from __future__ import annotations

from collections.abc import Iterable

APP_MAIN = "main"
APP_MESSENGER = "messenger"
VALID_APPS = {APP_MAIN, APP_MESSENGER}

NOTIFICATION_CATEGORIES = (
    ("messages", "Сообщения"),
    ("tasks", "Задачи и доски"),
    ("requests", "Заявления"),
    ("procurement", "Закупки"),
    ("documents", "Документы и регламенты"),
    ("guests", "Гости"),
    ("calendar", "Календарь"),
    ("feed", "Новости"),
    ("other", "Остальные уведомления"),
)
CATEGORY_KEYS = tuple(key for key, _label in NOTIFICATION_CATEGORIES)

MESSAGE_VERBS = {
    "chat_added_to_chat",
    "chat_new_message",
    "chat_reply",
    "chat_mention",
    "announcement_new_message",
}

PREFIX_CATEGORIES = (
    (("task_", "board_"), "tasks"),
    (("request_",), "requests"),
    (("procurement_",), "procurement"),
    (("document_", "regulation_"), "documents"),
    (("guest_",), "guests"),
    (("event_", "calendar_"), "calendar"),
    (("feed_",), "feed"),
)


def notification_category(verb: str) -> str:
    if verb in MESSAGE_VERBS or verb.startswith("chat_"):
        return "messages"
    for prefixes, category in PREFIX_CATEGORIES:
        if verb.startswith(prefixes):
            return category
    return "other"


def default_routes() -> dict[str, list[str]]:
    return {key: [APP_MAIN] for key in CATEGORY_KEYS}


def normalize_destinations(destinations: object) -> list[str]:
    if not isinstance(destinations, Iterable) or isinstance(
        destinations,
        (str, bytes),
    ):
        return [APP_MAIN]
    normalized = []
    for destination in destinations:
        if destination in VALID_APPS and destination not in normalized:
            normalized.append(destination)
    return normalized or [APP_MAIN]


def normalize_routes(routes: object) -> dict[str, list[str]]:
    source = routes if isinstance(routes, dict) else {}
    return {
        key: normalize_destinations(source.get(key, [APP_MAIN]))
        for key in CATEGORY_KEYS
    }