text: # coding=utf-8
  """
  oauthlib.oauth2.rfc6749.errors
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
  Error used both by OAuth 2 clients and providers to represent the spec
  defined error responses for all four core grant types.
  """
  from __future__ import unicode_literals
  
  import json
  
  from oauthlib.common import add_params_to_uri, urlencode
  
  
  class OAuth2Error(Exception):
      error = None
      status_code = 400
      description = ''
  
      def __init__(self, description=None, uri=None, state=None,
                   status_code=None, request=None):
          """
          :param description: A human-readable ASCII [USASCII] text providing
                              additional information, used to assist the client
                              developer in understanding the error that occurred.
                              Values for the "error_description" parameter
                              MUST NOT include characters outside the set
                              x20-21 / x23-5B / x5D-7E.
  
          :param uri: A URI identifying a human-readable web page with information
                      about the error, used to provide the client developer with
                      additional information about the error.  Values for the
                      "error_uri" parameter MUST conform to the URI- Reference
                      syntax, and thus MUST NOT include characters outside the set
                      x21 / x23-5B / x5D-7E.
  
          :param state: A CSRF protection value received from the client.
  
          :param status_code:
  
          :param request: OAuthlib request.
          :type request: oauthlib.common.Request
          """
          if description is not None:
              self.description = description
  
          message = '(%s) %s' % (self.error, self.description)
          if request:
              message += ' ' + repr(request)
          super(OAuth2Error, self).__init__(message)
  
          self.uri = uri
          self.state = state
  
          if status_code:
              self.status_code = status_code
  
          if request:
              self.redirect_uri = request.redirect_uri
              self.client_id = request.client_id
              self.scopes = request.scopes
              self.response_type = request.response_type
              self.response_mode = request.response_mode
              self.grant_type = request.grant_type
              if not state:
                  self.state = request.state
          else:
              self.redirect_uri = None
              self.client_id = None
              self.scopes = None
              self.response_type = None
              self.response_mode = None
              self.grant_type = None
  
      def in_uri(self, uri):
          fragment = self.response_mode == "fragment"
          return add_params_to_uri(uri, self.twotuples, fragment)
  
      @property
      def twotuples(self):
          error = [('error', self.error)]
          if self.description:
              error.append(('error_description', self.description))
          if self.uri:
              error.append(('error_uri', self.uri))
          if self.state:
              error.append(('state', self.state))
          return error
  
      @property
      def urlencoded(self):
          return urlencode(self.twotuples)
  
      @property
      def json(self):
          return json.dumps(dict(self.twotuples))
  
      @property
      def headers(self):
          if self.status_code == 401:
              """
              https://tools.ietf.org/html/rfc6750#section-3
  
              All challenges defined by this specification MUST use the auth-scheme
              value "Bearer".  This scheme MUST be followed by one or more
              auth-param values.
              """
              authvalues = [
                  "Bearer",
                  'error="{}"'.format(self.error)
              ]
              if self.description:
                  authvalues.append('error_description="{}"'.format(self.description))
              if self.uri:
                  authvalues.append('error_uri="{}"'.format(self.uri))
              return {"WWW-Authenticate": ", ".join(authvalues)}
          return {}
  
  
  class TokenExpiredError(OAuth2Error):
      error = 'token_expired'
  
  
  class InsecureTransportError(OAuth2Error):
      error = 'insecure_transport'
      description = 'OAuth 2 MUST utilize https.'
  
  
  class MismatchingStateError(OAuth2Error):
      error = 'mismatching_state'
      description = 'CSRF Warning! State not equal in request and response.'
  
  
  class MissingCodeError(OAuth2Error):
      error = 'missing_code'
  
  
  class MissingTokenError(OAuth2Error):
      error = 'missing_token'
  
  
  class MissingTokenTypeError(OAuth2Error):
      error = 'missing_token_type'
  
  
  class FatalClientError(OAuth2Error):
      """
      Errors during authorization where user should not be redirected back.
  
