import http
import os
from time import sleep
from typing import Optional
from urllib.parse import urljoin

import requests
from django.conf import settings
from django.core.files.base import ContentFile

from store.utils import is_migration_running

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'poizonstore.settings')


class CDEKClient:
    AUTH_ENDPOINT = 'oauth/token'
    ORDER_INFO_ENDPOINT = 'orders'
    CALCULATOR_TARIFF_ENDPOINT = 'calculator/tariff'
    BARCODE_ENDPOINT = 'print/barcodes'

    MAX_RETRIES = 2

    def __init__(self, client_id, client_secret, grant_type='client_credentials'):
        self.api_url = 'https://api.cdek.ru/v2/'
        self.client_id = client_id
        self.client_secret = client_secret
        self.grant_type = grant_type

        self.session = requests.Session()

    def request(self, method, url, *args, **kwargs):
        joined_url = urljoin(self.api_url, url)
        request = requests.Request(method, joined_url, *args, **kwargs)

        retries = 0
        while retries < self.MAX_RETRIES:
            retries += 1
            prepared = self.session.prepare_request(request)
            r = self.session.send(prepared)

            # TODO: handle/log errors
            if r.status_code == http.HTTPStatus.UNAUTHORIZED:
                self.authorize()
                continue
            return r

    def authorize(self):
        params = {
            'client_id': self.client_id,
            'client_secret': self.client_secret,
            'grant_type': self.grant_type
        }
        r = self.request('POST', self.AUTH_ENDPOINT, params=params)
        if r:
            data = r.json()
            token = data['access_token']
            self.session.headers.update({'Authorization': f'Bearer {token}'})

    def get_order_info(self, im_number):
        params = {
            'im_number': str(im_number)
        }
        return self.request('GET', self.ORDER_INFO_ENDPOINT, params=params)

    def create_order(self, order_data):
        return self.request('POST', self.ORDER_INFO_ENDPOINT, json=order_data)

    def edit_order(self, order_data):
        return self.request('PATCH', self.ORDER_INFO_ENDPOINT, json=order_data)

    def calculate_tariff(self, data):
        return self.request('POST', self.CALCULATOR_TARIFF_ENDPOINT, json=data)

    def generate_barcode(self, cdek_number, format="A6") -> Optional[str]:
        request_data = {
            "orders": [{"cdek_number": cdek_number}],
            "copy_count": 1,
            "format": format
        }

        r = self.request('POST', self.BARCODE_ENDPOINT, json=request_data)
        if not r:
            return None

        resp_data = r.json()
        if 'entity' not in resp_data:
            return None

        barcode_uuid = resp_data['entity']['uuid']
        return barcode_uuid

    def get_barcode_url(self, uuid) -> Optional[str]:
        if not uuid:
            return None

        r = self.request('GET', f'{self.BARCODE_ENDPOINT}/{uuid}')
        if not r:
            return None

        resp_data = r.json()
        if 'entity' not in resp_data:
            return None

        url = resp_data['entity'].get('url')
        return url

    def get_barcode_file(self, cdek_number):
        uuid = self.generate_barcode(cdek_number)
        sleep(2)  # Sometimes url are not yet created, so be prepared for this
        url = self.get_barcode_url(uuid)
        if not url:
            return None

        r = self.request('GET', url)
        return ContentFile(r.content) if r and r.content else None


client = CDEKClient(settings.CDEK_CLIENT_ID, settings.CDEK_CLIENT_SECRET)

if not is_migration_running():
    client.authorize()