import requests
import unittest
from unittest import mock
# from blenderpack import Repositories, fetch_repo
from datetime import datetime
import json

# based on https://stackoverflow.com/a/28507806/2730823

# This method will be used by the mock to replace requests.get
def mocked_requests_get(*args, **kwargs):
    cidict = requests.structures.CaseInsensitiveDict
    req_headers = cidict(kwargs.get('headers'))
    t_fmt = '%a, %m %b %Y %X %Z'

    class MockResponse:
        def __init__(self, headers: cidict, status_code: int):
            self.headers = headers
            self.status_code = status_code

        def json(self):
            return json.dumps({'url': 'http://someurl.tld/repo.json'})

    if args[0] == 'http://someurl.tld/repo.json':
        resp_headers = cidict({
            "ETag": '"2a0094b-b74-55326ced274f3"',
            "Last-Modified": 'Sun, 13 Mar 2011 13:38:53 GMT',
        })

        if req_headers == {}:
            resp_code = 200
        else:
            req_headers = cidict(req_headers)
            resp_code = 304 if req_headers.get('if-none-match', '') == resp_headers['etag']\
                        or datetime.strptime(req_headers.get('if-modified-since', ''), t_fmt) < \
                           datetime.strptime(resp_headers['last-modified'], t_fmt) \
                        else 200
        return MockResponse(resp_headers, resp_code)

    return MockResponse(None, 404)

class MockRepositories:
    storage = {}

    def load(self, *args, **kwargs):
        if args[0] not in self.storage:
            self.storage[args[0]] = {'url': args[0]}

        return self.storage[args[0]]

    def write(self, *args, **kwargs):
        self.storage[args[0]['url']] = args[0]


class fetch_url_twice(unittest.TestCase):

    @mock.patch('requests.get', side_effect=mocked_requests_get)
    def test_fetch(self, mock_get):
        self.fail('unfinished test')
        repos = MockRepositories()
        fetch_repo('http://someurl.tld/repo.json', repos)
        mock_get.assert_called_with('http://someurl.tld/repo.json', headers={})

        fetch_repo('http://someurl.tld/repo.json', repos)
        mock_get.assert_called_with('http://someurl.tld/repo.json', headers={
            'If-None-Match': '"2a0094b-b74-55326ced274f3"',
            'If-Modified-Since': 'Sun, 13 Mar 2011 13:38:53 GMT'
            })


if __name__ == '__main__':
    unittest.main()