from functools import wraps

from jsonschema import validate
from jsonschema import ValidationError
from oto import response
from oto.adaptors.flask import flaskify as oto_flaskify


from masters_registry.constant import error


def validate_headers(request, schema):
    """A decorator to call when validating HTTP request headers.

    Args:
        request (werkzeug.local.LocalProxy): request object from the handler.
        schema (Draft4Validator): the JSON Draft4 Schema to validate against.

    Returns:
        callable: the wrapped function.
    """

    def wrap(function):
        @wraps(function)
        def wrapped_f(*args, **kwargs):
            try:
                validate(dict(request.headers), schema)
            except ValidationError as err:
                return oto_flaskify(
                    response.create_error_response(
                        code=error.HEADER_VALIDATION_ERROR,
                        message=str(err)))
            return function(*args, **kwargs)
        return wrapped_f
    return wrap


def validate_body(request, schema):
    """A decorator to call when validating HTTP request body.

    Args:
        request (werkzeug.local.LocalProxy): request object from the handler.
        schema (Draft4Validator): the JSON Draft4 Schema to validate against.

    Returns:
        callable: the wrapped function.
    """

    def wrap(function):
        @wraps(function)
        def wrapped_f(*args, **kwargs):
            try:
                validate(request.get_json(), schema)
            except ValidationError as err:
                return oto_flaskify(
                    response.create_error_response(
                        code=error.BODY_VALIDATION_ERROR,
                        message=str(err)))
            return function(*args, **kwargs)
        return wrapped_f
    return wrap