From b21f118600b60554bebd45d9f81fb46cbadc8431 Mon Sep 17 00:00:00 2001
From: Charles Gould <charles@gould.dev>
Date: Wed, 4 Jan 2017 19:27:32 -0500
Subject: [PATCH] Add server announcements

---
 .../src/main/java/lingo/client/api/StompTopics.java |  2 ++
 .../src/main/java/lingo/server/LingoController.java | 13 ++++++++++++-
 server/src/main/resources/static/multiplayer.js     |  3 +++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/client-api/src/main/java/lingo/client/api/StompTopics.java b/client-api/src/main/java/lingo/client/api/StompTopics.java
index 81a15b6..9364ced 100644
--- a/client-api/src/main/java/lingo/client/api/StompTopics.java
+++ b/client-api/src/main/java/lingo/client/api/StompTopics.java
@@ -2,6 +2,8 @@ package lingo.client.api;
 
 public class StompTopics {
 
+	public static final String CHAT = createTopicName("chat");
+
 	public static final String OPPONENT_JOINED = createTopicName("opponentJoined");
 
 	public static final String OPPONENT_LEFT = createTopicName("opponentLeft");
diff --git a/server/src/main/java/lingo/server/LingoController.java b/server/src/main/java/lingo/server/LingoController.java
index e25dfdd..46a38e4 100644
--- a/server/src/main/java/lingo/server/LingoController.java
+++ b/server/src/main/java/lingo/server/LingoController.java
@@ -89,6 +89,7 @@ public class LingoController implements ApplicationListener<AbstractSubProtocolE
 	public void join(String username, @Header(SESSION_ID_HEADER) String sessionId) {
 		log.info("Player joined: {}, {}", sessionId, username);
 		usernameBySession.put(sessionId, username);
+		sendAnnouncement(username + " joined");
 		joinWaitingList(sessionId);
 	}
 
@@ -102,7 +103,10 @@ public class LingoController implements ApplicationListener<AbstractSubProtocolE
 	}
 
 	private void leave(String sessionId) {
-		usernameBySession.remove(sessionId);
+		final String username = usernameBySession.remove(sessionId);
+		if (username != null) {
+			sendAnnouncement(username + " left");
+		}
 		final Game game = gameBySession.remove(sessionId);
 		if (game == null) {
 			leaveWaitingList(sessionId);
@@ -180,6 +184,12 @@ public class LingoController implements ApplicationListener<AbstractSubProtocolE
 		sendToUser(sessionId, StompTopics.PRACTICE_REPORTS, report);
 	}
 
+	private void sendAnnouncement(String message) {
+		final String source = "[Server]";
+		final ChatMessage payload = new ChatMessage(source, message);
+		messagingTemplate.convertAndSend(StompTopics.CHAT, payload);
+	}
+
 	private void sendToUser(String user, String destination, Object payload) {
 		// TODO: cache the headers?
 		final SimpMessageHeaderAccessor headerAccessor = SimpMessageHeaderAccessor.create(SimpMessageType.MESSAGE);
@@ -222,6 +232,7 @@ public class LingoController implements ApplicationListener<AbstractSubProtocolE
 				final String[] playerTwoMessage = new String[] { firstLetter, playerOneUsername };
 				sendToUser(playerOne, StompTopics.OPPONENT_JOINED, playerOneMessage);
 				sendToUser(playerTwo, StompTopics.OPPONENT_JOINED, playerTwoMessage);
+				sendAnnouncement(playerOneUsername + " is playing against " + playerTwoUsername);
 			}
 		}
 	}
diff --git a/server/src/main/resources/static/multiplayer.js b/server/src/main/resources/static/multiplayer.js
index 24ef37a..b524757 100644
--- a/server/src/main/resources/static/multiplayer.js
+++ b/server/src/main/resources/static/multiplayer.js
@@ -137,6 +137,9 @@ function addChatMessage(sender, body) {
 	chatMessage.appendChild(usernameNode);
 	chatMessage.appendChild(messageTextNode);
 	messageList.appendChild(chatMessage);
+
+	// Auto-scroll if necessary
+	messageList.scrollTop = messageList.scrollHeight;
 }
 
 function drawMyBoard() {