python-map-manager/map_manager/services.py
2025-12-02 09:09:22 +01:00

136 lines
5.2 KiB
Python

"""Provides map service implementations (OpenStreetMap) for python-map-manager.
This file is migrated from the original project and contains the
BaseMapService and OpenStreetMapService classes plus a factory helper.
"""
import abc
import logging
from urllib.parse import urlparse
from typing import Optional, Tuple
logger = logging.getLogger(__name__)
class BaseMapService(abc.ABC):
DEFAULT_TILE_PIXEL_SIZE: int = 256
DEFAULT_MAX_ZOOM_LEVEL: int = 19
def __init__(
self,
service_api_key: Optional[str] = None,
tile_pixel_dim: int = DEFAULT_TILE_PIXEL_SIZE,
max_supported_zoom: int = DEFAULT_MAX_ZOOM_LEVEL
) -> None:
self._service_log_prefix = f"[{self.__class__.__name__}]"
logger.debug(f"{self._service_log_prefix} Initializing base map service.")
self.api_key: Optional[str] = service_api_key
self.tile_size: int = tile_pixel_dim
self.max_zoom: int = max_supported_zoom
if not (isinstance(self.tile_size, int) and self.tile_size > 0):
logger.warning(
f"{self._service_log_prefix} Invalid tile_size '{self.tile_size}'. Using default: {self.DEFAULT_TILE_PIXEL_SIZE}px."
)
self.tile_size = self.DEFAULT_TILE_PIXEL_SIZE
if not (isinstance(self.max_zoom, int) and 0 <= self.max_zoom <= 25):
logger.warning(
f"{self._service_log_prefix} Invalid max_zoom '{self.max_zoom}'. Using default: {self.DEFAULT_MAX_ZOOM_LEVEL}."
)
self.max_zoom = self.DEFAULT_MAX_ZOOM_LEVEL
@property
@abc.abstractmethod
def name(self) -> str:
pass
@property
@abc.abstractmethod
def attribution(self) -> str:
pass
@abc.abstractmethod
def get_tile_url(self, z: int, x: int, y: int) -> Optional[str]:
pass
def is_zoom_level_valid(self, zoom_level: int) -> bool:
is_valid = 0 <= zoom_level <= self.max_zoom
if not is_valid:
logger.warning(
f"{self._service_log_prefix} Requested zoom level {zoom_level} is outside the valid range [0, {self.max_zoom}] for this service."
)
return is_valid
def _is_generated_url_structurally_valid(self, url_string: str) -> bool:
if not url_string:
logger.error(f"{self._service_log_prefix} Generated URL is empty.")
return False
try:
parsed_url = urlparse(url_string)
has_scheme_and_netloc = bool(parsed_url.scheme and parsed_url.netloc)
if not has_scheme_and_netloc:
logger.error(f"{self._service_log_prefix} Generated URL '{url_string}' appears malformed (missing scheme or netloc).")
return has_scheme_and_netloc
except Exception as e_url_parse:
logger.error(
f"{self._service_log_prefix} Error parsing generated URL '{url_string}': {e_url_parse}"
)
return False
def __repr__(self) -> str:
return (
f"<{self.__class__.__name__}(Name: '{self.name}', MaxZoom: {self.max_zoom}, TileSize: {self.tile_size})>"
)
class OpenStreetMapService(BaseMapService):
SERVICE_IDENTIFIER_NAME: str = "osm"
SERVICE_ATTRIBUTION_TEXT: str = (
"© OpenStreetMap contributors (openstreetmap.org/copyright)"
)
TILE_URL_TEMPLATE: str = "https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
OSM_MAX_ZOOM_LEVEL: int = 19
SUBDOMAINS: Tuple[str, ...] = ("a", "b", "c")
_subdomain_index: int = 0
def __init__(self) -> None:
super().__init__(service_api_key=None, max_supported_zoom=self.OSM_MAX_ZOOM_LEVEL)
logger.info(f"{self._service_log_prefix} OpenStreetMap service instance ready.")
@property
def name(self) -> str:
return self.SERVICE_IDENTIFIER_NAME
@property
def attribution(self) -> str:
return self.SERVICE_ATTRIBUTION_TEXT
def get_tile_url(self, z: int, x: int, y: int) -> Optional[str]:
if not self.is_zoom_level_valid(z):
return None
subdomain = self.SUBDOMAINS[OpenStreetMapService._subdomain_index % len(self.SUBDOMAINS)]
OpenStreetMapService._subdomain_index += 1
try:
tile_url = self.TILE_URL_TEMPLATE.format(s=subdomain, z=z, x=x, y=y)
if not self._is_generated_url_structurally_valid(tile_url):
return None
logger.debug(f"{self._service_log_prefix} Generated URL for ({z},{x},{y}): {tile_url}")
return tile_url
except Exception as e_url_format:
logger.error(
f"{self._service_log_prefix} Error formatting tile URL for ({z},{x},{y}): {e_url_format}"
)
return None
def get_map_service_instance(service_name_key: str, api_key_value: Optional[str] = None) -> Optional[BaseMapService]:
log_prefix_factory = "[MapServiceFactory]"
normalized_service_name = service_name_key.lower().strip()
logger.debug(f"{log_prefix_factory} Requesting map service instance for '{normalized_service_name}'.")
if normalized_service_name == OpenStreetMapService.SERVICE_IDENTIFIER_NAME:
return OpenStreetMapService()
else:
logger.error(f"{log_prefix_factory} Unknown map service name specified: '{service_name_key}'.")
return None