Refactor PyServer class

Improve readability and add documentation
main
Bram van den Heuvel 2026-06-06 17:48:28 +02:00
parent dcc8bb9636
commit f9911507f4
2 changed files with 132 additions and 73 deletions

View File

@ -83,7 +83,7 @@ if __name__ == "__main__":
c = PyClient([
"http://127.0.0.1:5001",
"http://127.0.0.1:5002"
"http://127.0.0.1:5002",
], debug=True)
out = c.play_game("/tic-tac-toe", TicTacToe)
out = c.play_game("tic-tac-toe", TicTacToe)

View File

@ -5,124 +5,183 @@ from __future__ import annotations
from collections.abc import Callable, Mapping
from typing import Any, Optional
from flask import Flask, jsonify, request
from flask import Flask, Response, jsonify, request
from functools import wraps
GameHandler = Callable[[Any], Any]
PayloadType = dict[str, Any]
GameHandler = Callable[[PayloadType], PayloadType]
class PyServer:
"""A tiny stateless Flask app that serves discovery and game routes."""
def __init__(self, name: str, profile: Optional[Mapping[str, Any]] = None, import_name: str = __name__) -> None:
def __init__(self,
name: str,
import_name: str = __name__,
profile: Optional[PayloadType] = None,
subpath : str = "",
) -> None:
"""
Create a PyServer.
:param name: Preferred display name for discovery.
:param profile: Additional root-level discovery metadata.
:type name: str
:param import_name: Flask import name.
:type import_name: str
:param profile: Additional root-level discovery metadata.
:type profile: Optional[Dict[str, Any]]
:type subpath: str
:raises ValueError: The input contains invalid information.
"""
self.name = name
self.profile = dict(profile or {})
if "name" in self.profile:
raise ValueError("Root profile metadata must not define 'name'.")
raise ValueError(
"Root profile metadata must not define 'name'."
)
if "games" in self.profile:
raise ValueError("Root profile metadata must not define 'games'.")
raise ValueError(
"Root profile metadata must not define 'games'."
)
self.app = Flask(import_name)
self._games: dict[str, dict[str, Any]] = {}
self._registered_routes: set[str] = set()
self.__games: dict[str, PayloadType] = {}
self.__registered_routes: set[str] = set()
self._register_root()
# Register the root
self.__add_api_endpoint("", "", lambda _ : self.__discovery())
# self.app.add_url_rule("/",
# endpoint="botman_discovery",
# view_func=self.__discovery,
# methods=["GET"]
# )
def __add_api_endpoint(self, name : str, route : str, func : GameHandler) -> None:
"""
Create a new API endpoint.
def _register_root(self) -> None:
def discovery() -> Any:
payload = {"name": self.name, **self.profile, "games": dict(self._games)}
return jsonify(payload)
:param name: The name of the action to undertake.
:type name: str
:param func: The player's function that determines what action to take.
:type func: Callable[[dict[str, Any]], dict[str, Any]]
:raises ValueError: The URL has already been registered.
"""
url = self.__make_url(name, route)
self.app.add_url_rule("/", endpoint="botman_discovery", view_func=discovery, methods=["GET"])
if url in self.__registered_routes:
raise ValueError(
f"Route already registered: {url}"
)
self.__registered_routes.add(url)
@staticmethod
def _normalize_segment(segment: str) -> str:
normalized = segment.strip("/")
if not normalized:
raise ValueError("Route segments must not be empty.")
return normalized
return self.app.add_url_rule(url,
endpoint="botman_" + name.replace("/", "_"),
view_func=self.__func_wrapper(func),
methods=["GET"],
)
def __discovery(self) -> PayloadType:
"""
Return the server's discovery information.
def _compose_route(self, game_name: str, action_name: str) -> str:
normalized_game = self._normalize_segment(game_name)
normalized_action = action_name.strip("/")
return f"/{normalized_game}" if not normalized_action else f"/{normalized_game}/{normalized_action}"
:return: The personal discovery information.
:rtype: dict[str, Any]
"""
return {
"name": self.name,
"games": dict(self.__games),
**self.profile,
}
def _register_action(self, route: str, handler: GameHandler) -> None:
if route in self._registered_routes:
raise ValueError(f"Route already registered: {route}")
def __func_wrapper(self, func : GameHandler) -> Callable[[], Response]:
"""
Wrapper that catches an incoming request, parses it, and responds
with a player's action response.
"""
@wraps(func)
def exec():
payload = request.get_json(silent=True) or {}
result = func(payload) or {}
