Added mod update notification (opt-out via /moo config)

Standardized versioning (now includes Minecraft version)

Bug fixes:
- Reduced greediness of login/logout notification detection

14 files changed, 326 insertions, 28 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..14ac786
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,28 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
+
+## [1.8.9-0.2.0] - 08.03.2020
+### Added
+- Mod update notification (opt-out via config)
+
+### Changed
+- *Mod versioning now includes Minecraft version*: `<mc-version>-<modversion>` instead of just `<modversion>`
+- Manage 'best friends' list via GUI instead of add/remove commands
+
+### Fixed
+- Reduced greediness of login/logout notification detection 
+
+## [0.1] - 01.03.2020
+### Added
+- Toggle to hide all join/leave notifications (`/moo toggle`)
+- 'Best friends' list to limit the amount of join and leave notifications (see below)
+- Auto-replace `/r` with `/msg <latest username>`
+- Copy chat components via <kbd>ALT</kbd> + <kbd>right click</kbd>
+- Change guiScale to any value (`/moo guiscale [newValue]`)
+
+*Note:* The 'best friends' list is currently available via <kbd>ESC</kbd> > Mod Options > Cowmoonication > Config > bestFriends.
+
+[1.8.9-0.2.0]: https://github.com/cow-mc/Cowmoonication/compare/v0.1...v1.8.9-0.2.0
+[0.1]: https://github.com/cow-mc/Cowmoonication/releases/tag/v0.1
diff --git a/README.md b/README.md
index b033172..8630a93 100644
--- a/README.md
+++ b/README.md
@@ -1,12 +1,19 @@
 # Cowmoonication
-A client-side only Forge mod by [Cow](https://namemc.com/profile/Cow) providing various things related to communication.
-
-**Current features:**
+A client-side only Forge mod by [Cow](https://namemc.com/profile/Cow) providing various things related to communication. :cow2:
 
+## Current features
 | Feature                                                                 | Command/Usage                           |
 |-------------------------------------------------------------------------|-----------------------------------------|
 | Toggle to hide all join/leave notifications                             | `/moo toggle`                           |
 | 'Best friends' list to limit the amount of join and leave notifications | `/moo friends`                          |
 | Change guiScale to any value                                            | `/moo guiscale [newValue]`              |
-| Auto-replace `/r` with `/msg <latest username>`                         | `/r `                                   |
+| Auto-replace `/r` with `/w <latest username>`                           | `/r `                                   |
 | Copy chat components                                                    | <kbd>ALT</kbd> + <kbd>right click</kbd> |
+| Check for mod updates on server login and via command                   | `/moo update`                           |
+
+➜ Use `/moo help` to see all available commands.
+
+## Download
+You can download the compiled .jar files from the [release section](https://github.com/cow-mc/Cowmoonication/releases).
+
+➜ View [Changelog](CHANGELOG.md)
diff --git a/build.gradle b/build.gradle
index 3d002c6..f108a60 100644
--- a/build.gradle
+++ b/build.gradle
@@ -20,7 +20,7 @@ plugins {
     id "net.minecraftforge.gradle.forge" version "2.0.2"
 }
 */
-version = "0.1"
+version = "1.8.9-0.2.0"
 group= "eu.olli.cowmoonication" // http://maven.apache.org/guides/mini/guide-naming-conventions.html
 archivesBaseName = "Cowmoonication"
 
diff --git a/src/main/java/eu/olli/cowmoonication/Cowmoonication.java b/src/main/java/eu/olli/cowmoonication/Cowmoonication.java
index 3a93fe6..78f1905 100644
--- a/src/main/java/eu/olli/cowmoonication/Cowmoonication.java
+++ b/src/main/java/eu/olli/cowmoonication/Cowmoonication.java
@@ -3,24 +3,32 @@ package eu.olli.cowmoonication;
 import eu.olli.cowmoonication.command.MooCommand;
 import eu.olli.cowmoonication.config.MooConfig;
 import eu.olli.cowmoonication.listener.ChatListener;
+import eu.olli.cowmoonication.listener.PlayerListener;
 import eu.olli.cowmoonication.util.Utils;
+import eu.olli.cowmoonication.util.VersionChecker;
 import net.minecraftforge.client.ClientCommandHandler;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.common.config.Configuration;
 import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.Mod.EventHandler;
 import net.minecraftforge.fml.common.event.FMLInitializationEvent;
+import net.minecraftforge.fml.common.event.FMLPostInitializationEvent;
 import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
 import org.apache.logging.log4j.Logger;
 
 import java.io.File;
 
