initial commit

.gitignore

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+/bin/
+/target/
+/.settings/
+/.classpath
+/dependency-reduced-pom.xml

.project

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+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>ShareServer</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.eclipse.m2e.core.maven2Builder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.m2e.core.maven2Nature</nature>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

pom.xml

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+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>me.mrletsplay</groupId>
+	<artifactId>ShareServer</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<build>
+		<plugins>
+			<plugin>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<version>3.8.1</version>
+				<configuration>
+					<release>17</release>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
+	<dependencies>
+		<dependency>
+			<groupId>me.mrletsplay</groupId>
+			<artifactId>ShareClient-Core</artifactId>
+			<version>1.0-SNAPSHOT</version>
+		</dependency>
+		<dependency>
+			<groupId>org.java-websocket</groupId>
+			<artifactId>Java-WebSocket</artifactId>
+			<version>1.5.4</version>
+		</dependency>
+	</dependencies>
+</project>

src/main/java/me/mrletsplay/shareserver/Session.java

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+package me.mrletsplay.shareserver;
+
+public class Session {
+
+	private String id;
+	private int nextSiteID = 0;
+
+	public Session(String id) {
+		this.id = id;
+	}
+
+	public String getID() {
+		return id;
+	}
+
+	public int getNewSiteID() {
+		return nextSiteID++;
+	}
+
+}

src/main/java/me/mrletsplay/shareserver/SessionUser.java

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+package me.mrletsplay.shareserver;
+
+public record SessionUser(Session session, int siteID) {}

src/main/java/me/mrletsplay/shareserver/ShareServer.java

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+package me.mrletsplay.shareserver;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class ShareServer {
+
+	private static final Map<String, Session> SESSIONS = new HashMap<>();
+
+	public static void main(String[] args) {
+		new ShareWSServer().start();
+	}
+
+	public static Session getOrCreateSession(String sessionID) {
+		return SESSIONS.computeIfAbsent(sessionID, Session::new);
+	}
+
+	public static void deleteSession(String sessionID) {
+		SESSIONS.remove(sessionID);
+	}
+
+}

src/main/java/me/mrletsplay/shareserver/ShareWSServer.java

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+package me.mrletsplay.shareserver;
+
+import java.io.ByteArrayOutputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.nio.ByteBuffer;
+import java.util.List;
+import java.util.Objects;
+
+import org.java_websocket.WebSocket;
+import org.java_websocket.framing.CloseFrame;
+import org.java_websocket.handshake.ClientHandshake;
+import org.java_websocket.server.WebSocketServer;
+
+import me.mrletsplay.shareclientcore.connection.RemoteConnection;
+import me.mrletsplay.shareclientcore.connection.message.ChangeMessage;
+import me.mrletsplay.shareclientcore.connection.message.ClientHelloMessage;
+import me.mrletsplay.shareclientcore.connection.message.Message;
+import me.mrletsplay.shareclientcore.connection.message.PeerJoinMessage;
+import me.mrletsplay.shareclientcore.connection.message.PeerLeaveMessage;
+import me.mrletsplay.shareclientcore.connection.message.ServerHelloMessage;
+
+public class ShareWSServer extends WebSocketServer {
+
+	public ShareWSServer() {
+		super(new InetSocketAddress("0.0.0.0", 5473));
+	}
+
+	@Override
+	public void onOpen(WebSocket conn, ClientHandshake handshake) {
+		System.out.println("Client connected");
+	}
+
+	@Override
+	public void onClose(WebSocket conn, int code, String reason, boolean remote) {
+		System.out.println("Client disconnected");
+		if(conn.getAttachment() != null) {
+			SessionUser user = conn.getAttachment();
+			var peers = getPeers(user.session());
+			if(peers.isEmpty()) {
+				ShareServer.deleteSession(reason);
+				return;
+			}
+			peers.forEach(peer -> send(peer, new PeerLeaveMessage(user.siteID())));
+		}
+	}
+
+	@Override
+	public void onMessage(WebSocket conn, String message) {
+
+	}
+
+	@Override
+	public void onMessage(WebSocket conn, ByteBuffer bytes) {
+		Message m;
+		try {
+			m = Message.deserialize(bytes);
+		}catch(IOException e) {
+			conn.close(CloseFrame.POLICY_VALIDATION, "Invalid message");
+			return;
+		}
+
+		if(conn.getAttachment() == null) {
+			// Only valid message is CLIENT_HELLO
+			if(m instanceof ClientHelloMessage hello) {
+				Session session = ShareServer.getOrCreateSession(hello.sessionID());
+				int siteID = session.getNewSiteID();
+				conn.setAttachment(new SessionUser(session, siteID));
+				send(conn, new ServerHelloMessage(RemoteConnection.PROTOCOL_VERSION, siteID));
+				getPeers(session).forEach(peer -> send(peer, new PeerJoinMessage(hello.username(), siteID)));
+			}else {
+				conn.close(CloseFrame.POLICY_VALIDATION, "First message must be CLIENT_HELLO");
+			}
+			return;
+		}
+
+		Session session = conn.getAttachment();
+		if(m instanceof ChangeMessage change) {
+			getPeers(session).forEach(peer -> send(peer, m));
+		}
+
+//		System.out.println("Got a message");
+//		getConnections().forEach(c -> {
+//			if(conn != c) c.send(message);
+//		});
+	}
+
+	private List<WebSocket> getPeers(Session session) {
+		return getConnections().stream()
+			.filter(c -> Objects.equals(c.getAttachment(), session))
+			.toList();
+	}
+
+	@Override
+	public void onError(WebSocket conn, Exception ex) {
+
+	}
+
+	@Override
+	public void onStart() {
+
+	}
+
+	public void send(WebSocket connection, Message message) {
+		try {
+			ByteArrayOutputStream bOut = new ByteArrayOutputStream();
+			DataOutputStream dOut = new DataOutputStream(bOut);
+
+			dOut.writeUTF(message.getType().name());
+			message.serialize(dOut);
+
+			connection.send(bOut.toByteArray());
+		} catch (IOException e) {
+			connection.close(CloseFrame.PROTOCOL_ERROR);
+		}
+	}
+
+}