Add CurseForge Update checker

src/main/java/at/helpch/placeholderapi/PlaceholderAPIPlugin.java

@@ -4,6 +4,7 @@ import at.helpch.placeholderapi.commands.PlaceholderCommandRouter;
 import at.helpch.placeholderapi.configuration.ConfigManager;
 import at.helpch.placeholderapi.expansion.manager.CloudExpansionManager;
 import at.helpch.placeholderapi.expansion.manager.LocalExpansionManager;
+import at.helpch.placeholderapi.updatechecker.UpdateChecker;
 import com.hypixel.hytale.event.EventPriority;
 import com.hypixel.hytale.server.core.command.system.CommandSender;
 import com.hypixel.hytale.server.core.console.ConsoleSender;
@@ -34,6 +35,7 @@ public class PlaceholderAPIPlugin extends JavaPlugin {
     @Override
     protected void setup() {
         configManager.setup();
+
         getEventRegistry().register(PlayerDisconnectEvent.class, localExpansionManager::onQuit);
         getEventRegistry().register(EventPriority.LAST, BootEvent.class, this::onServerLoad);
 
@@ -46,7 +48,9 @@ public class PlaceholderAPIPlugin extends JavaPlugin {
     protected void start() {
         getCommandRegistry().registerCommand(new PlaceholderCommandRouter(this));
 
-//        localExpansionManager().load(ConsoleSender.INSTANCE);
+        if (configManager.config().checkUpdates()) {
+            new UpdateChecker(this).fetch();
+        }
 
         super.start();
     }

src/main/java/at/helpch/placeholderapi/configuration/PlaceholderAPIConfig.java

@@ -26,6 +26,7 @@ import java.util.HashMap;
 import java.util.Map;
 
 public final class PlaceholderAPIConfig {
+    private boolean checkUpdates;
     private boolean cloudEnabled;
     private boolean debugMode;
     private ExpansionSort cloudSorting;
@@ -33,8 +34,9 @@ public final class PlaceholderAPIConfig {
     private String dateFormat;
     private Map<String, Object> expansions;
 
-    public PlaceholderAPIConfig(boolean cloudEnabled, boolean debugMode, @NotNull ExpansionSort cloudSorting,
+    public PlaceholderAPIConfig(boolean checkUpdates, boolean cloudEnabled, boolean debugMode, @NotNull ExpansionSort cloudSorting,
                                 @NotNull BooleanValue booleanValue, @NotNull String dateFormat) {
+        this.checkUpdates = checkUpdates;
         this.cloudEnabled = cloudEnabled;
         this.debugMode = debugMode;
         this.cloudSorting = cloudSorting;
@@ -43,8 +45,9 @@ public final class PlaceholderAPIConfig {
         this.expansions = new HashMap<>();
     }
 
-    public PlaceholderAPIConfig(boolean cloudEnabled, boolean debugMode, @NotNull ExpansionSort cloudSorting,
+    public PlaceholderAPIConfig(boolean checkUpdates, boolean cloudEnabled, boolean debugMode, @NotNull ExpansionSort cloudSorting,
                                 @NotNull BooleanValue booleanValue, @NotNull String dateFormat, Map<String, Object> expansions) {
+        this.checkUpdates = checkUpdates;
         this.cloudEnabled = cloudEnabled;
         this.debugMode = debugMode;
         this.cloudSorting = cloudSorting;
@@ -53,6 +56,10 @@ public final class PlaceholderAPIConfig {
         this.expansions = expansions;
     }
 
+    public boolean checkUpdates() {
+        return checkUpdates;
+    }
+
     public boolean cloudEnabled() {
         return cloudEnabled;
     }

