import os
import tomllib
from pathlib import Path
from typing import Literal

from pydantic import BaseModel, Field, ValidationError


class ServiceConfig(BaseModel):
	name: str
	type: Literal["http", "tcp"]
	timeout: int = 5
	category: str | None = None


class HTTPServiceConfig(ServiceConfig):
	url: str = Field(alias="address")


class TCPServiceConfig(ServiceConfig):
	port: int
	hostname: str
	ipv: Literal[4, 6] = Field(alias="ip_version", default=4)


class WebConfig(BaseModel):
	addr: str = Field(alias="address", default="::")
	port: int = 4200
	name: str = "velping"
	pings: int = 25


class PingingConfig(BaseModel):
	rate: int = Field(alias="seconds_between_ping", default=60)


class NtfyConfig(BaseModel):
	enabled: bool = False
	server: str = "ntfy.sh"
	topic: str


Service = TCPServiceConfig | HTTPServiceConfig


class Config(BaseModel):
	web: WebConfig = Field(alias="frontend", default={})
	ntfy: NtfyConfig = NtfyConfig(topic="")
	pinging: PingingConfig
	# NOTE: dict is legacy and likely to be removed in a future release.
	services: list[Service] | dict[str, Service] = []


def load_cfg() -> Config:
	try:
		with Path(os.environ.get("VELPING_CONFIG", "config.toml")).open("rb") as f:
			cfg = Config(**tomllib.load(f))

		if isinstance(cfg.services, dict):
			print("Your services config is using a dict, which is deprecated.")
			cfg.services = list(cfg.services.values())

		cfg.services = sorted(cfg.services, key=lambda s: s.category or "")
	except ValidationError as e:
		raise SystemExit(str(e))

	return cfg