feat(character-image): 이미지 단독 구매 API 및 결제 연동 추가

- 구매 요청/응답 DTO 추가
- 미보유 시 캔 차감 및 구매 이력 저장
- 서명 URL(5분) 반환

src/main/kotlin/kr/co/vividnext/sodalive/can/payment/CanPaymentService.kt

@@ -13,6 +13,7 @@ import kr.co.vividnext.sodalive.can.use.UseCanCalculate
 import kr.co.vividnext.sodalive.can.use.UseCanCalculateRepository
 import kr.co.vividnext.sodalive.can.use.UseCanCalculateStatus
 import kr.co.vividnext.sodalive.can.use.UseCanRepository
+import kr.co.vividnext.sodalive.chat.character.image.CharacterImage
 import kr.co.vividnext.sodalive.common.SodaException
 import kr.co.vividnext.sodalive.content.AudioContent
 import kr.co.vividnext.sodalive.content.order.Order
@@ -327,4 +328,49 @@ class CanPaymentService(
             chargeRepository.save(charge)
         }
     }
+
+    @Transactional
+    fun spendCanForCharacterImage(
+        memberId: Long,
+        needCan: Int,
+        image: CharacterImage,
+        container: String
+    ) {
+        val member = memberRepository.findByIdOrNull(id = memberId)
+            ?: throw SodaException("잘못된 요청입니다.\n다시 시도해 주세요.")
+
+        val useRewardCan = spendRewardCan(member, needCan, container)
+        val useChargeCan = if (needCan - useRewardCan.total > 0) {
+            spendChargeCan(member, needCan = needCan - useRewardCan.total, container = container)
+        } else {
+            null
+        }
+
+        if (needCan - useRewardCan.total - (useChargeCan?.total ?: 0) > 0) {
+            throw SodaException(
+                "${needCan - useRewardCan.total - (useChargeCan?.total ?: 0)} " +
+                    "캔이 부족합니다. 충전 후 이용해 주세요."
+            )
+        }
+
+        if (!useRewardCan.verify() || useChargeCan?.verify() == false) {
+            throw SodaException("잘못된 요청입니다.\n다시 시도해 주세요.")
+        }
+
+        val useCan = UseCan(
+            canUsage = CanUsage.CHARACTER_IMAGE_PURCHASE,
+            can = useChargeCan?.total ?: 0,
+            rewardCan = useRewardCan.total,
+            isSecret = false
+        )
+        useCan.member = member
+        useCan.characterImage = image
+
+        useCanRepository.save(useCan)
+
+        setUseCanCalculate(null, useRewardCan, useChargeCan, useCan, paymentGateway = PaymentGateway.PG)
+        setUseCanCalculate(null, useRewardCan, useChargeCan, useCan, paymentGateway = PaymentGateway.POINT_CLICK_AD)
+        setUseCanCalculate(null, useRewardCan, useChargeCan, useCan, paymentGateway = PaymentGateway.GOOGLE_IAP)
+        setUseCanCalculate(null, useRewardCan, useChargeCan, useCan, paymentGateway = PaymentGateway.APPLE_IAP)
+    }
 }

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/image/CharacterImageController.kt

@@ -1,8 +1,11 @@
 package kr.co.vividnext.sodalive.chat.character.image
 
 import kr.co.vividnext.sodalive.aws.cloudfront.ImageContentCloudFront
+import kr.co.vividnext.sodalive.can.payment.CanPaymentService
 import kr.co.vividnext.sodalive.chat.character.image.dto.CharacterImageListItemResponse
 import kr.co.vividnext.sodalive.chat.character.image.dto.CharacterImageListResponse
+import kr.co.vividnext.sodalive.chat.character.image.dto.CharacterImagePurchaseRequest
+import kr.co.vividnext.sodalive.chat.character.image.dto.CharacterImagePurchaseResponse
 import kr.co.vividnext.sodalive.common.ApiResponse
 import kr.co.vividnext.sodalive.common.SodaException
 import kr.co.vividnext.sodalive.member.Member
@@ -10,6 +13,8 @@ import org.springframework.beans.factory.annotation.Value
 import org.springframework.data.domain.PageRequest
 import org.springframework.security.core.annotation.AuthenticationPrincipal
 import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.RequestBody
 import org.springframework.web.bind.annotation.RequestMapping
 import org.springframework.web.bind.annotation.RequestParam
 import org.springframework.web.bind.annotation.RestController
@@ -19,6 +24,7 @@ import org.springframework.web.bind.annotation.RestController
 class CharacterImageController(
     private val imageService: CharacterImageService,
     private val imageCloudFront: ImageContentCloudFront,
+    private val canPaymentService: CanPaymentService,
     @Value("\${cloud.aws.cloud-front.host}")
     private val imageHost: String
 ) {
@@ -67,4 +73,35 @@ class CharacterImageController(
             )
         )
     }
+
+    @PostMapping("/purchase")
+    fun purchase(
+        @RequestBody req: CharacterImagePurchaseRequest,
+        @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?
+    ) = run {
+        if (member == null) throw SodaException("로그인 정보를 확인해주세요.")
+        if (member.auth == null) throw SodaException("본인인증을 하셔야 합니다.")
+
+        val image = imageService.getById(req.imageId)
+        if (!image.isActive) throw SodaException("비활성화된 이미지입니다.")
+
+        val isOwned = (image.imagePriceCan == 0L) ||
+            imageService.isOwnedImageByMember(image.id!!, member.id!!)
+
+        if (!isOwned) {
+            val needCan = image.imagePriceCan.toInt()
+            if (needCan <= 0) throw SodaException("구매 가격이 잘못되었습니다.")
+
+            canPaymentService.spendCanForCharacterImage(
+                memberId = member.id!!,
+                needCan = needCan,
+                image = image,
+                container = req.container
+            )
+        }
+
+        val expiration = 5L * 60L * 1000L // 5분
+        val signedUrl = imageCloudFront.generateSignedURL(image.imagePath, expiration)
+        ApiResponse.ok(CharacterImagePurchaseResponse(imageUrl = signedUrl))
+    }
 }

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/image/dto/CharacterImagePurchaseDtos.kt

@@ -0,0 +1,12 @@
+package kr.co.vividnext.sodalive.chat.character.image.dto
+
+import com.fasterxml.jackson.annotation.JsonProperty
+
+data class CharacterImagePurchaseRequest(
+    @JsonProperty("imageId") val imageId: Long,
+    @JsonProperty("container") val container: String
+)
+
+data class CharacterImagePurchaseResponse(
+    @JsonProperty("imageUrl") val imageUrl: String
+)