package top.tangyh.lamp.filing.utils

import io.jsonwebtoken.Jwts
import io.jsonwebtoken.SignatureAlgorithm
import io.jsonwebtoken.security.Keys
import org.springframework.beans.factory.annotation.Value
import org.springframework.stereotype.Component
import java.time.LocalDateTime
import java.time.ZoneId
import java.util.*
import javax.crypto.SecretKey

@Component
class JwtUtil(
    @Value("\${jwt.secret}")
    private val secretKey: String
) {


    // 生成签名 Key（HS256）
    private val signingKey: SecretKey = Keys.hmacShaKeyFor(Base64.getDecoder().decode(secretKey))

    /**
     * 生成 Token
     * */
    fun generateToken(subject: String, claims: Map<String, Any> = emptyMap(), expireDays: Long = 7): String {
        val now = LocalDateTime.now()
        val expiration = now.plusDays(expireDays)

        return Jwts.builder()
            .setSubject(subject)
            .setClaims(claims)
            .setIssuedAt(Date.from(now.atZone(ZoneId.systemDefault()).toInstant()))
            .setExpiration(Date.from(expiration.atZone(ZoneId.systemDefault()).toInstant()))
            .signWith(signingKey, SignatureAlgorithm.HS256)
            .compact()
    }


    /**
     * 解析 Token 获取 Claims
     */
    fun parseToken(token: String): Map<String, Any> {
        return Jwts.parserBuilder()
            .setSigningKey(signingKey)
            .build()
            .parseClaimsJws(token)
            .body
    }
}