return jsonify(result)
return exec
endpoint = f"botman_{len(self._registered_routes)}"
def view() -> Any:
payload = request.get_json(silent=True)
return jsonify(handler(payload))
self.app.add_url_rule(route, endpoint=endpoint, view_func=view, methods=["GET"])
self._registered_routes.add(route)
def __make_url(self, name : str, route : str) -> str:
return "/" + "/".join([ name.strip("/"), route.strip("/") ]).strip("/")
def add_game(
self,
game_name: str,
custom_profile: Mapping[str, Any],
actions: Mapping[str, GameHandler],
required_actions: Optional[tuple[str, ...]] = None,
name: str,
profile: PayloadType,
actions: dict[str, GameHandler],
required_actions: Optional[list[str]] = None,
) -> None:
"""
Register a stateless game with one or more action routes.
:param game_name: Base route name for the game.
:param custom_profile: Game-specific discovery metadata.
:param name: Base route name for the game.
:type name: str
:param profile: Game-specific discovery metadata.
:type profile: dict[str, Any]
:param actions: Mapping of action subpaths to handlers.
:type actions: dict[str, Callable[[dict[str, Any]], dict[str, Any]]]
:param required_actions: Optional completeness check. If provided, all
required action names must exist in ``actions`` and map to callables.
:type required_actions: Optional[list[str]]
:raises AssertionError: Some of the required actions aren't present.
:raises ValueError: Some of the requested URL paths are already occupied.
"""
if not isinstance(custom_profile, Mapping):
raise TypeError("custom_profile must be a mapping.")
if not isinstance(actions, Mapping) or not actions:
raise ValueError("actions must be a non-empty mapping.")
normalized_profile = dict(custom_profile)
# Verify that all required actions are present
if required_actions is not None:
missing_actions = [action_name for action_name in required_actions if action_name not in actions]
if missing_actions:
raise ValueError(f"Missing required action handlers: {', '.join(sorted(missing_actions))}")
missing_actions = [ action for action in required_actions if action not in actions ]
prepared_routes: list[tuple[str, GameHandler]] = []
for action_name, handler in actions.items():
if not isinstance(action_name, str):
raise TypeError("Action names must be strings.")
if handler is None or not callable(handler):
raise TypeError(f"Action handler for '{action_name}' must be callable.")
prepared_routes.append((self._compose_route(game_name, action_name), handler))
if len(missing_actions) > 0:
raise AssertionError(
f"Missing required action handlers: {', '.join(sorted(missing_actions))}"
)
# Verify that there are no duplicate URLs being registered
# Even though this will automatically be checked later, checking this
# now ensures that the operation is atomic and doesn't add
# games partially.
new_routes : set[str] = set()
normalized_routes = [route for route, _ in prepared_routes]
if len(set(normalized_routes)) != len(normalized_routes):
raise ValueError("Action routes must be unique after normalization.")
for route in actions:
url = self.__make_url(name, route)
duplicate_routes = [route for route, _ in prepared_routes if route in self._registered_routes or route in self._games]
if duplicate_routes:
raise ValueError(f"Route already registered: {duplicate_routes[0]}")
if url in self.__registered_routes:
raise ValueError(
"Route {url} was already registered"
)
if url in new_routes:
raise ValueError(
"Route {url} was registered twice by the same function call"
)
new_routes.add(url)
# Register all actions
for route, func in actions.items():
self.__add_api_endpoint(name=name, route=route, func=func)
# Add profile data
self.__games[name] = profile
for route, handler in prepared_routes:
self._register_action(route, handler)
self._games[route] = dict(normalized_profile)
def add_tic_tac_toe(self, custom_profile: Mapping[str, Any], on_move: GameHandler) -> None:
def add_tic_tac_toe(self, profile: PayloadType, on_move: GameHandler) -> None:
"""
Convenience registration for tic-tac-toe.
The game is exposed at ``/tic-tac-toe``.
The game is exposed at `/tic-tac-toe`.
"""
self.add_game("tic-tac-toe", custom_profile, {"": on_move})
self.add_game(
name="tic-tac-toe",
profile=profile,
actions={"": on_move},
required_actions=[""],
)
def start(self, host: str = "127.0.0.1", port: int = 5000, debug: bool = False, **kwargs: Any) -> None:
"""Start the Flask development server."""