# vim: fileencoding=utf-8
#
from .base_format import BaseFormat
from ..template_engine import ParametersContainer
from collections import OrderedDict
from pyparsing import Word, Literal, alphanums, printables, originalTextFor,\
                      ZeroOrMore, OneOrMore, ParseException,\
                      pyparsing_unicode, Group, Optional


class PostfixFormat(BaseFormat):
    FORMAT = 'postfix'
    EXECUTABLE = False

    _initialized = False

    def __new__(cls, *args, **kwargs):
        if not cls._initialized:
            cls._initialize_parser()
        return super().__new__(cls)

    def __init__(self, document_text: str,
                 ignore_comments=False,
                 join_before=False,
                 parameters=ParametersContainer()):
        processing_methods = [self._parse_comment_line,
                              self._parse_parameter_line,
                              self._parse_to_delete_line]

        super().__init__(processing_methods)
        self._ignore_comments = ignore_comments
        self._comments_processing = True

        self._last_comments_list = []

        if document_text == '':
            self._document_dictionary = OrderedDict()
        else:
            document_lines = self._get_list_of_logic_lines(document_text)
            self._lines_to_dictionary(document_lines)

    @classmethod
    def _initialize_parser(cls):
        '''Метод для инициализации парсеров.'''
        parameter_name = Word(alphanums+'_')

        parameter_value = originalTextFor(OneOrMore(Word(printables)))

        action_symbols = (Literal('!') | Literal('-'))

        assignment = Literal('=')

        cls._parameter_line = (Group(Optional(action_symbols,
                                              default='')('action')
                                     + parameter_name)('parameter_name')
                               + assignment.suppress()
                               + parameter_value('parameter_value'))

        cls._parameter_to_delete = (action_symbols('action')
                                    + parameter_name('Name')
                                    )('parameter_name')

        cls._comment_line = originalTextFor(
                             Literal('#')
                             + ZeroOrMore(Word(printables
                                               + pyparsing_unicode.alphanums))
                                            )('comment')

    def _parse_parameter_line(self, line):
        '''Метод для парсинга строк содержащих параметр.'''
        try:
            self._item_to_add = OrderedDict()
            parsing_result = self._parameter_line.parseString(line)
            self._match = True

            key_value = tuple(parsing_result.parameter_name.asList())
            parameter_value = parsing_result.parameter_value

            parameter_value = self._last_comments_list + [parameter_value]
            self._last_comments_list = []

            self._item_to_add[key_value] = parameter_value
            self._ready_to_update = True
        except ParseException:
            return

    def _parse_to_delete_line(self, line):
        '''Метод для парсинга строк, подлежащих удалению, т.е. для которых
        указано имя параметра со знаком !, и опционально присутствует значение
        параметра.'''
        try:
            self._item_to_add = OrderedDict()
            parsing_result = self._parameter_to_delete.parseString(line)
            self._match = True

            if parsing_result.action == '-':
                return

            key_value = tuple(parsing_result.parameter_name.asList())
            parameter_value = self._last_comments_list
            self._last_comments_list = []

            self._item_to_add[key_value] = parameter_value
            self._ready_to_update = True
        except ParseException:
            return

    def _parse_comment_line(self, line):
        '''Метод для парсинга строк содержащих комментарий.'''
        try:
            parsing_result = self._comment_line.parseString(line)
            self._match = True

            if not self._ignore_comments:
                self._last_comments_list.append(parsing_result.comment)
        except ParseException:
            return