import re
import sys
import os
import importlib
import importlib.util
import site
from calculate.variables.old_vars.datavars import Variable, HashVariable,\
                                                  TableVariable
from calculate.variables.datavars import NamespaceNode, VariableNode,\
                                         ListType, IntegerType,\
                                         FloatType, IniType, TableType,\
                                         Namespace, VariableError
from calculate.utils.gentoo import ProfileWalker
from calculate.utils.files import list_directory, read_file, FilesError
from pyparsing import Literal, Word, ZeroOrMore, Group, Optional, restOfLine,\
                      empty, printables, OneOrMore, lineno, line, col, SkipTo,\
                      LineEnd, Combine, nums
from enum import Enum
from contextlib import contextmanager


class Define(Enum):
    assign = 0
    append = 1
    remove = 2


class CalculateIniParser:
    '''Класс парсера calculate.ini файлов.'''

    def __init__(self):
        self._errors = []

        self.operations = {"=": Define.assign,
                           "+=": Define.append,
                           "-=": Define.remove}

        lbrack = Literal("[")
        rbrack = Literal("]")

        # comma = Literal(",").suppress()
        comment_symbol = Literal(';') | Literal('#')

        # Define = self.Define
        value_operation = (Literal("=") | Combine(Literal("+") + Literal("="))
                           | Combine(Literal("-") + Literal("=")))

        comment = comment_symbol + Optional(restOfLine)

        section_name = (lbrack.suppress() + (~Word(nums)
                                             + Word(printables+'\t',
                                                    excludeChars='[]'))
                        + rbrack.suppress())

        value_name = Word(printables+'\t', excludeChars='=-+')

        # non_comma = Word(printables+'\t', excludeChars=',')
        clear_section = lbrack.suppress() + Group(empty) + rbrack.suppress()
        row_index = lbrack.suppress() + Word(nums) + rbrack.suppress()

        namespace_start = Group(OneOrMore(section_name)
                                + (clear_section | ~lbrack)
                                + LineEnd().suppress())

        table_start = Group(OneOrMore(section_name)
                            + (row_index | clear_section | ~lbrack)
                            + LineEnd().suppress())

        section_start = (namespace_start('namespace') |
                         table_start('table'))

        # Если содержимое ini-файла не предваряется заголовком секции,
        # значит эта строка ошибочна.
        unexpected = Group(~section_start + SkipTo(LineEnd(),
                                                   include=True))("error")
        unexpected.setParseAction(self._unexpected_token)

        key_value = (~lbrack + value_name
                     + value_operation + empty
                     + restOfLine + LineEnd().suppress())

        def strip_key_value(tokens):
            tokens[0] = tokens[0].strip()
            tokens[1] = tokens[1].strip()

        key_value.setParseAction(strip_key_value)

        self.ini_section_parser = (section_start
                                   + Group(ZeroOrMore(
                                                Group(key_value | unexpected)))
                                   | unexpected)
        self.ini_section_parser.ignore(comment)

    def parse(self, data: str):
        for tokens, start, end in self.ini_section_parser.scanString(data):
            if tokens.getName() == "error":
                continue

            section, defkeys = tokens

            if section.getName() == 'namespace':
                section_list = section.asList()
                if section_list[-1] == []:
                    yield {'clear_section': (section_list[:-1], )}
                else:
                    yield {'start_section': (section_list, )}

                for defkey in defkeys:
                    if defkey.getName() == "error":
                        continue
                    yield {'define_key': (defkey[0], defkey[2],
                                          self.operations[defkey[1]])}
            else:
                table_list = section.asList()
                if table_list[-1] == []:
                    yield {'clear_table': (table_list[:-1], )}
                else:
                    table_values = {}
                    for defkey in defkeys:
                        if defkey.getName() == "error":
                            continue
                        table_values.update({defkey[0]: defkey[2]})
                    yield {'start_table': (table_list, table_values)}

    def _unexpected_token(self, string, location, tokens):
        '''Метод вызываемый парсером, если обнаружена некорректная строка,
        предназначен для получения некорректной строки и ее дальнейшего
        разбора.'''
        error_line = line(location, string).strip()
        if error_line:
            self._errors.append((error_line, lineno(location, string),
                                col(location, string)))

