From d65f676b937b0c51dcb331360079ce7403d9040a Mon Sep 17 00:00:00 2001
From: Greg Gibeling <gdgib@outlook.com>
Date: Wed, 25 Sep 2024 19:32:46 -0700
Subject: [PATCH] G2-1649 Support flexible arity for parent & child paths

---
 .../g2forge/alexandria/path/file/IFile.java   |  6 ++--
 .../alexandria/path/file/LocalFile.java       |  6 ++--
 .../path/file/system/ISelfFileSystem.java     | 23 ++++++++++++++
 .../path/file/system/IStandardFileSystem.java |  7 +----
 .../path/file/system/ITreeFileSystem.java     | 31 +++++++++++++++++++
 .../path/file/system/OSFileSystem.java        |  2 +-
 6 files changed, 62 insertions(+), 13 deletions(-)
 create mode 100644 ax-path/src/main/java/com/g2forge/alexandria/path/file/system/ISelfFileSystem.java
 create mode 100644 ax-path/src/main/java/com/g2forge/alexandria/path/file/system/ITreeFileSystem.java

diff --git a/ax-path/src/main/java/com/g2forge/alexandria/path/file/IFile.java b/ax-path/src/main/java/com/g2forge/alexandria/path/file/IFile.java
index efe93d0d..bc38b387 100644
--- a/ax-path/src/main/java/com/g2forge/alexandria/path/file/IFile.java
+++ b/ax-path/src/main/java/com/g2forge/alexandria/path/file/IFile.java
@@ -3,11 +3,11 @@
 import com.g2forge.alexandria.path.file.system.IFileSystem;
 
 public interface IFile<T> {
-	public IFileSystem<T> getDirectorySystem();
+	public IFile<T> get(T filename);
 
-	public IFile<T> getParent();
+	public IFileSystem<T> getFileSystem();
 
-	public IFile<T> get(T filename);
+	public IFile<T> getParent();
 
 	public boolean isDirectory();
 }
diff --git a/ax-path/src/main/java/com/g2forge/alexandria/path/file/LocalFile.java b/ax-path/src/main/java/com/g2forge/alexandria/path/file/LocalFile.java
index 609ebe24..aaac9171 100644
--- a/ax-path/src/main/java/com/g2forge/alexandria/path/file/LocalFile.java
+++ b/ax-path/src/main/java/com/g2forge/alexandria/path/file/LocalFile.java
@@ -3,8 +3,8 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 
-import com.g2forge.alexandria.path.file.system.OSFileSystem;
 import com.g2forge.alexandria.path.file.system.IFileSystem;
+import com.g2forge.alexandria.path.file.system.OSFileSystem;
 
 import lombok.Builder;
 import lombok.Data;
@@ -26,8 +26,8 @@ public IFile<String> get(String filename) {
 	}
 
 	@Override
-	public IFileSystem<String> getDirectorySystem() {
-		return OSFileSystem.getDirectorySystem();
+	public IFileSystem<String> getFileSystem() {
+		return OSFileSystem.getFileSystem();
 	}
 
 	@Override
diff --git a/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/ISelfFileSystem.java b/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/ISelfFileSystem.java
new file mode 100644
index 00000000..d2dc2679
--- /dev/null
+++ b/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/ISelfFileSystem.java
@@ -0,0 +1,23 @@
+package com.g2forge.alexandria.path.file.system;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.g2forge.alexandria.path.path.IPath;
+import com.g2forge.alexandria.path.path.Path;
+
+public interface ISelfFileSystem<T> extends IFileSystem<T> {
+	public T getSelf();
+
+	@Override
+	public default IPath<T> normalize(IPath<T> path) {
+		if (path.isEmpty()) return path;
+
+		final List<T> retVal = new ArrayList<>(path.getComponents().toCollection());
+		for (int i = 0; i < retVal.size(); i++) {
+			final T current = retVal.get(i);
+			if (getSelf().equals(current)) retVal.remove(i--);
+		}
+		return new Path<>(retVal);
+	}
+}
diff --git a/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/IStandardFileSystem.java b/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/IStandardFileSystem.java
index 7fae0783..ab0c3dc7 100644
--- a/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/IStandardFileSystem.java
+++ b/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/IStandardFileSystem.java
@@ -6,7 +6,7 @@
 import com.g2forge.alexandria.path.path.IPath;
 import com.g2forge.alexandria.path.path.Path;
 
-public interface IStandardFileSystem extends IFileSystem<String> {
+public interface IStandardFileSystem extends ISelfFileSystem<String>, ITreeFileSystem<String> {
 	public default String getParent() {
 		return "..";
 	}
@@ -15,11 +15,6 @@ public default String getSelf() {
 		return ".";
 	}
 
-	@Override
-	public default boolean isRootEscape(IPath<String> path) {
-		return normalize(path).startsWith(new Path<>(getParent()));
-	}
-
 	@Override
 	public default IPath<String> normalize(IPath<String> path) {
 		if (path.isEmpty()) return path;
diff --git a/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/ITreeFileSystem.java b/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/ITreeFileSystem.java
new file mode 100644
index 00000000..449328e2
--- /dev/null
+++ b/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/ITreeFileSystem.java
@@ -0,0 +1,31 @@
+package com.g2forge.alexandria.path.file.system;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.g2forge.alexandria.path.path.IPath;
+import com.g2forge.alexandria.path.path.Path;
+
+public interface ITreeFileSystem<T> extends IFileSystem<T> {
+	public T getParent();
+
+	@Override
+	public default boolean isRootEscape(IPath<T> path) {
+		return normalize(path).startsWith(new Path<>(getParent()));
+	}
+
+	@Override
+	public default IPath<T> normalize(IPath<T> path) {
+		if (path.isEmpty()) return path;
+
+		final List<T> retVal = new ArrayList<>(path.getComponents().toCollection());
+		for (int i = 0; i < retVal.size(); i++) {
+			final T current = retVal.get(i);
+			if (getParent().equals(current) && (i > 0) && !getParent().equals(retVal.get(i - 1))) {
+				retVal.remove(i--);
+				retVal.remove(i--);
+			}
+		}
+		return new Path<>(retVal);
+	}
+}
diff --git a/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/OSFileSystem.java b/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/OSFileSystem.java
index 6dab60a9..45770ca0 100644
--- a/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/OSFileSystem.java
+++ b/ax-path/src/main/java/com/g2forge/alexandria/path/file/system/OSFileSystem.java
@@ -8,7 +8,7 @@ public enum OSFileSystem implements IStandardFileSystem {
 	Microsoft,
 	POSIX;
 
-	public static OSFileSystem getDirectorySystem() {
+	public static OSFileSystem getFileSystem() {
 		final PlatformCategory category = HPlatform.getPlatform().getCategory();
 		switch (category) {
 			case Microsoft: