Add optional web jukebox: vote for arena music tracks via a small HTTP API

src/main/java/us/tss3/blockparty/BlockPartyPlugin.java

@@ -10,6 +10,9 @@ import us.tss3.blockparty.arena.ArenaManager;
 import us.tss3.blockparty.command.BlockPartyCommand;
 import us.tss3.blockparty.config.ConfigManager;
 import us.tss3.blockparty.config.MessagesManager;
+import us.tss3.blockparty.jukebox.JukeboxServer;
+import us.tss3.blockparty.jukebox.VoteCodeManager;
+import us.tss3.blockparty.jukebox.VoteManager;
 import us.tss3.blockparty.listener.GameplayRestrictionListener;
 import us.tss3.blockparty.listener.PlayerConnectionListener;
 import us.tss3.blockparty.persistence.StatsManager;
@@ -29,6 +32,9 @@ public class BlockPartyPlugin extends JavaPlugin implements Listener {
     private RewardManager rewardManager;
     private StatsManager statsManager;
     private SoundUtil soundUtil;
+    private VoteManager voteManager;
+    private VoteCodeManager voteCodeManager;
+    private JukeboxServer jukeboxServer;
 
     @Override
     public void onEnable() {
@@ -45,9 +51,15 @@ public class BlockPartyPlugin extends JavaPlugin implements Listener {
         this.statsManager = new StatsManager(this, configManager.getStorageSettings());
         statsManager.init();
 
+        this.voteManager = new VoteManager();
+        this.voteCodeManager = new VoteCodeManager();
+
         this.arenaManager = new ArenaManager(this);
         arenaManager.loadAll();
 
+        this.jukeboxServer = new JukeboxServer(this, voteManager, voteCodeManager);
+        jukeboxServer.start();
+
         this.scoreboardManager = new ScoreboardManager(this);
         scoreboardManager.start();
 
@@ -69,6 +81,9 @@ public class BlockPartyPlugin extends JavaPlugin implements Listener {
 
     @Override
     public void onDisable() {
+        if (jukeboxServer != null) {
+            jukeboxServer.stop();
+        }
         if (arenaManager != null) {
             arenaManager.shutdownAll();
         }
@@ -144,4 +159,12 @@ public class BlockPartyPlugin extends JavaPlugin implements Listener {
     public SoundUtil getSoundUtil() {
         return soundUtil;
     }
+
+    public VoteManager getVoteManager() {
+        return voteManager;
+    }
+
+    public VoteCodeManager getVoteCodeManager() {
+        return voteCodeManager;
+    }
 }

src/main/java/us/tss3/blockparty/arena/Arena.java

@@ -53,6 +53,7 @@ public class Arena {
      *  the match doesn't end just because "one player remains" — it keeps running rounds until
      *  that player is actually eliminated or leaves. */
     private boolean soloMode;
+    private String currentMusicTrack;
     private Material currentTarget;
     private Material previousTarget;
     private int currentRoundTime;
@@ -118,6 +119,7 @@ public class Arena {
         cancelAllTasks();
         billboardManager.despawn();
         pauseMusic();
+        plugin.getVoteManager().clear(config.getName());
         // Force reset players out regardless of state
         List<UUID> all = new ArrayList<>();
         all.addAll(players);
@@ -385,14 +387,23 @@ public class Arena {
         }
     }
 
-    /** Starts the configured background music (if enabled) for every current player/spectator,
-     *  from the beginning of the track — Bukkit has no true "resume from position" API, so
-     *  pause/resume below is implemented as stop/replay-from-start rather than a real seek. */
+    /** The track currently playing (or last played) for this arena's match, or null if music
+     *  is disabled/hasn't started yet. Exposed for the optional jukebox web API. */
+    public String getCurrentMusicTrack() {
+        return currentMusicTrack;
+    }
+
+    /** Starts the configured (or currently vote-winning, if the jukebox has votes) background
+     *  music for every current player/spectator, from the beginning of the track — Bukkit has
+     *  no true "resume from position" API, so pause/resume below is implemented as
+     *  stop/replay-from-start rather than a real seek. Re-checking the vote on every resume
+     *  means the crowd can democratically change the track between rounds mid-match. */
     private void startMusic() {
         if (!plugin.getConfigManager().isMusicEnabled()) {
             return;
         }
-        String track = plugin.getConfigManager().getMusicTrack();
+        String voted = plugin.getVoteManager().winningTrack(config.getName());
+        String track = voted != null ? voted : plugin.getConfigManager().getMusicTrack();
         float volume = plugin.getConfigManager().getMusicVolume();
         for (UUID uuid : allParticipants()) {
             Player p = plugin.getServer().getPlayer(uuid);
@@ -400,17 +411,17 @@ public class Arena {
                 plugin.getSoundUtil().playMusic(p, track, volume);
             }
         }
+        currentMusicTrack = track;
     }
 