-@Mod(modid = Cowmoonication.MODID, version = Cowmoonication.VERSION, clientSideOnly = true, guiFactory = "eu.olli." + Cowmoonication.MODID + ".config.MooGuiFactory")
+@Mod(modid = Cowmoonication.MODID, name = Cowmoonication.MODNAME, version = Cowmoonication.VERSION,
+        clientSideOnly = true,
+        guiFactory = "eu.olli." + Cowmoonication.MODID + ".config.MooGuiFactory",
+        updateJSON = "https://raw.githubusercontent.com/cow-mc/Cowmoonication/master/update.json")
 public class Cowmoonication {
     public static final String MODID = "cowmoonication";
-    public static final String VERSION = "1.0";
+    public static final String VERSION = "1.8.9-0.2.0";
+    public static final String MODNAME = "Cowmoonication";
     private MooConfig config;
     private Friends friends;
+    private VersionChecker versionChecker;
     private Utils utils;
     private Logger logger;
 
@@ -35,16 +43,23 @@ public class Cowmoonication {
 
         friends = new Friends(this);
         config = new MooConfig(new Configuration(new File(modDir, MODID + ".cfg")), this);
+
+        utils = new Utils(this, e.getSourceFile());
     }
 
     @EventHandler
     public void init(FMLInitializationEvent e) {
-        utils = new Utils(this);
 
         MinecraftForge.EVENT_BUS.register(new ChatListener(this));
+        MinecraftForge.EVENT_BUS.register(new PlayerListener(this));
         ClientCommandHandler.instance.registerCommand(new MooCommand(this));
     }
 
+    @EventHandler
+    public void postInit(FMLPostInitializationEvent e) {
+        versionChecker = new VersionChecker(this);
+    }
+
     public MooConfig getConfig() {
         return config;
     }
@@ -53,6 +68,10 @@ public class Cowmoonication {
         return friends;
     }
 
+    public VersionChecker getVersionChecker() {
+        return versionChecker;
+    }
+
     public Utils getUtils() {
         return utils;
     }
@@ -60,5 +79,4 @@ public class Cowmoonication {
     public Logger getLogger() {
         return logger;
     }
-
 }
diff --git a/src/main/java/eu/olli/cowmoonication/command/MooCommand.java b/src/main/java/eu/olli/cowmoonication/command/MooCommand.java
index f3d234b..08c377d 100644
--- a/src/main/java/eu/olli/cowmoonication/command/MooCommand.java
+++ b/src/main/java/eu/olli/cowmoonication/command/MooCommand.java
@@ -8,13 +8,15 @@ import net.minecraft.client.Minecraft;
 import net.minecraft.command.CommandBase;
 import net.minecraft.command.CommandException;
 import net.minecraft.command.ICommandSender;
-import net.minecraft.util.BlockPos;
-import net.minecraft.util.ChatComponentTranslation;
-import net.minecraft.util.EnumChatFormatting;
-import net.minecraft.util.MathHelper;
+import net.minecraft.event.ClickEvent;
+import net.minecraft.event.HoverEvent;
+import net.minecraft.util.*;
 
+import java.awt.*;
+import java.io.IOException;
 import java.util.List;
 import java.util.Set;
+import java.util.concurrent.TimeUnit;
 
