refactor: PresignedUrlProvider에서 S3 URL 생성 로직을 CDN URL로 수정

Author: Kimxxunu

global/src/main/kotlin/zipbap/global/global/cloud/service/PresignedUrlProvider.kt

@@ -4,23 +4,37 @@ import com.amazonaws.HttpMethod
 import com.amazonaws.services.s3.AmazonS3
 import org.springframework.beans.factory.annotation.Value
 import org.springframework.stereotype.Service
+import java.net.URL
 import java.util.*
 
 @Service
 class PresignedUrlProvider(
     private val amazonS3: AmazonS3,
-    @Value("\${cloud.aws.s3.bucket}") private val bucket: String
+
+    @Value("\${cloud.aws.s3.bucket}")
+    private val bucket: String,
+
+    @Value("\${cloud.cdn.domain}")
+    private val cdnDomain: String
 ) {
 
     /**
-     * Presigned URL 생성 (임시 업로드 전용)
+     * Presigned URL 생성 (업로드는 S3에, 조회는 CDN으로!)
      */
-    fun generateUploadUrl(userId: Long, fileName: String, expirationMinutes: Int = 5): Map<String, String> {
+    fun generateUploadUrl(
+        userId: Long,
+        fileName: String,
+        expirationMinutes: Int = 5
+    ): Map<String, String> {
+
         val key = "temp/$userId/${UUID.randomUUID()}-$fileName"
         val expiration = Date(System.currentTimeMillis() + expirationMinutes * 60 * 1000)
 
+        // 1) 업로드 URL (S3 PUT 용) 그대로 유지
         val uploadUrl = amazonS3.generatePresignedUrl(bucket, key, expiration, HttpMethod.PUT)
-        val fileUrl = amazonS3.getUrl(bucket, key).toString()
+
+        // 2) 조회 URL은 CloudFront CDN 도메인으로 생성
+        val fileUrl = buildCdnUrl(key)
 
         return mapOf(
             "uploadUrl" to uploadUrl.toString(),
@@ -34,19 +48,36 @@ class PresignedUrlProvider(
      */
     fun copyTempToRecipe(fileUrl: String, recipeId: String): String {
         val sourceKey = extractKeyFromUrl(fileUrl)
+
         if (!sourceKey.startsWith("temp/")) {
             throw IllegalArgumentException("Source key must start with temp/: $sourceKey")
         }
 
         val targetKey = sourceKey.replaceFirst("temp/", "recipes/$recipeId/")
-
         amazonS3.copyObject(bucket, sourceKey, bucket, targetKey)
 
-        return amazonS3.getUrl(bucket, targetKey).toString()
+        // CloudFront URL 반환
+        return buildCdnUrl(targetKey)
+    }
+
+    /**
+     * CloudFront URL 또는 S3 URL에서 key 추출
+     */
+    private fun extractKeyFromUrl(url: String): String {
+        return when {
+            url.contains(cdnDomain) -> {
+                // ex: https://dxxxxxxx.cloudfront.net/temp/1/xxx.jpg
+                URL(url).path.removePrefix("/")
+            }
+            else -> {
+                // 기존 S3 URL fallback
+                val bucketUrlPrefix = amazonS3.getUrl(bucket, "").toString()
+                url.removePrefix(bucketUrlPrefix)
+            }
+        }
     }
 
-    private fun extractKeyFromUrl(fileUrl: String): String {
-        val urlPrefix = amazonS3.getUrl(bucket, "").toString()
-        return fileUrl.removePrefix(urlPrefix)
+    private fun buildCdnUrl(key: String): String {
+        return "https://$cdnDomain/$key"
     }
 }