roomescape-refactored/src/main/kotlin/roomescape/auth/infrastructure/jwt/JwtUtils.kt

package roomescape.auth.infrastructure.jwt

import io.github.oshai.kotlinlogging.KLogger
import io.github.oshai.kotlinlogging.KotlinLogging
import io.jsonwebtoken.Claims
import io.jsonwebtoken.ExpiredJwtException
import io.jsonwebtoken.Jwts
import io.jsonwebtoken.security.Keys
import org.slf4j.MDC
import org.springframework.beans.factory.annotation.Value
import org.springframework.stereotype.Component
import roomescape.auth.business.CLAIM_TYPE_KEY
import roomescape.auth.exception.AuthErrorCode
import roomescape.auth.exception.AuthException
import roomescape.common.dto.MDC_PRINCIPAL_ID_KEY
import roomescape.common.dto.PrincipalType
import java.util.*
import javax.crypto.SecretKey

private val log: KLogger = KotlinLogging.logger {}

@Component
class JwtUtils(
    @Value("\${security.jwt.token.secret-key}")
    private val secretKeyString: String,

    @Value("\${security.jwt.token.ttl-seconds}")
    private val tokenTtlSeconds: Long
) {
    private val secretKey: SecretKey = Keys.hmacShaKeyFor(secretKeyString.toByteArray())

    fun createToken(subject: String, claims: Map<String, Any>): String {
        log.debug { "[JwtUtils.createToken] 토큰 생성 시작: subject=$subject, claims=${claims}" }

        val date = Date()
        val accessTokenExpiredAt = Date(date.time + (tokenTtlSeconds * 1_000))

        return Jwts.builder()
            .subject(subject)
            .claims(claims)
            .issuedAt(date)
            .expiration(accessTokenExpiredAt)
            .signWith(secretKey)
            .compact()
            .also {
                log.debug { "[JwtUtils.createToken] 토큰 생성 완료. token=${it}" }
            }
    }

    fun extractIdAndType(token: String?): Pair<Long, PrincipalType> {
        val id: Long = extractSubject(token)
            .also { MDC.put(MDC_PRINCIPAL_ID_KEY, it) }
            .toLong()

        val type: PrincipalType = extractClaim(token, CLAIM_TYPE_KEY)
            ?.let { PrincipalType.valueOf(it) }
            ?: run {
                log.info { "[JwtUtils.extractIdAndType] 회원 타입 조회 실패. id=$id" }
                throw AuthException(AuthErrorCode.MEMBER_NOT_FOUND)
            }

        return id to type
    }

    fun extractSubject(token: String?): String {
        if (token.isNullOrBlank()) {
            throw AuthException(AuthErrorCode.TOKEN_NOT_FOUND)
        }
        val claims = extractAllClaims(token)

        return claims.subject ?: run {
            log.info { "[JwtUtils.extractSubject] subject를 찾을 수 없음.: token = ${token}" }
            throw AuthException(AuthErrorCode.INVALID_TOKEN)
        }
    }

    fun extractClaim(token: String?, key: String): String? {
        if (token.isNullOrBlank()) {
            throw AuthException(AuthErrorCode.TOKEN_NOT_FOUND)
        }
        val claims = extractAllClaims(token)

        return claims.get(key, String::class.java)
    }

    private fun extractAllClaims(token: String): Claims {
        try {
            return Jwts.parser()
                .verifyWith(secretKey)
                .build()
                .parseSignedClaims(token)
                .payload
        } catch (_: ExpiredJwtException) {
            throw AuthException(AuthErrorCode.EXPIRED_TOKEN)
        } catch (ex: Exception) {
            log.warn { "[JwtUtils] 유효하지 않은 토큰 요청: ${ex.message}" }
            throw AuthException(AuthErrorCode.INVALID_TOKEN)
        }
    }
}