 public class MooCommand extends CommandBase {
     private final Cowmoonication main;
@@ -29,21 +31,55 @@ public class MooCommand extends CommandBase {
             main.getUtils().sendMessage(new ChatComponentTranslation(getCommandUsage(sender)));
             return;
         }
-        if (args[0].equalsIgnoreCase("friends") || args[0].equalsIgnoreCase("f")) {
+        if (args[0].equalsIgnoreCase("friends") || args[0].equalsIgnoreCase("config")) {
             new TickDelay(() -> Minecraft.getMinecraft().displayGuiScreen(new MooGuiConfig(null)), 1); // delay by 1 tick, because the chat closing would close the new gui instantly as well.
         } else if (args[0].equalsIgnoreCase("list")) {
             handleListBestFriends();
         } else if (args[0].equalsIgnoreCase("toggle")) {
             main.getConfig().toggleNotifications();
-            main.getUtils().sendMessage(EnumChatFormatting.GREEN + "Switched all non-best friend login/logout notifications " + (MooConfig.filterFriendNotifications ? EnumChatFormatting.DARK_GREEN + "off" : EnumChatFormatting.DARK_RED + "on"));
+            main.getUtils().sendMessage(EnumChatFormatting.GREEN + "\u2714 Switched all non-best friend login/logout notifications " + (MooConfig.filterFriendNotifications ? EnumChatFormatting.DARK_GREEN + "off" : EnumChatFormatting.DARK_RED + "on"));
         } else if (args[0].equalsIgnoreCase("guiscale")) {
             int currentGuiScale = (Minecraft.getMinecraft()).gameSettings.guiScale;
             if (args.length == 1) {
-                main.getUtils().sendMessage(EnumChatFormatting.GREEN + "Current GUI scale: " + EnumChatFormatting.DARK_GREEN + currentGuiScale);
+                main.getUtils().sendMessage(EnumChatFormatting.GREEN + "\u279C Current GUI scale: " + EnumChatFormatting.DARK_GREEN + currentGuiScale);
             } else {
                 int scale = Math.min(10, MathHelper.parseIntWithDefault(args[1], 6));
                 Minecraft.getMinecraft().gameSettings.guiScale = scale;
-                main.getUtils().sendMessage(EnumChatFormatting.GREEN + "New GUI scale: " + EnumChatFormatting.DARK_GREEN + scale + EnumChatFormatting.GREEN + " (previous: " + EnumChatFormatting.DARK_GREEN + currentGuiScale + EnumChatFormatting.GREEN + ")");
+                main.getUtils().sendMessage(EnumChatFormatting.GREEN + "\u2714 New GUI scale: " + EnumChatFormatting.DARK_GREEN + scale + EnumChatFormatting.GREEN + " (previous: " + EnumChatFormatting.DARK_GREEN + currentGuiScale + EnumChatFormatting.GREEN + ")");
+            }
+        } else if (args[0].equalsIgnoreCase("update")) {
+            boolean updateCheckStarted = main.getVersionChecker().runUpdateCheck(true);
+
+            if (updateCheckStarted) {
+                main.getUtils().sendMessage(EnumChatFormatting.GREEN + "\u279C Checking for a newer mod version...");
+                // VersionChecker#handleVersionStatus will run with a 5 seconds delay
+            } else {
+                long nextUpdate = main.getVersionChecker().getNextCheck();
+                String waitingTime = String.format("%02d:%02d",
+                        TimeUnit.MILLISECONDS.toMinutes(nextUpdate),
+                        TimeUnit.MILLISECONDS.toSeconds(nextUpdate) - TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(nextUpdate)));
+                main.getUtils().sendMessage(new ChatComponentText("\u26A0 Update checker is on cooldown. Please wait " + EnumChatFormatting.GOLD + EnumChatFormatting.BOLD + waitingTime + EnumChatFormatting.RESET + EnumChatFormatting.RED + " more minutes before checking again.").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.RED)));
+            }
+        } else if (args[0].equalsIgnoreCase("updateHelp")) {
+            main.getUtils().sendMessage(new ChatComponentText("\u279C Update instructions:").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.GOLD).setBold(true))
+                    .appendSibling(new ChatComponentText("\n\u278A" + EnumChatFormatting.YELLOW + " download latest mod version").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.GOLD).setBold(false)
+                            .setChatClickEvent(new ClickEvent(ClickEvent.Action.OPEN_URL, main.getVersionChecker().getDownloadUrl()))
+                            .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.YELLOW + "Download the latest version of Cowmoonication\n\u279C Click to download latest mod file")))))
+                    .appendSibling(new ChatComponentText("\n\u278B" + EnumChatFormatting.YELLOW + " exit Minecraft").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.GOLD).setBold(false)
+                            .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.GOLD + "\u278B" + EnumChatFormatting.YELLOW + " Without closing Minecraft first,\n" + EnumChatFormatting.YELLOW + "you can't delete the old .jar file!")))))
+                    .appendSibling(new ChatComponentText("\n\u278C" + EnumChatFormatting.YELLOW + " copy " + EnumChatFormatting.GOLD + "Cowmoonication-" + main.getVersionChecker().getNewVersion() + ".jar" + EnumChatFormatting.YELLOW + " into mods folder").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.GOLD).setBold(false)
+                            .setChatClickEvent(new ClickEvent(ClickEvent.Action.RUN_COMMAND, "/moo folder"))
+                            .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.YELLOW + "Open mods folder with command " + EnumChatFormatting.GOLD + "/moo folder\n\u279C Click to open mods folder")))))
+                    .appendSibling(new ChatComponentText("\n\u278D" + EnumChatFormatting.YELLOW + " delete old mod file " + EnumChatFormatting.GOLD + "Cowmoonication-" + Cowmoonication.VERSION + ".jar ").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.GOLD).setBold(false)))
+                    .appendSibling(new ChatComponentText("\n\u278E" + EnumChatFormatting.YELLOW + " start Minecraft again").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.GOLD).setBold(false))));
+        } else if (args[0].equalsIgnoreCase("version")) {
+            main.getVersionChecker().handleVersionStatus(true);
+        } else if (args[0].equalsIgnoreCase("folder")) {
+            try {
+                Desktop.getDesktop().open(main.getUtils().getModsFolder());
+            } catch (IOException e) {
+                main.getUtils().sendMessage(new ChatComponentText("\u2716 An error occurred trying to open the mod's folder. I guess you have to open it manually \u00af\\_(\u30c4)_/\u00af").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.RED)));
+                e.printStackTrace();
             }
         } else {
             main.getUtils().sendMessage(new ChatComponentTranslation(getCommandUsage(sender)));
@@ -54,7 +90,7 @@ public class MooCommand extends CommandBase {
         Set<String> bestFriends = main.getFriends().getBestFriends();
 