    @property
    def errors(self):
        errors = self._errors
        self._errors = []
        return errors


class NamespaceIniFiller:
    '''Класс, предназначенный для наполнения Namespace объекта переменными
    из calculate.ini файла.'''
    available_sections = {'custom'}

    def __init__(self, restrict_creation=True):
        self.ini_parser = CalculateIniParser()
        self.restricted = restrict_creation
        self.modify_only = False

    def error(self, lineno, error_message):
        self.errors.append(lineno, error_message)

    def fill(self, namespace: NamespaceNode, ini_file_text: str) -> None:
        '''Метод для разбора calculate.ini файла и добавления всех его
        переменных в указанное пространство имен.'''
        self.namespace = namespace
        self.current_namespace = self.namespace
        self.errors = []

        for parsed_line in self.ini_parser.parse(ini_file_text):
            self._line_processor(**parsed_line)

    def _line_processor(self, start_section=None,
                        clear_section=None,
                        start_table=None,
                        clear_table=None,
                        define_key=None,
                        error=None, **kwargs):
        if start_section is not None:
            self.start_section(*start_section)
        elif clear_section is not None:
            self.clear_section(*clear_section)
        elif start_table is not None:
            self.start_table(*start_table)
        elif clear_table is not None:
            self.clear_table(*clear_table)
        elif define_key is not None:
            self.define_key(*define_key)

        for error in self.ini_parser.errors:
            self.set_error(*error)

    def start_section(self, sections: str) -> None:
        '''Метод для получения доступа и создания пространств имен.'''
        print('SECTIONS: {}'.format(sections))
        if self.restricted:
            self.modify_only = sections[0] not in self.available_sections
        self.current_namespace = self.namespace
        for section in sections:
            print('START SECTION: {}'.format(section))
            if isinstance(self.current_namespace, Datavars):
                if section not in self.current_namespace:
                    raise VariableError("variables package '{}' is not found".
                                        format(section))
            elif isinstance(self.current_namespace, NamespaceNode):
                if section not in self.current_namespace.namespaces:
                    if not self.modify_only:
                        self.current_namespace.add_namespace(
                                                        NamespaceNode(section))
                    else:
                        self.current_namespace = None
                        return
            self.current_namespace = self.current_namespace.namespaces[section]

    def clear_section(self, sections: list) -> None:
        '''Метод для очистки пространства имен.'''
        if self.restricted:
            self.modify_only = sections[0] not in self.available_sections
        current_namespace = self.namespace

        for section in sections:
            if (isinstance(current_namespace, Datavars) and
               section in current_namespace):
                current_namespace = current_namespace[section]
            elif isinstance(current_namespace, NamespaceNode):
                if section in current_namespace.namespaces:
                    current_namespace = current_namespace[section]
                elif (section in current_namespace.variables and
                      current_namespace.variables[section].variable_type
                      is TableType):
                    table_variable = current_namespace.variables[section]
                    table_to_clear = table_variable.get_value()
                    table_to_clear.clear()
                    table_variable.source = table_to_clear
                    return
                else:
                    return
        if not self.modify_only:
            current_namespace.clear()

    def start_table(self, sections: str, row) -> None:
        '''Метод для создания и модификации таблиц.'''
        if self.restricted:
            self.modify_only = sections[0] not in self.available_sections
        self.current_namespace = self.namespace
        row_index = int(sections.pop())
        table_name = sections.pop()
        for section in sections:
            if section not in self.current_namespace.namespaces:
                if not self.modify_only:
                    self.current_namespace.add_namespace(
                                                        NamespaceNode(section))
                else:
                    self.current_namespace = None
                    return
            self.current_namespace = self.current_namespace.namespaces[section]
        if table_name not in self.current_namespace.variables:
            if not self.modify_only:
                table_variable = VariableNode(table_name,
                                              self.current_namespace,
                                              variable_type=TableType,
                                              source=[row])
        else:
            table_variable = self.current_namespace.variables[table_name]
            table = table_variable.get_value()
            if row_index < len(table):
                table.change_row(row, row_index)
            else:
                table.add_row(row)
            table_variable.source = table

