from __future__ import annotations

from dataclasses import dataclass, field
from typing import Any


class ServiceRegistry:
    def __init__(self) -> None:
        self._services: dict[str, Any] = {}

    def provide(self, name: str, service: Any) -> None:
        if not name:
            raise ValueError("service name must not be empty")
        self._services[name] = service

    def get(self, name: str, default: Any = None) -> Any:
        return self._services.get(name, default)

    def require(self, name: str) -> Any:
        if name not in self._services:
            raise KeyError(f"service not provided: {name}")
        return self._services[name]

    def has(self, name: str) -> bool:
        return name in self._services

    def names(self) -> tuple[str, ...]:
        return tuple(self._services)


@dataclass
class Context:
    services: ServiceRegistry = field(default_factory=ServiceRegistry)

    def provide(self, name: str, service: Any) -> None:
        self.services.provide(name, service)

    def get(self, name: str, default: Any = None) -> Any:
        return self.services.get(name, default)

    def require(self, name: str) -> Any:
        return self.services.require(name)