     private void pauseMusic() {
-        if (!plugin.getConfigManager().isMusicEnabled()) {
+        if (!plugin.getConfigManager().isMusicEnabled() || currentMusicTrack == null) {
             return;
         }
-        String track = plugin.getConfigManager().getMusicTrack();
         for (UUID uuid : allParticipants()) {
             Player p = plugin.getServer().getPlayer(uuid);
             if (p != null) {
-                plugin.getSoundUtil().stopMusic(p, track);
+                plugin.getSoundUtil().stopMusic(p, currentMusicTrack);
             }
         }
     }
@@ -572,6 +583,8 @@ public class Arena {
         floorManager.cancelActiveTask();
         cancelAllTasks();
         round = 0;
+        currentMusicTrack = null;
+        plugin.getVoteManager().clear(config.getName());
         billboardManager.clear();
         stateMachine.transition(ArenaPhase.WAITING);
     }

src/main/java/us/tss3/blockparty/command/BlockPartyCommand.java

@@ -60,6 +60,7 @@ public class BlockPartyCommand implements CommandExecutor, TabCompleter {
             case "leave" -> leave(sender);
             case "arenas" -> list(sender);
             case "stats" -> stats(sender, args);
+            case "musicvote" -> musicVote(sender);
             default -> sendHelp(sender);
         }
         return true;
@@ -72,6 +73,7 @@ public class BlockPartyCommand implements CommandExecutor, TabCompleter {
                 "/blockparty leave",
                 "/blockparty arenas",
                 "/blockparty stats [player]",
+                "/blockparty musicvote",
                 "/blockparty create <arena>",
                 "/blockparty delete <arena>",
                 "/blockparty enable <arena>",
@@ -442,6 +444,19 @@ public class BlockPartyCommand implements CommandExecutor, TabCompleter {
         sender.sendMessage(plugin.getMessages().get("player.left"));
     }
 
+    private void musicVote(CommandSender sender) {
+        if (!requirePlayer(sender)) return;
+        if (!plugin.getConfigManager().isJukeboxEnabled()) {
+            sender.sendMessage(plugin.getMessages().get("errors.jukebox-disabled"));
+            return;
+        }
+        Player player = (Player) sender;
+        String code = plugin.getVoteCodeManager().issueCode(player.getUniqueId(),
+                plugin.getConfigManager().getJukeboxVoteCodeMinutes());
+        sender.sendMessage(plugin.getMessages().get("player.musicvote-code",
+                Map.of("code", code, "minutes", String.valueOf(plugin.getConfigManager().getJukeboxVoteCodeMinutes()))));
+    }
+
     private void stats(CommandSender sender, String[] args) {
         UUID target;
         String targetName;
@@ -485,7 +500,7 @@ public class BlockPartyCommand implements CommandExecutor, TabCompleter {
     @Override
     public List<String> onTabComplete(CommandSender sender, Command command, String alias, String[] args) {
         if (args.length == 1) {
-            return List.of("help", "join", "leave", "arenas", "stats", "create", "delete", "enable", "disable",
+            return List.of("help", "join", "leave", "arenas", "stats", "musicvote", "create", "delete", "enable", "disable",
                             "setlobby", "setspawn", "setspectator", "setbillboard", "delbillboard", "billboards", "pos1", "pos2", "setfloor", "generate", "info", "list", "reload")
                     .stream().filter(s -> s.startsWith(args[0].toLowerCase())).collect(Collectors.toList());
         }

src/main/java/us/tss3/blockparty/config/ConfigManager.java

@@ -109,6 +109,30 @@ public class ConfigManager {
         return (float) config.getDouble("music.volume", 1.0);
     }
 
