Commit this WIP code because I might change my mind

build.gradle

@@ -7,6 +7,7 @@ plugins {
 
 dependencies {
 	implementation 'commons-cli:commons-cli:1.4'
+	implementation 'com.moandjiezana.toml:toml4j:0.7.2'
     //testImplementation 'junit:junit:4.12'
 }
 
@@ -26,9 +27,10 @@ jar {
     }
 }
 
-// Commons CLI is already included in packwiz-installer-bootstrap
+// Commons CLI and Minimal JSON are already included in packwiz-installer-bootstrap
 shadowJar {
    dependencies {
        exclude(dependency('commons-cli:commons-cli:1.4'))
+       exclude(dependency('com.eclipsesource.minimal-json:minimal-json:0.9.5'))
    }
 }

src/main/java/link/infra/packwiz/installer/request/HandlerManager.java

@@ -0,0 +1,153 @@
+package link.infra.packwiz.installer.request;
+
+import java.io.InputStream;
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Stack;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.function.Consumer;
+
+import link.infra.packwiz.installer.request.handlers.RequestHandlerHTTP;
+
+public abstract class HandlerManager {
+	
+	public static List<IRequestHandler> handlers = new ArrayList<IRequestHandler>();
+	
+	static {
+		handlers.add(new RequestHandlerHTTP());
+	}
+	
+	public static URI getNewLoc(URI base, URI loc) {
+		if (base != null) {
+			loc = base.resolve(loc);
+		}
+		if (loc == null) return null;
+		
+		for (IRequestHandler handler : handlers) {
+			if (handler.matchesHandler(loc)) {
+				return handler.getNewLoc(loc);
+			}
+		}
+		return loc;
+	}
+
+	public static InputStream getFileInputStream(URI loc) {
+		for (IRequestHandler handler : handlers) {
+			if (handler.matchesHandler(loc)) {
+				return handler.getFileInputStream(loc);
+			}
+		}
+		return null;
+	}
+	
+	public class RequestTaskManager {
+		private Map<URI, RequestTask> tasks = new HashMap<URI, RequestTask>();
+		private int numTasks = 0;
+		private int numRemainingTasks = 0;
+		private ExecutorService threadPool = Executors.newFixedThreadPool(10);
+		
+		public int getNumTasks() {
+			synchronized (tasks) {
+				return numTasks;
+			}
+		}
+		
+		public int getNumTasksRemaining() {
+			synchronized (tasks) {
+				return numRemainingTasks;
+			}
+		}
+		
+		// UHHHHHHHH fix this maybe? it's O(n^2) and kinda bad
+		// because it has to be done every time you download a thing, to check if you can download more
+		// maybe:
+		// store list of dependents and dependencies for all tasks, update when task completes??????
+		// this is hard!!!
+		// still have the issue of how to read while also allowing it to be re-read (cachedinputstream)
+		// or go to a dependency free system in some way, but just have 2 types of request: progress only, and actual download???????
+		// and how to multithread it???
+		private boolean hasRemainingDependencies(RequestTask task) {
+			synchronized (tasks) {
+				return Arrays.stream(task.getDependencies()).filter(depUri -> {
+					RequestTask depTask = tasks.get(depUri);
+					if (depTask == null) {
+						return true;
+					} else {
+						return !depTask.isDone();
+					}
+				}).count() > 0;
+			}
+		}
+		
+		public void enqueue(URI loc) {
+			// get a requesttask somehow
+			RequestTask task = null;
+			
+			Stack<URI> toEnqueue = new Stack<URI>();
+			
+			URI[] remainingDeps;
+			synchronized (tasks) {
+				remainingDeps = Arrays.stream(task.getDependencies()).filter(depUri -> {
+					RequestTask depTask = tasks.get(depUri);
+					if (depTask == null) {
+						toEnqueue.add(depUri);
+						return true;
+					} else {
+						return !depTask.isDone();
+					}
+				}).toArray(URI[]::new);
+			}
+			
+			synchronized (tasks) {
+				tasks.put(loc, null);
+			}
+			
+			while (toEnqueue.size() > 0) {
+				enqueue(toEnqueue.pop());
+			}
+			
+			if (remainingDeps.length == 0) {
+				// execute it
+				// after executing, check deps of other tasks
+			}
+		}
+	}
+	
+	public abstract class RequestTask implements Future<byte[]> {
+		
+		protected final Consumer<Integer> setProgress;
+		public final URI requestLocation;
+		
+		public abstract URI[] getDependencies();
+		
+		public RequestTask(Consumer<Integer> setProgress, URI requestLocation) {
+			this.setProgress = setProgress;
+			this.requestLocation = requestLocation;
+		}
+	}
+	
+	// how to handle progress of zip download, for zip/github downloads?
+	
+	// github toml resolution
+	// e.g. https://github.com/comp500/Demagnetize -> demagnetize.toml
+	// https://github.com/comp500/Demagnetize/blob/master/demagnetize.toml
+	
+	// Use a Request class?
+	// sub requests, can get progress (but not data) of sub things
+	// function to get length -> -1 means indeterminate
+	// function / callback to get progress
+	// input stream progress tracker, like the bootstrapper?
+	// https://docs.oracle.com/javase/tutorial/uiswing/components/progress.html -> swingworker, other magic to get progress
+	
+	// stack of request tasks
+	// deduplicated
+	
+	
+	// UHHHHH I THINK I HAVE THE HALTING PROBLEM AND ITS NOT NICE
+}

src/main/java/link/infra/packwiz/installer/request/IRequestHandler.java

@@ -0,0 +1,16 @@
+package link.infra.packwiz.installer.request;
+
+import java.io.InputStream;
+import java.net.URI;
+
+public interface IRequestHandler {
+	
+	public boolean matchesHandler(URI loc);
+	
+	public default URI getNewLoc(URI loc) {
+		return loc;
+	}
+	
+	public InputStream getFileInputStream(URI loc);
+
+}

src/main/java/link/infra/packwiz/installer/request/handlers/RequestHandlerHTTP.java

@@ -0,0 +1,22 @@
+package link.infra.packwiz.installer.request.handlers;
+
+import java.io.InputStream;
+import java.net.URI;
+
+import link.infra.packwiz.installer.request.IRequestHandler;
+
+public class RequestHandlerHTTP implements IRequestHandler {
+
+	@Override
+	public boolean matchesHandler(URI loc) {
+		String scheme = loc.getScheme();
+		return scheme.equals("http") || scheme.equals("https");
+	}
+
+	@Override
+	public InputStream getFileInputStream(URI loc) {
+		// TODO Auto-generated method stub
+		return null;
+	}
+
+}

src/main/java/link/infra/packwiz/installer/util/CachedInputStream.java

@@ -0,0 +1,25 @@
+package link.infra.packwiz.installer.util;
+
+import java.io.FilterInputStream;
+import java.io.InputStream;
+
+public class CachedInputStream extends FilterInputStream {
+	
+	public CachedInputStream(InputStream stream, boolean isMaster) {
+		if (!isMaster) {
+			
+		}
+		super(stream);
+	}
+
+	public CachedInputStream(InputStream stream) {
+		super(stream, true);
+	}
+	
+	public CachedInputStream getNewStream() {
+		
+	}
+	
+	
+
+}