"""Schemas for get_<type>_conflicts endpoints."""
import marshmallow

from conflict_manager.constants import error as error_consts
from conflict_manager.constants import query_parameters as query_consts


class PaginationSchema(marshmallow.Schema):
    """Validation schema for query parameters of get_conflicts endpoints."""

    class Meta:
        """Schema options."""

        unknown = marshmallow.EXCLUDE

    def __init__(self, *args, **kwargs):
        """Constructor.

        Args:
            sort_by_options (list<str>): Optional list of sort options.
            default_sort_by (str): Option default column to sort_by.
        """
        self.sort_by_options = kwargs.pop('sort_by_options', [])
        self.default_sort_by = kwargs.pop('default_sort_by', None)
        super().__init__(*args, **kwargs)

    sort_by = marshmallow.fields.String(
        load_default=None, required=False)

    sort_order = marshmallow.fields.String(
        load_default=query_consts.DEFAULT_SORT_ORDER,
        validate=marshmallow.validate.OneOf(
            query_consts.ALLOWED_SORT_ORDER,
            error=error_consts.INVALID_SORT_ORDER_MSG))

    offset = marshmallow.fields.Integer(
        data_key=query_consts.PAGE_OFFSET,
        load_default=query_consts.DEFAULT_OFFSET,
        validate=marshmallow.validate.Range(
            min=0, error=error_consts.INVALID_PAGE_OFFSET_MSG))

    limit = marshmallow.fields.Integer(
        data_key=query_consts.PAGE_LIMIT,
        load_default=query_consts.DEFAULT_LIMIT,
        validate=marshmallow.validate.Range(
            min=0, error=error_consts.INVALID_PAGE_LIMIT_MSG))

    @marshmallow.validates(query_consts.SORT_BY)
    def validate_sort_by(self, value, **kwargs):
        """Validate sort_by parameter.

        Args:
            value (str): Value to validate. Can also be None.

        Raises:
            ValidationError
        """
        if value is None or value == '':
            value = self.default_sort_by

        if value is not None and value not in self.sort_by_options:
            raise marshmallow.ValidationError(
                error_consts.INVALID_SORT_BY_MSG.format(
                    input=value, choices=', '.join(self.sort_by_options)))

    @marshmallow.post_load
    def finalize_output(self, data, **kwargs):
        """Finalize output.

        Args:
            data (dict): Deserialized dict

        Return:
            dict
        """
        if self.default_sort_by and not data[query_consts.SORT_BY]:
            data[query_consts.SORT_BY] = self.default_sort_by
        return data