      If the request fails due to a missing, invalid, or mismatching
      redirection URI, or if the client identifier is missing or invalid,
      the authorization server SHOULD inform the resource owner of the
      error and MUST NOT automatically redirect the user-agent to the
      invalid redirection URI.
  
      Instead the user should be informed of the error by the provider itself.
      """
      pass
  
  
  class InvalidRequestFatalError(FatalClientError):
      """
      For fatal errors, the request is missing a required parameter, includes
      an invalid parameter value, includes a parameter more than once, or is
      otherwise malformed.
      """
      error = 'invalid_request'
  
  
  class InvalidRedirectURIError(InvalidRequestFatalError):
      description = 'Invalid redirect URI.'
  
  
  class MissingRedirectURIError(InvalidRequestFatalError):
      description = 'Missing redirect URI.'
  
  
  class MismatchingRedirectURIError(InvalidRequestFatalError):
      description = 'Mismatching redirect URI.'
  
  
  class InvalidClientIdError(InvalidRequestFatalError):
      description = 'Invalid client_id parameter value.'
  
  
  class MissingClientIdError(InvalidRequestFatalError):
      description = 'Missing client_id parameter.'
  
  
  class InvalidRequestError(OAuth2Error):
      """
      The request is missing a required parameter, includes an invalid
      parameter value, includes a parameter more than once, or is
      otherwise malformed.
      """
      error = 'invalid_request'
  
  
  class MissingResponseTypeError(InvalidRequestError):
      description = 'Missing response_type parameter.'
  
  
  class MissingCodeChallengeError(InvalidRequestError):
      """
      If the server requires Proof Key for Code Exchange (PKCE) by OAuth
      public clients and the client does not send the "code_challenge" in
      the request, the authorization endpoint MUST return the authorization
      error response with the "error" value set to "invalid_request".  The
      "error_description" or the response of "error_uri" SHOULD explain the
      nature of error, e.g., code challenge required.
      """
      description = 'Code challenge required.'
  
  
  class MissingCodeVerifierError(InvalidRequestError):
      """
      The request to the token endpoint, when PKCE is enabled, has
      the parameter `code_verifier` REQUIRED.
      """
      description = 'Code verifier required.'
  
  
  class AccessDeniedError(OAuth2Error):
      """
      The resource owner or authorization server denied the request.
      """
      error = 'access_denied'
  
  
  class UnsupportedResponseTypeError(OAuth2Error):
      """
      The authorization server does not support obtaining an authorization
      code using this method.
      """
      error = 'unsupported_response_type'
  
  
  class UnsupportedCodeChallengeMethodError(InvalidRequestError):
      """
      If the server supporting PKCE does not support the requested
      transformation, the authorization endpoint MUST return the
      authorization error response with "error" value set to
      "invalid_request".  The "error_description" or the response of
      "error_uri" SHOULD explain the nature of error, e.g., transform
      algorithm not supported.
      """
      description = 'Transform algorithm not supported.'
  
  
  class InvalidScopeError(OAuth2Error):
      """
      The requested scope is invalid, unknown, or malformed, or
      exceeds the scope granted by the resource owner.
  
      https://tools.ietf.org/html/rfc6749#section-5.2
      """
      error = 'invalid_scope'
  
  
  class ServerError(OAuth2Error):
      """
      The authorization server encountered an unexpected condition that
      prevented it from fulfilling the request.  (This error code is needed
      because a 500 Internal Server Error HTTP status code cannot be returned
      to the client via a HTTP redirect.)
      """
      error = 'server_error'
  
  
  class TemporarilyUnavailableError(OAuth2Error):
      """
      The authorization server is currently unable to handle the request
      due to a temporary overloading or maintenance of the server.
      (This error code is needed because a 503 Service Unavailable HTTP
      status code cannot be returned to the client via a HTTP redirect.)
      """
      error = 'temporarily_unavailable'
  
