refactor: 저자 정보 추출 로직 개선 및 데이터 생성 안정성 강화 (#104)

* refactor: apis, global-utils - (지은이) 외에 (글)도 저자 표시로 함께 처리하도록 변경

* chore: global-utils - 정규식을 유틸클래스에서 가져와 사용하도록 변경

* refactor: apis - 기본값을 지정해서 예상치 못한 에러에 대응

* [BOOK-276] fix: apis - 누락된 필드 수정 및 제목 default value 추가

* [BOOK-276] refactor: apis, global-utils - 코드레빗 리뷰 반영

Author: move-hoon

apis/src/main/kotlin/org/yapp/apis/book/dto/request/BookCreateRequest.kt

@@ -90,21 +90,31 @@ data class BookCreateRequest private constructor(
     fun validCoverImageUrl(): String = coverImageUrl!!
 
     companion object {
+        private const val UNKNOWN_TITLE = "제목 정보 없음"
+        private const val UNKNOWN_AUTHOR = "저자 정보 없음"
+        private const val UNKNOWN_PUBLISHER = "출판사 정보 없음"
+        private const val DEFAULT_COVER_IMAGE = "https://github.com/user-attachments/assets/7ba556a4-3a76-4f27-aecb-e58924e66843"
+
         fun from(bookDetailResponse: BookDetailResponse): BookCreateRequest {
             val finalIsbn13 = bookDetailResponse.isbn13
-            ?: throw IllegalArgumentException("ISBN13이 존재하지 않습니다.")
+                ?: throw IllegalArgumentException("ISBN13이 존재하지 않습니다.")
 
             return BookCreateRequest(
                 isbn13 = finalIsbn13,
-                title = bookDetailResponse.title,
-                author = bookDetailResponse.author,
-                publisher = bookDetailResponse.publisher,
+                title = provideDefaultIfBlank(bookDetailResponse.title, UNKNOWN_TITLE),
+                author = provideDefaultIfBlank(bookDetailResponse.author, UNKNOWN_AUTHOR),
+                publisher = provideDefaultIfBlank(bookDetailResponse.publisher, UNKNOWN_PUBLISHER),
                 publicationYear = parsePublicationYear(bookDetailResponse.pubDate),
-                coverImageUrl = bookDetailResponse.coverImageUrl,
-                description = bookDetailResponse.description,
+                coverImageUrl = provideDefaultIfBlank(bookDetailResponse.coverImageUrl, DEFAULT_COVER_IMAGE),
+                description = bookDetailResponse.description
             )
         }
 
+        private fun provideDefaultIfBlank(input: String?, defaultValue: String): String {
+            val trimmed = input?.trim()
+            return if (trimmed.isNullOrEmpty()) defaultValue else trimmed
+        }
+
         private fun parsePublicationYear(pubDate: String?): Int? {
             return pubDate
                 ?.takeIf { it.length >= 4 && it.substring(0, 4).all { ch -> ch.isDigit() } }

apis/src/main/kotlin/org/yapp/apis/book/util/AuthorExtractor.kt

@@ -1,21 +1,40 @@
 package org.yapp.apis.book.util
 
+import org.yapp.globalutils.util.RegexUtils
+
 object AuthorExtractor {
-    private const val AUTHOR_MARKER = "(지은이)"
+    private val AUTHOR_MARKER_REGEX = Regex(RegexUtils.AUTHOR_MARKER_PATTERN)
     private const val CLOSING_PAREN = ")"
     private const val DELIMITER = "), "
+    private const val EXPECTED_PARTS_ON_SPLIT = 2
+    private const val AUTHOR_PART_INDEX = 0
 
     fun extractAuthors(authorString: String?): String {
-        if (authorString.isNullOrBlank() || !authorString.contains(AUTHOR_MARKER)) {
+        if (authorString.isNullOrBlank()) {
             return ""
         }
 
-        var authorsPart = authorString.substringBefore(" $AUTHOR_MARKER")
+        val partBeforeMarker = getPartBeforeMarker(authorString) ?: return ""
+        val finalAuthor = cleanUpContributors(partBeforeMarker)
+
+        return finalAuthor.trim()
+    }
+
+    private fun getPartBeforeMarker(text: String): String? {
+        val parts = text.split(AUTHOR_MARKER_REGEX, limit = EXPECTED_PARTS_ON_SPLIT)
 
-        if (authorsPart.contains(CLOSING_PAREN)) {
-            authorsPart = authorsPart.substringAfterLast(DELIMITER)
+        return if (parts.size == EXPECTED_PARTS_ON_SPLIT) {
+            parts[AUTHOR_PART_INDEX]
+        } else {
+            null
         }
+    }
 
-        return authorsPart.trim()
+    private fun cleanUpContributors(authorPart: String): String {
+        return if (authorPart.contains(CLOSING_PAREN)) {
+            authorPart.substringAfterLast(DELIMITER, missingDelimiterValue = authorPart)
+        } else {
+            authorPart
+        }
     }
 }

global-utils/src/main/kotlin/org/yapp/globalutils/util/RegexUtils.kt

@@ -3,4 +3,7 @@ package org.yapp.globalutils.util
 object RegexUtils {
     const val ISBN10_PATTERN = "^[0-9]{9}[0-9X]$"
     const val ISBN13_PATTERN = "^(978|979)\\d{10}$"
+    const val AUTHOR_MARKER_PATTERN = "\\s*\\((?:지은이|글)\\)"
+    const val PARENTHESIS_PATTERN = "\\s*\\([^)]*\\)\\s*"
+    const val EMAIL_PATTERN="^[a-zA-Z0-9_!#$%&'*+/=?`{|}~^.-]+@[a-zA-Z0-9.-]+$"
 }

global-utils/src/main/kotlin/org/yapp/globalutils/validator/BookDataValidator.kt

@@ -1,8 +1,9 @@
 package org.yapp.globalutils.validator
 
-object BookDataValidator {
+import org.yapp.globalutils.util.RegexUtils
 
-    private val PARENTHESIS_REGEX = "\\s*\\([^)]*\\)\\s*".toRegex()
+object BookDataValidator {
+    private val PARENTHESIS_REGEX = Regex(RegexUtils.PARENTHESIS_PATTERN)
 
     fun removeParenthesesFromAuthor(author: String): String {
         return author.replace(PARENTHESIS_REGEX, "")

global-utils/src/main/kotlin/org/yapp/globalutils/validator/EmailValidator.kt

@@ -1,7 +1,9 @@
 package org.yapp.globalutils.validator
 
+import org.yapp.globalutils.util.RegexUtils
+
 object EmailValidator {
-    private val EMAIL_REGEX = "^[a-zA-Z0-9_!#$%&'*+/=?`{|}~^.-]+@[a-zA-Z0-9.-]+$".toRegex()
+    private val EMAIL_REGEX = Regex(RegexUtils.EMAIL_PATTERN)
 
     fun isValidEmail(email: String): Boolean {
         return email.matches(EMAIL_REGEX)