overpass as class

backend/src/overpass/overpass.py

@@ -5,13 +5,27 @@ import logging
 import xml.etree.ElementTree as ET
 
 from .caching_strategy import get_cache_key, CachingStrategy
+from ..constants import OSM_CACHE_DIR
+
+logger = logging.getLogger('Overpass')
+osm_types = List[Literal['way', 'node', 'relation']]
 
 
-logger = logging.getLogger('overpass')
-ElementTypes = List[Literal['way', 'node', 'relation']]
+class Overpass :
+    """
+    Overpass class to manage the query building and sending to overpass api.
+    The caching strategy is a part of this class and initialized upon creation of the Overpass object.
+    """
+    def __init__(self, caching_strategy: str = 'XML', cache_dir: str = OSM_CACHE_DIR) :
+        """
+        Initialize the Overpass instance with the url, headers and caching strategy.
+        """
+        self.overpass_url = "https://overpass-api.de/api/interpreter"
+        self.headers = {'User-Agent': 'Mozilla/5.0 (compatible; OverpassQuery/1.0; +http://example.com)',}
+        self.caching_strategy = CachingStrategy.use(caching_strategy, cache_dir=cache_dir)
 
 
-def build_query(area: tuple, element_types: ElementTypes,
+    def build_query(self, area: tuple, osm_types: osm_types,
                     selector: str, conditions=[], out='center'):
         """
         Constructs a query string for the Overpass API to retrieve OpenStreetMap (OSM) data.
@@ -21,7 +35,7 @@ def build_query(area: tuple, element_types: ElementTypes,
                         (radius, latitude, longitude). The first element is a string like "around:2000" 
                         specifying the search radius, and the second and third elements represent 
                         the latitude and longitude as floats or strings.
-        element_types (list[str]): A list of OSM element types to search for. Must be one or more of 
+            osm_types (list[str]): A list of OSM element types to search for. Must be one or more of 
                                     'Way', 'Node', or 'Relation'.
             selector (str): The key or tag to filter the OSM elements (e.g., 'amenity', 'highway', etc.).
             conditions (list, optional): A list of conditions to apply as additional filters for the 
@@ -41,8 +55,8 @@ def build_query(area: tuple, element_types: ElementTypes,
         """
         if not isinstance(conditions, list) :
             conditions = [conditions]
-    if not isinstance(element_types, list) :
-        element_types = [element_types]
+        if not isinstance(osm_types, list) :
+            osm_types = [osm_types]
 
         query = '('
 
@@ -61,7 +75,7 @@ def build_query(area: tuple, element_types: ElementTypes,
         else :
             conditions = ''
 
-    for elem in element_types :
+        for elem in osm_types :
             query += elem + '[' + selector + ']' + conditions + search_area + ';'
 
         query += ');' + f'out {out};'
@@ -69,7 +83,7 @@ def build_query(area: tuple, element_types: ElementTypes,
         return query
 
 
-def send_query(query: str) -> dict:
+    def send_query(self, query: str) -> dict:
         """
         Sends the Overpass QL query to the Overpass API and returns the parsed JSON response.
 
@@ -84,25 +98,17 @@ def send_query(query: str) -> dict:
         cache_key = get_cache_key(query)
 
         # Try to fetch the result from the cache
-    cached_response = CachingStrategy.get(cache_key)
+        cached_response = self.caching_strategy.get(cache_key)
         if cached_response is not None :
             logger.debug("Cache hit.")
             return cached_response
 
-    # Define the Overpass API endpoint
-    overpass_url = "https://overpass-api.de/api/interpreter"
-
         # Prepare the data to be sent as POST request, encoded as bytes
         data = urllib.parse.urlencode({'data': query}).encode('utf-8')
 
-    # Create a custom header with a User-Agent
-    headers = {
-        'User-Agent': 'Mozilla/5.0 (compatible; OverpassQuery/1.0; +http://example.com)',
-    }
-
         try:
             # Create a Request object with the specified URL, data, and headers
-        request = urllib.request.Request(overpass_url, data=data, headers=headers)
+            request = urllib.request.Request(self.overpass_url, data=data, headers=self.headers)
 
             # Send the request and read the response
             with urllib.request.urlopen(request) as response:
@@ -111,7 +117,7 @@ def send_query(query: str) -> dict:
                 root = ET.fromstring(response_data)
 
                 # Cache the response data as an ElementTree root
-            CachingStrategy.set(cache_key, root)
+                self.caching_strategy.set(cache_key, root)
                 logger.debug("Response data added to cache.")
 
                 return root

backend/src/utils/cluster_manager.py

@@ -6,15 +6,14 @@ import numpy as np
 from sklearn.cluster import DBSCAN
 from pydantic import BaseModel
 
-from ..overpass.overpass import build_query, send_query
-from ..overpass.caching_strategy import CachingStrategy
+from ..overpass.overpass import Overpass
 from ..structs.landmark import Landmark
 from .get_time_distance import get_distance
 from ..constants import OSM_CACHE_DIR
 
