"""
This module implements a custom JSON writer to be able to serialize data
returned by Weboob and pretty print the output JSON.
"""
import json

from datetime import date, datetime
from decimal import Decimal


class CustomJSONEncoder(json.JSONEncoder):
    """
    Custom JSONEncoder to support more types.
    """
    def default(self, o):
        if isinstance(o, datetime) or isinstance(o, date):
            # Serialize datetime objects to ISO dates
            return o.isoformat()
        elif isinstance(o, Decimal):
            # Serialize Decimal objects to string
            return str(o)
        return json.JSONEncoder.default(self, o)


def pretty_json(obj):
    """
    Pretty printing of JSON output, using the custom JSONEncoder.

    Args:
        obj: the object to JSON serialize.
    Returns:
        the pretty printed JSON string.
    """
    return json.dumps(obj, sort_keys=True,
                      indent=4, separators=(',', ': '),
                      cls=CustomJSONEncoder)