[FEATURE] Support OverlayVfsDirectory

LauncherAPI/src/main/java/pro/gravit/launcher/base/vfs/VfsDirectory.java

@@ -5,22 +5,6 @@
 
 public abstract class VfsDirectory extends VfsEntry {
     public abstract VfsEntry find(String name);
-    public VfsEntry resolve(Path path) {
+    public abstract VfsEntry resolve(Path path);
-        if(path == null) {
+    public abstract Stream<String> getFiles();
-            return null;
-        }
-
-        VfsDirectory current = this;
-        for(int i=0;i<path.getNameCount();++i) {
-            String s = path.getName(i).toString();
-            VfsEntry entity = current.find(s);
-            if(entity instanceof VfsDirectory newDir) {
-                current = newDir;
-            } else {
-                return entity;
-            }
-        }
-        return null;
-    }
-    protected abstract Stream<String> getFiles();
 }

LauncherAPI/src/main/java/pro/gravit/launcher/base/vfs/directory/FileVfsDirectory.java

@@ -30,9 +30,25 @@ public VfsEntry find(String name) {
         return null;
     }
 
+    @Override
+    public VfsEntry resolve(Path path) {
+        if(path == null) {
+            return null;
+        }
+
+        Path target = path.resolve(path);
+        if(Files.exists(target)) {
+            if(Files.isDirectory(target)) {
+                return new FileVfsDirectory(target);
+            }
+            return new FileVfsFile(target);
+        }
+        return null;
+    }
+
     @SuppressWarnings("resource")
     @Override
-    protected Stream<String> getFiles() {
+    public Stream<String> getFiles() {
         try {
             return Files.list(path).map(Path::getFileName).map(Path::toString);
         } catch (IOException e) {

LauncherAPI/src/main/java/pro/gravit/launcher/base/vfs/directory/OverlayVfsDirectory.java

@@ -0,0 +1,50 @@
+package pro.gravit.launcher.base.vfs.directory;
+
+import pro.gravit.launcher.base.vfs.VfsDirectory;
+import pro.gravit.launcher.base.vfs.VfsEntry;
+
+import java.nio.file.Path;
+import java.util.List;
+import java.util.stream.Stream;
+
+public class OverlayVfsDirectory extends VfsDirectory {
+    private final List<VfsDirectory> list;
+
+    public OverlayVfsDirectory(List<VfsDirectory> list) {
+        this.list = list;
+    }
+
+    @Override
+    public VfsEntry find(String name) {
+        for(var e : list) {
+            var result = e.find(name);
+            if(result != null) {
+                return result;
+            }
+        }
+        return null;
+    }
+
+    @Override
+    public VfsEntry resolve(Path path) {
+        for(var e : list) {
+            var result = e.resolve(path);
+            if(result != null) {
+                return result;
+            }
+        }
+        return null;
+    }
+
+    @Override
+    public Stream<String> getFiles() {
+        Stream<String> stream = Stream.empty();
+        for(var e : list) {
+            var result = e.getFiles();
+            if(result != null) {
+                stream = Stream.concat(stream, result);
+            }
+        }
+        return stream;
+    }
+}

LauncherAPI/src/main/java/pro/gravit/launcher/base/vfs/directory/SimpleVfsDirectory.java

@@ -4,6 +4,7 @@
 import pro.gravit.launcher.base.vfs.VfsDirectory;
 import pro.gravit.launcher.base.vfs.VfsEntry;
 
+import java.nio.file.Path;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.stream.Stream;
@@ -15,6 +16,30 @@ public VfsEntry find(String name) {
         return map.get(name);
     }
 
+    @Override
+    public VfsEntry resolve(Path path)  {
+        if(path == null) {
+            return null;
+        }
+
+        VfsDirectory current = this;
+        for(int i=0;i<path.getNameCount();++i) {
+            String s = path.getName(i).toString();
+            VfsEntry entity = current.find(s);
+            if(entity instanceof VfsDirectory newDir) {
+                if(entity instanceof SimpleVfsDirectory) {
+                    current = newDir;
+                } else {
+                    Path newPath = path.subpath(i+1, path.getNameCount());
+                    return newDir.resolve(newPath);
+                }
+            } else {
+                return entity;
+            }
+        }
+        return null;
+    }
+
     public VfsEntry remove(String name) {
         return map.remove(name);
     }
@@ -24,7 +49,7 @@ public void put(String name, VfsEntry entry) {
     }
 
     @Override
-    protected Stream<String> getFiles() {
+    public Stream<String> getFiles() {
         return map.keySet().stream();
     }
 }