feat: Hex Wars - Schlangen-Mechanik, nur vom Kopf aus expandieren

backend/src/tools/gebietseroberung/routes.js

@@ -28,6 +28,8 @@ const router  = express.Router();
     ['move_count',  'INTEGER NOT NULL DEFAULT 0'],
     ['terrain',     'TEXT'],
     ['last_event',  'TEXT'],
+    ['owner_head',  'TEXT'],
+    ['opp_head',    'TEXT'],
   ]) {
     if (!cols.includes(col)) db.exec(`ALTER TABLE geo_games ADD COLUMN ${col} ${def}`);
   }
@@ -82,6 +84,12 @@ function createGrid(ownerId, oppId) {
   return g;
 }
 
+// Prüft ob [row,col] an den Kopf [hr,hc] angrenzt (8 Richtungen)
+function isAdjacentToHead(row, col, hr, hc) {
+  return Math.abs(row - hr) <= 1 && Math.abs(col - hc) <= 1 && !(row === hr && col === hc);
+}
+
+// Fallback für canMove: prüft ob Spieler noch irgendwo vom Kopf aus ziehen kann
 function isAdjacent(grid, row, col, playerId) {
   for (const [dr,dc] of DIRS8) {
     const r=row+dr, c=col+dc;
@@ -90,7 +98,16 @@ function isAdjacent(grid, row, col, playerId) {
   return false;
 }
 
-function canMove(grid, terrain, playerId) {
+function canMove(grid, terrain, playerId, headRow, headCol) {
+  // Schlangen-Regel: nur Felder die an den Kopf grenzen sind erreichbar
+  if (headRow !== undefined && headCol !== undefined) {
+    for (const [dr,dc] of DIRS8) {
+      const r=headRow+dr, c=headCol+dc;
+      if (r>=0&&r<GRID&&c>=0&&c<GRID&&grid[r][c]===0&&terrain[r][c]!==T_ROCK) return true;
+    }
+    return false;
+  }
+  // Fallback (alte Spiele ohne head)
   for (let r=0;r<GRID;r++) for (let c=0;c<GRID;c++)
     if (grid[r][c]===0 && terrain[r][c]!==T_ROCK && isAdjacent(grid,r,c,playerId)) return true;
   return false;
@@ -164,6 +181,10 @@ function getGameForUser(id, requesterId) {
   const maskedGrid    = grid.map((row,r) => row.map((cell,c) => visible[r][c] ? cell : (cell===requesterId ? cell : 0)));
   const maskedTerrain = terrain.map((row,r) => row.map((cell,c) => visible[r][c] ? cell : -1));
 
+  // Kopf des anfragenden Spielers mitliefern (für Frontend-Validierung)
+  const myHead  = requesterId === game.owner_id ? game.owner_head : game.opp_head;
+  const oppHead = requesterId === game.owner_id ? game.opp_head  : game.owner_head;
+
   return {
     ...game,
     grid:    JSON.stringify(maskedGrid),
@@ -171,6 +192,8 @@ function getGameForUser(id, requesterId) {
     fog:     JSON.stringify(visible),
     myScore,
     oppScore: oppSc,
+    myHead,
+    oppHead,
   };
 }
 
@@ -236,9 +259,9 @@ router.post('/', authenticate, (req, res) => {
   const terrain = generateTerrain();
 
   const result = db.prepare(`
-    INSERT INTO geo_games (owner_id, opponent_id, grid, terrain, current_turn, move_count)
+    INSERT INTO geo_games (owner_id, opponent_id, grid, terrain, current_turn, move_count, owner_head, opp_head)
-    VALUES (?, ?, ?, ?, ?, 0)
+    VALUES (?, ?, ?, ?, ?, 0, ?, ?)
-  `).run(me, Number(opponent_id), JSON.stringify(grid), JSON.stringify(terrain), me);
+  `).run(me, Number(opponent_id), JSON.stringify(grid), JSON.stringify(terrain), me, '0,0', `${GRID-1},${GRID-1}`);
 
