# vim: fileencoding=utf-8
#
from .base_format import BaseFormat, FormatError
from ..template_engine import ParametersContainer
from jinja2 import Environment, PackageLoader
from collections import OrderedDict
from pyparsing import originalTextFor, Literal, ZeroOrMore, Word, printables,\
                      OneOrMore, alphanums, ParseException, pyparsing_unicode,\
                      Group, Optional, alphas, Keyword


class ProFTPDFormat(BaseFormat):
    '''Класс формата ProFTPD. В отличие от других форматов, при разборе
    вложенных на несколько уровней блоков, в итоговый словарь добавляются не
    вложенные на несколько уровней словари, а отдельные объекты этих блоков,
    содержащие в названии последовательность имен тегов, к которым они
    относятся.
    '''
    FORMAT = 'proftpd'
    EXECUTABLE = False

    _initialized = False

    comment_symbol = '#'

    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_section_start_line,
                              self._parse_section_end_line,
                              self._parse_single_key_directive_line,
                              self._parse_double_key_directive_line,
                              self._parse_to_delete_double_key_directive_line,
                              self._parse_full_key_directive_line,
                              self._parse_plain_directive_line,
                              self._parse_to_delete_plain_directive_line]

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

        self._section_stack = []
        self._actions_stack = []

        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.'''
        left_angle_bracket = Literal('<')
        right_angle_bracket = Literal('>')
        slash = Literal('/')

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

        directive = Word(alphas, alphanums)

        section_value = Word(printables, excludeChars='<>')

        directive_value = Word(printables)

        cls._section_start_parser = (left_angle_bracket.suppress()
                                     + Optional(action_symbols,
                                                default='')('action')
                                     + Group(directive('name')
                                             + originalTextFor(
                                                      OneOrMore(section_value)
                                                              )('value')
                                             )('directive')
                                     + right_angle_bracket.suppress())

        cls._section_end_parser = (left_angle_bracket.suppress()
                                   + slash.suppress()
                                   + directive('directive')
                                   + right_angle_bracket.suppress())

        cls._plain_directive_parser = (Optional(action_symbols)('action')
                                       + Group(directive('name')
                                               + originalTextFor(
                                                    OneOrMore(directive_value)
                                                                )('value')
                                               )('directive')
                                       )

        cls._delete_plain_directive_parser = (action_symbols('action')
                                              + directive('directive'))

        single_key_directive = (Keyword('AllowAll') |
                                Keyword('DenyAll') |
                                Keyword('AccessDenyMsg') |
                                Keyword('AccessGrantMsg') |
                                Keyword('ByteRatioErrMsg') |
                                Keyword('LeechRatioMsg') |
                                Keyword('CwdRatioMsg') |
                                Keyword('FileRatioErrMsg'))

        cls._single_key_directive_parser = (Optional(action_symbols)('action')
                                            + single_key_directive(
                                                                    'directive'
                                                                    ))

        double_key_directive = (Keyword('AccessDenyMsg') |
                                Keyword('AccessGrantMsg') |
                                Keyword('ByteRatioErrMsg') |
                                Keyword('Allow from') | Keyword('Allow') |
                                Keyword('AllowFilter') |
                                Keyword('AnonymousGroup') |
                                Keyword('AuthPAMConfig') |
                                Keyword('Bind') |
                                Keyword('CDPath') |
                                Keyword('Define') |
                                Keyword('Deny from') | Keyword('Deny') |
                                Keyword('DenyFilter') |
                                Keyword('DisplayChdir') |
                                Keyword('ExtendedLog') |
                                Keyword('AnonRatio') |
                                Keyword('GroupRatio') |
                                Keyword('HideGroup') |
                                Keyword('HideUser') |
                                Keyword('HostRatio') |
                                Keyword('Include') |
                                Keyword('LDAPAttr') |
                                Keyword('LeechRatioMsg') |
                                Keyword('CwdRatioMsg') |
                                Keyword('FileRatioErrMsg') |
                                Keyword('LogFormat') |
                                Keyword('MaxClientsPerClass') |
                                Keyword('PIDFile') |
                                Keyword('RewriteMap') |
                                Keyword('RewriteRule') |
                                Keyword('SetEnv') |
                                Keyword('SQLConnectInfo') |
                                Keyword('SQLGroupWhereClause') |
                                Keyword('SQLLog') |
                                Keyword('SQLNamedQuery') |
                                Keyword('SQLShowInfo') |
                                Keyword('SQLUserInfo') |
                                Keyword('SQLUserWhereClause') |
                                Keyword('LoadModule') |
                                Keyword('LoadFile') |
                                Keyword('TransferRate') |
                                Keyword('UnsetEnv') |
                                Keyword('UserPassword') |
                                Keyword('UserRatio') |
                                Keyword('ModuleControlsACLs') |
                                Keyword('ControlsACLs'))