    def define_key(self, key: str, value: str, optype) -> None:
        print('DEFINE KEY: {} -> {} TO {}'.format(key, value,
                                                  self.current_namespace))
        if self.current_namespace is None:
            return

        if optype == Define.assign:
            if key not in self.current_namespace:
                self.define_variable(key, value)
            else:
                self.change_value(key, value)
        elif optype == Define.append:
            if key not in self.current_namespace:
                self.define_variable(key, value)
            else:
                self.append_value(key, value)
        elif optype == Define.remove:
            if key not in self.current_namespace:
                self.define_variable(key, value)
            else:
                self.remove_value(key, value)

    def change_value(self, key: str, value: str) -> None:
        '''Метод для изменения значения переменной.'''
        variable = self.current_namespace[key]
        variable.source = value

    def define_variable(self, key: str, value: str) -> None:
        '''Метод для создания переменных в calculate.ini файле.'''
        if not self.modify_only:
            VariableNode(key, self.current_namespace, variable_type=IniType,
                         source=value)
        else:
            # TODO Какая-то обработка ошибки.
            pass

    def append_value(self, key: str, value: str) -> None:
        '''Метод выполняющий действия возложенные на оператор +=.'''
        variable = self.current_namespace[key]
        variable_value = variable.get_value()

        if variable.variable_type is IniType:
            value_list = value.split(',')
            variable_list = variable_value.split(',')

            for item in value_list:
                if item not in variable_list:
                    variable_list.append(item.strip())
            variable_value = ','.join(variable_list)

        elif variable.variable_type is ListType:
            value_list = value.split(',')

            for item in value_list:
                if item not in variable_value:
                    variable_value.append(item.strip())

        elif variable.variable_type is IntegerType:
            variable_value += int(value)

        elif variable.variable_type is FloatType:
            variable_value += float(value)

        variable.source = variable_value

    def remove_value(self, key: str, value: str) -> None:
        '''Метод выполняющий действия возложенные на оператор -=.'''
        variable = self.current_namespace[key]
        variable_value = variable.get_value()
        if variable.variable_type is IniType:
            value_list = value.split(',')
            variable_list = [item.strip() for item in
                             variable_value.split(',')]

            for item in value_list:
                if item in variable_list:
                    variable_list.remove(item.strip())
            variable_value = ','.join(variable_list)

        elif variable.variable_type is ListType:
            value_list = value.split(',')
            for item in value_list:
                if item in variable_value:
                    variable_value.remove(item.strip())

        elif variable.variable_type is IntegerType:
            variable_value -= int(value)

        elif variable.variable_type is FloatType:
            variable_value -= float(value)

        variable.source = variable_value

    def set_error(self, line, lineno, col):
        '''Метод для добавления ошибки в лог.'''
        self.error(lineno, "Syntax error: {}".format(line))


class VariableLoader:
    '''Класс загрузчика переменных из python-файлов и из ini-файлов.'''
    ini_basename = "calculate.ini"

    def __init__(self, datavars, variables_path, repository_map=None):
        self.datavars = datavars
        self.ini_filler = NamespaceIniFiller()

        self.variables_path = variables_path
        self.variables_package = '.'.join(variables_path.split('/'))
        self.repository_map = repository_map

    def load_variables_package(self, package_name: str) -> None:
        '''Метод для загрузки пакетов с переменными.'''
        directory_path = os.path.join(self.variables_path, package_name)
        package = '{}.{}'.format(self.variables_package, package_name)
        package_namespace = NamespaceNode(package_name)
        self.datavars.root.add_namespace(package_namespace)
        self._fill_from_package(package_namespace, directory_path, package)

