diff --git a/app/routers/search_sites.py b/app/routers/search_sites.py
index d440463..ff08a04 100644
--- a/app/routers/search_sites.py
+++ b/app/routers/search_sites.py
@@ -3,11 +3,12 @@ API Router pour la gestion des sites de recherche
 """
 
 import logging
+import os
 
 from fastapi import APIRouter, BackgroundTasks, Depends, HTTPException
 from sqlalchemy.orm import Session
 
-from app.database import get_db
+from app.database import SessionLocal, get_db
 from app.schemas import SearchSiteCreate, SearchSiteResponse, SearchSiteUpdate
 from app.services import search_service
 from app.services.search_url_discovery import discover_search_url
@@ -35,8 +36,6 @@ async def get_site(site_id: int, db: Session = Depends(get_db)):
 
 async def _discover_and_update_site(site_id: int, domain: str, db_url: str):
     """Découvre l'URL de recherche en background et met à jour le site"""
-    from app.database import SessionLocal
-
     try:
         logger.info(f"Discovering search URL for site {site_id} ({domain})")
         result = await discover_search_url(domain)
@@ -78,7 +77,6 @@ async def create_site(
 
         # Si pas de search_url, lancer la découverte en background
         if not site.search_url:
-            import os
             db_url = os.getenv("DATABASE_URL", "")
             background_tasks.add_task(
                 _discover_and_update_site,
@@ -90,7 +88,7 @@ async def create_site(
 
         return new_site
     except Exception as e:
-        raise HTTPException(status_code=400, detail=str(e))
+        raise HTTPException(status_code=400, detail=str(e)) from e
 
 
 @router.put("/{site_id}", response_model=SearchSiteResponse)
@@ -114,7 +112,6 @@ async def delete_site(site_id: int, db: Session = Depends(get_db)):
     deleted = search_service.delete_site(db, site_id)
     if not deleted:
         raise HTTPException(status_code=404, detail="Site not found")
-    return None
 
 
 @router.post("/{site_id}/discover", response_model=dict)
diff --git a/app/services/search_url_discovery.py b/app/services/search_url_discovery.py
index 22bb40a..f7d5265 100644
--- a/app/services/search_url_discovery.py
+++ b/app/services/search_url_discovery.py
@@ -5,16 +5,18 @@ Search URL Discovery Service - Découvre automatiquement l'URL de recherche d'un
 import asyncio
 import logging
 import os
-import re
-from urllib.parse import urljoin, urlparse
+from urllib.parse import urljoin
 
-from bs4 import BeautifulSoup
 from playwright.async_api import async_playwright
 
 logger = logging.getLogger(__name__)
 
 BROWSERLESS_URL = os.getenv("BROWSERLESS_URL", "ws://browserless:3000")
 
+# Constants
+HTTP_OK = 200
+MIN_PRODUCTS_TO_MATCH = 2
+
 # Patterns communs pour les URLs de recherche
 COMMON_SEARCH_PATTERNS = [
     "/search?q={query}",
@@ -101,7 +103,7 @@ async def discover_search_url(domain: str) -> dict:
     return result
 
 
-async def _find_search_form(page, base_url: str, domain: str) -> str | None:
+async def _find_search_form(page, base_url: str, domain: str) -> str | None:  # noqa: PLR0912
     """Trouve le formulaire de recherche sur la page"""
     try:
         # Chercher les formulaires de recherche
@@ -125,7 +127,11 @@ async def _find_search_form(page, base_url: str, domain: str) -> str | None:
                     action = await form.get_attribute("action")
                     if action:
                         # Trouver le nom du champ de recherche
-                        input_field = await form.query_selector('input[type="search"], input[type="text"], input[name*="q"], input[name*="query"], input[name*="search"]')
+                        input_selector = (
+                            'input[type="search"], input[type="text"], '
+                            'input[name*="q"], input[name*="query"], input[name*="search"]'
+                        )
+                        input_field = await form.query_selector(input_selector)
                         if input_field:
                             input_name = await input_field.get_attribute("name") or "q"
 
@@ -192,7 +198,7 @@ async def _try_common_patterns(page, base_url: str, domain: str) -> str | None:
         test_url = f"https://www.{domain}{pattern}".replace("{query}", "test")
         try:
             response = await page.goto(test_url, wait_until="domcontentloaded", timeout=10000)
-            if response and response.status == 200:
+            if response and response.status == HTTP_OK:
                 # Vérifier qu'on est sur une page de résultats
                 content = await page.content()
                 if "test" in content.lower() or "résultat" in content.lower() or "result" in content.lower():
@@ -229,7 +235,7 @@ async def _discover_product_selector(page, search_url: str, domain: str) -> str
         for selector in product_selectors:
             try:
                 elements = await page.query_selector_all(selector)
-                if len(elements) >= 2:  # Au moins 2 produits trouvés
+                if len(elements) >= MIN_PRODUCTS_TO_MATCH:
                     return selector
             except Exception:
                 continue