         // TODO show fancy gui with list of best friends (maybe just the mod's settings?)
-        main.getUtils().sendMessage(EnumChatFormatting.GREEN + "Best friends: " + String.join(", ", bestFriends));
+        main.getUtils().sendMessage(EnumChatFormatting.GREEN + "\u279C Best friends: " + EnumChatFormatting.DARK_GREEN + String.join(EnumChatFormatting.GREEN + ", " + EnumChatFormatting.DARK_GREEN, bestFriends));
     }
 
     @Override
@@ -64,7 +100,35 @@ public class MooCommand extends CommandBase {
 
     @Override
     public String getCommandUsage(ICommandSender sender) {
-        return Cowmoonication.MODID + ":command.moo.usage";
+        IChatComponent usage = new ChatComponentText("\u279C Cowmoonication commands:").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.GOLD).setBold(true))
+                .appendSibling(createCmdHelpSection(1, "Login/Logout Notifications"))
+                .appendSibling(createCmdHelpEntry("friends", "Add/remove best friends"))
+                .appendSibling(createCmdHelpEntry("list", "View list of best friends"))
+                .appendSibling(createCmdHelpEntry("toggle", "Toggle show/hide all join/leave notifications"))
+                .appendSibling(createCmdHelpSection(2, "Miscellaneous"))
+                .appendSibling(createCmdHelpEntry("config", "Open configuration GUI"))
+                .appendSibling(createCmdHelpEntry("guiScale", "Change GUI scale"))
+                .appendSibling(createCmdHelpSection(3, "Update mod"))
+                .appendSibling(createCmdHelpEntry("update", "Check for new mod updates"))
+                .appendSibling(createCmdHelpEntry("updateHelp", "Show mod update instructions"))
+                .appendSibling(createCmdHelpEntry("version", "View results of last mod update check"))
+                .appendSibling(createCmdHelpEntry("folder", "Open Minecraft's mods folder"));
+        sender.addChatMessage(usage);
+        return "";
+    }
+
+    private IChatComponent createCmdHelpSection(int nr, String title) {
+        String prefix = Character.toString((char) (0x2789 + nr));
+        return new ChatComponentText("\n").appendSibling(new ChatComponentText(prefix + " " + title).setChatStyle(new ChatStyle().setColor(EnumChatFormatting.GOLD).setBold(true)));
+    }
+
+    private IChatComponent createCmdHelpEntry(String cmd, String usage) {
+        String command = "/" + this.getCommandName() + " " + cmd;
+        ChatStyle clickableMsg = new ChatStyle()
+                .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.YELLOW + "Run " + EnumChatFormatting.GOLD + command)))
+                .setChatClickEvent(new ClickEvent(ClickEvent.Action.SUGGEST_COMMAND, command));
+        return new ChatComponentText("\n").appendSibling(new ChatComponentText(command).setChatStyle(clickableMsg.createDeepCopy().setColor(EnumChatFormatting.GOLD)))
+                .appendSibling(new ChatComponentText(" \u27A1 " + usage).setChatStyle(clickableMsg.createDeepCopy().setColor(EnumChatFormatting.YELLOW)));
     }
 
