"""Module for requests validation."""

import copy

from functools import wraps

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

from salessheets.constants import error
from salessheets.constants import field_const
from salessheets.validation.schema import header


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

    Args:
        schema (Draft4Validator): the JSON Draft4 Schema to validate against.

    Returns:
        callable: the wrapped function.
    """
    def wrap(function):
        @wraps(function)
        def wrapped_f(*args, **kwargs):
            validation_schema = schema
            if (field_const.GRASS_ACCOUNT_ID in request.headers
                    or field_const.GRASS_ACCOUNT_TYPE in request.headers):
                validation_schema = header.alw_schema
            elif field_const.ORCHARD_USER_ID in request.headers:
                pass
            else:
                return function(*args, **kwargs)
            try:
                validate(dict(request.headers), validation_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(schema, schema_tweaks=None):
    """A decorator to call when validating HTTP request body.

    Args:
        schema (Draft4Validator): the JSON Draft4 Schema to validate against.
        schema_tweaks(callable): the function choosing the schema depending on
         feature flag.

    Returns:
        callable: the wrapped function.
    """
    def wrap(function):
        @wraps(function)
        def wrapped_f(*args, **kwargs):
            body_schema = schema
            if schema_tweaks:
                body_schema = copy.deepcopy(schema)
                schema_tweaks(body_schema)
            try:
                validate(request.get_json(), body_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