#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from typing import Self, Callable, Any, Optional

class Event:

    def __init__(self:Self) -> None:
        self.__events:dict[int, Callable[[Optional[Any]], Any|None]] = {}

    def execute(self:Self, *inputs:Any|None) -> None:

        results:dict[int, Any|None] = {}
        
        for i, event in self.__events.items():
            results[i] = event(*inputs)

        return results
    
    def add(self:Self, event:Callable[[Optional[Any]], Any|None]) -> int:

        i:int = 0
        l:int = len(self.__events)

        while i < l:
            if i not in self.__events:
                break
            i += 1

        self.__events[i] = event

        return i
    
    def remove(self:Self, i:int) -> None:
        if i in self.__events:
            del self.__events[i]

    def clean(self:Self) -> None:
        self.__events = {}