""" Various decorators for endpoint and API handlers. """

from functools import wraps
from flask import abort, request, make_response

import features

from app import app
from auth.auth_context import (
  get_validated_oauth_token, get_authenticated_user, get_validated_token, get_grant_context)
from util.names import parse_namespace_repository


def parse_repository_name(include_tag=False,
                          ns_kwarg_name='namespace_name',
                          repo_kwarg_name='repo_name',
                          tag_kwarg_name='tag_name',
                          incoming_repo_kwarg='repository'):
  """ Decorator which parses the repository name found in the incoming_repo_kwarg argument,
      and applies its pieces to the decorated function.
  """
  def inner(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
      repo_name_components = parse_namespace_repository(kwargs[incoming_repo_kwarg],
                                                        app.config['LIBRARY_NAMESPACE'],
                                                        include_tag=include_tag)
      del kwargs[incoming_repo_kwarg]
      kwargs[ns_kwarg_name] = repo_name_components[0]
      kwargs[repo_kwarg_name] = repo_name_components[1]
      if include_tag:
        kwargs[tag_kwarg_name] = repo_name_components[2]
      return func(*args, **kwargs)
    return wrapper
  return inner


def param_required(param_name, allow_body=False):
  """ Marks a route as requiring a parameter with the given name to exist in the request's arguments
      or (if allow_body=True) in its body values. If the parameter is not present, the request will
      fail with a 400.
  """
  def wrapper(wrapped):
    @wraps(wrapped)
    def decorated(*args, **kwargs):
      if param_name not in request.args:
        if not allow_body or param_name not in request.values:
          abort(make_response('Required param: %s' % param_name, 400))
      return wrapped(*args, **kwargs)
    return decorated
  return wrapper


def anon_allowed(func):
  """ Marks a method to allow anonymous access where it would otherwise be disallowed. """
  func.__anon_allowed = True
  return func


def anon_protect(func):
  """ Marks a method as requiring some form of valid user auth before it can be executed. """
  func.__anon_protected = True
  return check_anon_protection(func)


def check_anon_protection(func):
  """ Validates a method as requiring some form of valid user auth before it can be executed. """

  @wraps(func)
  def wrapper(*args, **kwargs):
    # Skip if anonymous access is allowed.
    if features.ANONYMOUS_ACCESS or '__anon_allowed' in dir(func):
      return func(*args, **kwargs)

    # Check for validated context. If none exists, fail with a 401.
    if (get_authenticated_user() or get_validated_oauth_token() or get_validated_token() or
        get_grant_context()):
      return func(*args, **kwargs)

    abort(401)

  return wrapper


def route_show_if(value):
  """ Adds/shows the decorated route if the given value is True. """

  def decorator(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
      if not value:
        abort(404)

      return f(*args, **kwargs)
    return decorated_function
  return decorator