feat(content): 콘텐츠 전체보기 조회 정책을 추가한다

src/main/kotlin/kr/co/vividnext/sodalive/v2/api/content/overview/application/ContentOverviewQueryPolicy.kt

@@ -0,0 +1,38 @@
+package kr.co.vividnext.sodalive.v2.api.content.overview.application
+
+import kr.co.vividnext.sodalive.v2.api.content.overview.dto.ContentOverviewType
+
+data class ContentOverviewPage(
+    val page: Int,
+    val size: Int
+) {
+    val offset: Long = page.toLong() * size
+}
+
+class ContentOverviewQueryPolicy {
+    fun resolveType(type: String?): ContentOverviewType {
+        return ContentOverviewType.from(type)
+    }
+
+    fun createPage(page: Int?, size: Int?): ContentOverviewPage {
+        val resolvedPage = (page ?: DEFAULT_PAGE).coerceAtLeast(DEFAULT_PAGE)
+        val requestedSize = size ?: DEFAULT_SIZE
+        val resolvedSize = if (requestedSize < MIN_SIZE) DEFAULT_SIZE else minOf(requestedSize, MAX_SIZE)
+        return ContentOverviewPage(page = resolvedPage, size = resolvedSize)
+    }
+
+    fun <T> pageItems(items: List<T>, page: ContentOverviewPage): List<T> {
+        return items.take(page.size)
+    }
+
+    fun <T> hasNext(items: List<T>, page: ContentOverviewPage): Boolean {
+        return items.size > page.size
+    }
+
+    companion object {
+        const val DEFAULT_PAGE = 0
+        const val DEFAULT_SIZE = 20
+        const val MIN_SIZE = 20
+        const val MAX_SIZE = 50
+    }
+}

src/test/kotlin/kr/co/vividnext/sodalive/v2/api/content/overview/application/ContentOverviewQueryPolicyTest.kt

@@ -0,0 +1,45 @@
+package kr.co.vividnext.sodalive.v2.api.content.overview.application
+
+import kr.co.vividnext.sodalive.v2.api.content.overview.dto.ContentOverviewType
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.api.Test
+
+class ContentOverviewQueryPolicyTest {
+    private val policy = ContentOverviewQueryPolicy()
+
+    @Test
+    @DisplayName("콘텐츠 전체보기 type은 null 또는 invalid 값을 기본 타입으로 보정한다")
+    fun shouldResolveTypeWithDefaultFallback() {
+        assertEquals(ContentOverviewType.NEW_AND_HOT_AUDIO, policy.resolveType(null))
+        assertEquals(ContentOverviewType.NEW_AND_HOT_AUDIO, policy.resolveType("UNKNOWN"))
+        assertEquals(ContentOverviewType.FIRST_AUDIO_CONTENT, policy.resolveType("FIRST_AUDIO_CONTENT"))
+    }
+
+    @Test
+    @DisplayName("콘텐츠 전체보기 page와 size를 기본값과 최대값으로 보정한다")
+    fun shouldNormalizePageAndSize() {
+        assertEquals(ContentOverviewPage(page = 0, size = 20), policy.createPage(null, null))
+        assertEquals(ContentOverviewPage(page = 0, size = 20), policy.createPage(-1, 0))
+        assertEquals(ContentOverviewPage(page = 0, size = 20), policy.createPage(0, 19))
+        assertEquals(ContentOverviewPage(page = 2, size = 50), policy.createPage(2, 100))
+    }
+
+    @Test
+    @DisplayName("콘텐츠 전체보기 offset은 큰 page 입력에서도 Int overflow 없이 계산한다")
+    fun shouldCalculateOffsetWithoutIntOverflow() {
+        val page = policy.createPage(Int.MAX_VALUE, 50)
+
+        assertEquals(Int.MAX_VALUE.toLong() * 50, page.offset)
+    }
+
+    @Test
+    @DisplayName("콘텐츠 전체보기 응답 목록과 hasNext는 size + 1 조회 결과로 계산한다")
+    fun shouldCalculatePageItemsAndHasNext() {
+        val page = ContentOverviewPage(page = 0, size = 2)
+        val items = listOf(1, 2, 3)
+
+        assertEquals(listOf(1, 2), policy.pageItems(items, page))
+        assertEquals(true, policy.hasNext(items, page))
+    }
+}