     @Override
@@ -75,7 +139,7 @@ public class MooCommand extends CommandBase {
     @Override
     public List<String> addTabCompletionOptions(ICommandSender sender, String[] args, BlockPos pos) {
         if (args.length == 1) {
-            return getListOfStringsMatchingLastWord(args, "friends", "list", "toggle", "guiscale");
+            return getListOfStringsMatchingLastWord(args, "config", "friends", "list", "toggle", "guiscale", "update", "updateHelp", "version", "folder", "help");
         }
         return null;
     }
diff --git a/src/main/java/eu/olli/cowmoonication/config/MooConfig.java b/src/main/java/eu/olli/cowmoonication/config/MooConfig.java
index 97cea9b..e9b2146 100644
--- a/src/main/java/eu/olli/cowmoonication/config/MooConfig.java
+++ b/src/main/java/eu/olli/cowmoonication/config/MooConfig.java
@@ -13,6 +13,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class MooConfig {
+    public static boolean doUpdateCheck;
     public static boolean filterFriendNotifications;
     private static String[] bestFriends;
     private static Configuration cfg = null;
@@ -69,6 +70,9 @@ public class MooConfig {
             cfg.load();
         }
 
+        final boolean DO_UPDATE_CHECK = true;
+        Property propDoUpdateCheck = cfg.get(Configuration.CATEGORY_CLIENT, "doUpdateCheck", DO_UPDATE_CHECK, "Check for mod updates?");
+
         final boolean FILTER_FRIEND_NOTIFICATIONS = true;
         Property propFilterFriendNotify = cfg.get(Configuration.CATEGORY_CLIENT, "filterFriendNotifications", FILTER_FRIEND_NOTIFICATIONS, "Set to false to receive all login/logout messages, set to true to only get notifications of 'best friends' joining/leaving");
 
@@ -77,15 +81,18 @@ public class MooConfig {
         propBestFriends.setValidationPattern(Utils.VALID_USERNAME);
 
         List<String> propOrderGeneral = new ArrayList<>();
+        propOrderGeneral.add(propDoUpdateCheck.getName());
         propOrderGeneral.add(propFilterFriendNotify.getName());
         propOrderGeneral.add(propBestFriends.getName());
         cfg.setCategoryPropertyOrder(Configuration.CATEGORY_CLIENT, propOrderGeneral);
 
         if (readFieldsFromConfig) {
+            doUpdateCheck = propDoUpdateCheck.getBoolean(DO_UPDATE_CHECK);
             filterFriendNotifications = propFilterFriendNotify.getBoolean(FILTER_FRIEND_NOTIFICATIONS);
             bestFriends = propBestFriends.getStringList();
         }
 
+        propDoUpdateCheck.set(doUpdateCheck);
         propFilterFriendNotify.set(filterFriendNotifications);
         propBestFriends.set(bestFriends);
 
diff --git a/src/main/java/eu/olli/cowmoonication/config/MooGuiConfig.java b/src/main/java/eu/olli/cowmoonication/config/MooGuiConfig.java
index e7b7862..c8c68c1 100644
--- a/src/main/java/eu/olli/cowmoonication/config/MooGuiConfig.java
+++ b/src/main/java/eu/olli/cowmoonication/config/MooGuiConfig.java
@@ -24,7 +24,6 @@ public class MooGuiConfig extends GuiConfig {
         // optional: add buttons and initialize fields
     }
 
