import os
import json
import logging

internal_logger = logging.getLogger(__name__)


def arg_or_env(name, args, default=None, env_key=None):
    env_name = env_key or 'STACKIFY_{0}'.format(name.upper())
    try:
        value = args.get(name)
        if not value:
            value = os.environ[env_name]
        return value
    except KeyError:
        if default is not None:
            return default
        else:
            raise NameError('You must specify the keyword argument {0} or environment variable {1}'.format(name, env_name))


def data_to_json(data):
    try:
        if object_is_iterable(data) and 'request' in data and hasattr(data['request'], '_messages'):
            data['request'] = get_default_object(data['request'])

        return json.dumps(data, default=lambda x: get_default_object(x))
    except ValueError as e:
        internal_logger.exception('Failed to serialize object to json: {} - Exception: {}'.format(data.__str__(), str(e)))
        return json.dumps(data.__str__())  # String representation of the object


def get_default_object(obj):
    return hasattr(obj, '__dict__') and obj.__dict__ or obj.__str__()


def object_is_iterable(obj):
    return hasattr(obj, '__iter__') or isinstance(obj, str)