feat(frontend): implement cook mode UI with wake lock and progress tracking

TODO.md

@@ -21,12 +21,11 @@
 - [x] Set up React Router
 - [x] Create recipe list page
 - [x] Create recipe detail/edit page
-- [ ] Implement cook mode UI
+- [x] Implement cook mode UI
 
 ### Features
 - [ ] Tag management (create, assign, filter)
 - [ ] Text search (title + ingredients)
-- [ ] Screen wake lock for cook mode
 - [ ] Basic error handling + loading states
 
 ### DevOps
@@ -46,6 +45,15 @@
 ## ✅ Completed Tasks
 
 ### 2026-03-24
+- **Cook mode UI implementation**
+  - Implemented full cooking interface with ingredient and step checklists
+  - Added progress tracking with visual progress bars
+  - Integrated Screen Wake Lock API to prevent screen sleep during cooking
+  - Created touch-friendly UI with large text and clear spacing
+  - Added completion celebration when all steps are done
+  - Included loading and error states with navigation back to recipe detail
+  - Verified TypeScript compilation and Vite build succeed
+
 - **Recipe detail/edit page implementation**
   - Created useRecipe hook for fetching single recipe with loading/error states
   - Created RecipeForm component with full validation (title, ingredients, instructions required)

frontend/src/pages/CookModePage.tsx

@@ -1,27 +1,301 @@
-import { useParams } from 'react-router-dom';
+import { useState, useEffect } from 'react';
+import { useParams, Link } from 'react-router-dom';
+import { useRecipe } from '../hooks/useRecipe';
 
 /**
  * CookModePage - Hands-free cooking interface with wake lock
  */
 export function CookModePage() {
   const { id } = useParams<{ id: string }>();
+  const recipeId = id ? parseInt(id, 10) : null;
+  const { recipe, loading, error } = useRecipe(recipeId);
+  
+  // Track checked ingredients and steps
+  const [checkedIngredients, setCheckedIngredients] = useState<Set<number>>(new Set());
+  const [checkedSteps, setCheckedSteps] = useState<Set<number>>(new Set());
+  
+  // Wake lock state
+  const [wakeLock, setWakeLock] = useState<WakeLockSentinel | null>(null);
+  const [wakeLockSupported, setWakeLockSupported] = useState(false);
+  
+  // Check if Wake Lock API is supported
+  useEffect(() => {
+    setWakeLockSupported('wakeLock' in navigator);
+  }, []);
+  
+  // Request wake lock
+  const requestWakeLock = async () => {
+    if (!wakeLockSupported) return;
+    
+    try {
+      const lock = await navigator.wakeLock.request('screen');
+      setWakeLock(lock);
+      
+      // Handle wake lock release
+      lock.addEventListener('release', () => {
+        setWakeLock(null);
+      });
+    } catch (err) {
+      console.error('Failed to request wake lock:', err);
+    }
+  };
+  
+  // Release wake lock
+  const releaseWakeLock = async () => {
+    if (wakeLock) {
+      await wakeLock.release();
+      setWakeLock(null);
+    }
+  };
+  
+  // Toggle wake lock
+  const toggleWakeLock = () => {
+    if (wakeLock) {
+      releaseWakeLock();
+    } else {
+      requestWakeLock();
+    }
+  };
+  
+  // Release wake lock when leaving page
+  useEffect(() => {
+    return () => {
+      if (wakeLock) {
+        wakeLock.release();
+      }
+    };
+  }, [wakeLock]);
+  
+  // Toggle ingredient checkbox
+  const toggleIngredient = (index: number) => {
+    setCheckedIngredients(prev => {
+      const next = new Set(prev);
+      if (next.has(index)) {
+        next.delete(index);
+      } else {
+        next.add(index);
+      }
+      return next;
+    });
+  };
+  
+  // Toggle step checkbox
+  const toggleStep = (index: number) => {
+    setCheckedSteps(prev => {
+      const next = new Set(prev);
+      if (next.has(index)) {
+        next.delete(index);
+      } else {
+        next.add(index);
+      }
+      return next;
+    });
+  };
+  
+  // Loading state
+  if (loading) {
+    return (
+      <div className="flex justify-center items-center min-h-[50vh]">
+        <div className="text-center">
+          <div className="inline-block animate-spin rounded-full h-12 w-12 border-b-2 border-blue-600"></div>
+          <p className="mt-4 text-gray-600">Loading recipe...</p>
+        </div>
+      </div>
+    );
+  }
+  
+  // Error state
+  if (error || !recipe) {
+    return (
+      <div className="bg-red-50 border border-red-200 rounded-lg p-6">
+        <h2 className="text-xl font-bold text-red-800 mb-2">Error Loading Recipe</h2>
+        <p className="text-red-600 mb-4">{error || 'Recipe not found'}</p>
+        <Link 
+          to="/"
+          className="inline-block px-4 py-2 bg-red-600 text-white rounded-lg hover:bg-red-700 transition-colors"
+        >
+          Back to Recipes
+        </Link>
+      </div>
+    );
+  }
+  
+  // Calculate progress
+  const ingredientsTotal = recipe.ingredients.length;
+  const ingredientsChecked = checkedIngredients.size;
+  const stepsTotal = recipe.instructions.length;
+  const stepsChecked = checkedSteps.size;
+  const ingredientsProgress = ingredientsTotal > 0 ? (ingredientsChecked / ingredientsTotal) * 100 : 0;
+  const stepsProgress = stepsTotal > 0 ? (stepsChecked / stepsTotal) * 100 : 0;
   
