feat: Implement initial real-time multiplayer game server and client-side UI for core game functionality.

src/server-deno/application/GameService.ts

@@ -15,7 +15,7 @@ export class GameService {
     private readonly trackService: TrackService,
     private readonly audioStreaming: AudioStreamingService,
     private readonly answerCheck: AnswerCheckService,
-  ) {}
+  ) { }
 
   /**
    * Start a game in a room
@@ -35,7 +35,7 @@ export class GameService {
 
     // Load shuffled deck
     const tracks = await this.trackService.loadShuffledDeck(room.state.playlist);
-    
+
     if (tracks.length === 0) {
       throw new ValidationError('No tracks available in selected playlist');
     }
@@ -56,7 +56,7 @@ export class GameService {
    */
   async drawNextTrack(room: RoomModel): Promise<Track | null> {
     const track = room.drawTrack();
-    
+
     if (!track) {
       // No more tracks - end game
       room.state.endGame();
@@ -162,7 +162,7 @@ export class GameService {
    */
   placeCard(room: RoomModel, playerId: ID, year: number, position: number): boolean {
     const player = room.getPlayer(playerId);
-    
+
     if (!player) {
       throw new ValidationError('Player not found');
     }
@@ -267,7 +267,7 @@ export class GameService {
       room.state.tokens[playerId] = (room.state.tokens[playerId] || 0) + 1;
       room.state.titleArtistAwardedThisRound[playerId] = true;
       awarded = true;
-      
+
       logger.info(
         `Player ${playerId} correctly guessed title AND artist. Awarded 1 token for title+artist.`
       );
@@ -288,12 +288,16 @@ export class GameService {
    * - Correct placement: Adds track to timeline, increasing score (timeline.length)
    * - Incorrect placement: Track is discarded, no score increase
    * - NO tokens awarded here - tokens are only from title+artist guesses
+   * 
+   * TOKEN PURCHASE:
+   * - If useTokens is true and player has >= 3 tokens, deduct 3 tokens and force correct placement
    */
   async placeInTimeline(
     room: RoomModel,
     playerId: ID,
-    slot: number
-  ): Promise<{ correct: boolean }> {
+    slot: number,
+    useTokens: boolean = false
+  ): Promise<{ correct: boolean; tokensUsed: boolean }> {
     const track = room.state.currentTrack;
     if (!track) {
       throw new Error('No current track');
@@ -310,21 +314,38 @@ export class GameService {
     logger.info(`Timeline before placement: ${JSON.stringify(timeline.map(t => ({ year: t.year, title: t.title })))}`);
     logger.info(`Placing track: ${track.title} (${track.year}) at slot ${slot} of ${n}`);
 
+    // Check if player wants to use tokens to guarantee correct placement
+    let tokensUsed = false;
+    const TOKEN_COST = 3;
+    const playerTokens = room.state.tokens[playerId] || 0;
+
+    if (useTokens && playerTokens >= TOKEN_COST) {
+      // Deduct tokens and force correct placement
+      room.state.tokens[playerId] = playerTokens - TOKEN_COST;
+      tokensUsed = true;
+      logger.info(
+        `Player ${playerId} used ${TOKEN_COST} tokens to guarantee correct placement. Remaining tokens: ${room.state.tokens[playerId]}`
+      );
+    }
+
     // Check if placement is correct
     let correct = false;
-    if (track.year != null) {
+    if (tokensUsed) {
+      // Tokens used - placement is always correct
+      correct = true;
+    } else if (track.year != null) {
       if (n === 0) {
         correct = true; // First card is always correct
       } else {
         const leftYear = slot > 0 ? timeline[slot - 1]?.year : null;
         const rightYear = slot < n ? timeline[slot]?.year : null;
-        
+
         // Allow equal years (>=, <=) so cards from the same year can be placed anywhere relative to each other
         const leftOk = leftYear == null || track.year >= leftYear;
         const rightOk = rightYear == null || track.year <= rightYear;
-        
+
         correct = leftOk && rightOk;
-        
+
         // Debug logging
         logger.info(`Placement check - Track year: ${track.year}, Slot: ${slot}/${n}, Left: ${leftYear}, Right: ${rightYear}, LeftOk: ${leftOk}, RightOk: ${rightOk}, Correct: ${correct}`);
       }
@@ -342,7 +363,7 @@ export class GameService {
         artist: track.artist,
       });
       room.state.timeline[playerId] = newTimeline;
-      
+
       // Score increases automatically (it's the timeline length)
       // NO token awarded here - tokens are only from title+artist guesses
       logger.info(
@@ -351,12 +372,12 @@ export class GameService {
     } else {
       // Discard the track
       room.discard.push(track);
-      
+
       logger.info(
         `Player ${playerId} incorrectly placed track. No score increase.`
       );
     }
 
-    return { correct };
+    return { correct, tokensUsed };
   }
 }

src/server-deno/domain/types.ts

@@ -104,6 +104,7 @@ export interface GuessResult {
   type: 'title' | 'artist' | 'year' | 'placement';
   score?: number; // Similarity score for partial matches
   answer?: string; // The correct answer
+  tokensUsed?: boolean; // Whether tokens were used for guaranteed placement
 }
 
 /**

src/server-deno/presentation/WebSocketServer.ts

@@ -482,8 +482,11 @@ export class WebSocketServer {
       return;
     }
 
+    // Check if player wants to use tokens for guaranteed placement
+    const useTokens = !!msg.useTokens;
+
     try {
-      const result = await this.gameService.placeInTimeline(room, player.id, slot);
+      const result = await this.gameService.placeInTimeline(room, player.id, slot, useTokens);
 