src/main/java/at/helpch/placeholderapi/updatechecker/UpdateChecker.java

@@ -0,0 +1,116 @@
+package at.helpch.placeholderapi.updatechecker;
+
+import at.helpch.placeholderapi.PlaceholderAPIPlugin;
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.hypixel.hytale.server.core.HytaleServer;
+import com.hypixel.hytale.server.core.Message;
+import com.hypixel.hytale.server.core.event.events.player.PlayerReadyEvent;
+
+import javax.net.ssl.HttpsURLConnection;
+import java.awt.*;
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.net.URI;
+import java.net.URL;
+import java.util.Arrays;
+import java.util.concurrent.CompletableFuture;
+
+public class UpdateChecker {
+    private static final String CURSEFORGE_URL = "https://api.cfwidget.com/hytale/mods/placeholder-api";
+
+    private static final int RESOURCE_ID = 6245;
+    private final PlaceholderAPIPlugin plugin;
+    private final String pluginVersion;
+    private String curseforgeVersion;
+    private boolean updateAvailable;
+
+    public UpdateChecker(PlaceholderAPIPlugin plugin) {
+        this.plugin = plugin;
+        pluginVersion = plugin.getManifest().getVersion().toString();
+    }
+
+    public boolean hasUpdateAvailable() {
+        return updateAvailable;
+    }
+
+    public String getCurseforgeVersion() {
+        return curseforgeVersion;
+    }
+
+    public void fetch() {
+        plugin.getTaskRegistry().registerTask(CompletableFuture.runAsync(() -> {
+            try {
+                HttpsURLConnection con = (HttpsURLConnection) new URI(CURSEFORGE_URL).toURL().openConnection();
+                con.setRequestMethod("GET");
+                final JsonElement json = new Gson().fromJson(new BufferedReader(new InputStreamReader(con.getInputStream())), JsonElement.class);
+                final String jar = json.getAsJsonObject().get("download").getAsJsonObject().get("name").getAsString();
+                final String[] parts = jar.split("-");
+
+                if (parts.length >= 2) {
+                    curseforgeVersion = parts[1];
+                } else {
+                    return;
+                }
+            } catch (Exception ex) {
+                plugin.getLogger().atInfo().log("Failed to check for updates on curseforge.");
+                return;
+            }
+
+            if (curseforgeVersion == null || curseforgeVersion.isEmpty()) {
+                return;
+            }
+
+            updateAvailable = curseforgeIsNewer();
+
+            if (!updateAvailable) {
+                return;
+            }
+
+            plugin.getLogger().atInfo().log("An update for PlaceholderAPI (v" + getCurseforgeVersion() + ") is available at:");
+            plugin.getLogger().atInfo().log("https://placeholderapi.com/download");
+            plugin.getEventRegistry().registerGlobal(PlayerReadyEvent.class, this::onJoin);
+        }));
+    }
+
+    private boolean curseforgeIsNewer() {
+        if (curseforgeVersion == null || curseforgeVersion.isEmpty()) {
+            return false;
+        }
+
+        int[] plV = toReadable(pluginVersion);
+        int[] spV = toReadable(curseforgeVersion);
+
+        if (plV[0] < spV[0]) {
+            return true;
+        } else if ((plV[1] < spV[1])) {
+            return true;
+        } else {
+            return plV[2] < spV[2];
+        }
+    }
+
+    private int[] toReadable(String version) {
+        if (version.contains("-DEV")) {
+            version = version.split("-DEV")[0];
+        }
+
+        return Arrays.stream(version.split("\\.")).mapToInt(Integer::parseInt).toArray();
+    }
+
+    public void onJoin(PlayerReadyEvent e) {
+        if (e.getPlayer().hasPermission("placeholderapi.updatenotify")) {
+            final Message message = Message.raw("An update for ").color(Color.CYAN)
+                    .insert(Message.raw("Placeholder").color(Color.WHITE))
+                    .insert(Message.raw("API").color(Color.LIGHT_GRAY))
+                    .insert(Message.raw(" (").color(Color.YELLOW))
+                    .insert(Message.raw("Placeholder").color(Color.WHITE))
+                    .insert(Message.raw("API").color(Color.LIGHT_GRAY))
+                    .insert(Message.raw(" v" + getCurseforgeVersion()).color(Color.WHITE))
+                    .insert(Message.raw(")").color(Color.YELLOW))
+                    .insert(Message.raw("\nis available at ").color(Color.CYAN))
+                    .insert(Message.raw("https://placeholderapi.com/download").color(Color.YELLOW).link("https://www.curseforge.com/hytale/mods/placeholder-api").bold(true).italic(true));
+            e.getPlayer().sendMessage(message);
+        }
+    }
+}