-
     @Override
     public void drawScreen(int mouseX, int mouseY, float partialTicks) {
         super.drawScreen(mouseX, mouseY, partialTicks);
diff --git a/src/main/java/eu/olli/cowmoonication/listener/ChatListener.java b/src/main/java/eu/olli/cowmoonication/listener/ChatListener.java
index 83b3890..54f8025 100644
--- a/src/main/java/eu/olli/cowmoonication/listener/ChatListener.java
+++ b/src/main/java/eu/olli/cowmoonication/listener/ChatListener.java
@@ -36,8 +36,9 @@ public class ChatListener {
     public void onLogInOutMessage(ClientChatReceivedEvent e) {
         if (e.type != 2 && MooConfig.filterFriendNotifications) { // normal chat or system msg
             String text = e.message.getUnformattedText();
-            if (text.endsWith(" joined.") || text.endsWith(" left.") // Hypixel
-                    || text.endsWith(" joined the game") || text.endsWith(" left the game.")) { // Spigot
+            if (text.length() < 42 && // to prevent the party disbanded message from being filtered: "The party was disbanded because all invites have expired and all members have left."
+                    (text.endsWith(" joined.") || text.endsWith(" left.") // Hypixel
+                            || text.endsWith(" joined the game") || text.endsWith(" left the game."))) { // Spigot
                 // TODO maybe check which server thePlayer is on and check for logout pattern accordingly
                 int nameEnd = text.indexOf(" joined");
                 if (nameEnd == -1) {
@@ -76,7 +77,7 @@ public class ChatListener {
                 if (lastTypedChars.equalsIgnoreCase("/r ")) {
                     // replace /r with /msg <last user>
                     main.getUtils().sendAboveChatMessage("Sending message to " + lastPMSender + "!");
-                    Minecraft.getMinecraft().displayGuiScreen(new GuiChat("/msg " + lastPMSender + " "));
+                    Minecraft.getMinecraft().displayGuiScreen(new GuiChat("/w " + lastPMSender + " "));
                 }
             } else if (Keyboard.getEventKey() == Keyboard.KEY_BACK) { // Backspace
                 lastTypedChars = lastTypedChars.substring(0, Math.max(lastTypedChars.length() - 1, 0));
diff --git a/src/main/java/eu/olli/cowmoonication/listener/PlayerListener.java b/src/main/java/eu/olli/cowmoonication/listener/PlayerListener.java
new file mode 100644
index 0000000..b817ed8
--- /dev/null
+++ b/src/main/java/eu/olli/cowmoonication/listener/PlayerListener.java
@@ -0,0 +1,18 @@
+package eu.olli.cowmoonication.listener;
+
+import eu.olli.cowmoonication.Cowmoonication;
+import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+import net.minecraftforge.fml.common.network.FMLNetworkEvent;
+
+public class PlayerListener {
+    private final Cowmoonication main;
+
+    public PlayerListener(Cowmoonication main) {
+        this.main = main;
+    }
+
+    @SubscribeEvent
+    public void onServerJoin(FMLNetworkEvent.ClientConnectedToServerEvent e) {
+        main.getVersionChecker().runUpdateCheck(false);
+    }
+}
diff --git a/src/main/java/eu/olli/cowmoonication/util/Utils.java b/src/main/java/eu/olli/cowmoonication/util/Utils.java
index d10c2ed..60e2ea3 100644
--- a/src/main/java/eu/olli/cowmoonication/util/Utils.java
+++ b/src/main/java/eu/olli/cowmoonication/util/Utils.java
@@ -7,6 +7,7 @@ import net.minecraft.util.IChatComponent;
 import net.minecraftforge.client.event.ClientChatReceivedEvent;
 import net.minecraftforge.common.MinecraftForge;
 
+import java.io.File;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -14,11 +15,13 @@ public class Utils {
     public static final Pattern VALID_USERNAME = Pattern.compile("^[\\w]{1,16}$");
     private static final Pattern USELESS_JSON_CONTENT_PATTERN = Pattern.compile("\"[A-Za-z]+\":false,?");
     private final Cowmoonication main;
+    private final File modsDir;
     private String[] aboveChatMessage;
     private long aboveChatMessageExpiration;
 
-    public Utils(Cowmoonication main) {
+    public Utils(Cowmoonication main, File sourceFile) {
         this.main = main;
+        modsDir = sourceFile.getParentFile();
     }
 
