Add NRO TitleEntry parsing

app/src/main/java/gq/cyuubi/lightswitch/NroMeta.java

@@ -0,0 +1,57 @@
+package gq.cyuubi.lightswitch;
+
+import android.util.Log;
+
+import java.io.IOException;
+import java.io.RandomAccessFile;
+
+final class TitleEntry {
+    private final String name;
+    private final String author;
+
+    public TitleEntry(String name, String author) {
+        this.name = name;
+        this.author = author;
+    }
+
+    public String Name() {
+        return name;
+    }
+
+    public String Author() {
+        return author;
+    }
+}
+
+public class NroMeta {
+    public static TitleEntry GetNroTitle(String file) {
+        try {
+            RandomAccessFile f = new RandomAccessFile(file, "r");
+            f.seek(0x18); // Skip to NroHeader.size
+            int asetOffset = Integer.reverseBytes(f.readInt());
+            f.seek(asetOffset); // Skip to the offset specified by NroHeader.size
+            byte[] buffer = new byte[4];
+            f.read(buffer);
+            if(!(new String(buffer).equals("ASET")))
+                return null;
+
+            f.skipBytes(0x14);
+            long nacpOffset = Long.reverseBytes(f.readLong());
+            long nacpSize = Long.reverseBytes(f.readLong());
+            if(nacpOffset == 0 || nacpSize == 0)
+                return null;
+
+            f.seek(asetOffset + nacpOffset);
+            byte[] name = new byte[0x200];
+            f.read(name);
+            byte[] author = new byte[0x100];
+            f.read(author);
+
+            return new TitleEntry(new String(name).trim(), new String(author).trim());
+        }
+        catch(IOException e) {
+            Log.e("app_process64", "Error while loading ASET: " + e.getMessage());
+            return null;
+        }
+    }
+}