   const myName = db.prepare('SELECT username FROM users WHERE id=?').get(me)?.username || 'Jemand';
   sendPush(Number(opponent_id), '⬡ Hex Wars', `${myName} hat dich zu einem Spiel eingeladen! Du bist zuerst dran.`);
@@ -263,7 +286,13 @@ router.post('/:id/move', authenticate, (req, res) => {
   if (row<0||row>=GRID||col<0||col>=GRID) return res.status(400).json({ error: 'Ungültige Position' });
   if (grid[row][col] !== 0) return res.status(400).json({ error: 'Zelle belegt' });
   if (terrain.length && terrain[row][col] === T_ROCK) return res.status(400).json({ error: 'Felsen — nicht betretbar' });
-  if (!isAdjacent(grid, row, col, me)) return res.status(400).json({ error: 'Nicht angrenzend' });
+  // Schlangen-Regel: Zug muss an den eigenen Kopf angrenzen
+  const myHeadStr = game.owner_id === me ? game.owner_head : game.opp_head;
+  const [myHR, myHC] = myHeadStr ? myHeadStr.split(',').map(Number) : [null, null];
+  if (myHR !== null && !isAdjacentToHead(row, col, myHR, myHC))
+    return res.status(400).json({ error: 'Nur an deinen Kopf anbauen!' });
+  if (myHR === null && !isAdjacent(grid, row, col, me))
+    return res.status(400).json({ error: 'Nicht angrenzend' });
 
   const opponent  = game.owner_id === me ? game.opponent_id : game.owner_id;
   const newMoves  = (game.move_count || 0) + 1;
@@ -273,6 +302,12 @@ router.post('/:id/move', authenticate, (req, res) => {
   // Zug ausführen
   grid[row][col] = me;
 
+  // Neuen Kopf setzen
+  let newOwnerHead = game.owner_head;
+  let newOppHead   = game.opp_head;
+  if (game.owner_id === me) newOwnerHead = `${row},${col}`;
+  else                      newOppHead   = `${row},${col}`;
+
   let lastEvent  = null;
   let mineHit    = false;
   let blastCells = [];
@@ -300,10 +335,15 @@ router.post('/:id/move', authenticate, (req, res) => {
   let status   = 'active';
   let winnerId = null;
 
+  // Köpfe nach Zug
+  const oppHeadStr = game.owner_id === me ? game.opp_head : game.owner_head;
+  const [oppHR, oppHC] = oppHeadStr ? oppHeadStr.split(',').map(Number) : [null, null];
+  const myNewHR = row, myNewHC = col;
+
   // Spielende: niemand kann mehr ziehen
-  if (!canMove(grid, terrain, opponent) && !canMove(grid, terrain, me)) {
+  if (!canMove(grid, terrain, opponent, oppHR, oppHC) && !canMove(grid, terrain, me, myNewHR, myNewHC)) {
     status = 'finished';
-  } else if (!canMove(grid, terrain, opponent)) {
+  } else if (!canMove(grid, terrain, opponent, oppHR, oppHC)) {
     nextTurn = me;
   }
 
@@ -323,8 +363,8 @@ router.post('/:id/move', authenticate, (req, res) => {
 
   db.prepare(`
     UPDATE geo_games SET grid=?, current_turn=?, status=?, winner_id=?, move_count=?, last_event=?,
-    updated_at=datetime('now','localtime') WHERE id=?
+    owner_head=?, opp_head=?, updated_at=datetime('now','localtime') WHERE id=?
-  `).run(JSON.stringify(grid), nextTurn, status, winnerId, newMoves, lastEvent, game.id);
+  `).run(JSON.stringify(grid), nextTurn, status, winnerId, newMoves, lastEvent, newOwnerHead, newOppHead, game.id);
 