     public void sendMessage(String text) {
@@ -55,4 +58,8 @@ public class Utils {
         Matcher jsonMatcher = USELESS_JSON_CONTENT_PATTERN.matcher(component);
         return jsonMatcher.replaceAll("");
     }
+
+    public File getModsFolder() {
+        return modsDir;
+    }
 }
diff --git a/src/main/java/eu/olli/cowmoonication/util/VersionChecker.java b/src/main/java/eu/olli/cowmoonication/util/VersionChecker.java
new file mode 100644
index 0000000..5c29ae5
--- /dev/null
+++ b/src/main/java/eu/olli/cowmoonication/util/VersionChecker.java
@@ -0,0 +1,140 @@
+package eu.olli.cowmoonication.util;
+
+import eu.olli.cowmoonication.Cowmoonication;
+import eu.olli.cowmoonication.config.MooConfig;
+import net.minecraft.client.Minecraft;
+import net.minecraft.event.ClickEvent;
+import net.minecraft.event.HoverEvent;
+import net.minecraft.util.ChatComponentText;
+import net.minecraft.util.ChatStyle;
+import net.minecraft.util.EnumChatFormatting;
+import net.minecraft.util.IChatComponent;
+import net.minecraftforge.common.ForgeModContainer;
+import net.minecraftforge.common.ForgeVersion;
+import net.minecraftforge.fml.common.Loader;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * @see ForgeVersion
+ */
+public class VersionChecker {
+    /**
+     * Cooldown between to update checks in minutes
+     */
+    private static final int CHECK_COOLDOWN = 15;
+    private static final String CHANGELOG_URL = "https://github.com/cow-mc/Cowmoonication/blob/master/CHANGELOG.md";
+    private final Cowmoonication main;
+    private long lastCheck;
+    private String newVersion;
+    private String downloadUrl;
+
+    public VersionChecker(Cowmoonication main) {
+        this.main = main;
+        this.lastCheck = Minecraft.getSystemTime();
+        newVersion = "[newVersion]";
+        downloadUrl = "https://github.com/cow-mc/Cowmoonication/releases";
+    }
+
+    public boolean runUpdateCheck(boolean isCommandTriggered) {
+        if (isCommandTriggered || (!ForgeModContainer.disableVersionCheck && MooConfig.doUpdateCheck)) {
+            Runnable handleResults = () -> main.getVersionChecker().handleVersionStatus(isCommandTriggered);
+
+            long now = Minecraft.getSystemTime();
+
+            // only re-run if last check was >CHECK_COOLDOWN minutes ago#
+            if (getNextCheck() < 0) { // next allowed check is "in the past", so we're good to go
+                lastCheck = now;
+                ForgeVersion.startVersionCheck();
+
+                // check status after 5 seconds - hopefully that's enough to check
+                new TickDelay(handleResults, 5 * 20);
+                return true;
+            } else {
+                new TickDelay(handleResults, 1);
+            }
+        }
+        return false;
+    }
+
+    public void handleVersionStatus(boolean isCommandTriggered) {
+        ForgeVersion.CheckResult versionResult = ForgeVersion.getResult(Loader.instance().activeModContainer());
+        if (versionResult.target != null) {
+            newVersion = versionResult.target.toString();
+            downloadUrl = "https://github.com/cow-mc/Cowmoonication/releases/download/v" + newVersion + "/" + Cowmoonication.MODNAME + "-" + newVersion + ".jar";
+        }
+
+        IChatComponent statusMsg = null;
+
+        if (isCommandTriggered) {
+            if (versionResult.status == ForgeVersion.Status.UP_TO_DATE) {
+                // up to date
+                statusMsg = new ChatComponentText("\u2714 You're running the latest version (" + Cowmoonication.VERSION + ").").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.GREEN));
+            } else if (versionResult.status == ForgeVersion.Status.PENDING) {
+                // pending
+                statusMsg = new ChatComponentText("\u279C " + "Version check either failed or is still running.").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.YELLOW))
+                        .appendSibling(new ChatComponentText("\n \u278A Check for results again in a few seconds with " + EnumChatFormatting.GOLD + "/moo version").setChatStyle(new ChatStyle()
+                                .setColor(EnumChatFormatting.YELLOW)
+                                .setChatClickEvent(new ClickEvent(ClickEvent.Action.RUN_COMMAND, "/moo version"))
+                                .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.YELLOW + "Run " + EnumChatFormatting.GOLD + "/moo version")))))
+                        .appendSibling(new ChatComponentText("\n \u278B Re-run update check with " + EnumChatFormatting.GOLD + "/moo update").setChatStyle(new ChatStyle()
+                                .setColor(EnumChatFormatting.YELLOW)
+                                .setChatClickEvent(new ClickEvent(ClickEvent.Action.RUN_COMMAND, "/moo update"))
+                                .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.YELLOW + "Run " + EnumChatFormatting.GOLD + "/moo update")))));
+            } else if (versionResult.status == ForgeVersion.Status.FAILED) {
+                // check failed
