[O] Reduce duplicate code

src/main/java/icu/samnyan/aqua/sega/util/Compression.java

@@ -12,10 +12,10 @@ import java.util.zip.Inflater;
  */
 public class Compression {
 
-    public static byte[] decompress(byte[] src) {
+    public static byte[] decompress(byte[] src, boolean nowrap) {
         ByteBuf result = Unpooled.buffer();
         byte[] buffer = new byte[100];
-        Inflater decompressor = new Inflater();
+        Inflater decompressor = new Inflater(nowrap);
         decompressor.setInput(src);
 
         try {
@@ -36,6 +36,10 @@ public class Compression {
 
     }
 
+    public static byte[] decompress(byte[] src) {
+        return decompress(src, false);
+    }
+
     public static byte[] compress(byte[] src) {
         ByteBuf result = Unpooled.buffer();
         byte[] buffer = new byte[100];

src/main/java/icu/samnyan/aqua/sega/util/Decoder.kt

@@ -0,0 +1,33 @@
+package icu.samnyan.aqua.sega.util
+
+import java.nio.charset.StandardCharsets
+import java.util.*
+
+object Decoder {
+    /**
+     * Decode the input byte array from Base64 MIME encoding and decompress the decoded byte array
+     */
+    fun decode(src: ByteArray, base64: Boolean, nowrap: Boolean): Map<String, String> {
+        // Decode the input byte array from Base64 MIME encoding
+        var bytes = src
+        if (base64) bytes = Base64.getMimeDecoder().decode(bytes)
+
+        // Decompress the decoded byte array
+        val output = Compression.decompress(bytes, nowrap)
+
+        // Convert the decompressed byte array to a UTF-8 encoded string and trim any trailing spaces
+        val str = String(output, StandardCharsets.UTF_8).trim()
+
+        // Split the string by '&' symbol to separate key-value pairs
+        return str.split("&").associate {
+            val (key, value) = it.split("=")
+            key to value
+        }
+    }
+
+    @JvmStatic
+    fun decodeAllNet(src: ByteArray) = decode(src, base64 = true, nowrap = false)
+
+    @JvmStatic
+    fun decodeBilling(src: ByteArray) = decode(src, base64 = false, nowrap = true)
+}