import io
from datetime import datetime, timedelta
from typing import Mapping, Optional, Tuple, no_type_check

from bs4 import BeautifulSoup
import requests
import pandas as pd


class RossetiParser:
    def __init__(self, ndays=7, today=datetime.today(), file_path: Optional[str] = None):
        self.base_url = "https://rosseti-lenenergo.ru/planned_work"

        self.ndays = ndays
        self.today = today

        if file_path is None:
            self.fetch(ndays)
        else:
            self.load_df(file_path)

    def __str__(self):
        return f"From {self.today.date()} for {self.ndays} days with {len(self.df)}_records"

    @staticmethod
    def __format_date(date: datetime) -> str:
        return date.strftime("%d.%m.%y")

    def __compose_date_params(self, ndays: int, today: datetime) -> Mapping[str, str]:
        date_start = self.__format_date(today)
        date_finish = self.__format_date(today + timedelta(days=ndays))

        return {
            'date_start': date_start,
            'date_finish': date_finish
        }

    def __get_page(self, url: str, params: Mapping[str, str]):
        r = requests.get(url, params)

        self.soup = BeautifulSoup(r.text, features='html.parser')

    def __parse_nav(self) -> Tuple[str, str]:
        navigator = self.soup.find('span', attrs={'class': 'page-nav-i'})

        next_uri = navigator.find('a', attrs={'class': 'next'})['href']
        last_uri = navigator.find_all('a')[-1]['href']

        return next_uri, last_uri

    def __parse_table(self) -> pd.DataFrame:
        table = self.soup.find(
            'table', attrs={'class': 'tableous_facts funds'})

        return pd.read_html(io.StringIO(str(table)))[0]

    def __set_columns(self):
        self.df.columns = (
            "Регион РФ (область, край, город фед. значения, округ)",
            "Административный район",
            "Населённый пункт",
            "Улица",
            "Плановая дата начала отключения электроснабжения",
            "Плановое время начала отключения электроснабжения",
            "Плановая дата восстановления отключения электроснабжения",
            "Плановое время восстановления отключения электроснабжения",
            "Филиал",
            "РЭС",
            "Комментарий",
        )

    def fetch(self, ndays: Optional[int] = None, today: Optional[datetime] = None):
        if ndays is None:
            ndays = self.ndays
        if today is None:
            today = self.today

        params = self.__compose_date_params(ndays, today)

        self.__get_page(self.base_url, params)

        next_uri, last_uri = self.__parse_nav()

        self.df = self.__parse_table()

        def get(next_uri: str):
            self.__get_page(self.base_url + next_uri, params) # Instead of adding params to every request session could be used to store them with cookies
            self.df = pd.concat(
                (self.df, self.__parse_table()), ignore_index=True)

        while next_uri != last_uri:
            get(next_uri)

            next_uri, _ = self.__parse_nav()

        get(next_uri)

        self.__set_columns()

    def save_df(self, file_path: str):
        self.df.to_csv(file_path)

    def load_df(self, file_path: str):
        self.df = pd.read_csv(file_path)


def main():
    parser = RossetiParser()

    print(parser)

    parser.save_df('./data.csv')


if __name__ == "__main__":
    main()