   return (
-    <div>
-      <div className="mb-6">
-        <h2 className="text-2xl font-bold text-gray-900">
-          Cook Mode {id && `- Recipe #${id}`}
-        </h2>
-        <p className="mt-1 text-sm text-gray-500">
-          Step-by-step cooking interface
-        </p>
+    <div className="max-w-4xl mx-auto">
+      {/* Header */}
+      <div className="bg-white rounded-lg shadow-lg p-6 mb-6">
+        <div className="flex items-start justify-between mb-4">
+          <div className="flex-1">
+            <h1 className="text-3xl font-bold text-gray-900 mb-2">{recipe.title}</h1>
+            {recipe.description && (
+              <p className="text-gray-600 text-lg">{recipe.description}</p>
+            )}
+          </div>
+          <Link
+            to={`/recipe/${recipe.id}`}
+            className="ml-4 px-4 py-2 text-blue-600 hover:bg-blue-50 rounded-lg transition-colors text-sm font-medium"
+          >
+            Exit Cook Mode
+          </Link>
+        </div>
+        
+        {/* Recipe metadata */}
+        <div className="flex flex-wrap gap-4 text-sm text-gray-600 mb-4">
+          {recipe.servings && (
+            <div className="flex items-center">
+              <span className="font-medium">Servings:</span>
+              <span className="ml-1">{recipe.servings}</span>
+            </div>
+          )}
+          {recipe.prep_time_minutes && (
+            <div className="flex items-center">
+              <span className="font-medium">Prep:</span>
+              <span className="ml-1">{recipe.prep_time_minutes} min</span>
+            </div>
+          )}
+          {recipe.cook_time_minutes && (
+            <div className="flex items-center">
+              <span className="font-medium">Cook:</span>
+              <span className="ml-1">{recipe.cook_time_minutes} min</span>
+            </div>
+          )}
+        </div>
+        
+        {/* Wake lock toggle */}
+        {wakeLockSupported && (
+          <div className="border-t pt-4">
+            <button
+              onClick={toggleWakeLock}
+              className={`w-full sm:w-auto px-6 py-3 rounded-lg font-medium transition-colors ${
+                wakeLock
+                  ? 'bg-green-600 text-white hover:bg-green-700'
+                  : 'bg-gray-200 text-gray-700 hover:bg-gray-300'
+              }`}
+            >
+              {wakeLock ? '🔒 Screen Locked (Stay Awake)' : '🔓 Screen Will Sleep (Tap to Lock)'}
+            </button>
+            <p className="mt-2 text-sm text-gray-500">
+              {wakeLock 
+                ? 'Your screen will stay on while cooking' 
+                : 'Enable to prevent your screen from turning off'}
+            </p>
+          </div>
+        )}
       </div>
       
