vban-tui/src/vban_tui/settings.py

from pathlib import Path
from typing import Annotated, Type

from pydantic import AfterValidator
from pydantic_settings import BaseSettings, CliSettingsSource, SettingsConfigDict


def is_valid_host(value: str) -> str:
    if not value:
        raise ValueError('Host cannot be empty')
    return value


def is_valid_port(value: int) -> int:
    if not (0 < value < 65536):
        raise ValueError('Port must be between 1 and 65535')
    return value


def is_valid_streamname(value: str) -> str:
    if len(value) > 16:
        raise ValueError('Stream name cannot be longer than 16 characters')
    return value


class Settings(BaseSettings):
    host: Annotated[str, AfterValidator(is_valid_host)] = 'localhost'
    port: Annotated[int, AfterValidator(is_valid_port)] = 6980
    streamname: Annotated[str, AfterValidator(is_valid_streamname)] = 'Command1'

    model_config = SettingsConfigDict(
        env_file=(
            '.env',
            Path.home() / '.config' / 'vban-tui' / 'config.env',
        ),
        env_file_encoding='utf-8',
        env_prefix='VBAN_TUI_',
        cli_prefix='',
        cli_parse_args=True,
        cli_implicit_flags=True,
        validate_assignment=True,
        frozen=False,
    )

    @classmethod
    def settings_customise_sources(
        cls,
        settings_cls: Type[BaseSettings],
        init_settings: ...,
        env_settings: ...,
        dotenv_settings: ...,
        file_secret_settings: ...,
    ) -> tuple:
        return (
            CliSettingsSource(settings_cls),
            env_settings,
            dotenv_settings,
            init_settings,
        )