feat: US-004 - Backend API - Check-in endpoint with streak logic

dashboard/api.py

@@ -56,6 +56,8 @@ class TaskBoardHandler(SimpleHTTPRequestHandler):
             self.handle_pdf_post()
         elif self.path == '/api/habits':
             self.handle_habits_post()
+        elif self.path.startswith('/api/habits/') and self.path.endswith('/check'):
+            self.handle_habits_check()
         elif self.path == '/api/workspace/run':
             self.handle_workspace_run()
         elif self.path == '/api/workspace/stop':
@@ -1648,6 +1650,124 @@ class TaskBoardHandler(SimpleHTTPRequestHandler):
         except Exception as e:
             self.send_json({'error': str(e)}, 500)
     
+    def handle_habits_check(self):
+        """Check in on a habit (complete it for today)."""
+        try:
+            # Extract habit ID from path (/api/habits/{id}/check)
+            path_parts = self.path.split('/')
+            if len(path_parts) < 5:
+                self.send_json({'error': 'Invalid path'}, 400)
+                return
+            
+            habit_id = path_parts[3]
+            
+            # Read optional body (note, rating, mood)
+            body_data = {}
+            content_length = self.headers.get('Content-Length')
+            if content_length:
+                post_data = self.rfile.read(int(content_length)).decode('utf-8')
+                if post_data.strip():
+                    try:
+                        body_data = json.loads(post_data)
+                    except json.JSONDecodeError:
+                        self.send_json({'error': 'Invalid JSON'}, 400)
+                        return
+            
+            # Read existing habits
+            if not HABITS_FILE.exists():
+                self.send_json({'error': 'Habit not found'}, 404)
+                return
+            
+            with open(HABITS_FILE, 'r', encoding='utf-8') as f:
+                habits_data = json.load(f)
+            
+            # Find habit
+            habit = None
+            for h in habits_data.get('habits', []):
+                if h['id'] == habit_id:
+                    habit = h
+                    break
+            
+            if not habit:
+                self.send_json({'error': 'Habit not found'}, 404)
+                return
+            
+            # Verify habit is relevant for today
+            if not habits_helpers.should_check_today(habit):
+                self.send_json({'error': 'Habit is not relevant for today based on its frequency'}, 400)
+                return
+            
+            # Verify not already checked today
+            today = datetime.now().date().isoformat()
+            completions = habit.get('completions', [])
+            for completion in completions:
+                if completion.get('date') == today:
+                    self.send_json({'error': 'Habit already checked in today'}, 409)
+                    return
+            
+            # Create completion entry
+            completion_entry = {
+                'date': today,
+                'type': 'check'  # Distinguish from 'skip' for life restore logic
+            }
+            
+            # Add optional fields
+            if 'note' in body_data:
+                completion_entry['note'] = body_data['note']
+            if 'rating' in body_data:
+                rating = body_data['rating']
+                if not isinstance(rating, int) or rating < 1 or rating > 5:
+                    self.send_json({'error': 'rating must be an integer between 1 and 5'}, 400)
+                    return
+                completion_entry['rating'] = rating
+            if 'mood' in body_data:
+                mood = body_data['mood']
+                if mood not in ['happy', 'neutral', 'sad']:
+                    self.send_json({'error': 'mood must be one of: happy, neutral, sad'}, 400)
+                    return
+                completion_entry['mood'] = mood
+            
+            # Add completion to habit
+            habit['completions'].append(completion_entry)
+            
+            # Recalculate streak
+            current_streak = habits_helpers.calculate_streak(habit)
+            habit['streak']['current'] = current_streak
+            
+            # Update best streak if current is higher
+            if current_streak > habit['streak']['best']:
+                habit['streak']['best'] = current_streak
+            
+            # Update lastCheckIn
+            habit['streak']['lastCheckIn'] = today
+            
+            # Check for life restore: if last 7 completions are all check-ins (no skips) and lives < 3
+            if habit.get('lives', 3) < 3:
+                recent_completions = sorted(
+                    habit['completions'],
+                    key=lambda x: x.get('date', ''),
+                    reverse=True
+                )[:7]
+                
+                # Check if we have 7 completions and all are check-ins (not skips)
+                if len(recent_completions) == 7:
+                    all_checks = all(c.get('type') == 'check' for c in recent_completions)
+                    if all_checks:
+                        habit['lives'] = min(habit['lives'] + 1, 3)
+            
+            # Update timestamp
+            habit['updatedAt'] = datetime.now().isoformat()
+            habits_data['lastUpdated'] = habit['updatedAt']
+            
+            # Save to file
+            with open(HABITS_FILE, 'w', encoding='utf-8') as f:
+                json.dump(habits_data, f, indent=2)
+            
+            # Return updated habit
+            self.send_json(habit, 200)
+        except Exception as e:
+            self.send_json({'error': str(e)}, 500)
+    
     def send_json(self, data, code=200):
         self.send_response(code)
         self.send_header('Content-Type', 'application/json')