    def load_from_profile(self):
        if self.repository_map != {}:
            self.repository_map = (self.repository_map or
                                   self._get_repository_map(self.datavars))
            profile_path = self.datavars.os.gentoo.profile.path
            self._fill_from_ini(profile_path)

    def _fill_from_package(self, current_namespace: NamespaceNode,
                           directory_path: str, package: str) -> None:
        '''Метод для зaполнения переменных из python-файла.'''
        file_nodes = []
        directory_nodes = []
        # Просматриваем директорию
        for node in os.scandir(directory_path):
            if node.is_dir():
                directory_nodes.append(node)
            elif node.is_file() and node.name.endswith('.py'):
                file_nodes.append(node)

        # Сначала загружаем переменные из файлов.
        for file_node in file_nodes:
            file_name = file_node.name[:-3]
            Namespace.set_current_namespace(current_namespace)
            with self.test(file_name, current_namespace):
                # importlib.import_module('{}.{}'.format(package, file_name))
                spec = importlib.util.spec_from_file_location(
                                            '{}.{}'.format(package, file_name),
                                            file_node.path)
                module = importlib.util.module_from_spec(spec)
                spec.loader.exec_module(module)

        # Обходим остальные директории.
        for directory_node in directory_nodes:
            namespace = NamespaceNode(directory_node.name)
            current_namespace.add_namespace(namespace)
            self._fill_from_package(namespace, directory_node.path,
                                    '{}.{}'.format(package,
                                                   directory_node.name))

    def _fill_from_ini(self, profile_path):
        '''Метод для зaполнения переменных из ini-файла.'''
        print('PROCESSING INI FROM PROFILE')
        profile_walker = ProfileWalker(self.ini_basename,
                                       self.repository_map)
        for file_path in profile_walker.find(profile_path):
            try:
                print('PROCESS FILE: {}'.format(file_path))
                ini_file_text = read_file(file_path)
                self.ini_filler.fill(self.datavars, ini_file_text)
            except FilesError:
                # TODO продумать обработку ошибок.
                pass

    def _get_repository_map(self, datavars):
        return {repo['name']: repo['path']
                for repo in datavars.os.gentoo.repositories}

    def fill_from_custom_ini(self, file_path: str):
        '''Метод для заполнения переменных из конкретного указанного файла.'''
        print('LOAD FROM INI: {}'.format(file_path))
        if os.path.exists(file_path):
            ini_file_text = read_file(file_path)
            self.ini_filler.fill(self.datavars, ini_file_text)

    @contextmanager
    def test(self, file_name, namespace):
        print('IMPORT: {}.{}'.format(namespace.get_fullname(), file_name))
        try:
            yield self
        finally:
            print('IMPORTED FROM: {}.{}'.format(namespace.get_fullname(),
                                                file_name))


class Datavars:
    '''Класс для хранения переменных и управления ими.'''
    def __init__(self, variables_path='calculate/vars', repository_map=None):
        self._variables_path = variables_path
        self._available_packages = self._get_available_packages()

        self.root = NamespaceNode('<root>')
        self._loader = VariableLoader(self, self._variables_path,
                                      repository_map=repository_map)
        Namespace.reset()
        Namespace.set_datavars(self)

        self._loader.load_from_profile()

    def reset(self):
        '''Метод для сброса модуля переменных.'''
        self.root.clear()
        self.root = NamespaceNode('<root>')
        self._available_packages.clear()
        self._available_packages = self._get_available_packages()
        Namespace.set_datavars(self)

    def _get_available_packages(self) -> dict:
        '''Метод для получения словаря с имеющимися пакетами переменных
        и путями к ним.'''
        available_packages = dict()
        for file_name in os.listdir(self._variables_path):
            if file_name.startswith('__'):
                continue
            file_path = os.path.join(self._variables_path, file_name)
            if os.path.isdir(file_path):
                available_packages.update({file_name: file_path})
        return available_packages

