From d77c3eefd4aa4d5b28520361669dd36cb8aac569 Mon Sep 17 00:00:00 2001
From: DaniTheSkunk <>
Date: Fri, 18 Nov 2022 02:55:58 +0000
Subject: [PATCH] implemented Engine.watchFile

---
 com/danitheskunk/skunkworks/BaseGame.java |  1 +
 com/danitheskunk/skunkworks/Data.java     | 32 ++++++++++++++
 com/danitheskunk/skunkworks/Engine.java   | 51 +++++++++++++++++++++++
 com/danitheskunk/skunkworks/Test.java     |  9 ++++
 4 files changed, 93 insertions(+)
 create mode 100644 com/danitheskunk/skunkworks/Data.java

diff --git a/com/danitheskunk/skunkworks/BaseGame.java b/com/danitheskunk/skunkworks/BaseGame.java
index 13309d6..8451f3d 100644
--- a/com/danitheskunk/skunkworks/BaseGame.java
+++ b/com/danitheskunk/skunkworks/BaseGame.java
@@ -43,6 +43,7 @@ public abstract class BaseGame {
 			currentTime = GLFW.glfwGetTime();
 			delta = currentTime - lastTime;
 			lastTime = currentTime;
+			engine.tick();
 			window.tick();
 			//todo: frame rate control
 			rootNode.tick();
diff --git a/com/danitheskunk/skunkworks/Data.java b/com/danitheskunk/skunkworks/Data.java
new file mode 100644
index 0000000..fac3c51
--- /dev/null
+++ b/com/danitheskunk/skunkworks/Data.java
@@ -0,0 +1,32 @@
+package com.danitheskunk.skunkworks;
+
+import java.io.BufferedInputStream;
+import java.io.InputStreamReader;
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.util.LinkedHashMap;
+
+public class Data {
+	private LinkedHashMap<String, LinkedHashMap<String, String>> data;
+	private String currentCategory;
+
+	public Data(ByteBuffer data) {
+		this.data = new LinkedHashMap<>();
+		this.currentCategory = "";
+		this.data.put("", new LinkedHashMap<>());
+		StandardCharsets.UTF_8.decode(data).toString().lines().forEach(this::processLine);
+	}
+
+	private void processLine(String line) {
+		if(line.contains("=")) {
+			var parts = line.split("=", 2);
+			data.get(currentCategory).put(parts[0].strip(), parts[1].strip());
+		} else if(line.startsWith("[") && line.endsWith("]")) {
+			currentCategory = line.substring(1, line.length()-1);
+			if(!data.containsKey(currentCategory)) {
+				data.put(currentCategory, new LinkedHashMap<>());
+			}
+		}
+	}
+}
diff --git a/com/danitheskunk/skunkworks/Engine.java b/com/danitheskunk/skunkworks/Engine.java
index 6c7ada0..6385af6 100644
--- a/com/danitheskunk/skunkworks/Engine.java
+++ b/com/danitheskunk/skunkworks/Engine.java
@@ -8,11 +8,18 @@ import org.lwjgl.BufferUtils;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.nio.file.*;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.Callable;
 
 import static com.danitheskunk.skunkworks.gfx.GraphicsBackend.OPENGL;
 
 public class Engine {
 	private final GraphicsBackend graphicsBackend;
+	private final WatchService watchService;
+	private final Map<WatchKey, Callable<Boolean>> watchCallbacks;
+	private final Map<WatchKey, Path> watchPaths;
 
 	//Constructors
 	public Engine() {
@@ -21,6 +28,13 @@ public class Engine {
 
 	public Engine(GraphicsBackend graphicsBackend) {
 		this.graphicsBackend = graphicsBackend;
+		try {
+			watchService = FileSystems.getDefault().newWatchService();
+		} catch(IOException e) {
+			throw new RuntimeException(e);
+		}
+		watchCallbacks = new HashMap<>();
+		watchPaths = new HashMap<>();
 	}
 
 	//Methods
@@ -42,9 +56,46 @@ public class Engine {
 		return new Image(loadBytes(path));
 	}
 
+	public Data loadData(String path) {
+		return new Data(loadBytes(path));
+	}
+
+	//requires engine.tick() to be called regularly
+	public void watchFile(String path, Callable<Boolean> callback) {
+		var p = Paths.get(path);
+		var dir = p.getParent();
+		try {
+			var key = dir.register(watchService,
+				StandardWatchEventKinds.ENTRY_MODIFY
+			);
+			watchCallbacks.put(key, callback);
+			watchPaths.put(key, p.getFileName());
+		} catch(IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
 	public IWindow openWindow(Vec2i size, String title) {
 		return switch(graphicsBackend) {
 			case OPENGL -> new Window(size, title, this);
 		};
 	}
+
+	public void tick() {
+		WatchKey key;
+		while((key = watchService.poll()) != null) {
+			for(var event : key.pollEvents()) {
+				var path = ((WatchEvent<Path>) event).context();
+				if(path.equals(watchPaths.get(key))) {
+					try {
+						if(watchCallbacks.get(key).call()) {
+							key.reset();
+						}
+					} catch(Exception e) {
+						throw new RuntimeException(e);
+					}
+				}
+			}
+		}
+	}
 }
diff --git a/com/danitheskunk/skunkworks/Test.java b/com/danitheskunk/skunkworks/Test.java
index 5110f35..31d02b2 100644
--- a/com/danitheskunk/skunkworks/Test.java
+++ b/com/danitheskunk/skunkworks/Test.java
@@ -17,6 +17,15 @@ public class Test extends BaseGame {
 
 	@Override
 	protected void init() {
+		var path = "C:\\Program Files (x86)" +
+			"\\Steam\\steamapps\\common\\Unreal " +
+			"Tournament\\System\\UnrealTournament.ini";
+		var data = engine.loadData(path);
+		engine.watchFile(path, () -> {
+			System.out.println("changed");
+			return true;
+		});
+
 		var fontThin = window.loadFontTileset("fonts\\thin-6x12.png");
 		var fontThin2 = window.loadFontTileset("fonts\\thin-12x12.png");
 		term = new Terminal(new Vec2i(40, 22), fontThin2, fontThin);