"""
Slack OAuth2 backend, docs at:
    https://python-social-auth.readthedocs.io/en/latest/backends/slack.html
    https://api.slack.com/docs/oauth
"""

from .oauth import BaseOAuth2


class SlackOAuth2(BaseOAuth2):
    """Slack OAuth authentication backend"""

    name = "slack"
    AUTHORIZATION_URL = "https://slack.com/oauth/authorize"
    ACCESS_TOKEN_URL = "https://slack.com/api/oauth.access"
    ACCESS_TOKEN_METHOD = "POST"
    DEFAULT_SCOPE = ["identity.basic", "identity.email"]
    SCOPE_SEPARATOR = ","
    REDIRECT_STATE = False
    EXTRA_DATA = [("id", "id"), ("name", "name"), ("real_name", "real_name")]

    def auth_extra_arguments(self):
        params = super().auth_extra_arguments() or {}
        if self.setting("TEAM"):
            params["team"] = self.setting("TEAM")
        return params

    def get_user_details(self, response):
        """Return user details from Slack account"""
        # Build the username with the team $username@$team_url
        # Necessary to get unique names for all of slack
        user = response["user"]
        team = response.get("team")
        name = user["name"]
        email = user.get("email")
        username = email and email.split("@", 1)[0] or name
        fullname, first_name, last_name = self.get_user_names(name)

        if self.setting("USERNAME_WITH_TEAM", True) and team and "name" in team:
            username = "{}@{}".format(username, response["team"]["name"])

        return {
            "username": username,
            "email": email,
            "fullname": fullname,
            "first_name": first_name,
            "last_name": last_name,
        }

    def user_data(self, access_token, *args, **kwargs):
        """Loads user data from service"""
        response = self.get_json(
            "https://slack.com/api/users.identity",
            headers={"Authorization": "Bearer %s" % access_token},
        )
        if not response.get("id", None):
            response["id"] = response["user"]["id"]
        return response