# -*- coding: utf-8 -*-

"""
AuthconnKeystone implements implements the connector for
Openstack Keystone and leverages the RBAC model, to bring
it for OSM.
"""

__author__ = "Eduardo Sousa <esousa@whitestack.com>"
__date__ = "$27-jul-2018 23:59:59$"

from authconn import Authconn, AuthException, AuthconnOperationException

import logging
from keystoneauth1 import session
from keystoneauth1.identity import v3
from keystoneauth1.exceptions.base import ClientException
from keystoneclient.v3 import client
from http import HTTPStatus


class AuthconnKeystone(Authconn):
    def __init__(self, config):
        Authconn.__init__(self, config)

        self.logger = logging.getLogger("nbi.authenticator.keystone")

        self.auth_url = "http://{0}:{1}/v3".format(config.get("auth_url", "keystone"), config.get("auth_port", "5000"))
        self.user_domain_name = config.get("user_domain_name", "default")
        self.admin_project = config.get("service_project", "service")
        self.admin_username = config.get("service_username", "nbi")
        self.admin_password = config.get("service_password", "nbi")
        self.project_domain_name = config.get("project_domain_name", "default")

        self.auth = v3.Password(user_domain_name=self.user_domain_name,
                                username=self.admin_username,
                                password=self.admin_password,
                                project_domain_name=self.project_domain_name,
                                project_name=self.admin_project,
                                auth_url=self.auth_url)
        self.sess = session.Session(auth=self.auth)
        self.keystone = client.Client(session=self.sess)

    def authenticate_with_user_password(self, user, password):
        """
        Authenticate a user using username and password.

        :param user: username
        :param password: password
        :return: an unscoped token that grants access to project list
        """
        try:
            user_id = list(filter(lambda x: x.name == user, self.keystone.users.list()))[0].id
            project_names = [project.name for project in self.keystone.projects.list(user=user_id)]

            token = self.keystone.get_raw_token_from_identity_service(
                auth_url=self.auth_url,
                username=user,
                password=password,
                user_domain_name=self.user_domain_name,
                project_domain_name=self.project_domain_name)

            return token["auth_token"], project_names
        except ClientException:
            self.logger.exception("Error during user authentication using keystone. Method: basic")
            raise AuthException("Error during user authentication using Keystone", http_code=HTTPStatus.UNAUTHORIZED)

    def authenticate_with_token(self, token, project=None):
        """
        Authenticate a user using a token. Can be used to revalidate the token
        or to get a scoped token.

        :param token: a valid token.
        :param project: (optional) project for a scoped token.
        :return: return a revalidated token, scoped if a project was passed or
        the previous token was already scoped.
        """
        try:
            token_info = self.keystone.tokens.validate(token=token)
            projects = self.keystone.projects.list(user=token_info["user"]["id"])
            project_names = [project.name for project in projects]

            token = self.keystone.get_raw_token_from_identity_service(
                auth_url=self.auth_url,
                token=token,
                project_name=project,
                user_domain_name=self.user_domain_name,
                project_domain_name=self.project_domain_name)

            return token["auth_token"], project_names
        except ClientException:
            self.logger.exception("Error during user authentication using keystone. Method: bearer")
            raise AuthException("Error during user authentication using Keystone", http_code=HTTPStatus.UNAUTHORIZED)

    def validate_token(self, token):
        """
        Check if the token is valid.

        :param token: token to validate
        :return: dictionary with information associated with the token. If the
        token is not valid, returns None.
        """
        if not token:
            return

        try:
            token_info = self.keystone.tokens.validate(token=token)

            return token_info
        except ClientException:
            self.logger.exception("Error during token validation using keystone")
            raise AuthException("Error during token validation using Keystone", http_code=HTTPStatus.UNAUTHORIZED)

    def revoke_token(self, token):
        """
        Invalidate a token.

        :param token: token to be revoked
        """
        try:
            self.keystone.tokens.revoke_token(token=token)

            return True
        except ClientException:
            self.logger.exception("Error during token revocation using keystone")
            raise AuthException("Error during token revocation using Keystone", http_code=HTTPStatus.UNAUTHORIZED)

    def get_project_list(self, token):
        """
        Get all the projects associated with a user.

        :param token: valid token
        :return: list of projects
        """
        try:
            token_info = self.keystone.tokens.validate(token=token)
            projects = self.keystone.projects.list(user=token_info["user"]["id"])
            project_names = [project.name for project in projects]

            return project_names
        except ClientException:
            self.logger.exception("Error during user project listing using keystone")
            raise AuthException("Error during user project listing using Keystone", http_code=HTTPStatus.UNAUTHORIZED)

    def get_role_list(self, token):
        """
        Get role list for a scoped project.