+    public boolean isJukeboxEnabled() {
+        return config.getBoolean("jukebox.enabled", false);
+    }
+
+    public String getJukeboxBindAddress() {
+        return config.getString("jukebox.bind-address", "127.0.0.1");
+    }
+
+    public int getJukeboxPort() {
+        return config.getInt("jukebox.port", 8642);
+    }
+
+    public String getJukeboxAllowedOrigin() {
+        return config.getString("jukebox.allowed-origin", "*");
+    }
+
+    public int getJukeboxVoteCodeMinutes() {
+        return config.getInt("jukebox.vote-code-minutes", 10);
+    }
+
+    public List<String> getJukeboxTracks() {
+        return config.getStringList("jukebox.tracks");
+    }
+
     public boolean isPlaceholderApiEnabled() {
         return config.getBoolean("integrations.placeholderapi", true);
     }

src/main/java/us/tss3/blockparty/jukebox/JukeboxServer.java

@@ -0,0 +1,216 @@
+package us.tss3.blockparty.jukebox;
+
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpServer;
+import org.bukkit.Sound;
+import us.tss3.blockparty.BlockPartyPlugin;
+import us.tss3.blockparty.arena.Arena;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.InetSocketAddress;
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.Executors;
+import java.util.logging.Level;
+
+/**
+ * A minimal, dependency-free HTTP API (built on the JDK's own {@code com.sun.net.httpserver})
+ * that lets an external web page read an arena's available/current music track and cast
+ * votes for the next one. Off by default (see {@code jukebox.enabled} in config.yml) since
+ * it opens a real network port; see the README's "Jukebox" section for the security model
+ * and why this needs to sit behind an HTTPS reverse proxy to be reachable from a page served
+ * over HTTPS.
+ */
+public class JukeboxServer {
+
+    private final BlockPartyPlugin plugin;
+    private final VoteManager voteManager;
+    private final VoteCodeManager voteCodeManager;
+    private HttpServer server;
+
+    public JukeboxServer(BlockPartyPlugin plugin, VoteManager voteManager, VoteCodeManager voteCodeManager) {
+        this.plugin = plugin;
+        this.voteManager = voteManager;
+        this.voteCodeManager = voteCodeManager;
+    }
+
+    public void start() {
+        if (!plugin.getConfigManager().isJukeboxEnabled()) {
+            return;
+        }
+        String bind = plugin.getConfigManager().getJukeboxBindAddress();
+        int port = plugin.getConfigManager().getJukeboxPort();
+        try {
+            server = HttpServer.create(new InetSocketAddress(bind, port), 0);
+            server.createContext("/api/health", this::handleHealth);
+            server.createContext("/api/tracks", this::handleTracks);
+            server.createContext("/api/arenas", this::handleArenas);
+            server.createContext("/api/vote", this::handleVote);
+            server.setExecutor(Executors.newFixedThreadPool(2));
+            server.start();
+            plugin.getLogger().info("Jukebox HTTP API listening on " + bind + ":" + port
+                    + " - remember this needs an HTTPS reverse proxy in front of it to be reachable from a browser page.");
+        } catch (IOException ex) {
+            plugin.getLogger().log(Level.SEVERE, "Failed to start jukebox HTTP server on "
+                    + bind + ":" + port, ex);
+        }
+    }
+
+    public void stop() {
+        if (server != null) {
+            server.stop(0);
+            server = null;
+        }
+    }
+
+    // ---------- handlers ----------
+
+    private void handleHealth(HttpExchange exchange) throws IOException {
+        if (preflight(exchange)) return;
+        writeJson(exchange, 200, "{\"ok\":true}");
+    }
+
+    private void handleTracks(HttpExchange exchange) throws IOException {
+        if (preflight(exchange)) return;
+        List<String> configured = plugin.getConfigManager().getJukeboxTracks();
+        StringBuilder json = new StringBuilder("[");
+        boolean first = true;
+        for (String entry : configured) {
+            String[] parts = entry.split("\\|", 2);
+            String id = parts[0].trim();
+            String label = parts.length > 1 ? parts[1].trim() : id;
+            if (!isValidSound(id)) {
+                continue;
+            }
+            if (!first) json.append(',');
+            first = false;
+            json.append("{\"id\":\"").append(jsonEscape(id)).append("\",\"label\":\"").append(jsonEscape(label)).append("\"}");
+        }
+        json.append(']');
+        writeJson(exchange, 200, json.toString());
+    }
+
+    private void handleArenas(HttpExchange exchange) throws IOException {
+        if (preflight(exchange)) return;
+        StringBuilder json = new StringBuilder("[");
+        boolean first = true;
+        for (Arena arena : plugin.getArenaManager().all()) {
+            String name = arena.getConfig().getName();
+            if (!first) json.append(',');
