Merge some files and rewrite the update history

manager/app/src/main/java/shirkneko/zako/sukisu/utils/AssetsUtil.kt

@@ -0,0 +1,26 @@
+package shirkneko.zako.sukisu.utils
+
+import android.content.Context
+import java.io.File
+import java.io.FileOutputStream
+import java.io.IOException
+
+object AssetsUtil {
+    @Throws(IOException::class)
+    fun exportFiles(context: Context, src: String, out: String) {
+        val fileNames = context.assets.list(src)
+        if (fileNames?.isNotEmpty() == true) {
+            val file = File(out)
+            file.mkdirs()
+            fileNames.forEach { fileName ->
+                exportFiles(context, "$src/$fileName", "$out/$fileName")
+            }
+        } else {
+            context.assets.open(src).use { inputStream ->
+                FileOutputStream(File(out)).use { outputStream ->
+                    inputStream.copyTo(outputStream)
+                }
+            }
+        }
+    }
+}