feat(banner): 배너 자동 전환 동작을 추가한다

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

app/src/test/java/kr/co/vividnext/sodalive/v2/widget/banner/BannerViewTest.kt

@@ -18,7 +18,9 @@ import org.junit.Assert.assertTrue
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.robolectric.RobolectricTestRunner
+import org.robolectric.Shadows.shadowOf
 import org.robolectric.annotation.Config
+import java.time.Duration
 
 @RunWith(RobolectricTestRunner::class)
 @Config(sdk = [28], application = Application::class)
@@ -148,11 +150,152 @@ class BannerViewTest {
         assertNotNull(imageView.outlineProvider)
     }
 
+    @Test
+    fun `배너 view는 attach 후 5초가 지나면 다음 배너로 자동 이동한다`() {
+        val view = inflateBannerView()
+
+        view.setItems(listOf(sampleItem("1"), sampleItem("2"), sampleItem("3")))
+        view.measure(exactly(402.dpToPx()), exactly(402.dpToPx()))
+        view.layout(0, 0, 402.dpToPx(), 402.dpToPx())
+        view.dispatchAttachedForTest()
+
+        shadowOf(android.os.Looper.getMainLooper()).idleFor(Duration.ofMillis(5_000))
+
+        assertEquals("02", view.findViewById<TextView>(R.id.tv_banner_current_index).text.toString())
+    }
+
+    @Test
+    fun `배너 view는 사용자 drag 중에는 자동 이동 timer를 다시 시작하지 않는다`() {
+        val view = inflateBannerView()
+
+        view.setItems(listOf(sampleItem("1"), sampleItem("2"), sampleItem("3")))
+        view.measure(exactly(402.dpToPx()), exactly(402.dpToPx()))
+        view.layout(0, 0, 402.dpToPx(), 402.dpToPx())
+        view.dispatchAttachedForTest()
+        view.dispatchScrollStateForTest(RecyclerView.SCROLL_STATE_DRAGGING)
+        shadowOf(android.os.Looper.getMainLooper()).idleFor(Duration.ofMillis(5_000))
+
+        assertEquals("01", view.findViewById<TextView>(R.id.tv_banner_current_index).text.toString())
+
+        view.dispatchScrollStateForTest(RecyclerView.SCROLL_STATE_IDLE)
+        shadowOf(android.os.Looper.getMainLooper()).idleFor(Duration.ofMillis(4_999))
+        assertEquals("01", view.findViewById<TextView>(R.id.tv_banner_current_index).text.toString())
+
+        shadowOf(android.os.Looper.getMainLooper()).idleFor(Duration.ofMillis(1))
+        assertEquals("02", view.findViewById<TextView>(R.id.tv_banner_current_index).text.toString())
+    }
+
+    @Test
+    fun `배너 view는 detach 되면 자동 이동 callback을 제거한다`() {
+        val view = inflateBannerView()
+
+        view.setItems(listOf(sampleItem("1"), sampleItem("2")))
+        view.measure(exactly(402.dpToPx()), exactly(402.dpToPx()))
+        view.layout(0, 0, 402.dpToPx(), 402.dpToPx())
+        view.dispatchAttachedForTest()
+        view.dispatchDetachedForTest()
+        shadowOf(android.os.Looper.getMainLooper()).idleFor(Duration.ofMillis(5_000))
+
+        assertEquals("01", view.findViewById<TextView>(R.id.tv_banner_current_index).text.toString())
+    }
+
+    @Test
+    fun `배너 view는 단일 item이면 attach 후 5초가 지나도 자동 이동하지 않는다`() {
+        val view = inflateBannerView()
+
+        view.setItems(listOf(sampleItem("1")))
+        view.measure(exactly(402.dpToPx()), exactly(402.dpToPx()))
+        view.layout(0, 0, 402.dpToPx(), 402.dpToPx())
+        view.dispatchAttachedForTest()
+        shadowOf(android.os.Looper.getMainLooper()).idleFor(Duration.ofMillis(5_000))
+
+        assertEquals(View.GONE, view.findViewById<View>(R.id.layout_banner_counter).visibility)
+    }
+
+    @Test
+    fun `배너 view는 마지막 배너 다음에 첫 번째 counter로 순환한다`() {
+        val view = inflateBannerView()
+
+        view.setItems(listOf(sampleItem("1"), sampleItem("2")))
+        view.measure(exactly(402.dpToPx()), exactly(402.dpToPx()))
+        view.layout(0, 0, 402.dpToPx(), 402.dpToPx())
+        view.dispatchAttachedForTest()
+        shadowOf(android.os.Looper.getMainLooper()).idleFor(Duration.ofMillis(5_000))
+        assertEquals("02", view.findViewById<TextView>(R.id.tv_banner_current_index).text.toString())
+
+        shadowOf(android.os.Looper.getMainLooper()).idleFor(Duration.ofMillis(5_000))
+
+        assertEquals("01", view.findViewById<TextView>(R.id.tv_banner_current_index).text.toString())
+    }
+
+    @Test
+    fun `배너 view는 자동 전환 animation duration을 350ms로 사용한다`() {
+        assertEquals(350, BannerView.scrollAnimationDurationMsForTest())
+    }
+
+    @Test
+    fun `배너 view는 현재 virtual position 기준으로 다음 배너로 이동한다`() {
+        val view = inflateBannerView()
+        val recyclerView = view.findViewById<RecyclerView>(R.id.rv_banner)
+
+        view.setItems(listOf(sampleItem("1"), sampleItem("2"), sampleItem("3")))
+        val adapter = requireNotNull(recyclerView.adapter as? BannerAdapter)
+        val previousVirtualPosition = adapter.startPosition(0) - 1
+        view.measure(exactly(402.dpToPx()), exactly(402.dpToPx()))
+        view.layout(0, 0, 402.dpToPx(), 402.dpToPx())
+        view.setCurrentPositionForTest(previousVirtualPosition)
+        view.dispatchAttachedForTest()
+
+        shadowOf(android.os.Looper.getMainLooper()).idleFor(Duration.ofMillis(5_000))
+
+        assertEquals(previousVirtualPosition + 1, view.currentAdapterPositionForTest())
+        assertEquals("01", view.findViewById<TextView>(R.id.tv_banner_current_index).text.toString())
+    }
+
     private fun inflateBannerView(): BannerView {
         val context = ApplicationProvider.getApplicationContext<Context>()
         return BannerView(context)
     }
 
