import re

import textual.widgets


class MultiSelect(textual.widgets.Select):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.__new_options__ = []
        self.__seltion_states__ = {}
        self.__default_value__ = True
        self.__selection_regex__ = ""

    def __sorted_selection_keys__(self):
        rv = list(self.__seltion_states__.keys())
        rv.sort()
        return rv

    def SetSelectionRegEx(self, regex: str) -> None:
        self.__selection_regex__ = regex
        self.set_options(self.__get_select_list__())

    def AddEntry(self, entry) -> None:
        if entry not in self.__new_options__ and entry not in self.__seltion_states__:
            self.__seltion_states__[entry] = self.__default_value__
            self.__new_options__.append(entry)

    def __toggle__(self, entry_num):
        if entry_num < 0:
            if not self.__selection_regex__:
                self.__default_value__ = entry_num == -1
            for key in self.__seltion_states__:
                if self.__match__(key):
                    self.__seltion_states__[key] = entry_num == -1
        elif entry_num > len(self.__seltion_states__):
            raise ValueError(f"The Entry '{entry} is not in the list")
        else:
            entry = self.__sorted_selection_keys__()[entry_num]
            self.__seltion_states__[entry] = not self.__seltion_states__[entry]

    def __match__(self, key):
        try:
            match = len(re.findall(self.__selection_regex__, key)) > 0
        except re.error:
            match = True    # No valid regular expression
        return match

    def __get_select_list__(self):
        rv = []
        if len(self.__seltion_states__) > 2:
            rv.append(('All', -1))
            rv.append(('None', -2))
        for index, key in enumerate(self.__sorted_selection_keys__()):
            if self.__match__(key):
                prefix = "\\[X] " if self.__seltion_states__[key] else "\\[-] "
                rv.append((prefix + key, index))
        return rv

    def IsSelected(self, entry):
        return self.__seltion_states__.get(entry, self.__default_value__)

    def _on_blur(self, event):
        for entry in self.__new_options__:
            self.__seltion_states__[entry] = self.__default_value__
        self.__new_options__ = []
        self.set_options(self.__get_select_list__())
        return super()._on_blur(event)

    def _on_message(self, message):
        if type(message) == self.Changed:
            if type(message.value) is int:
                self.__toggle__(message.value)
                self.clear()
                self.set_options(self.__get_select_list__())
        return super()._on_message(message)