    def __getattr__(self, package_name: str):
        '''Метод возвращает ноду пространства имен, соответствующего искомому
        пакету.'''
        print('getattr: {}'.format(package_name))
        if package_name in self.root.namespaces:
            return self.root[package_name]
        elif package_name not in self._available_packages:
            raise VariableError("variables package '{}' is not found".
                                format(package_name))
        else:
            self._loader.load_variables_package(package_name)
            return self.root[package_name]

    def __getitem__(self, package_name: str) -> None:
        '''Метод возвращает ноду пространства имен, соответствующего искомому
        пакету.'''
        print('getitem: {}'.format(package_name))
        if package_name in self.root:
            return self.root[package_name]
        elif package_name not in self._available_packages:
            raise VariableError("variables package '{}' is not found".
                                format(package_name))
        else:
            self._loader.load_variables_package(package_name)
            return self.root[package_name]

    def __contains__(self, package_name):
        if package_name in self.root.namespaces:
            return True
        elif package_name not in self._available_packages:
            return False
        else:
            self._loader.load_variables_package(package_name)
            return True

    @property
    def namespaces(self):
        return self.root.namespaces


class OldVariableLoader:
    '''Класс, используемый для загрузки переменных из python модуля.'''
    re_upper = re.compile("(.)([A-Z])")

    def _get_varlike_attrs(self, obj):
        '''Метод для получения списка аттрибутов похожих на переменные.'''
        for attrname in (x for x in dir(obj) if x[:1].isupper()):
            yield self.re_upper.sub(r"\1_\2", attrname).lower(), \
                getattr(obj, attrname)

    def fill(self, namespace, dirpath, package):
        '''Загрузить в namespace переменные из указанных модулей.'''
        for fullfn in list_directory(dirpath, fullpath=True):
            dn, fn = os.path.split(fullfn)
            if os.path.isdir(fullfn):
                newns = namespace.add_namespace(Namespace(fn))
                self.fill(newns, fullfn, "{}.{}".format(package, fn))
            elif fn.endswith(".py"):
                module = self._load_module_source(package, fn, fullfn)
                for varname, cls in self._get_varlike_attrs(module):
                    if Variable.is_implementation(cls):
                        namespace.add_variable(cls(varname))
                    elif HashVariable.is_implementation(cls) or \
                        TableVariable.is_implementation(cls) or \
                            Namespace.is_implementation(cls):
                        _newns = namespace.add_namespace(cls(varname,
                                                             namespace))
                        for _varname, _cls in self._get_varlike_attrs(cls):
                            if Variable.is_implementation(_cls):
                                _newns.add_variable(_cls(_varname))

    @classmethod
    def default(cls):
        site_dirs = [os.path.normpath(x) for x in site.getsitepackages()]
        for site_dir in site_dirs:
            calculate_dir = os.path.join(site_dir, "calculate/vars")
            if os.path.exists(calculate_dir):
                return (calculate_dir, "calculate.vars")

    def _load_module_source(self, package, name, path):
        if name.startswith('calculate.vars.'):
            full_name = name
        else:
            full_name = '.'.join([package, name])

        if full_name in sys.modules:
            return sys.modules[full_name]

        spec = importlib.util.spec_from_file_location(full_name, path)
        module = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(module)
        sys.modules[full_name] = module
        return module


class OldProfileFiller:
    """
    Заполнитель значений переменных из файлов calculate.ini в профилях
    """
    basename = "calculate.ini"

    def get_repository_map(self, datavars):
        return {repo['name']: repo['path']
                for repo in datavars.os.gentoo.repositories}

    def fill(self, datavars, profile_path):
        ini_filler = NamespaceIniFiller()
        profile_walker = ProfileWalker(self.basename,
                                       self.get_repository_map(datavars))
        for file_path in profile_walker.find(profile_path):
            try:
                ini_file_text = read_file(file_path)
                ini_filler.fill(datavars, ini_file_text)
            except FilesError:
                pass