feat: ページネーションの統一化

src/main/kotlin/dev/usbharu/hideout/application/infrastructure/exposed/ExposedPaginationExtension.kt

@@ -0,0 +1,19 @@
+package dev.usbharu.hideout.application.infrastructure.exposed
+
+import org.jetbrains.exposed.sql.ExpressionWithColumnType
+import org.jetbrains.exposed.sql.Query
+import org.jetbrains.exposed.sql.SortOrder
+import org.jetbrains.exposed.sql.andWhere
+
+fun Query.pagination(page: Page, exp: ExpressionWithColumnType<Long>): Query {
+    if (page.minId != null) {
+        page.maxId?.let { andWhere { exp.lessEq(it) } }
+        page.minId?.let { andWhere { exp.greaterEq(it) } }
+    } else {
+        page.maxId?.let { andWhere { exp.lessEq(it) } }
+        page.sinceId?.let { andWhere { exp.greaterEq(it) } }
+        this.orderBy(exp, SortOrder.DESC)
+    }
+    page.limit?.let { limit(it) }
+    return this
+}

src/main/kotlin/dev/usbharu/hideout/application/infrastructure/exposed/Page.kt

@@ -0,0 +1,36 @@
+package dev.usbharu.hideout.application.infrastructure.exposed
+
+sealed class Page {
+    abstract val maxId: Long?
+    abstract val sinceId: Long?
+    abstract val minId: Long?
+    abstract val limit: Int?
+
+    data class PageByMaxId(
+        override val maxId: Long?,
+        override val sinceId: Long?,
+        override val limit: Int?
+    ) : Page() {
+        override val minId: Long? = null
+    }
+
+    data class PageByMinId(
+        override val maxId: Long?,
+        override val minId: Long?,
+        override val limit: Int?
+    ) : Page() {
+        override val sinceId: Long? = null
+    }
+
+    companion object {
+        fun of(maxId: Long?, sinceId: Long?, minId: Long?, limit: Int?): Page = if (minId != null) {
+            PageByMinId(
+                maxId, minId, limit
+            )
+        } else {
+            PageByMaxId(
+                maxId, sinceId, limit
+            )
+        }
+    }
+}