sodalive-backend-spring-boot/src/main/kotlin/kr/co/vividnext/sodalive/fcm/FcmService.kt

package kr.co.vividnext.sodalive.fcm

import com.google.firebase.messaging.AndroidConfig
import com.google.firebase.messaging.ApnsConfig
import com.google.firebase.messaging.Aps
import com.google.firebase.messaging.FirebaseMessaging
import com.google.firebase.messaging.FirebaseMessagingException
import com.google.firebase.messaging.Message
import com.google.firebase.messaging.MessagingErrorCode
import com.google.firebase.messaging.MulticastMessage
import com.google.firebase.messaging.Notification
import org.slf4j.LoggerFactory
import org.springframework.scheduling.annotation.Async
import org.springframework.stereotype.Service

@Service
class FcmService {
    private val logger = LoggerFactory.getLogger(this::class.java)

    @Async
    fun send(
        tokens: List<String>,
        title: String,
        message: String,
        container: String,
        roomId: Long? = null,
        messageId: Long? = null,
        contentId: Long? = null,
        creatorId: Long? = null,
        auditionId: Long? = null
    ) {
        if (tokens.isEmpty()) return
        logger.info("os: $container")

        var targets = tokens
        val maxAttempts = 3
        var attempt = 1

        while (attempt <= maxAttempts && targets.isNotEmpty()) {
            val multicastMessage = MulticastMessage.builder()
                .addAllTokens(tokens)

            multicastMessage.setAndroidConfig(
                AndroidConfig.builder()
                    .setPriority(AndroidConfig.Priority.HIGH)
                    .build()
            )

            multicastMessage.setApnsConfig(
                ApnsConfig.builder()
                    .setAps(
                        Aps.builder()
                            .setSound("default")
                            .build()
                    )
                    .build()
            )

            if (container == "ios") {
                multicastMessage
                    .setNotification(
                        Notification.builder()
                            .setTitle(title)
                            .setBody(message)
                            .build()
                    )
            } else {
                multicastMessage
                    .putData("title", title)
                    .putData("message", message)
            }

            if (roomId != null) {
                multicastMessage.putData("room_id", roomId.toString())
            }

            if (messageId != null) {
                multicastMessage.putData("message_id", messageId.toString())
            }

            if (contentId != null) {
                multicastMessage.putData("content_id", contentId.toString())
            }

            if (creatorId != null) {
                multicastMessage.putData("channel_id", creatorId.toString())
            }

            if (auditionId != null) {
                multicastMessage.putData("audition_id", auditionId.toString())
            }

            val response = FirebaseMessaging.getInstance().sendEachForMulticast(multicastMessage.build())
            val failedTokens = mutableListOf<String>()

            response.responses.forEachIndexed { index, res ->
                if (!res.isSuccessful) {
                    val exception = res.exception
                    val token = targets[index]

                    if (exception?.messagingErrorCode == MessagingErrorCode.UNREGISTERED) {
                        logger.error("[FCM] ❌ UNREGISTERED → $token")
                        // 필요 시 DB에서 삭제
                    } else {
                        logger.error("[FCM] ❌ 실패: $token / ${exception?.messagingErrorCode}")
                        failedTokens.add(token)
                    }
                }
            }

            if (failedTokens.isEmpty()) {
                logger.info("[FCM] ✅ 전체 전송 성공")
                return
            }

            targets = failedTokens
            attempt++
        }

        if (targets.isNotEmpty()) {
            logger.error("[FCM] ❌ 최종 실패 대상 ${targets.size}명 → $targets")
        }
    }

    fun sendPointGranted(token: String, point: Int) {
        val data = mapOf(
            "type" to "POINT_GRANTED",
            "point" to point.toString(),
            "message" to "${point}포인트가 지급되었습니다!"
        )

        var attempts = 0
        val maxAttempts = 3

        while (attempts < maxAttempts) {
            try {
                val message = Message.builder()
                    .setToken(token)
                    .putAllData(data)
                    .build()

                val response = FirebaseMessaging.getInstance().send(message)
                logger.info("[FCM] ✅ 성공 (attempt ${attempts + 1}): messageId=$response")
                return // 성공 시 즉시 종료
            } catch (e: FirebaseMessagingException) {
                attempts++

                // "registration-token-not-registered" 예외 코드 확인
                if (e.messagingErrorCode == MessagingErrorCode.UNREGISTERED) {
                    logger.error("[FCM] ❌ 실패: 토큰이 등록되지 않음 (등록 해제됨) → 재시도 안함")
                    return
                }

                logger.error("[FCM] ❌ 실패 (attempt $attempts): ${e.errorCode} - ${e.message}")

                if (attempts >= maxAttempts) {
                    logger.error("[FCM] ❌ 최종 실패: 전송 불가")
                }
            } catch (e: Exception) {
                // Firebase 이외의 예외도 잡기
                attempts++
                logger.error("[FCM] ❌ 실패 (attempt $attempts): ${e.message}")

                if (attempts >= maxAttempts) {
                    logger.error("[FCM] ❌ 최종 실패: 알 수 없는 오류")
                }
            }
        }
    }
}