        :param token: scoped token.
        :return: returns the list of roles for the user in that project. If
        the token is unscoped it returns None.
        """
        try:
            token_info = self.keystone.tokens.validate(token=token)
            roles = self.keystone.roles.list(user=token_info["user"]["id"], project=token_info["project"]["id"])

            return roles
        except ClientException:
            self.logger.exception("Error during user role listing using keystone")
            raise AuthException("Error during user role listing using Keystone", http_code=HTTPStatus.UNAUTHORIZED)

    def create_user(self, user, password):
        """
        Create a user.

        :param user: username.
        :param password: password.
        :raises AuthconnOperationException: if user creation failed.
        """
        try:
            result = self.keystone.users.create(user, password=password, domain=self.user_domain_name)

            if not result:
                raise ClientException()
        except ClientException:
            self.logger.exception("Error during user creation using keystone")
            raise AuthconnOperationException("Error during user creation using Keystone")

    def change_password(self, user, new_password):
        """
        Change the user password.

        :param user: username.
        :param new_password: new password.
        :raises AuthconnOperationException: if user password change failed.
        """
        try:
            result = self.keystone.users.update(user, password=new_password)

            if not result:
                raise ClientException()
        except ClientException:
            self.logger.exception("Error during user password update using keystone")
            raise AuthconnOperationException("Error during user password update using Keystone")

    def delete_user(self, user):
        """
        Delete user.

        :param user: username.
        :raises AuthconnOperationException: if user deletion failed.
        """
        try:
            result = self.keystone.users.delete(user)

            if not result:
                raise ClientException()
        except ClientException:
            self.logger.exception("Error during user deletion using keystone")
            raise AuthconnOperationException("Error during user deletion using Keystone")

    def create_role(self, role):
        """
        Create a role.

        :param role: role name.
        :raises AuthconnOperationException: if role creation failed.
        """
        try:
            result = self.keystone.roles.create(role, domain=self.user_domain_name)

            if not result:
                raise ClientException()
        except ClientException:
            self.logger.exception("Error during role creation using keystone")
            raise AuthconnOperationException("Error during role creation using Keystone")

    def delete_role(self, role):
        """
        Delete a role.

        :param role: role name.
        :raises AuthconnOperationException: if role deletion failed.
        """
        try:
            result = self.keystone.roles.delete(role)

            if not result:
                raise ClientException()
        except ClientException:
            self.logger.exception("Error during role deletion using keystone")
            raise AuthconnOperationException("Error during role deletion using Keystone")

    def create_project(self, project):
        """
        Create a project.

        :param project: project name.
        :raises AuthconnOperationException: if project creation failed.
        """
        try:
            result = self.keystone.project.create(project, self.project_domain_name)

            if not result:
                raise ClientException()
        except ClientException:
            self.logger.exception("Error during project creation using keystone")
            raise AuthconnOperationException("Error during project creation using Keystone")

    def delete_project(self, project):
        """
        Delete a project.

        :param project: project name.
        :raises AuthconnOperationException: if project deletion failed.
        """
        try:
            result = self.keystone.project.delete(project)

            if not result:
                raise ClientException()
        except ClientException:
            self.logger.exception("Error during project deletion using keystone")
            raise AuthconnOperationException("Error during project deletion using Keystone")

    def assign_role_to_user(self, user, project, role):
        """
        Assigning a role to a user in a project.

        :param user: username.
        :param project: project name.
        :param role: role name.
        :raises AuthconnOperationException: if role assignment failed.
        """
        try:
            result = self.keystone.roles.grant(role, user=user, project=project)

            if not result:
                raise ClientException()
        except ClientException:
            self.logger.exception("Error during user role assignment using keystone")
            raise AuthconnOperationException("Error during user role assignment using Keystone")

    def remove_role_from_user(self, user, project, role):
        """
        Remove a role from a user in a project.

        :param user: username.
        :param project: project name.
        :param role: role name.
        :raises AuthconnOperationException: if role assignment revocation failed.
        """
        try:
            result = self.keystone.roles.revoke(role, user=user, project=project)

            if not result:
                raise ClientException()
        except ClientException:
            self.logger.exception("Error during user role revocation using keystone")
            raise AuthconnOperationException("Error during user role revocation using Keystone")