       // Store the result
       room.state.lastResult = {
@@ -491,6 +494,7 @@ export class WebSocketServer {
         correct: result.correct,
         guess: null,
         type: 'placement',
+        tokensUsed: result.tokensUsed,
       };
 
       // Move to reveal phase - DON'T auto-skip, wait for user to click next

src/server-deno/public/index.html

@@ -343,14 +343,18 @@
           <h3 class="text-lg font-semibold">Position</h3>
           <p class="text-sm text-slate-500 dark:text-slate-400 mb-2">Wähle die Position und klicke Platzieren.</p>
           <div class="flex flex-wrap items-center gap-3">
-            <div id="placeArea"
-              class="hidden flex flex-col sm:flex-row items-stretch sm:items-center gap-2 w-full sm:w-auto">
+            <div id="placeArea" class="hidden flex flex-wrap items-stretch sm:items-center gap-2 w-full">
               <select id="slotSelect"
-                class="h-10 rounded-lg border border-slate-300 dark:border-slate-700 bg-white/80 dark:bg-slate-800 px-3 w-full sm:w-auto"></select>
+                class="h-10 rounded-lg border border-slate-300 dark:border-slate-700 bg-white/80 dark:bg-slate-800 px-3 flex-1 min-w-0"></select>
               <button id="placeBtn"
-                class="h-10 px-4 rounded-lg bg-slate-900 hover:bg-slate-700 text-white font-medium dark:bg-slate-700 dark:hover:bg-slate-600 w-full sm:w-auto">
+                class="h-10 px-4 rounded-lg bg-slate-900 hover:bg-slate-700 text-white font-medium dark:bg-slate-700 dark:hover:bg-slate-600 shrink-0">
                 Platzieren
               </button>
+              <button id="placeWithTokensBtn"
+                class="h-10 px-3 rounded-lg bg-amber-500 hover:bg-amber-600 text-white font-medium flex items-center justify-center gap-1 whitespace-nowrap shrink-0 disabled:opacity-50 disabled:cursor-not-allowed"
+                title="Nutze 3 Tokens um die Karte automatisch richtig zu platzieren">
+                🪙 3 Tokens
+              </button>
             </div>
             <div id="nextArea" class="hidden w-full sm:w-auto">
               <button id="nextBtn"

src/server-deno/public/js/dom.js

@@ -17,6 +17,7 @@ export const $revealBanner = el("revealBanner");
 export const $placeArea = el("placeArea");
 export const $slotSelect = el("slotSelect");
 export const $placeBtn = el("placeBtn");
+export const $placeWithTokensBtn = el("placeWithTokensBtn");
 export const $mediaControls = el("mediaControls");
 export const $playBtn = el("playBtn");
 export const $pauseBtn = el("pauseBtn");

src/server-deno/public/js/render.js

@@ -10,6 +10,7 @@ import {
   $nextArea,
   $np,
   $placeArea,
+  $placeWithTokensBtn,
   $readyChk,
   $revealBanner,
   $room,
@@ -212,6 +213,8 @@ export function renderRoom(room) {
   if ($placeArea && $slotSelect) {
     if (canGuess) {
       const tl = room.state.timeline?.[state.playerId] || [];
+      // Preserve selected slot across re-renders
+      const previousValue = $slotSelect.value;
       $slotSelect.innerHTML = '';
       for (let i = 0; i <= tl.length; i++) {
         const left = i > 0 ? (tl[i - 1]?.year ?? '?') : null;
@@ -226,6 +229,21 @@ export function renderRoom(room) {
         opt.textContent = label;
         $slotSelect.appendChild(opt);
       }
+      // Restore previous selection if still valid
+      if (previousValue && parseInt(previousValue, 10) <= tl.length) {
+        $slotSelect.value = previousValue;
+      }
+
+      // Enable/disable the "use tokens" button based on token count
+      if ($placeWithTokensBtn) {
+        const myTokens = room.state.tokens?.[state.playerId] ?? 0;
+        const TOKEN_COST = 3;
+        const canUseTokens = myTokens >= TOKEN_COST;
+        $placeWithTokensBtn.disabled = !canUseTokens;
+        $placeWithTokensBtn.title = canUseTokens
+          ? 'Nutze 3 Tokens um die Karte automatisch richtig zu platzieren'
+          : `Du brauchst mindestens ${TOKEN_COST} Tokens (aktuell: ${myTokens})`;
+      }
     } else {
       // Clear options when not guessing
       $slotSelect.innerHTML = '';

src/server-deno/public/js/ui.js

@@ -11,6 +11,7 @@ import {
   $nextBtn,
   $pauseBtn,
   $placeBtn,
+  $placeWithTokensBtn,
   $readyChk,
   $room,
   $roomCode,
@@ -188,6 +189,12 @@ export function wireUi() {
     sendMsg({ type: "place_guess", slot });
   });
 
+  // Use tokens to place card correctly
+  wire($placeWithTokensBtn, "click", () => {
+    const slot = parseInt($slotSelect.value, 10);
+    sendMsg({ type: "place_guess", slot, useTokens: true });
+  });
+
   wire($playBtn, "click", () => sendMsg({ type: "resume_play" }));
   wire($pauseBtn, "click", () => sendMsg({ type: "pause" }));
   wire($nextBtn, "click", () => sendMsg({ type: "skip_track" }));