   // Pushover
   if (status === 'finished') {

frontend/src/tools/gebietseroberung.jsx

@@ -35,7 +35,7 @@ function HelpModal({ onClose }) {
           </p>
 
           <p><strong style={{ color:'#fff' }}>Ablauf:</strong><br/>
-            Beide starten in gegenüberliegenden Ecken. Reihum wählst du ein freies Feld das an dein Gebiet grenzt (auch diagonal) und besetzt es. Tippe es an, bestätige — fertig.
+            Beide starten in gegenüberliegenden Ecken. Du hast einen <strong style={{ color:myColor }}>Kopf</strong> — dein letzter Zug, markiert mit einem leuchtenden Rahmen. Du kannst <strong>nur an den Kopf anbauen</strong> (alle 8 Richtungen). Dein Gebiet bleibt erhalten, aber du kannst nicht mehr von alten Feldern aus expandieren. Tippe ein Feld an, bestätige — fertig.
           </p>
 
           <div style={{ background:'rgba(255,255,255,0.04)', borderRadius:8, padding:'12px 14px', marginBottom:12, border:'1px solid rgba(255,255,255,0.08)' }}>
@@ -169,18 +169,27 @@ function GameBoard({ game, myId, onMove, toast }) {
     } catch {}
   }, [game.last_event]);
 
-  const isAdj = (r, c) => DIRS8.some(([dr,dc]) => {
+  // Schlangen-Kopf aus Server-Response
-    const nr=r+dr, nc=c+dc;
+  const myHeadStr = game.myHead;
-    return nr>=0&&nr<GRID&&nc>=0&&nc<GRID&&grid[nr][nc]===myId;
+  const myHead    = myHeadStr ? myHeadStr.split(',').map(Number) : null;
-  });
+  const [myHR, myHC] = myHead ?? [null, null];
+
+  const isAdjacentToHead = (r, c) => {
+    if (myHR === null) return false;
+    return Math.abs(r - myHR) <= 1 && Math.abs(c - myHC) <= 1 && !(r === myHR && c === myHC);
+  };
 
   const canClick = (r, c) => {
     if (!isMyTurn || game.status !== 'active') return false;
     if (grid[r][c] !== 0) return false;
-    // T_ROCK kommt vom Server auch im Nebel nicht — Felsen sind immer sichtbar
-    // T_FOG darf canClick NICHT blocken: Felder können klickbar aber noch im Nebel sein
     if (hasTerrain && terrain[r][c] === T_ROCK) return false;
-    return isAdj(r, c);
+    // Schlangen-Regel: nur Felder an den Kopf
+    if (myHead) return isAdjacentToHead(r, c);
+    // Fallback für alte Spiele ohne head
+    return DIRS8.some(([dr,dc]) => {
+      const nr=r+dr, nc=c+dc;
+      return nr>=0&&nr<GRID&&nc>=0&&nc<GRID&&grid[nr][nc]===myId;
+    });
   };
 
   const handleCellClick = (r, c) => {
@@ -243,6 +252,7 @@ function GameBoard({ game, myId, onMove, toast }) {
     const clic    = canClick(r, c);
     const isPend  = pending?.row === r && pending?.col === c;
     const isBlast = blastHighlight.has(`${r}-${c}`);
+    const isHead  = myHR === r && myHC === c; // eigener Kopf
     const isFog   = t === T_FOG;
     const isRock  = t === T_ROCK;
     const isGold  = t === T_GOLD;
@@ -271,8 +281,9 @@ function GameBoard({ game, myId, onMove, toast }) {
     }
 
     if (isBlast) { bg = '#ff440066'; border = '2px solid #ff4400'; }
+    if (isHead && !isPend) { border = `2px solid ${myColor}`; } // Kopf immer markieren
     if (isPend) { bg = myColor; border = `2px solid ${myColor}`; }
-    else if (clic && !isPend && !isBlast) border = `1px solid ${myColor}44`;
+    else if (clic && !isPend && !isBlast && !isHead) border = `1px solid ${myColor}44`;
 
     return (
       <div
@@ -341,7 +352,7 @@ function GameBoard({ game, myId, onMove, toast }) {
           )}
           {isMyTurn && !pending && (
             <div style={{ color:myColor, fontFamily:'monospace', fontSize:11, textAlign:'center', padding:'4px 0' }}>
-              ▶ Wähle ein Feld — Vorsicht vor Minen! 💣
+              ▶ Baue vom Kopf aus — Vorsicht vor Minen! 💣
             </div>
           )}
           {pending && (