+                statusMsg = new ChatComponentText("\u2716 Version check failed for an unknown reason. Check again in a few seconds with ").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.RED))
+                        .appendSibling(new ChatComponentText("/moo update").setChatStyle(new ChatStyle()
+                                .setColor(EnumChatFormatting.GOLD)
+                                .setChatClickEvent(new ClickEvent(ClickEvent.Action.RUN_COMMAND, "/moo update"))
+                                .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.YELLOW + "Run " + EnumChatFormatting.GOLD + "/moo update")))));
+            }
+        }
+        if (versionResult.status == ForgeVersion.Status.OUTDATED || versionResult.status == ForgeVersion.Status.BETA_OUTDATED) {
+            // outdated
+            IChatComponent spacer = new ChatComponentText(" ").setChatStyle(new ChatStyle().setParentStyle(null));
+
+            IChatComponent text = new ChatComponentText("\u279C New version of " + EnumChatFormatting.DARK_GREEN + "Cowmoonication " + EnumChatFormatting.GREEN + "available (" + Cowmoonication.VERSION + " \u27A1 " + newVersion + ")\n").setChatStyle(new ChatStyle().setColor(EnumChatFormatting.GREEN));
+
+            IChatComponent download = new ChatComponentText("[Download]").setChatStyle(new ChatStyle()
+                    .setColor(EnumChatFormatting.DARK_GREEN).setBold(true)
+                    .setChatClickEvent(new ClickEvent(ClickEvent.Action.OPEN_URL, downloadUrl))
+                    .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.YELLOW + "Download the latest version of Cowmoonication"))));
+
+            IChatComponent changelog = new ChatComponentText("[Changelog]").setChatStyle(new ChatStyle()
+                    .setColor(EnumChatFormatting.DARK_AQUA).setBold(true)
+                    .setChatClickEvent(new ClickEvent(ClickEvent.Action.OPEN_URL, CHANGELOG_URL))
+                    .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.YELLOW + "View changelog"))));
+
+            IChatComponent updateInstructions = new ChatComponentText("[Update instructions]").setChatStyle(new ChatStyle()
+                    .setColor(EnumChatFormatting.GOLD).setBold(true)
+                    .setChatClickEvent(new ClickEvent(ClickEvent.Action.RUN_COMMAND, "/moo updateHelp"))
+                    .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.YELLOW + "Run " + EnumChatFormatting.GOLD + "/moo updateHelp"))));
+
+            IChatComponent openModsFolder = new ChatComponentText("\n[Open Mods folder]").setChatStyle(new ChatStyle()
+                    .setColor(EnumChatFormatting.GREEN).setBold(true)
+                    .setChatClickEvent(new ClickEvent(ClickEvent.Action.RUN_COMMAND, "/moo folder"))
+                    .setChatHoverEvent(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new ChatComponentText(EnumChatFormatting.YELLOW + "Open mods folder with command " + EnumChatFormatting.GOLD + "/moo folder\n\u279C Click to open mods folder"))));
+
+            statusMsg = text.appendSibling(download).appendSibling(spacer).appendSibling(changelog).appendSibling(spacer).appendSibling(updateInstructions).appendSibling(spacer).appendSibling(openModsFolder);
+        }
+
+        if (statusMsg != null) {
+            main.getUtils().sendMessage(statusMsg);
+        }
+    }
+
+    public long getNextCheck() {
+        long cooldown = TimeUnit.MINUTES.toMillis(CHECK_COOLDOWN);
+        long systemTime = Minecraft.getSystemTime();
+        return cooldown - (systemTime - lastCheck);
+    }
+
+    public String getNewVersion() {
+        return newVersion;
+    }
+
+    public String getDownloadUrl() {
+        return downloadUrl;
+    }
+}
diff --git a/src/main/resources/assets/cowmoonication/lang/en_us.lang b/src/main/resources/assets/cowmoonication/lang/en_us.lang
deleted file mode 100644
index b7e77d4..0000000
--- a/src/main/resources/assets/cowmoonication/lang/en_us.lang
+++ /dev/null
@@ -1 +0,0 @@
-cowmoonication:command.moo.usage=/moo
diff --git a/src/main/resources/mcmod.info b/src/main/resources/mcmod.info
index e6c8f6e..581572b 100644
--- a/src/main/resources/mcmod.info
+++ b/src/main/resources/mcmod.info
@@ -4,8 +4,8 @@
   "description": "Adding various things related to communication.",
   "version": "${version}",
   "mcversion": "${mcversion}",
-  "url": "https://github.com/cow-mc/Cowmoonication",
-  "updateUrl": "",
+  "url": "https://github.com/cow-mc/Cowmoonication/",
+  "updateUrl": "https://raw.githubusercontent.com/cow-mc/Cowmoonication/master/update.json",
   "authorList": ["Cow"],
   "logoFile": "",
   "screenshots": [],
diff --git a/update.json b/update.json
new file mode 100644
index 0000000..44a3ab2
--- /dev/null
+++ b/update.json
@@ -0,0 +1,10 @@
+{
+  "homepage": "https://github.com/cow-mc/Cowmoonication/",
+  "1.8.9": {
+    "1.8.9-0.2.0": "https://github.com/cow-mc/Cowmoonication/blob/master/CHANGELOG.md"
+  },
+  "promos": {
+    "1.8.9-latest": "1.8.9-0.2.0",
+    "1.8.9-recommended": "1.8.9-0.2.0"
+  }
+}