  
  class InvalidClientError(FatalClientError):
      """
      Client authentication failed (e.g. unknown client, no client
      authentication included, or unsupported authentication method).
      The authorization server MAY return an HTTP 401 (Unauthorized) status
      code to indicate which HTTP authentication schemes are supported.
      If the client attempted to authenticate via the "Authorization" request
      header field, the authorization server MUST respond with an
      HTTP 401 (Unauthorized) status code, and include the "WWW-Authenticate"
      response header field matching the authentication scheme used by the
      client.
      """
      error = 'invalid_client'
      status_code = 401
  
  
  class InvalidGrantError(OAuth2Error):
      """
      The provided authorization grant (e.g. authorization code, resource
      owner credentials) or refresh token is invalid, expired, revoked, does
      not match the redirection URI used in the authorization request, or was
      issued to another client.
  
      https://tools.ietf.org/html/rfc6749#section-5.2
      """
      error = 'invalid_grant'
      status_code = 400
  
  
  class UnauthorizedClientError(OAuth2Error):
      """
      The authenticated client is not authorized to use this authorization
      grant type.
      """
      error = 'unauthorized_client'
  
  
  class UnsupportedGrantTypeError(OAuth2Error):
      """
      The authorization grant type is not supported by the authorization
      server.
      """
      error = 'unsupported_grant_type'
  
  
  class UnsupportedTokenTypeError(OAuth2Error):
      """
      The authorization server does not support the hint of the
      presented token type.  I.e. the client tried to revoke an access token
      on a server not supporting this feature.
      """
      error = 'unsupported_token_type'
  
  
  class InvalidTokenError(OAuth2Error):
      """
      The access token provided is expired, revoked, malformed, or
      invalid for other reasons.  The resource SHOULD respond with
      the HTTP 401 (Unauthorized) status code.  The client MAY
      request a new access token and retry the protected resource
      request.
      """
      error = 'invalid_token'
      status_code = 401
      description = ("The access token provided is expired, revoked, malformed, "
                     "or invalid for other reasons.")
  
  
  class InsufficientScopeError(OAuth2Error):
      """
      The request requires higher privileges than provided by the
      access token.  The resource server SHOULD respond with the HTTP
      403 (Forbidden) status code and MAY include the "scope"
      attribute with the scope necessary to access the protected
      resource.
      """
      error = 'insufficient_scope'
      status_code = 403
      description = ("The request requires higher privileges than provided by "
                     "the access token.")
  
  
  class ConsentRequired(OAuth2Error):
      """
      The Authorization Server requires End-User consent.
  
      This error MAY be returned when the prompt parameter value in the
      Authentication Request is none, but the Authentication Request cannot be
      completed without displaying a user interface for End-User consent.
      """
      error = 'consent_required'
  
  
  class LoginRequired(OAuth2Error):
      """
      The Authorization Server requires End-User authentication.
  
      This error MAY be returned when the prompt parameter value in the
      Authentication Request is none, but the Authentication Request cannot be
      completed without displaying a user interface for End-User authentication.
      """
      error = 'login_required'
  
  
  class CustomOAuth2Error(OAuth2Error):
      """
      This error is a placeholder for all custom errors not described by the RFC.
      Some of the popular OAuth2 providers are using custom errors.
      """
      def __init__(self, error, *args, **kwargs):
          self.error = error
          super(CustomOAuth2Error, self).__init__(*args, **kwargs)
  
  
  def raise_from_error(error, params=None):
      import inspect
      import sys
      kwargs = {
          'description': params.get('error_description'),
          'uri': params.get('error_uri'),
          'state': params.get('state')
      }
      for _, cls in inspect.getmembers(sys.modules[__name__], inspect.isclass):
          if cls.error == error:
              raise cls(**kwargs)
      raise CustomOAuth2Error(error=error, **kwargs)
  