 
 # silence the overpass logger
-logging.getLogger('overpass').setLevel(level=logging.CRITICAL)
+logging.getLogger('Overpass').setLevel(level=logging.CRITICAL)
 
 
 class Cluster(BaseModel):
@@ -79,7 +78,9 @@ class ClusterManager:
         Args: 
             bbox: The bounding box coordinates (around:radius, center_lat, center_lon).
         """
-        CachingStrategy.use('XML', cache_dir=OSM_CACHE_DIR)
+        # Setup the caching in the Overpass class.
+        self.overpass = Overpass(caching_strategy='XML', cache_dir=OSM_CACHE_DIR)
+
 
         self.cluster_type = cluster_type
         if cluster_type == 'shopping' :
@@ -94,16 +95,16 @@ class ClusterManager:
             raise NotImplementedError("Please choose only an available option for cluster detection")
 
         # Initialize the points for cluster detection
-        query = build_query(
+        query = self.overpass.build_query(
             area = bbox,
-            element_types = osm_types,
+            osm_types = osm_types,
             selector = sel,
             out = out
         )
         self.logger.debug(f"Cluster query: {query}")
 
         try:
-            result = send_query(query)
+            result = self.overpass.send_query(query)
         except Exception as e:
             self.logger.error(f"Error fetching landmarks: {e}")
 
@@ -243,15 +244,15 @@ class ClusterManager:
         osm_types = ['node', 'way', 'relation']
 
         for sel in selectors :
-            query = build_query(
+            query = self.overpass.build_query(
                 area = bbox,
-                element_types = osm_types,
+                osm_types = osm_types,
                 selector = sel,
                 out = 'ids center'
             )
 
             try:
-                result = send_query(query)
+                result = self.overpass.send_query(query)
             except Exception as e:
                 self.logger.error(f"Error fetching landmarks: {e}")
                 continue

backend/src/utils/landmarks_manager.py

@@ -8,13 +8,12 @@ from ..structs.preferences import Preferences
 from ..structs.landmark import Landmark
 from .take_most_important import take_most_important
 from .cluster_manager import ClusterManager
-from ..overpass.overpass import build_query, send_query
-from ..overpass.caching_strategy import CachingStrategy
+from ..overpass.overpass import Overpass
 
 from ..constants import AMENITY_SELECTORS_PATH, LANDMARK_PARAMETERS_PATH, OPTIMIZER_PARAMETERS_PATH, OSM_CACHE_DIR
 
 # silence the overpass logger
-logging.getLogger('overpass').setLevel(level=logging.CRITICAL)
+logging.getLogger('Overpass').setLevel(level=logging.CRITICAL)
 
 
 class LandmarkManager:
@@ -56,7 +55,8 @@ class LandmarkManager:
             self.walking_speed = parameters['average_walking_speed']
             self.detour_factor = parameters['detour_factor']
 
-        CachingStrategy.use('XML', cache_dir=OSM_CACHE_DIR)
+        # Setup the caching in the Overpass class.
+        self.overpass = Overpass(caching_strategy='XML', cache_dir=OSM_CACHE_DIR)
 
         self.logger.info('LandmakManager successfully initialized.')
 
@@ -189,15 +189,15 @@ class LandmarkManager:
         for sel in dict_to_selector_list(amenity_selector):
             # self.logger.debug(f"Current selector: {sel}")
 
-            element_types = ['way', 'relation']
+            osm_types = ['way', 'relation']
 
             if 'viewpoint' in sel :
                 query_conditions = []
-                element_types.append('node')
+                osm_types.append('node')
 
-            query = build_query(
+            query = self.overpass.build_query(
                 area = bbox,
-                element_types = element_types,
+                osm_types = osm_types,
                 selector = sel,
                 conditions = query_conditions,        # except for nature....
                 out = 'center'
@@ -205,7 +205,7 @@ class LandmarkManager:
             self.logger.debug(f"Query: {query}")
 
             try:
-                result = send_query(query)
+                result = self.overpass.send_query(query)
             except Exception as e:
                 self.logger.error(f"Error fetching landmarks: {e}")
                 continue

backend/src/utils/toilets_manager.py

@@ -2,14 +2,13 @@
 import logging
 import xml.etree.ElementTree as ET
 
-from ..overpass.overpass import build_query, send_query
-from ..overpass.caching_strategy import CachingStrategy
+from ..overpass.overpass import Overpass
 from ..structs.landmark import Toilets
 from ..constants import OSM_CACHE_DIR
 
 
 # silence the overpass logger
-logging.getLogger('overpass').setLevel(level=logging.CRITICAL)
+logging.getLogger('Overpass').setLevel(level=logging.CRITICAL)
 
 class ToiletsManager:
     """
@@ -40,7 +39,9 @@ class ToiletsManager:
 
         self.radius = radius
         self.location = location
-        CachingStrategy.use('XML', cache_dir=OSM_CACHE_DIR)
+
+        # Setup the caching in the Overpass class.
+        self.overpass = Overpass(caching_strategy='XML', cache_dir=OSM_CACHE_DIR)
 
 
     def generate_toilet_list(self) -> list[Toilets] :
@@ -56,16 +57,16 @@ class ToiletsManager:
         osm_types = ['node', 'way', 'relation']
         toilets_list = []
 
-        query = build_query(
+        query = self.overpass.build_query(
                 area = bbox,
-                element_types = osm_types,
+                osm_types = osm_types,
                 selector = '"amenity"="toilets"',
                 out = 'ids center tags'
                 )
         self.logger.debug(f"Query: {query}")
 
         try:
-            result = send_query(query)
+            result = self.overpass.send_query(query)
         except Exception as e:
             self.logger.error(f"Error fetching landmarks: {e}")
             return None