from functools import wraps

from authlib.oauth2 import OAuth2Error
from authlib.oauth2.rfc6749 import MissingAuthorizationError
from flask import request
from flask_apispec import marshal_with
from flask_apispec.views import MethodResource
from flask_security import current_user

from project import db
from project.api.schemas import ErrorResponseSchema, UnprocessableEntityResponseSchema
from project.oauth2 import require_oauth


def etag_cache(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        response = func(*args, **kwargs)
        response.add_etag()
        return response.make_conditional(request)

    return wrapper


def require_api_access(scopes=None, optional=False):
    def inner_decorator(func):
        def wrapped(*args, **kwargs):  # see authlib ResourceProtector#__call__
            try:  # pragma: no cover
                try:
                    require_oauth.acquire_token(scopes)
                except MissingAuthorizationError as error:
                    if optional:
                        return func(*args, **kwargs)
                    require_oauth.raise_error_response(error)
                except OAuth2Error as error:
                    require_oauth.raise_error_response(error)
            except Exception as e:
                if not current_user or not current_user.is_authenticated:
                    raise e
            return func(*args, **kwargs)

        return wrapped

    return inner_decorator


@marshal_with(ErrorResponseSchema, 400, "Bad Request")
@marshal_with(UnprocessableEntityResponseSchema, 422, "Unprocessable Entity")
class BaseResource(MethodResource):
    decorators = [etag_cache]

    def create_instance(self, schema_cls, **kwargs):
        instance = schema_cls().load(request.json, session=db.session)

        for key, value in kwargs.items():
            if hasattr(instance, key):
                setattr(instance, key, value)

        validate = getattr(instance, "validate", None)
        if callable(validate):
            validate()

        return instance

    def update_instance(self, schema_cls, instance):
        with db.session.no_autoflush:
            instance = schema_cls().load(
                request.json, session=db.session, instance=instance
            )

            validate = getattr(instance, "validate", None)
            if callable(validate):
                validate()

        return instance