+    private fun BannerView.dispatchAttachedForTest() {
+        BannerView::class.java.getDeclaredMethod("onAttachedToWindow").apply {
+            isAccessible = true
+            invoke(this@dispatchAttachedForTest)
+        }
+    }
+
+    private fun BannerView.dispatchDetachedForTest() {
+        BannerView::class.java.getDeclaredMethod("onDetachedFromWindow").apply {
+            isAccessible = true
+            invoke(this@dispatchDetachedForTest)
+        }
+    }
+
+    private fun BannerView.dispatchScrollStateForTest(state: Int) {
+        val listenerField = BannerView::class.java.getDeclaredField("bannerScrollListener").apply { isAccessible = true }
+        val listener = listenerField.get(this) as RecyclerView.OnScrollListener
+        listener.onScrollStateChanged(findViewById(R.id.rv_banner), state)
+    }
+
+
+    private fun BannerView.setCurrentPositionForTest(position: Int) {
+        BannerView::class.java.getDeclaredField("currentAdapterPosition").apply {
+            isAccessible = true
+            setInt(this@setCurrentPositionForTest, position)
+        }
+        BannerView::class.java.getDeclaredField("currentIndex").apply {
+            isAccessible = true
+            setInt(this@setCurrentPositionForTest, requireNotNull(findViewById<RecyclerView>(R.id.rv_banner).adapter as? BannerAdapter).toRealIndex(position))
+        }
+    }
+
+    private fun BannerView.currentAdapterPositionForTest(): Int {
+        return BannerView::class.java.getDeclaredField("currentAdapterPosition").run {
+            isAccessible = true
+            getInt(this@currentAdapterPositionForTest)
+        }
+    }
+
     private fun sampleItem(id: String) = BannerItem(
         bannerId = id,
         imageUrl = "https://example.com/banner-$id.png"