"""JSON Util.

Util for encoding in JSON a response. Some classes cannot be directly
encoded, so this method does this automatically for us.
"""

from flask.json import JSONEncoder
from sukimu import exceptions


class CustomJSONEncoder(JSONEncoder):
    """Custom JSON Encoder."""

    def default(self, obj):
        """Default encoding behavior.

        Args:
            obj (object): any object that needs to be json encoded.
        """
        if (isinstance(obj, exceptions.FieldException) and
                len(obj.args) == 1 and isinstance(obj.args[0], str)):
            return str(obj)
        return JSONEncoder.default(self, obj)