] args) {
        String token = TokenUtils.createJwtToken("admin");
        System.out.println("Token: " + token);
        System.out.println("Is expired: " + TokenUtils.isTokenExpired(token));
    }
}