-      <div className="bg-white rounded-lg shadow p-6">
-        <p className="text-gray-600">
-          Cook mode interface will be implemented later
-        </p>
+      {/* Ingredients Section */}
+      <div className="bg-white rounded-lg shadow-lg p-6 mb-6">
+        <div className="flex items-center justify-between mb-4">
+          <h2 className="text-2xl font-bold text-gray-900">Ingredients</h2>
+          <div className="text-sm font-medium text-gray-600">
+            {ingredientsChecked} of {ingredientsTotal}
+          </div>
+        </div>
+        
+        {/* Progress bar */}
+        <div className="mb-6 bg-gray-200 rounded-full h-2 overflow-hidden">
+          <div 
+            className="bg-green-600 h-full transition-all duration-300"
+            style={{ width: `${ingredientsProgress}%` }}
+          />
+        </div>
+        
+        {/* Ingredient checklist */}
+        <div className="space-y-3">
+          {recipe.ingredients.map((ingredient, index) => (
+            <label
+              key={index}
+              className="flex items-start gap-3 p-3 rounded-lg hover:bg-gray-50 cursor-pointer transition-colors"
+            >
+              <input
+                type="checkbox"
+                checked={checkedIngredients.has(index)}
+                onChange={() => toggleIngredient(index)}
+                className="mt-1 h-5 w-5 rounded border-gray-300 text-blue-600 focus:ring-blue-500 cursor-pointer"
+              />
+              <span className={`text-lg flex-1 ${
+                checkedIngredients.has(index) ? 'line-through text-gray-500' : 'text-gray-900'
+              }`}>
+                {ingredient}
+              </span>
+            </label>
+          ))}
+        </div>
       </div>
+      
+      {/* Instructions Section */}
+      <div className="bg-white rounded-lg shadow-lg p-6 mb-6">
+        <div className="flex items-center justify-between mb-4">
+          <h2 className="text-2xl font-bold text-gray-900">Instructions</h2>
+          <div className="text-sm font-medium text-gray-600">
+            {stepsChecked} of {stepsTotal}
+          </div>
+        </div>
+        
+        {/* Progress bar */}
+        <div className="mb-6 bg-gray-200 rounded-full h-2 overflow-hidden">
+          <div 
+            className="bg-blue-600 h-full transition-all duration-300"
+            style={{ width: `${stepsProgress}%` }}
+          />
+        </div>
+        
+        {/* Instruction steps */}
+        <div className="space-y-4">
+          {recipe.instructions.map((instruction, index) => (
+            <label
+              key={index}
+              className="flex items-start gap-4 p-4 rounded-lg hover:bg-gray-50 cursor-pointer transition-colors border-l-4 border-transparent hover:border-blue-600"
+            >
+              <div className="flex items-center gap-3">
+                <div className={`flex-shrink-0 w-8 h-8 rounded-full flex items-center justify-center font-bold ${
+                  checkedSteps.has(index) 
+                    ? 'bg-blue-600 text-white' 
+                    : 'bg-gray-200 text-gray-600'
+                }`}>
+                  {index + 1}
+                </div>
+                <input
+                  type="checkbox"
+                  checked={checkedSteps.has(index)}
+                  onChange={() => toggleStep(index)}
+                  className="h-5 w-5 rounded border-gray-300 text-blue-600 focus:ring-blue-500 cursor-pointer"
+                />
+              </div>
+              <span className={`text-lg flex-1 ${
+                checkedSteps.has(index) ? 'line-through text-gray-500' : 'text-gray-900'
+              }`}>
+                {instruction}
+              </span>
+            </label>
+          ))}
+        </div>
+      </div>
+      
+      {/* Completion message */}
+      {ingredientsChecked === ingredientsTotal && stepsChecked === stepsTotal && (
+        <div className="bg-green-50 border-2 border-green-500 rounded-lg p-6 mb-6 text-center">
+          <div className="text-4xl mb-3">🎉</div>
+          <h3 className="text-2xl font-bold text-green-800 mb-2">All Done!</h3>
+          <p className="text-green-700 text-lg mb-4">
+            You've completed all steps. Enjoy your meal!
+          </p>
+          <Link
+            to={`/recipe/${recipe.id}`}
+            className="inline-block px-6 py-3 bg-green-600 text-white rounded-lg hover:bg-green-700 transition-colors font-medium"
+          >
+            Back to Recipe
+          </Link>
+        </div>
+      )}
     </div>
   );
 }