import json
import re

from django.apps import apps
from python_http_client import UnauthorizedError
from sendgrid import SendGridAPIClient
from telegram import Bot
from twilio.base.exceptions import TwilioException
from twilio.rest import Client


class LiveSettingProxy:
    def __dir__(self):
        LiveSetting = apps.get_model("base", "LiveSetting")
        return LiveSetting.AVAILABLE_NAMES

    def __getattr__(self, item):
        LiveSetting = apps.get_model("base", "LiveSetting")

        value = LiveSetting.get_setting(item)
        return value

    def __setattr__(self, key, value):
        LiveSetting = apps.get_model("base", "LiveSetting")
        LiveSetting.objects.update_or_create(name=key, defaults={"value": value})


live_settings = LiveSettingProxy()


class LiveSettingValidator:
    def __init__(self, live_setting):
        self.live_setting = live_setting

    def get_error(self):
        check_fn_name = f"_check_{self.live_setting.name.lower()}"

        if self.live_setting.value is None:
            return "Empty"

        # skip validation if there's no handler for it
        if not hasattr(self, check_fn_name):
            return None

        check_fn = getattr(self, check_fn_name)
        return check_fn(self.live_setting.value)

    @classmethod
    def _check_twilio_account_sid(cls, twilio_account_sid):
        try:
            Client(twilio_account_sid, live_settings.TWILIO_AUTH_TOKEN).api.accounts.list(limit=1)
        except Exception as e:
            return cls._prettify_twilio_error(e)

    @classmethod
    def _check_twilio_auth_token(cls, twilio_auth_token):
        try:
            Client(live_settings.TWILIO_ACCOUNT_SID, twilio_auth_token).api.accounts.list(limit=1)
        except Exception as e:
            return cls._prettify_twilio_error(e)

    @classmethod
    def _check_twilio_verify_service_sid(cls, twilio_verify_service_sid):
        try:
            twilio_client = Client(live_settings.TWILIO_ACCOUNT_SID, live_settings.TWILIO_AUTH_TOKEN)
            twilio_client.verify.services(twilio_verify_service_sid).rate_limits.list(limit=1)
        except Exception as e:
            return cls._prettify_twilio_error(e)

    @classmethod
    def _check_twilio_number(cls, twilio_number):
        if not cls._is_phone_number_valid(twilio_number):
            return "Please specify a valid phone number in the following format: +XXXXXXXXXXX"

    @classmethod
    def _check_sendgrid_api_key(cls, sendgrid_api_key):
        sendgrid_client = SendGridAPIClient(sendgrid_api_key)

        try:
            sendgrid_client.client.mail_settings.get()
        except Exception as e:
            return cls._prettify_sendgrid_error(e)

    @classmethod
    def _check_sendgrid_from_email(cls, sendgrid_from_email):
        if not cls._is_email_valid(sendgrid_from_email):
            return "Please specify a valid email"

    @classmethod
    def _check_telegram_token(cls, telegram_token):
        try:
            bot = Bot(telegram_token)
            bot.get_me()
        except Exception as e:
            return f"Telegram error: {str(e)}"

    @staticmethod
    def _is_email_valid(email):
        return re.match(r"^[^@]+@[^@]+\.[^@]+$", email)

    @staticmethod
    def _is_phone_number_valid(phone_number):
        return re.match(r"^\+\d{11}$", phone_number)

    @staticmethod
    def _prettify_twilio_error(exc):
        if isinstance(exc, TwilioException):
            if len(exc.args) > 1:
                response_content = exc.args[1].content
                content = json.loads(response_content)

                error_code = content["code"]
                more_info = content["more_info"]
                return f"Twilio error: code {error_code}. Learn more: {more_info}"
            else:
                return f"Twilio error: {exc.args[0]}"
        else:
            return f"Twilio error: {str(exc)}"

    @staticmethod
    def _prettify_sendgrid_error(exc):
        if isinstance(exc, UnauthorizedError):
            return "Sendgrid error: couldn't authorize with given credentials"
        else:
            return f"Sendgrid error: {str(exc)}"