# -*- coding: utf-8 -*-
# Part of Odoo. See LICENSE file for full copyright and licensing details.

import json

import requests
import werkzeug.http

from odoo import api, fields, models
from odoo.exceptions import AccessDenied, UserError
from odoo.addons.auth_signup.models.res_users import SignupError

from odoo.addons import base
base.models.res_users.USER_PRIVATE_FIELDS.append('oauth_access_token')

class ResUsers(models.Model):
    _inherit = 'res.users'

    oauth_provider_id = fields.Many2one('auth.oauth.provider', string='OAuth Provider')
    oauth_uid = fields.Char(string='OAuth User ID', help="Oauth Provider user_id", copy=False)
    oauth_access_token = fields.Char(string='OAuth Access Token', readonly=True, copy=False, prefetch=False)

    _sql_constraints = [
        ('uniq_users_oauth_provider_oauth_uid', 'unique(oauth_provider_id, oauth_uid)', 'OAuth UID must be unique per provider'),
    ]

    def _auth_oauth_rpc(self, endpoint, access_token):
        if self.env['ir.config_parameter'].sudo().get_param('auth_oauth.authorization_header'):
            response = requests.get(endpoint, headers={'Authorization': 'Bearer %s' % access_token}, timeout=10)
        else:
            response = requests.get(endpoint, params={'access_token': access_token}, timeout=10)

        if response.ok: # nb: could be a successful failure
            return response.json()

        auth_challenge = werkzeug.http.parse_www_authenticate_header(
            response.headers.get('WWW-Authenticate'))
        if auth_challenge.type == 'bearer' and 'error' in auth_challenge:
            return dict(auth_challenge)

        return {'error': 'invalid_request'}

    @api.model
    def _auth_oauth_validate(self, provider, access_token):
        """ return the validation data corresponding to the access token """
        oauth_provider = self.env['auth.oauth.provider'].browse(provider)
        validation = self._auth_oauth_rpc(oauth_provider.validation_endpoint, access_token)
        if validation.get("error"):
            raise Exception(validation['error'])
        if oauth_provider.data_endpoint:
            data = self._auth_oauth_rpc(oauth_provider.data_endpoint, access_token)
            validation.update(data)
        # unify subject key, pop all possible and get most sensible. When this
        # is reworked, BC should be dropped and only the `sub` key should be
        # used (here, in _generate_signup_values, and in _auth_oauth_signin)
        subject = next(filter(None, [
            validation.pop(key, None)
            for key in [
                'sub', # standard
                'id', # google v1 userinfo, facebook opengraph
                'user_id', # google tokeninfo, odoo (tokeninfo)
            ]
        ]), None)
        if not subject:
            raise AccessDenied('Missing subject identity')
        validation['user_id'] = subject

        return validation

    @api.model
    def _generate_signup_values(self, provider, validation, params):
        oauth_uid = validation['user_id']
        email = validation.get('email', 'provider_%s_user_%s' % (provider, oauth_uid))
        name = validation.get('name', email)
        return {
            'name': name,
            'login': email,
            'email': email,
            'oauth_provider_id': provider,
            'oauth_uid': oauth_uid,
            'oauth_access_token': params['access_token'],
            'active': True,
        }

    @api.model
    def _auth_oauth_signin(self, provider, validation, params):
        """ retrieve and sign in the user corresponding to provider and validated access token
            :param provider: oauth provider id (int)
            :param validation: result of validation of access token (dict)
            :param params: oauth parameters (dict)
            :return: user login (str)
            :raise: AccessDenied if signin failed

            This method can be overridden to add alternative signin methods.
        """
        oauth_uid = validation['user_id']
        try:
            oauth_user = self.search([("oauth_uid", "=", oauth_uid), ('oauth_provider_id', '=', provider)])
            if not oauth_user:
                raise AccessDenied()
            assert len(oauth_user) == 1
            oauth_user.write({'oauth_access_token': params['access_token']})
            return oauth_user.login
        except AccessDenied as access_denied_exception:
            if self.env.context.get('no_user_creation'):
                return None
            state = json.loads(params['state'])
            token = state.get('t')
            values = self._generate_signup_values(provider, validation, params)
            try:
                login, _ = self.signup(values, token)
                return login
            except (SignupError, UserError):
                raise access_denied_exception

    @api.model
    def auth_oauth(self, provider, params):
        # Advice by Google (to avoid Confused Deputy Problem)
        # if validation.audience != OUR_CLIENT_ID:
        #   abort()
        # else:
        #   continue with the process
        access_token = params.get('access_token')
        validation = self._auth_oauth_validate(provider, access_token)

        # retrieve and sign in user
        login = self._auth_oauth_signin(provider, validation, params)
        if not login:
            raise AccessDenied()
        # return user credentials
        return (self.env.cr.dbname, login, access_token)

    def _check_credentials(self, credential, env):
        try:
            return super()._check_credentials(credential, env)
        except AccessDenied:
            if not (credential['type'] == 'oauth_token' and credential['token']):
                raise
            passwd_allowed = env['interactive'] or not self.env.user._rpc_api_keys_only()
            if passwd_allowed and self.env.user.active:
                res = self.sudo().search([('id', '=', self.env.uid), ('oauth_access_token', '=', credential['token'])])
                if res:
                    return {
                        'uid': self.env.user.id,
                        'auth_method': 'oauth',
                        'mfa': 'default',
                    }
            raise

    def _get_session_token_fields(self):
        return super(ResUsers, self)._get_session_token_fields() | {'oauth_access_token'}