+            first = false;
+            Map<String, Integer> tally = voteManager.tally(name);
+            StringBuilder votesJson = new StringBuilder("{");
+            boolean firstVote = true;
+            for (Map.Entry<String, Integer> e : tally.entrySet()) {
+                if (!firstVote) votesJson.append(',');
+                firstVote = false;
+                votesJson.append('"').append(jsonEscape(e.getKey())).append("\":").append(e.getValue());
+            }
+            votesJson.append('}');
+            String currentTrack = arena.getCurrentMusicTrack();
+            json.append("{\"name\":\"").append(jsonEscape(name))
+                    .append("\",\"state\":\"").append(arena.getPhase())
+                    .append("\",\"currentTrack\":").append(currentTrack == null ? "null" : "\"" + jsonEscape(currentTrack) + "\"")
+                    .append(",\"votes\":").append(votesJson)
+                    .append('}');
+        }
+        json.append(']');
+        writeJson(exchange, 200, json.toString());
+    }
+
+    private void handleVote(HttpExchange exchange) throws IOException {
+        if (preflight(exchange)) return;
+        if (!"POST".equalsIgnoreCase(exchange.getRequestMethod())) {
+            writeJson(exchange, 405, "{\"error\":\"POST required\"}");
+            return;
+        }
+        Map<String, String> params = queryParams(exchange.getRequestURI());
+        String arena = params.get("arena");
+        String code = params.get("code");
+        String track = params.get("track");
+        if (arena == null || code == null || track == null) {
+            writeJson(exchange, 400, "{\"error\":\"arena, code and track are all required\"}");
+            return;
+        }
+        if (plugin.getArenaManager().get(arena).isEmpty()) {
+            writeJson(exchange, 404, "{\"error\":\"unknown arena\"}");
+            return;
+        }
+        if (!isValidSound(track)) {
+            writeJson(exchange, 400, "{\"error\":\"unknown track\"}");
+            return;
+        }
+        UUID playerId = voteCodeManager.resolve(code);
+        if (playerId == null) {
+            writeJson(exchange, 401, "{\"error\":\"invalid or expired code - run /blockparty musicvote in-game for a new one\"}");
+            return;
+        }
+        voteManager.castVote(arena, playerId, track);
+        StringBuilder json = new StringBuilder("{\"ok\":true,\"votes\":{");
+        boolean first = true;
+        for (Map.Entry<String, Integer> e : voteManager.tally(arena).entrySet()) {
+            if (!first) json.append(',');
+            first = false;
+            json.append('"').append(jsonEscape(e.getKey())).append("\":").append(e.getValue());
+        }
+        json.append("}}");
+        writeJson(exchange, 200, json.toString());
+    }
+
+    // ---------- helpers ----------
+
+    private boolean isValidSound(String name) {
+        try {
+            Sound.valueOf(name);
+            return true;
+        } catch (IllegalArgumentException ex) {
+            return false;
+        }
+    }
+
+    private boolean preflight(HttpExchange exchange) throws IOException {
+        exchange.getResponseHeaders().add("Access-Control-Allow-Origin", plugin.getConfigManager().getJukeboxAllowedOrigin());
+        exchange.getResponseHeaders().add("Access-Control-Allow-Methods", "GET, POST, OPTIONS");
+        exchange.getResponseHeaders().add("Access-Control-Allow-Headers", "Content-Type");
+        if ("OPTIONS".equalsIgnoreCase(exchange.getRequestMethod())) {
+            exchange.sendResponseHeaders(204, -1);
+            return true;
+        }
+        return false;
+    }
+
+    private void writeJson(HttpExchange exchange, int status, String json) throws IOException {
+        byte[] body = json.getBytes(StandardCharsets.UTF_8);
+        exchange.getResponseHeaders().add("Content-Type", "application/json; charset=utf-8");
+        exchange.sendResponseHeaders(status, body.length);
+        try (OutputStream os = exchange.getResponseBody()) {
+            os.write(body);
+        }
+    }
+
+    private Map<String, String> queryParams(URI uri) {
+        Map<String, String> params = new java.util.HashMap<>();
+        String query = uri.getRawQuery();
+        if (query == null || query.isBlank()) {
+            return params;
+        }
+        for (String pair : query.split("&")) {
+            int eq = pair.indexOf('=');
+            if (eq < 0) {
+                continue;
+            }
+            String key = java.net.URLDecoder.decode(pair.substring(0, eq), StandardCharsets.UTF_8);
+            String value = java.net.URLDecoder.decode(pair.substring(eq + 1), StandardCharsets.UTF_8);
+            params.put(key, value);
+        }
+        return params;
+    }
+
+    private String jsonEscape(String s) {
+        return s.replace("\\", "\\\\").replace("\"", "\\\"");
+    }
+}

