fix(zopk): Add Brave API rate limit handling and heartbeat limit fix

Brave free tier was returning 429 for ~50% of queries due to back-to-back
requests. Added 1.1s delay between queries and retry with exponential
backoff (1.5s, 3s). Heartbeat endpoint exempted from Flask-Limiter and
interval increased from 30s to 60s to reduce log noise.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

blueprints/api/routes_analytics.py

@@ -13,6 +13,7 @@ from flask import jsonify, request, session, current_app
 from flask_login import current_user
 
 from database import SessionLocal, UserSession, UserClick, PageView, JSError
+from extensions import limiter
 from . import bp
 
 logger = logging.getLogger(__name__)
@@ -88,6 +89,7 @@ def api_analytics_track():
 
 
 @bp.route('/analytics/heartbeat', methods=['POST'])
+@limiter.exempt
 def api_analytics_heartbeat():
     """Keep session alive and update duration"""
     analytics_session_id = session.get('analytics_session_id')

static/js/analytics-tracker.js

@@ -7,7 +7,7 @@
 (function() {
     'use strict';
 
-    const HEARTBEAT_INTERVAL = 30000; // 30 seconds
+    const HEARTBEAT_INTERVAL = 60000; // 60 seconds
     const SCROLL_DEBOUNCE_MS = 500;
     const TRACK_ENDPOINT = '/api/analytics/track';
     const HEARTBEAT_ENDPOINT = '/api/analytics/heartbeat';

zopk_news_service.py

@@ -21,6 +21,7 @@ Created: 2026-01-11
 
 import os
 import re
+import time
 import hashlib
 import logging
 import unicodedata
@@ -678,6 +679,10 @@ class ZOPKNewsService:
 
                 if progress_callback:
                     progress_callback('search', f"Brave: {query_config['description']} ({len(brave_items)})", i + 1, len(BRAVE_QUERIES))
+
+                # Rate limit: Brave free tier ~1 req/s
+                if i < len(BRAVE_QUERIES) - 1:
+                    time.sleep(1.1)
         else:
             process_log.append({
                 'phase': 'search',
@@ -947,50 +952,63 @@ class ZOPKNewsService:
         }
 
     def _search_brave_single(self, query: str) -> List[NewsItem]:
-        """Search Brave API with a single query"""
+        """Search Brave API with a single query, with retry on 429"""
         if not self.brave_api_key:
             return []
 
         items = []
-        try:
-            headers = {
-                'Accept': 'application/json',
-                'X-Subscription-Token': self.brave_api_key
-            }
-            params = {
-                'q': query,
-                'count': 10,  # Fewer results per query (we have 8 queries)
-                'freshness': 'pw',  # past week (more relevant than past month)
-                'country': 'pl',
-                'search_lang': 'pl'
-            }
+        max_retries = 2
 
-            response = requests.get(
-                'https://api.search.brave.com/res/v1/news/search',
-                headers=headers,
-                params=params,
-                timeout=30
-            )
+        for attempt in range(max_retries + 1):
+            try:
+                headers = {
+                    'Accept': 'application/json',
+                    'X-Subscription-Token': self.brave_api_key
+                }
+                params = {
+                    'q': query,
+                    'count': 10,
+                    'freshness': 'pw',
+                    'country': 'pl',
+                    'search_lang': 'pl'
+                }
 
-            if response.status_code == 200:
-                results = response.json().get('results', [])
-                for item in results:
-                    if item.get('url'):
-                        items.append(NewsItem(
-                            title=item.get('title', 'Bez tytułu'),
-                            url=item['url'],
-                            description=item.get('description', ''),
-                            source_name=item.get('source', ''),
-                            source_type='brave',
-                            source_id=f'brave_{query[:20]}',
-                            published_at=datetime.now(),
-                            image_url=item.get('thumbnail', {}).get('src')
-                        ))
-            else:
-                logger.error(f"Brave API error for '{query[:30]}': {response.status_code}")
+                response = requests.get(
+                    'https://api.search.brave.com/res/v1/news/search',
+                    headers=headers,
+                    params=params,
+                    timeout=30
+                )
 
-        except Exception as e:
-            logger.error(f"Brave search error: {e}")
+                if response.status_code == 200:
+                    results = response.json().get('results', [])
+                    for item in results:
+                        if item.get('url'):
+                            items.append(NewsItem(
+                                title=item.get('title', 'Bez tytułu'),
+                                url=item['url'],
+                                description=item.get('description', ''),
+                                source_name=item.get('source', ''),
+                                source_type='brave',
+                                source_id=f'brave_{query[:20]}',
+                                published_at=datetime.now(),
+                                image_url=item.get('thumbnail', {}).get('src')
+                            ))
+                    break  # success
+                elif response.status_code == 429:
+                    if attempt < max_retries:
+                        wait = 1.5 * (2 ** attempt)  # 1.5s, 3s
+                        logger.warning(f"Brave API 429 for '{query[:30]}', retry {attempt+1} after {wait}s")
+                        time.sleep(wait)
+                    else:
+                        logger.error(f"Brave API 429 for '{query[:30]}' after {max_retries} retries, skipping")
+                else:
+                    logger.error(f"Brave API error for '{query[:30]}': {response.status_code}")
+                    break
+
+            except Exception as e:
+                logger.error(f"Brave search error: {e}")
+                break
 
         return items