import datetime
import re
from pathlib import Path
from typing import Dict, Optional, List
from datetime import *

from PyTeX.base import Attributes, Args


class TexFormatter:
    def __init__(self, name: str, author: str, header: Optional[List[str]], file_extension: str,
                 tex_version: str, version: str):
        self.version = version
        self.header = header
        self.name_raw = name
        self.author = author
        author_parts = self.author.lower().replace('ß', 'ss').split(' ')
        self.author_acronym = author_parts[0][0] + author_parts[-1]
        self.date = datetime.now().strftime('%Y/%m/%d')
        self.year = int(datetime.now().strftime('%Y'))
        self.replace_dict: Dict = {}
        self.arg_replace_dict: Dict = {}
        self.source_file_name = "not specified"
        self.name_lowercase = r'{prefix}-{name}'.format(prefix=self.author_acronym,
                                                        name=self.name_raw.lower().strip().replace(' ', '-'))
        self.file_name = self.name_lowercase + file_extension
        if tex_version == 'LaTeX2e':
            self.prefix = self.name_lowercase.replace('-', '@') + '@'
        elif tex_version == 'LaTeX3':
            self.prefix = '__' + self.name_lowercase.replace('-', '_') + '_'
        else:
            raise Exception('Unknown TeX version')

    @staticmethod
    def __command_name2keyword(keyword: str):
        return '__' + keyword.upper().strip().replace(' ', '_') + '__'

    @property
    def filename(self):
        return self.file_name

    def __parse_replacement_args(self, match_groups, *user_args, **user_kwargs):
        new_args = []
        for arg in user_args:
            if type(arg) == Attributes:
                new_args.append(getattr(self, arg.value))
            elif type(arg) == Args:
                new_args.append(match_groups[arg.value].strip())
            elif type(arg) == str:
                new_args.append(arg.strip())
            else:
                new_args += 'ERROR'
        new_args = tuple(new_args)
        new_kwargs = {}
        for kw in user_kwargs:
            if type(user_kwargs[kw]) == Attributes:
                new_kwargs[kw] = getattr(self, user_kwargs[kw].value)
            elif type(user_kwargs[kw]) == Args:
                new_kwargs[kw] = match_groups[user_kwargs[kw].value].strip()
            elif type(user_kwargs[kw]) == str:
                new_kwargs[kw] = user_kwargs[kw]
            else:
                new_kwargs[kw] = 'ERROR'
        return new_args, new_kwargs

    def __format_string(self, contents: str) -> str:
        for key in self.replace_dict.keys():
            contents = contents.replace(key, self.replace_dict[key])
        return contents

    def __format_string_with_arg(self, contents: str) -> str:
        for command in self.arg_replace_dict.keys():
            search_regex = re.compile(r'{keyword}\({arguments}(?<!@)\)'.format(
                keyword=command,
                arguments=','.join(['(.*?)'] * self.arg_replace_dict[command]['num_args'])
            ))
            match = re.search(search_regex, contents)
            while match is not None:
                format_args, format_kwargs = self.__parse_replacement_args(
                    list(map(lambda group: group.replace('@)', ')'), match.groups())),
                    *self.arg_replace_dict[command]['format_args'],
                    **self.arg_replace_dict[command]['format_kwargs']
                )
                contents = contents.replace(
                    match.group(),
                    self.arg_replace_dict[command]['replacement'].format(*format_args, **format_kwargs)
                )
                match = re.search(search_regex, contents)
        return contents

    def add_replacement(self, keyword: str, replacement: str, *args, **kwargs):
        args, kwargs = self.__parse_replacement_args([], *args, **kwargs)
        self.replace_dict[self.__command_name2keyword(keyword)] = replacement.format(*args, **kwargs)

    def add_arg_replacement(self, num_args: int, keyword: str, replacement: str, *args, **kwargs):
        self.arg_replace_dict[self.__command_name2keyword(keyword)] = {
            'num_args': num_args,
            'replacement': replacement,
            'format_args': args,
            'format_kwargs': kwargs
        }

    def format_file(self, input_path: Path, output_dir: Path = None):
        self.source_file_name = str(input_path.name)
        input_file = input_path.open()
        lines = input_file.readlines()
        if self.header:
            newlines = '%' * 80 + '\n' \
                       + '\n'.join(map(lambda line: '% ' + line, self.header)) \
                       + '\n' + '%' * 80 + '\n\n'
        else:
            newlines = []
        for line in lines:
            newlines += self.__format_string_with_arg(self.__format_string(line))
        if output_dir is None:
            output_dir = input_path.parent
        output_dir.mkdir(parents=True, exist_ok=True)
        (output_dir / self.file_name).write_text(''.join(newlines))