start online game

src/GameController.java

@@ -2,19 +2,29 @@ import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
+import java.net.SocketTimeoutException;
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 public class GameController {
 
+	// Connection timeout for client sockets in milliseconds
+	public static final int CONNECTION_TIMEOUT = 10 * 1000;
+	
 	public HashMap<String, Class<? extends OnlinePlayer>> supportedVersions = new HashMap<>(Map.of(
 		"1.1.0", OnlinePlayer_1_1_0.class
 	));
 
 	public void startOnlineGame(Class<? extends LocalPlayer> localPlayerClass, InetSocketAddress address) throws IOException {
 		AsyncSocket clientSocket;
-		if (address.getHostName() == null) {
+
+		boolean localPlayerIsServer = address.getHostName() == null;
+
+		if (localPlayerIsServer) {
 			// SERVER MODE
+
 			ServerSocket serverSocket = new ServerSocket(address.getPort());
 
 			System.out.println("Waiting for client connection...");
@@ -23,10 +33,21 @@ public class GameController {
 
 			serverSocket.close();
 		} else {
-			Socket socket = new Socket();
-			socket.connect(address);
+			// CLIENT MODE
+			
+			Socket socket = new Socket();
+
+			try {
+				socket.connect(address, CONNECTION_TIMEOUT);
+
+				clientSocket = new AsyncSocket(socket, null);
+			} catch (SocketTimeoutException e) {
+				e.printStackTrace();
+				throw new RuntimeException("Connection timed out");
+			} finally {
+				socket.close();
+			}
 
-			clientSocket = new AsyncSocket(socket, null);
 		}
 
 		clientSocket.send("VERSION", "Gruppe03 " + String.join(" ", supportedVersions.keySet()));
@@ -34,15 +55,101 @@ public class GameController {
 
 			SocketPackage socketPackage = new SocketPackage(message);
 			if (socketPackage.getName().equals("VERSION")) {
-				// TODO: check version matches - instantiate online player
+
+				List<String> opponentSupportedVersions = socketPackage.splitData();
+
+				String usedVersion = findMostRecentVersion(new ArrayList<String>(supportedVersions.keySet()), opponentSupportedVersions);
+
+				if (usedVersion == null) {
+					throw new RuntimeException("No common versions found");
+				}
+
+				// instantiate players
+				Class<? extends OnlinePlayer> onlinePlayerClass = supportedVersions.get(usedVersion);
+
+				LocalPlayer localPlayer;
+				OnlinePlayer onlinePlayer;
+				try {
+					localPlayer = localPlayerClass.getDeclaredConstructor().newInstance();
+					onlinePlayer = onlinePlayerClass.getDeclaredConstructor().newInstance();
+				} catch (Exception e) {
+					e.printStackTrace();
+					throw new RuntimeException("Unable to instantiate players");
+				}
+
+				localPlayer.isServer = localPlayerIsServer;
+				onlinePlayer.isServer = !localPlayerIsServer;
+
+				startGameWithInstancedPlayers(localPlayer, onlinePlayer);
+
 			} else {
-				// TODO: received invalid package / package out of order
+				throw new RuntimeException("Unexpected Package received before game initialisation");
 			}
 		});
-		// TODO: instantiate local player, set server / client roles
 
 	}
 
+	/**
+	 * finds the largest common version in two lists of version strings
+	 * @return null if no common versions are found
+	 */
+	public String findMostRecentVersion(List<String> versions1, List<String> versions2) {
+		if (versions1 == null || versions2 == null) return null;
+		String largestCommonVersion = null;
+		for (String v1 : versions1) {
+			if (!checkVersionString(v1)) continue;
+
+			for (String v2 : versions2) {
+				if (!checkVersionString(v2)) continue;
+
+				// strings within the lists must be equal
+				// if no largest common version has been found or currently checked version is larger than
+				// previous largest common version, new largest version has been found
+				if (compareVersions(v1, v2) == 0 && (largestCommonVersion == null || compareVersions(v1, largestCommonVersion) >= 1)) {
+					largestCommonVersion = v1;
+					continue;
+				}
+			}
+		}
+		return largestCommonVersion;
+	}
+
+	/**
+	 * compares two version strings
+	 * @return
+	 *  0 if versions are equal
+	 *  1 if version1 is more recent than version2
+	 *  -1 otherwise
+	 */
+	public int compareVersions(String version1, String version2) {
+		if (!checkVersionString(version1) || !checkVersionString(version2)) {
+			throw new IllegalArgumentException("Version is not valid version string");
+		}
+
+		String[] version1Split = version1.split("\\.");
+		String[] version2Split = version2.split("\\.");
+
+		for (int i = 0; i < version1Split.length; i++) {
+			int v1 = Integer.parseInt(version1Split[i]);
+			int v2 = Integer.parseInt(version2Split[i]);
+
+			if (v1 == v2) continue;
+			if (v1 > v2) {
+				return 1;
+			} else {
+				return -1;
+			}
+		}
+		return 0;
+	}
+
+	/**
+	 * checks if a provided string matches the format of a version number
+	 */
+	public boolean checkVersionString(String versionString) {
+		return versionString != null && versionString.matches("\\d+\\.\\d+\\.\\d+");
+	}
+
 	public void startLocalGame(Class<? extends  LocalPlayer> localPlayerClass, Class<? extends AiPlayer> enemyClass, int size) {
 
 		LocalPlayer localPlayer;
@@ -52,10 +159,16 @@ public class GameController {
 			aiPlayer = enemyClass.getDeclaredConstructor().newInstance();
 		} catch (Exception e) {
 			e.printStackTrace();
-			return;
+			throw new RuntimeException("Unable to instantiate players"); 
 		}
-		localPlayer.setEnemy(aiPlayer);
-		aiPlayer.setEnemy(localPlayer);
+		startGameWithInstancedPlayers(localPlayer, aiPlayer);
+	}
+
+	private void startGameWithInstancedPlayers(LocalPlayer p1, Player p2) {
+		p1.setEnemy(p2);
+		p2.setEnemy(p1);
+
+		// TODO: frontend configuration
 	}
 
 }