        cls._double_key_directive_parser = (Optional(action_symbols)('action')
                                            + Group((double_key_directive
                                                     + directive_value
                                                     )('name')
                                                    + originalTextFor(
                                                              ZeroOrMore(
                                                                directive_value
                                                                        )
                                                                     )('value')
                                                    )('directive')
                                            )

        cls._delete_double_key_directive_parser = (action_symbols('action')
                                                   + Group(
                                                        (
                                                           double_key_directive
                                                           + directive_value
                                                        )('name')
                                                          )('directive')
                                                   )

        full_key_directive = (Keyword('AllowClass') |
                              Keyword('AllowGroup') |
                              Keyword('AllowUser') |
                              Keyword('Class') |
                              Keyword('DenyClass') |
                              Keyword('DenyGroup') |
                              Keyword('DenyUser') |
                              Keyword('DirFakeGroup') |
                              Keyword('DirFakeUser') |
                              Keyword('HideFiles') |
                              Keyword('MaxRetrieveFileSize') |
                              Keyword('MaxStoreFileSize') |
                              Keyword('RewriteCondition') |
                              Keyword('RewriteLock') |
                              Keyword('TimeoutSession') |
                              Keyword('UserAlias'))

        cls._full_key_directive_parser = (Optional(action_symbols)('action')
                                          + Group(full_key_directive
                                                  + OneOrMore(
                                                              directive_value
                                                             )
                                                  )('directive')
                                          )

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

    def _parse_section_start_line(self, line):
        '''Метод для разбора тега открывающего секцию.'''
        try:
            parsing_result = self._section_start_parser.parseString(line)
            self._match = True

            section_name = tuple(parsing_result.directive.asList())
            self._actions_stack.append(parsing_result.action)
            self._section_stack.append(section_name)

        except ParseException:
            return

    def _parse_section_end_line(self, line):
        '''Метод для разбора тега закрывающего секцию.'''
        try:
            parsing_result = self._section_end_parser.parseString(line)
            self._match = True

            current_section = self._section_stack.pop()
            self._actions_stack.pop()
            directive = tuple(parsing_result.directive)

            if not current_section[1] != directive:
                raise FormatError("incorrect end tag </{}>, expected </{}>".
                                  format(directive, current_section))
        except ParseException:
            return

    def _parse_plain_directive_line(self, line):
        '''Метод для разбора строк состоящих из имени параметра и его значения.
        '''
        try:
            parsing_result = self._plain_directive_parser.parseString(line)
            self._match = True

            for action_item in self._actions_stack:
                if not action_item == '':
                    action = (action_item, )
                    break
            else:
                action = (parsing_result.action, )

            if not self._section_stack == []:
                context = (tuple(self._section_stack), )
            else:
                context = ('', )

            directive = (parsing_result.directive.name, )
            directive_value = [parsing_result.directive.value]

            directive_name = action + context + directive
            directive_value = self._last_comments_list + directive_value
            self._last_comments_list = []

            self._item_to_add = OrderedDict({directive_name: directive_value})
            self._ready_to_update = True
        except ParseException:
            return

    def _parse_to_delete_plain_directive_line(self, line):
        '''Метод для разбора строк с параметрами, подлежащими удалению, то есть
        содержащих имя параметра с символом ! и, опционально, его значение.'''
        try:
            parsing_result = self._delete_plain_directive_parser.parseString(
                                                                           line
                                                                            )
            self._match = True

            action = (parsing_result.action, )

            if not self._section_stack == []:
                context = (tuple(self._section_stack), )
            else:
                context = ('', )

            directive = (parsing_result.directive, )
            directive_name = action + context + directive

