import requests
from json import JSONDecodeError

HTTP_STATUS_OK = 200
HTTP_STATUS_AUTHENTICATE = 401


class WikiException(Exception):
    pass


def _filter_params(params):
    result = {}
    for key, value in sorted(params.items(), key=lambda t: t[0] == "token"):
        if isinstance(value, bool):
            if value:
                result[key] = ""
        else:
            result[key] = value
    return result


class WikiClient:
    def __init__(self, endpoint):
        self.endpoint = endpoint
        self.token = None
        self.cookies = requests.cookies.RequestsCookieJar()

    def is_logged_in(self):
        return self.token is not None

    def login(self, user, password, domain=None):
        # todo: Change this to the new MediaWiki tokens api
        token_answer = self.do_action("login", method="post", lgname=user)
        if "login" not in token_answer or "token" not in token_answer["login"]:
            raise WikiException("No token in login answer.")
        lgtoken = token_answer["login"]["token"]
        login_answer = self.do_action(
            "login", method="post", lgname=user, lgpassword=password,
            lgdomain=domain, lgtoken=lgtoken)
        if ("login" not in login_answer
                or "result" not in login_answer["login"]
                or login_answer["login"]["result"] != "Success"):
            raise WikiException("Login not successful.")

    def logout(self):
        self.do_action("logout")

    def do_action(self, action, method="get", data=None, **kwargs):
        kwargs["action"] = action
        kwargs["format"] = "json"
        params = _filter_params(kwargs)

        def _do_request():
            if method == "get":
                return requests.get(
                    self.endpoint, cookies=self.cookies, params=params)
            elif method == "post":
                return requests.post(
                    self.endpoint, cookies=self.cookies, data=data,
                    params=params)
        req = _do_request()
        if req.status_code != HTTP_STATUS_OK:
            raise WikiException(
                "HTTP status code {} on action {}.".format(
                    req.status_code, action))
        self.cookies.update(req.cookies)
        try:
            return req.json()
        except JSONDecodeError:
            raise WikiException("Server did not return valid JSON.")