"""JSON Draft3 Schema Validator Wrapper.

A Wrapper for a JSON Draft3 schema validation library which allows us to
transform the results into an internal Response() format.
"""

from jsonschema import Draft3Validator
from oto import response

from sales_goals.constants import error


def _format_error(validator, validator_value, message):
    """Format error.

    Args:
        validator (string): type of validator that generated the error
        validator_value (any): type of value the validator expected
        message (string): a description of the error
    Returns:
        (dict): formatted error.
    """
    return {
        'validator': validator,
        'validator_value': validator_value,
        'message': message
    }


def add_error_to_errors(errors, field, validator, validator_value, message):
    """Standardize validation error format.

    Args:
        errors (dict): errors to add error to
        field (string): field to add error for
        validator (string): type of validator that generated the error
        validator_value (any): type of value the validator expected
        message (string): a description of the error
    Returns:
        errors (dict): standartized errors.
    """
    errors[field] = _format_error(validator, validator_value, message)
    return errors


def validate(data, validator):
    """Generic JSON Draft3 Schema Validation.

    Args:
        data (dict): the JSON to be validated.
        validator (Draft3Validator): the JSON Draft3 Schema to validate against
    Returns:
        Response: the response of the create operation.
    """
    errors = {}
    for e in sorted(validator.iter_errors(data), key=str):
        field = None
        if e.relative_path:
            field = e.relative_path.pop()
        elif e.absolute_schema_path:
            field = e.absolute_schema_path.pop()

        add_error_to_errors(
            errors, field, e.validator, e.validator_value, e.message)

    if len(errors) > 0:
        return response.create_error_response(
            code=error.VALIDATION_ERROR,
            message=errors,
            status=400)

    return response.Response(message={'status': 'ok'}, status=200)


def json_validator(schema):
    """Make validator from schema json.

    Args:
        schema (dict): Loaded json file
    """
    return Draft3Validator(schema)