import httplib
import json

import requests

from testapiclient.utils import user


class HTTPClient(object):

    __instance = None
    headers = {'Content-type': 'application/json', 'Accept': 'text/plain'}

    @staticmethod
    def get_Instance():
        """ Static access method. """
        if HTTPClient.__instance is None:
            HTTPClient()
        return HTTPClient.__instance

    def __init__(self):
        """ Virtually private constructor. """
        if HTTPClient.__instance is not None:
            raise Exception("This class is a singleton!")
        else:
            HTTPClient.__instance = self

    def get(self, url):
        return self._parse_response('Get', requests.get(url))

    def post(self, url, data):
        return self._parse_response('Create',
                                    self._request('post', url,
                                                  data=json.dumps(data),
                                                  headers=self.headers))

    def put(self, url, data):
        return self._parse_response('Update',
                                    self._request('put', url,
                                                  data=json.dumps(data),
                                                  headers=self.headers))

    def delete(self, url, *args):
        data = json.dumps(args[0]) if len(args) > 0 else None
        return self._parse_response('Delete',
                                    self._request('delete', url,
                                                  data=data,
                                                  headers=self.headers))

    def _request(self, method, *args, **kwargs):
        return getattr(user.User.session, method)(*args, **kwargs)

    def _raise_failure(self, op, response):
        raise Exception('{} failed: {}'.format(op, response.reason))

    def _parse_response(self, op, response):
        if response.status_code == httplib.OK:
            return response.json() if op != 'Delete' else None
        else:
            self._raise_failure(op, response)


def _request(method, *args, **kwargs):
    return getattr(HTTPClient.get_Instance(), method)(*args, **kwargs)


def get(url):
    return _request('get', url)


def post(url, data):
    return _request('post', url, data)


def put(url, data):
    return _request('put', url, data)


def delete(url, data=None):
    return _request('delete', url, data)