#!/usr/bin/env python3
import asyncio
import hashlib
import json
import string

import aiohttp
import requests
import re
import logging
import yaml

from aiogram import Dispatcher, types, Bot

# Constants
DDG_URL = 'https://duckduckgo.com/js/spice/currency'
COINAPI_URL = 'https://rest.coinapi.io/v1/exchangerate'

config = yaml.safe_load(open("config.yaml"))

log = logging.getLogger('shirino')
handler = logging.StreamHandler()
fmt = logging.Formatter('%(asctime)s %(levelname)s %(message)s')

handler.setFormatter(fmt)
log.addHandler(handler)

if config['debug']:
    handler.setLevel(logging.DEBUG)
    log.setLevel(logging.DEBUG)


coinapi_len = len(config['coinapi_keys'])
coinapi_active = [0]
dp = Dispatcher()


class CurrencyConverter:
    def __init__(self):
        self.amount = 1.0
        self.conv_amount = 0.0
        self.from_currency = 'RUB'
        self.conv_currency = 'USD'

    def convert(self):
        if not self.ddgapi():
            self.coinapi()

        str_amount = f'{self.conv_amount}'
        point = str_amount.find(".")
        after_point = str_amount[point + 1:]

        fnz = min(
            (
                after_point.index(i)
                for i in string.digits[1:]
                if i in after_point
            ),
            default=-1,
        )

        if fnz == -1:
            return

        ndigits = fnz + config['ndigits']

        self.conv_amount = round(self.conv_amount, ndigits)

    def ddgapi(self):
        res = requests.get(f'{DDG_URL}/{self.amount}/{self.from_currency}/{self.conv_currency}')
        data = json.loads(re.findall(r'\(\s*(.*)\s*\);$', res.text)[0])

        del data['terms']
        del data['privacy']
        del data['timestamp']

        log.debug(data)

        if len(data.get('to')) == 0:
            return False

        conv = data.get('to')[0]
        conv_amount = conv.get("mid")

        if conv_amount is None:
            raise RuntimeError('Ошибка при конвертации валюты через DuckDuckGo')

        log.debug(conv)
        log.debug(conv_amount)

        self.conv_amount = float(conv_amount)

        return True

    def coinapi(self, depth: int = config['coinapi_keys']):
        if depth <= 0:
            raise RecursionError('Рейтлимит на всех токенах')

        resp = requests.get(
            (
                f'{COINAPI_URL}/{self.from_currency}'
                f'/{self.conv_currency}'
            ),
            headers={
                'X-CoinAPI-Key': config['coinapi_keys'][coinapi_active[0]],
            },
            timeout=config['timeout'],
        )

        if resp.status_code == 429:
            log.warning('CoinAPI ratelimited, rotating token')
            rotate_token(config['coinapi_keys'], coinapi_active)
            self.coinapi(depth - 1)

        data = resp.json()
        rate = data.get('rate')
        if rate is None:
            raise RuntimeError('Не удалось получить курс валюты от CoinAPI')
        self.conv_amount = float(rate * self.amount)


def rotate_token(lst, active):
    active[0] = (active[0] + 1) % len(lst)


async def inline_reply(result_id: str, title: str, description: str or None, inline_query: types.InlineQuery):
    article = [None]
    article[0] = types.InlineQueryResultArticle(
        id=result_id,
        title=title,
        description=description,
        input_message_content=types.InputTextMessageContent(
            message_text=title
        )
    )

    await inline_query.answer(
        article,
        cache_time=1,
        is_personal=True,
    )


@dp.inline_query()
async def currency(inline_query: types.InlineQuery):
    query = inline_query.query
    args = query.split()

    result_id = hashlib.md5(query.encode()).hexdigest()
    conv = CurrencyConverter()

    try:
        log.debug(len(args))
        if len(args) <= 1:
            await inline_reply(result_id,
                               "Требуется 2, либо 3 аргумента",
                               f"@shirino_bot USD RUB \n@shirino_bot 12 USD RUB", inline_query)

        if len(args) == 3:
            conv.amount = float(args[0])
            conv.from_currency = args[1].upper()
            conv.conv_currency = args[2].upper()
            conv.convert()
        elif len(args) == 2:
            conv.from_currency = args[0].upper()
            conv.conv_currency = args[1].upper()
            conv.convert()

        result = (
            f'{conv.amount} {conv.from_currency} = '
            f'{conv.conv_amount} {conv.conv_currency}'
        )

    except aiohttp.client_exceptions.ClientError as ex:
        await inline_reply(result_id,
                           "Rate-limit от API Telegram, повторите запрос позже",
                           None,
                           inline_query)

        log.debug(ex)
        await asyncio.sleep(1)

    except Exception as ex:
        log.debug(ex)
        await inline_reply(result_id, "Неверный формат данных",
                           "@shirino_bot USD RUB \n@shirino_bot 12 USD RUB",
                           inline_query)

    await inline_reply(result_id, result, None, inline_query)


async def main() -> None:
    log.debug(config)
    bot = Bot(config['telegram_token'])
    await dp.start_polling(bot)


if __name__ == '__main__':
    asyncio.run(main())