            directive_value = self._last_comments_list + ['']
            self._last_comments_list = []

            self._item_to_add = OrderedDict({directive_name: directive_value})
            self._ready_to_update = True
        except ParseException:
            return

    def _parse_single_key_directive_line(self, line):
        '''Метод для разбора строк с директивами, состоящих лишь из одного
        имени директивы.
        '''
        try:
            parsing_result = self._single_key_directive_parser.parseString(
                                                                           line
                                                                          )
            self._match = True

            for action_item in self._actions_stack:
                if not action_item == '':
                    action = (action_item, )
                    break
            else:
                action = (parsing_result.action, )

            if not self._section_stack == []:
                context = (tuple(self._section_stack), )
            else:
                context = ('', )

            directive = (parsing_result.directive, )
            directive_value = ['']

            directive_name = action + context + directive
            directive_value = self._last_comments_list + directive_value
            self._last_comments_list = []

            self._item_to_add = OrderedDict({directive_name: directive_value})
            self._ready_to_update = True
        except ParseException:
            return

    def _parse_double_key_directive_line(self, line):
        '''Метод для разбора директив, добавление в словарь которых возможно
        посредством формирования ключа из названия директивы и последующего за
        ней значения.'''
        try:
            parsing_result = self._double_key_directive_parser.parseString(
                                                                           line
                                                                          )
            self._match = True

            for action_item in self._actions_stack:
                if not action_item == '':
                    action = (action_item, )
                    break
            else:
                action = (parsing_result.action, )

            if not self._section_stack == []:
                context = (tuple(self._section_stack), )
            else:
                context = ('', )

            directive = tuple(parsing_result.directive.name.asList())
            directive_value = [parsing_result.directive.value]

            directive_name = action + context + directive
            directive_value = self._last_comments_list + directive_value
            self._last_comments_list = []

            self._item_to_add = OrderedDict({directive_name: directive_value})
            self._ready_to_update = True
        except ParseException:
            return

    def _parse_to_delete_double_key_directive_line(self, line):
        '''Метод для разбора директив, подлежащих удалению, ключи которых
        формируются из названия директивы и последующего за ней значения.'''
        try:
            parsing_result = self._delete_double_key_directive_parser.\
                    parseString(line)
            self._match = True

            action = (parsing_result.action, )

            if not self._section_stack == []:
                context = (tuple(self._section_stack), )
            else:
                context = ('', )

            directive = tuple(parsing_result.directive.name.asList())
            directive_name = action + context + directive

            directive_value = self._last_comments_list + ['']
            self._last_comments_list = []

            self._item_to_add = OrderedDict({directive_name: directive_value})
            self._ready_to_update = True
        except ParseException:
            return

    def _parse_full_key_directive_line(self, line):
        '''Метод для разбора строк с директивами, из имен которых невозможно
        составить уникальный ключ для итогового словаря. Такие директивы
        разбираем полностью как ключ для пустого значения в словаре.'''
        try:
            parsing_result = self._full_key_directive_parser.parseString(line)
            self._match = True

            for action_item in self._actions_stack:
                if not action_item == '':
                    action = (action_item, )
                    break
            else:
                action = (parsing_result.action, )

            if not self._section_stack == []:
                context = (tuple(self._section_stack), )
            else:
                context = ('', )

            directive = tuple(parsing_result.directive.asList())
            directive_value = ['']

            directive_name = action + context + directive
            directive_value = self._last_comments_list + directive_value
            self._last_comments_list = []

            self._item_to_add = OrderedDict({directive_name: directive_value})
            self._ready_to_update = True
        except ParseException:
            return

    def _parse_comment_line(self, line):
        '''Метод для разбора строк, содержащих комментарии.'''
        try:
            result = self._comment_line.parseString(line)
            self._match = True

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

    @property
    def document_text(self):
        file_loader = PackageLoader('calculate.templates.format',
                                    self.TEMPLATES_DIRECTORY)
        formats_environment = Environment(loader=file_loader)
        formats_environment.globals.update(zip=zip)
        formats_environment.add_extension('jinja2.ext.do')
        template = formats_environment.get_template(self.FORMAT)
        document_text = template.render(
                                  document_dictionary=self._document_dictionary
                                      )
        return document_text