src/main/java/us/tss3/blockparty/jukebox/VoteCodeManager.java

@@ -0,0 +1,48 @@
+package us.tss3.blockparty.jukebox;
+
+import java.security.SecureRandom;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Issues short-lived, easy-to-type numeric codes that link a web voting session back to a
+ * specific logged-in player, without requiring any real account/password auth on the web
+ * page. A code is only ever handed out via the in-game {@code /blockparty musicvote}
+ * command, so possessing one proves you're the player who ran it (or someone they showed it
+ * to) for as long as it's valid.
+ */
+public class VoteCodeManager {
+
+    private record CodeEntry(UUID playerId, long expiresAtMs) {
+    }
+
+    private final Map<String, CodeEntry> codes = new ConcurrentHashMap<>();
+    private final SecureRandom random = new SecureRandom();
+
+    public String issueCode(UUID playerId, int ttlMinutes) {
+        codes.values().removeIf(e -> e.playerId().equals(playerId));
+        String code;
+        do {
+            code = String.valueOf(100000 + random.nextInt(900000));
+        } while (codes.containsKey(code));
+        codes.put(code, new CodeEntry(playerId, System.currentTimeMillis() + ttlMinutes * 60_000L));
+        return code;
+    }
+
+    /** Resolves a code to the player who issued it, or null if unknown/expired. */
+    public UUID resolve(String code) {
+        if (code == null) {
+            return null;
+        }
+        CodeEntry entry = codes.get(code);
+        if (entry == null) {
+            return null;
+        }
+        if (System.currentTimeMillis() > entry.expiresAtMs()) {
+            codes.remove(code);
+            return null;
+        }
+        return entry.playerId();
+    }
+}

src/main/java/us/tss3/blockparty/jukebox/VoteManager.java

@@ -0,0 +1,43 @@
+package us.tss3.blockparty.jukebox;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Tracks per-arena, per-player music track votes in memory (one vote per player per arena,
+ * re-voting replaces their previous pick). Never persisted - votes are a live, ephemeral
+ * "what should play next" signal, reset whenever an arena returns to WAITING.
+ */
+public class VoteManager {
+
+    /** arena name -> (player uuid -> track id) */
+    private final Map<String, Map<UUID, String>> votes = new ConcurrentHashMap<>();
+
+    public void castVote(String arena, UUID playerId, String track) {
+        votes.computeIfAbsent(arena, k -> new ConcurrentHashMap<>()).put(playerId, track);
+    }
+
+    /** track id -> vote count, insertion order not meaningful. */
+    public Map<String, Integer> tally(String arena) {
+        Map<UUID, String> arenaVotes = votes.getOrDefault(arena, Map.of());
+        Map<String, Integer> counts = new LinkedHashMap<>();
+        for (String track : arenaVotes.values()) {
+            counts.merge(track, 1, Integer::sum);
+        }
+        return counts;
+    }
+
+    /** The current leading track for an arena, or null if nobody has voted. */
+    public String winningTrack(String arena) {
+        return tally(arena).entrySet().stream()
+                .max(Map.Entry.comparingByValue())
+                .map(Map.Entry::getKey)
+                .orElse(null);
+    }
+
+    public void clear(String arena) {
+        votes.remove(arena);
+    }
+}