refactor: optimize solver to use pure logic without guessing

src/components/CustomGameModal.vue

@@ -2,6 +2,7 @@
 import { ref, computed } from 'vue';
 import { usePuzzleStore } from '@/stores/puzzle';
 import { useI18n } from '@/composables/useI18n';
+import { calculateDifficulty } from '@/utils/puzzleUtils';
 
 const emit = defineEmits(['close']);
 const store = usePuzzleStore();
@@ -21,13 +22,7 @@ const handleSnap = () => {
 };
 
 const difficultyLevel = computed(() => {
-  const rate = fillRate.value;
+  return calculateDifficulty(fillRate.value / 100);
-  const dist = Math.abs(rate - 50);
-  
-  if (dist <= 5) return 'extreme';
-  if (dist <= 15) return 'hardest';
-  if (dist <= 25) return 'harder';
-  return 'easy';
 });
 
 const difficultyColor = computed(() => {

src/components/WinModal.vue

@@ -7,6 +7,7 @@ import { useTimer } from '@/composables/useTimer';
 import xIcon from '@/assets/brands/x.svg';
 import facebookIcon from '@/assets/brands/facebook.svg';
 import whatsappIcon from '@/assets/brands/whatsapp.svg';
+import { calculateDifficulty } from '@/utils/puzzleUtils';
 
 const store = usePuzzleStore();
 const { t } = useI18n();
@@ -113,12 +114,11 @@ const buildShareCanvas = () => {
   
   // Difficulty & Density Info
   const densityPercent = Math.round(store.currentDensity * 100);
-  const dist = Math.abs(densityPercent - 50);
+  const difficultyKey = calculateDifficulty(store.currentDensity);
-  let difficultyKey = 'easy';
   let diffColor = '#33ff33';
-  if (dist <= 5) { difficultyKey = 'extreme'; diffColor = '#ff3333'; }
+  if (difficultyKey === 'extreme') diffColor = '#ff3333';
-  else if (dist <= 15) { difficultyKey = 'hardest'; diffColor = '#ff9933'; }
+  else if (difficultyKey === 'hardest') diffColor = '#ff9933';
-  else if (dist <= 25) { difficultyKey = 'harder'; diffColor = '#ffff33'; }
+  else if (difficultyKey === 'harder') diffColor = '#ffff33';
   
   const difficultyText = t(`difficulty.${difficultyKey}`);
   ctx.font = '600 14px "Segoe UI", sans-serif';

src/composables/useSolver.js

@@ -78,6 +78,9 @@ export function useSolver() {
             } else if (type === 'done') {
                 isProcessing.value = false;
                 pause();
+            } else if (type === 'stuck') {
+                isProcessing.value = false;
+                pause();
             } else {
                 isProcessing.value = false;
             }

src/utils/puzzleUtils.js

@@ -51,3 +51,25 @@ export function generateRandomGrid(size, density = 0.5) {
     }
     return grid;
 }
+
+export function calculateDifficulty(density) {
+    // Shannon Entropy: H(x) = -x*log2(x) - (1-x)*log2(1-x)
+    // Normalized to 0-1 range (since max entropy at 0.5 is 1)
+    
+    // Avoid log(0)
+    if (density <= 0 || density >= 1) return 'easy';
+    
+    const entropy = -density * Math.log2(density) - (1 - density) * Math.log2(1 - density);
+    
+    // Thresholds based on entropy
+    // 0.5 density -> entropy 1.0 (Extreme)
+    // 0.4/0.6 density -> entropy ~0.97 (Extreme)
+    // 0.3/0.7 density -> entropy ~0.88 (Hardest)
+    // 0.2/0.8 density -> entropy ~0.72 (Harder)
+    // <0.2/>0.8 density -> entropy <0.72 (Easy)
+
+    if (entropy >= 0.96) return 'extreme'; // approx 38% - 62%
+    if (entropy >= 0.85) return 'hardest'; // approx 28% - 38% & 62% - 72%
+    if (entropy >= 0.65) return 'harder';  // approx 17% - 28% & 72% - 83%
+    return 'easy';
+}

src/workers/solverWorker.js

@@ -5,7 +5,7 @@ const messages = {
     'worker.solved': 'Rozwiązane!',
     'worker.logicRow': 'Logika: Wiersz {row}, Kolumna {col} -> {state}',
     'worker.logicCol': 'Logika: Kolumna {col}, Wiersz {row} -> {state}',
-    'worker.guess': 'Zgadywanie: Wiersz {row}, Kolumna {col}',
+    'worker.stuck': 'Brak logicznego ruchu. Spróbuj zgadnąć lub cofnąć.',
     'worker.done': 'Koniec!',
     'worker.state.filled': 'Pełne',
     'worker.state.empty': 'Puste'
@@ -14,7 +14,7 @@ const messages = {
     'worker.solved': 'Solved!',
     'worker.logicRow': 'Logic: Row {row}, Column {col} -> {state}',
     'worker.logicCol': 'Logic: Column {col}, Row {row} -> {state}',
-    'worker.guess': 'Guessing: Row {row}, Column {col}',
+    'worker.stuck': 'No logical move found. Try guessing or undoing.',
     'worker.done': 'Done!',
     'worker.state.filled': 'Filled',
     'worker.state.empty': 'Empty'
@@ -236,29 +236,9 @@ const handleStep = (playerGrid, solution, locale) => {
     }
   }
 
-  for (let r = 0; r < size; r++) {
+  // Check for guess logic - we want to avoid this unless strictly necessary
-    for (let c = 0; c < size; c++) {
+  // If no logic move found, return 'stuck' instead of cheating
-      const current = playerGrid[r][c];
+  return { type: 'stuck', statusText: t(locale, 'worker.stuck') };
-      const target = solution[r][c];
-      let isCorrect = false;
-      if (target === 1 && current === 1) isCorrect = true;
-      if (target === 0 && current === 2) isCorrect = true;
-      if (target === 0 && current === 0) isCorrect = false;
-      if (target === 1 && current === 0) isCorrect = false;
-      if (!isCorrect) {
-        const newState = target === 1 ? 1 : 2;
-        return {
-          type: 'move',
-          r,
-          c,
-          state: newState,
-          statusText: t(locale, 'worker.guess', { row: r + 1, col: c + 1 })
-        };
-      }
-    }
-  }
-
-  return { type: 'done', statusText: t(locale, 'worker.done') };
 };
 
 self.onmessage = (event) => {